This document summarizes a seminar presentation on karyotype variability in plant pathogenic fungi. It discusses types of karyotype variability including chromosome number polymorphisms and chromosome length polymorphisms. Mechanisms that can lead to karyotype variability are described, such as meiotic recombination, DNA repair pathways, parasexual recombination, transposon-associated rearrangements, and lateral DNA transfer. Case studies on fungi like Mycosphaerella graminicola and Alternaria alternata are provided that demonstrate karyotype changes through these mechanisms. The importance of karyotype variability in the evolution and emergence of new virulence strains in fungi is also noted.
This document summarizes previous research on the Epstein-Barr virus (EBV) and describes a study that mapped interactions between EBV proteins and human proteins. EBV infects 95% of humans and can cause cancers. The study used a yeast two-hybrid method to screen 216 EBV proteins against 15,483 human proteins, identifying 188 interacting pairs. Mapping these virus-host interactions may reveal how EBV disrupts cellular pathways to cause disease.
1. A chronic and fatal disease called withering syndrome (WS) was first observed in black abalone in the 1980s off southern California and has since spread to multiple abalone species.
2. WS is caused by a rickettsial organism that causes digestive gland degeneration and foot muscle atrophy, leading to high mortality.
3. Studies found that black abalone populations that survived WS epidemics have developed resistance to the disease compared to naive populations, as evidenced by less infection and longer survival times.
This document describes a study that used polymerase chain reaction (PCR) to amplify 16S ribosomal DNA (rDNA) from various bacterial species for phylogenetic analysis. The researchers designed universal primers that could amplify nearly full-length 16S rDNA from many bacterial genera. They demonstrated that this method allowed phylogenetic analysis of fastidious or pathogenic bacteria directly from lyophilized cultures without requiring cultivation. As an example, they amplified, cloned, sequenced and phylogenetically analyzed the 16S rDNA of Anaplasma marginale, placing it within the genera Rickettsia and Ehrlichia.
identification and characterization of FQ-non-susceptable S. Pyogenescamilomesa22
The aim of this study was to investigate the frequency, mechanism, and epidemiological association of FQ non susceptibility in S.pyogenes during 2011 and 2016 from Shanghai, China.
characterization of FQ Non-susceptible S. Pyogenescamilomesa22
The aim of this study was to investigate the frequency, mechanism, and epidemiological association of FQ non susceptibility in S.pyogenes during 2011 and 2016 from Shanghai, China.
Researchers studying chromosomal loss in aneuploid C. elegans currently lack a cost-effective way to distinguish homologous chromosomes from different strains. This document proposes using insertions and deletions (indels) to create size polymorphisms in amplified sequences from different strains, which can be detected through gel electrophoresis. The researchers identified six strain pairs with at least two regions on each chromosome containing significant size differences. Initial laboratory validation of one such region in one strain pair supported this method. Further results are pending, but current findings indicate amplicon size polymorphisms provide a viable, low-cost means of distinguishing homologous chromosomes in C. elegans and potentially other organisms.
EcoTILLING is a method for identifying natural mutations and polymorphisms in populations using TILLING techniques. It allows for the detection of point mutations and small insertions/deletions in DNA in a high-throughput but low-cost manner using gel electrophoresis. EcoTILLING has been used to identify allelic variants in genes related to powdery mildew resistance (mlo and Mla) in barley. It has also been applied to identify natural variation in 196 Arabidopsis ecotypes and 41 cottonwood trees. The method shows potential for discovering alleles relevant to salt tolerance in rice varieties and resistance to potato virus Y in pepper varieties.
This document summarizes previous research on the Epstein-Barr virus (EBV) and describes a study that mapped interactions between EBV proteins and human proteins. EBV infects 95% of humans and can cause cancers. The study used a yeast two-hybrid method to screen 216 EBV proteins against 15,483 human proteins, identifying 188 interacting pairs. Mapping these virus-host interactions may reveal how EBV disrupts cellular pathways to cause disease.
1. A chronic and fatal disease called withering syndrome (WS) was first observed in black abalone in the 1980s off southern California and has since spread to multiple abalone species.
2. WS is caused by a rickettsial organism that causes digestive gland degeneration and foot muscle atrophy, leading to high mortality.
3. Studies found that black abalone populations that survived WS epidemics have developed resistance to the disease compared to naive populations, as evidenced by less infection and longer survival times.
This document describes a study that used polymerase chain reaction (PCR) to amplify 16S ribosomal DNA (rDNA) from various bacterial species for phylogenetic analysis. The researchers designed universal primers that could amplify nearly full-length 16S rDNA from many bacterial genera. They demonstrated that this method allowed phylogenetic analysis of fastidious or pathogenic bacteria directly from lyophilized cultures without requiring cultivation. As an example, they amplified, cloned, sequenced and phylogenetically analyzed the 16S rDNA of Anaplasma marginale, placing it within the genera Rickettsia and Ehrlichia.
identification and characterization of FQ-non-susceptable S. Pyogenescamilomesa22
The aim of this study was to investigate the frequency, mechanism, and epidemiological association of FQ non susceptibility in S.pyogenes during 2011 and 2016 from Shanghai, China.
characterization of FQ Non-susceptible S. Pyogenescamilomesa22
The aim of this study was to investigate the frequency, mechanism, and epidemiological association of FQ non susceptibility in S.pyogenes during 2011 and 2016 from Shanghai, China.
Researchers studying chromosomal loss in aneuploid C. elegans currently lack a cost-effective way to distinguish homologous chromosomes from different strains. This document proposes using insertions and deletions (indels) to create size polymorphisms in amplified sequences from different strains, which can be detected through gel electrophoresis. The researchers identified six strain pairs with at least two regions on each chromosome containing significant size differences. Initial laboratory validation of one such region in one strain pair supported this method. Further results are pending, but current findings indicate amplicon size polymorphisms provide a viable, low-cost means of distinguishing homologous chromosomes in C. elegans and potentially other organisms.
EcoTILLING is a method for identifying natural mutations and polymorphisms in populations using TILLING techniques. It allows for the detection of point mutations and small insertions/deletions in DNA in a high-throughput but low-cost manner using gel electrophoresis. EcoTILLING has been used to identify allelic variants in genes related to powdery mildew resistance (mlo and Mla) in barley. It has also been applied to identify natural variation in 196 Arabidopsis ecotypes and 41 cottonwood trees. The method shows potential for discovering alleles relevant to salt tolerance in rice varieties and resistance to potato virus Y in pepper varieties.
This document discusses the concepts of genetics and genetic variation in bacteria. It explains that bacteria can inherit genetic traits from parents but also exhibit variability through mechanisms like mutation, adaptation, genetic recombination, and gene expression changes. The document also outlines several genetic elements in bacteria, like plasmids and transposons, that allow for genetic transfer and variation.
HRV-1A infection fragments the Golgi apparatus and redistributes Golgi membranes into vesicles approximately 250-500nm in diameter. These Golgi-derived vesicles colocalize with viral RNA replication templates, indicating they serve as sites of viral RNA replication. Expression of the HRV-1A 3A protein alone is sufficient to induce Golgi fragmentation similar to infection and the 3A protein localizes to the Golgi-derived membranes, suggesting it plays a role in Golgi fragmentation to generate membranes for viral replication.
This document discusses various methods of genetic recombination including transformation, conjugation, transduction, and protoplast fusion. It provides definitions and examples of key terms. Transformation involves the direct uptake of exogenous DNA by a cell. Conjugation is the transfer of genetic material between bacterial cells through direct contact. Transduction is the transfer of genes between bacteria mediated by bacteriophages. Protoplast fusion involves fusing plant protoplasts using electric shock or chemicals to produce somatic hybrid plants. The document also discusses applications of these techniques such as gene cloning, production of monoclonal antibodies, and genetic engineering.
The document discusses the genetic epidemiology of tuberculosis. It summarizes that analysis of TB epidemics in Europe from the 18th-19th centuries found mortality rates of up to 2% per year without chemotherapy. There was an initial spike in cases over the first 50-100 years, followed by a slow decline over the next 200-250 years. This supports the hypothesis that the initial phase eliminated the most susceptible 20% of the population.
This study sequenced the genomes of 11 clinical Mycobacterium abscessus isolates from 8 US patients with pulmonary infections. Core genome analysis compared these isolates to 30 globally diverse strains to investigate population structure. Longitudinally sampled isolates showed very few genetic differences, suggesting homogenous infection populations. Genome content variation between isolates was 0.3-8.3% compared to the reference strain, indicating plasticity.
Oncolytic virotherapy uses viruses that selectively infect and kill cancer cells. Viruses are engineered to target features of cancer cells like overexpression of certain receptors. The viruses infect and replicate within cancer cells, causing them to lyse and release new virus particles to infect neighboring cancer cells. This repeats to destroy the tumor. Additionally, the viral infection stimulates anti-tumor immune responses. Oncolytic viruses show potential as a cancer therapy but challenges remain around the immune system clearing viruses too quickly and risks of new viral strains emerging.
This document discusses the use of genetic markers to characterize livestock breeds for conservation purposes. It explains that livestock breeds represent a valuable genetic resource but many are at risk of extinction. Molecular genetic characterization using DNA markers provides a precise way to measure genetic diversity and relationships between breeds. This can help prioritize breeds for conservation in order to maintain maximum genetic diversity.
Candidemia in HIV-positive patients in Dschang District Hospital (West Region...Claude Nangwat
Candidemia has been identified as a public health problem in HIV-infected patients. The evaluation of CD4 count, transaminases and blood glucose, are being used as a means to monitor the health of HIV-infected patients, without excluding the diagnosis of candidemia and other opportunistic infections. In order to contribute in improving the care of HIV-infected patients attending Dschang District Hospital and later on, in other hospitals in Cameroon, we conducted from June to September 2014 a cross-sectional study, with general objective; to determine the association between candidemia and selected biochemical and haematological parameter changes in HIV-infected patients, as a possible indicator in monitoring HIV disease progression.
To do this, blood samples were collected from HIV-infected patients assigned to the UPEC of Dschang District Hospital for follow up, and haemogram report, CD4 counts, ALAT level, ASAT level, and glucose level in blood were evaluated by cytometric and spectrophotometric assays. Candida species were isolated from some blood samples, and then identified using CHROMagar Candida culture medium. The broth microdilution method was afterwards used to test the susceptibility of the fungal isolates vis-a-vis three conventional antifungal agents.
Mycological analysis of blood samples showed that eight (08) patients had candidemia, a prevalence of 6.11%. Eight (08) isolates were obtained from these eight (08) candidemic HIV-infected patients; this consisted of 4(50%) Candida albicans, 3(37.5%) Candida parapsilosis and 1(12.5%) Candida glabrata. All these isolates were resistant (MICs ranged from 2 to >256 µg/mL) to the antifungals used, that is, ketoconazole, amphotericin B and nystatin.
A significant correlation was found between candidemia and white blood cell count, with a correlation coefficient of r = 0.240 (p < 0.05). Based on the results obtained, the systematic diagnosis of candidemia should be performed in patients infected with HIV in Cameroon in order to improve on their care.
Key words: Candidemia, HIV, biochemical parameters, hematological parameters, Antifungals activities.
This study analyzed genome and methylome variations in the bacterial pathogen Helicobacter pylori during experimental infection in humans. Researchers used single-molecule real-time sequencing to analyze H. pylori isolates obtained from human volunteers involved in a vaccine trial. The isolates came from individuals infected with a strain known as BCM-300, which has virulence factors associated with disease. The results showed changes in key virulence genes in the bacteria, suggesting an ability to adapt during infection, even in vaccinated individuals. However, the small number of volunteers limited conclusions about differences between vaccinated and unvaccinated groups.
The document discusses a study on MRSA 252, a methicillin-resistant Staphylococcus aureus strain. It aims to construct a prophage-free host strain of MRSA 252 that can propagate lytic bacteriophages. 31 mutant strains of MRSA 252 were created using mitomycin C to induce prophages. Prophage screening using PCR found that mutations 7 and 8 did not contain the φSa2 and φSa3 prophages. Most mutant strains were susceptible to lytic phages in spot tests, but were resistant to some phages and high dilutions of others. Mutations 7 and 8 were resistant to all tested phages. The attempt to mobilize prophages from M
PCR-OLA is a technique that combines polymerase chain reaction with oligonucleotide ligation assay to detect single nucleotide polymorphisms by distinguishing between ligation and non-ligation of oligonucleotides. It involves two phases - a multiplex PCR amplification to amplify the target DNA, followed by a multiplex oligonucleotide ligation assay where detection probes hybridize adjacent to each other and are ligated if complementary, which can identify normal vs. mutant genotypes. Ligation is regulated by the specificity of oligonucleotide hybridization, the need for adjacent hybridization of probes, and perfect complementarity of two bases.
1) Huanglongbing (HLB) is a disease affecting citrus trees that is caused by a bacterium and spread by an insect. It reduces fruit yield and quality and ultimately kills trees.
2) HLB symptoms can take years to appear, allowing the disease to spread widely before detection. Earlier detection is needed to prevent further spread and losses.
3) Researchers are using metabolomics to detect early physiological changes in trees infected with the HLB bacterium, before visual symptoms appear. They hope to identify reliable metabolic biomarkers for improved early detection of the disease.
I. Computational analysis identified novel B- and T- cell epitopes from the glycoprotein and nucleoprotein of Ebola virus, including AIGLAWIPY, YDDDDDIPF, SQDTTIPDV, VSHLTTLAT, DLVLFDLDE, LRQLANETTT, and DYHKILTAGL.
II. A novel B-cell epitope was extracted from the 3D structure of Ebola glycoprotein bound to an antibody, and its sequence motifs were predicted by multiple algorithms.
III. An epitope from the nucleoprotein contained a conserved protein fingerprint that defines the WW domain-containing WAC protein, and a potential WW domain was
This document summarizes a seminar presentation on mixotrophy in land plants. Mixotrophy refers to the dual capability of both photosynthesis and organic carbon uptake. The presentation discusses the evolutionary pathways and diversity of mixotrophy strategies across eukaryotes. Tools for studying mixotrophy like isotopic tracing and genomic analysis are also reviewed. A case study examining the nuclear genomes of three mycoheterotrophic plants found profound reductions in photosynthesis and plastid-related genes, as well as increased substitution rates, demonstrating convergent evolution to heterotrophy.
I have a serious deal but i'm looking for God fearing person that will handle the deal for me while i finish my studies.If you are interested, contact me Direct to my personal email address here amandadiarra@hotmail.com
The initial objective of this work was to isolate Tomato spotted wilt virus (TSWV) from asymptomatic infected plants and then identify the virus on the basis of biological properties among the most common or other hosts if possible after inoculation. Phylogenetic analysis was then conducted to gain information about the similar identity of the TSWV-isolate that reported in this study with available TSWV sequences from other parts of the world.
This experiment aimed to generate Escherichia coli resistant to bacteriophage T1 and classify mutations. Plaque assays to isolate resistant mutants were unsuccessful, yielding no plaques. Regrowth of mutants from previous research was successful, as was MRVP testing to confirm the regrown cultures were E. coli. Genomic DNA was isolated from positive mutant cultures and will undergo PCR amplification and analysis. In summary, the experiment generated no new resistant mutants but validated previous work characterizing E. coli mutations that confer resistance to bacteriophage infection.
Single Cell Insights: Studying Environmental Microbial Communities Cell by CellQIAGEN
Dissecting complex microbial communities has incredible potential in the quest to decipher the world around us and find new sources of enzymes, antibiotics and other drugs. The challenge that remains is how to gain a deeper understanding of the roles and interactions of individual microbes. Single cell sequencing has emerged as an innovative investigational approach that provides a view of the cell-by-cell community by separating out individual microbes prior to sequencing. This issue of Single Cell Insights reviews peer-reviewed journal articles that describe applications and methodologies for single cell sequencing of environmental microbial communities.
The document provides information about midterm exams and extra office hours for a class. It announces that the first midterm exam will be on Thursday, February 15 at 6pm in room 155 Dwinelle, and that review sessions will be held during the regular class time that day. It also notes that the professor will not have office hours on February 13.
This document describes a proposed study to produce insect-resistant transgenic plants through chloroplast transformation. Researchers will construct a chloroplast transformation vector containing insecticidal genes and a selectable marker gene driven by a chloroplast-specific promoter. This will allow expression of the insecticidal proteins to be confined to the green parts of plants. Explants will be biolistically transformed with the vector and transgenic lines containing and expressing the insecticidal genes will be selected and analyzed. The goal is to develop transplastomic plants for use in integrated pest management programs to control major insect pests in an environmentally sustainable way.
This document discusses the topic of pathogenomics in plant pathology. It begins with an introduction to key terms and techniques used in pathogenomics such as marker genes, effectors, and high throughput gene sequencing. It then discusses the role of effectors in pathogenesis and host-pathogen interactions. It provides examples of pathogenomic studies on various pathogens such as Puccinia graminis f. sp. tritici (wheat rust) and Xanthomonas axonopodis pv. manihotis (cassava bacterial blight). It discusses how pathogenomics can help develop diagnostic tools, provide durable resistance to plants, and uncover plant processes through analysis of pathogen genomes and effectors.
This document discusses the concepts of genetics and genetic variation in bacteria. It explains that bacteria can inherit genetic traits from parents but also exhibit variability through mechanisms like mutation, adaptation, genetic recombination, and gene expression changes. The document also outlines several genetic elements in bacteria, like plasmids and transposons, that allow for genetic transfer and variation.
HRV-1A infection fragments the Golgi apparatus and redistributes Golgi membranes into vesicles approximately 250-500nm in diameter. These Golgi-derived vesicles colocalize with viral RNA replication templates, indicating they serve as sites of viral RNA replication. Expression of the HRV-1A 3A protein alone is sufficient to induce Golgi fragmentation similar to infection and the 3A protein localizes to the Golgi-derived membranes, suggesting it plays a role in Golgi fragmentation to generate membranes for viral replication.
This document discusses various methods of genetic recombination including transformation, conjugation, transduction, and protoplast fusion. It provides definitions and examples of key terms. Transformation involves the direct uptake of exogenous DNA by a cell. Conjugation is the transfer of genetic material between bacterial cells through direct contact. Transduction is the transfer of genes between bacteria mediated by bacteriophages. Protoplast fusion involves fusing plant protoplasts using electric shock or chemicals to produce somatic hybrid plants. The document also discusses applications of these techniques such as gene cloning, production of monoclonal antibodies, and genetic engineering.
The document discusses the genetic epidemiology of tuberculosis. It summarizes that analysis of TB epidemics in Europe from the 18th-19th centuries found mortality rates of up to 2% per year without chemotherapy. There was an initial spike in cases over the first 50-100 years, followed by a slow decline over the next 200-250 years. This supports the hypothesis that the initial phase eliminated the most susceptible 20% of the population.
This study sequenced the genomes of 11 clinical Mycobacterium abscessus isolates from 8 US patients with pulmonary infections. Core genome analysis compared these isolates to 30 globally diverse strains to investigate population structure. Longitudinally sampled isolates showed very few genetic differences, suggesting homogenous infection populations. Genome content variation between isolates was 0.3-8.3% compared to the reference strain, indicating plasticity.
Oncolytic virotherapy uses viruses that selectively infect and kill cancer cells. Viruses are engineered to target features of cancer cells like overexpression of certain receptors. The viruses infect and replicate within cancer cells, causing them to lyse and release new virus particles to infect neighboring cancer cells. This repeats to destroy the tumor. Additionally, the viral infection stimulates anti-tumor immune responses. Oncolytic viruses show potential as a cancer therapy but challenges remain around the immune system clearing viruses too quickly and risks of new viral strains emerging.
This document discusses the use of genetic markers to characterize livestock breeds for conservation purposes. It explains that livestock breeds represent a valuable genetic resource but many are at risk of extinction. Molecular genetic characterization using DNA markers provides a precise way to measure genetic diversity and relationships between breeds. This can help prioritize breeds for conservation in order to maintain maximum genetic diversity.
Candidemia in HIV-positive patients in Dschang District Hospital (West Region...Claude Nangwat
Candidemia has been identified as a public health problem in HIV-infected patients. The evaluation of CD4 count, transaminases and blood glucose, are being used as a means to monitor the health of HIV-infected patients, without excluding the diagnosis of candidemia and other opportunistic infections. In order to contribute in improving the care of HIV-infected patients attending Dschang District Hospital and later on, in other hospitals in Cameroon, we conducted from June to September 2014 a cross-sectional study, with general objective; to determine the association between candidemia and selected biochemical and haematological parameter changes in HIV-infected patients, as a possible indicator in monitoring HIV disease progression.
To do this, blood samples were collected from HIV-infected patients assigned to the UPEC of Dschang District Hospital for follow up, and haemogram report, CD4 counts, ALAT level, ASAT level, and glucose level in blood were evaluated by cytometric and spectrophotometric assays. Candida species were isolated from some blood samples, and then identified using CHROMagar Candida culture medium. The broth microdilution method was afterwards used to test the susceptibility of the fungal isolates vis-a-vis three conventional antifungal agents.
Mycological analysis of blood samples showed that eight (08) patients had candidemia, a prevalence of 6.11%. Eight (08) isolates were obtained from these eight (08) candidemic HIV-infected patients; this consisted of 4(50%) Candida albicans, 3(37.5%) Candida parapsilosis and 1(12.5%) Candida glabrata. All these isolates were resistant (MICs ranged from 2 to >256 µg/mL) to the antifungals used, that is, ketoconazole, amphotericin B and nystatin.
A significant correlation was found between candidemia and white blood cell count, with a correlation coefficient of r = 0.240 (p < 0.05). Based on the results obtained, the systematic diagnosis of candidemia should be performed in patients infected with HIV in Cameroon in order to improve on their care.
Key words: Candidemia, HIV, biochemical parameters, hematological parameters, Antifungals activities.
This study analyzed genome and methylome variations in the bacterial pathogen Helicobacter pylori during experimental infection in humans. Researchers used single-molecule real-time sequencing to analyze H. pylori isolates obtained from human volunteers involved in a vaccine trial. The isolates came from individuals infected with a strain known as BCM-300, which has virulence factors associated with disease. The results showed changes in key virulence genes in the bacteria, suggesting an ability to adapt during infection, even in vaccinated individuals. However, the small number of volunteers limited conclusions about differences between vaccinated and unvaccinated groups.
The document discusses a study on MRSA 252, a methicillin-resistant Staphylococcus aureus strain. It aims to construct a prophage-free host strain of MRSA 252 that can propagate lytic bacteriophages. 31 mutant strains of MRSA 252 were created using mitomycin C to induce prophages. Prophage screening using PCR found that mutations 7 and 8 did not contain the φSa2 and φSa3 prophages. Most mutant strains were susceptible to lytic phages in spot tests, but were resistant to some phages and high dilutions of others. Mutations 7 and 8 were resistant to all tested phages. The attempt to mobilize prophages from M
PCR-OLA is a technique that combines polymerase chain reaction with oligonucleotide ligation assay to detect single nucleotide polymorphisms by distinguishing between ligation and non-ligation of oligonucleotides. It involves two phases - a multiplex PCR amplification to amplify the target DNA, followed by a multiplex oligonucleotide ligation assay where detection probes hybridize adjacent to each other and are ligated if complementary, which can identify normal vs. mutant genotypes. Ligation is regulated by the specificity of oligonucleotide hybridization, the need for adjacent hybridization of probes, and perfect complementarity of two bases.
1) Huanglongbing (HLB) is a disease affecting citrus trees that is caused by a bacterium and spread by an insect. It reduces fruit yield and quality and ultimately kills trees.
2) HLB symptoms can take years to appear, allowing the disease to spread widely before detection. Earlier detection is needed to prevent further spread and losses.
3) Researchers are using metabolomics to detect early physiological changes in trees infected with the HLB bacterium, before visual symptoms appear. They hope to identify reliable metabolic biomarkers for improved early detection of the disease.
I. Computational analysis identified novel B- and T- cell epitopes from the glycoprotein and nucleoprotein of Ebola virus, including AIGLAWIPY, YDDDDDIPF, SQDTTIPDV, VSHLTTLAT, DLVLFDLDE, LRQLANETTT, and DYHKILTAGL.
II. A novel B-cell epitope was extracted from the 3D structure of Ebola glycoprotein bound to an antibody, and its sequence motifs were predicted by multiple algorithms.
III. An epitope from the nucleoprotein contained a conserved protein fingerprint that defines the WW domain-containing WAC protein, and a potential WW domain was
This document summarizes a seminar presentation on mixotrophy in land plants. Mixotrophy refers to the dual capability of both photosynthesis and organic carbon uptake. The presentation discusses the evolutionary pathways and diversity of mixotrophy strategies across eukaryotes. Tools for studying mixotrophy like isotopic tracing and genomic analysis are also reviewed. A case study examining the nuclear genomes of three mycoheterotrophic plants found profound reductions in photosynthesis and plastid-related genes, as well as increased substitution rates, demonstrating convergent evolution to heterotrophy.
I have a serious deal but i'm looking for God fearing person that will handle the deal for me while i finish my studies.If you are interested, contact me Direct to my personal email address here amandadiarra@hotmail.com
The initial objective of this work was to isolate Tomato spotted wilt virus (TSWV) from asymptomatic infected plants and then identify the virus on the basis of biological properties among the most common or other hosts if possible after inoculation. Phylogenetic analysis was then conducted to gain information about the similar identity of the TSWV-isolate that reported in this study with available TSWV sequences from other parts of the world.
This experiment aimed to generate Escherichia coli resistant to bacteriophage T1 and classify mutations. Plaque assays to isolate resistant mutants were unsuccessful, yielding no plaques. Regrowth of mutants from previous research was successful, as was MRVP testing to confirm the regrown cultures were E. coli. Genomic DNA was isolated from positive mutant cultures and will undergo PCR amplification and analysis. In summary, the experiment generated no new resistant mutants but validated previous work characterizing E. coli mutations that confer resistance to bacteriophage infection.
Single Cell Insights: Studying Environmental Microbial Communities Cell by CellQIAGEN
Dissecting complex microbial communities has incredible potential in the quest to decipher the world around us and find new sources of enzymes, antibiotics and other drugs. The challenge that remains is how to gain a deeper understanding of the roles and interactions of individual microbes. Single cell sequencing has emerged as an innovative investigational approach that provides a view of the cell-by-cell community by separating out individual microbes prior to sequencing. This issue of Single Cell Insights reviews peer-reviewed journal articles that describe applications and methodologies for single cell sequencing of environmental microbial communities.
The document provides information about midterm exams and extra office hours for a class. It announces that the first midterm exam will be on Thursday, February 15 at 6pm in room 155 Dwinelle, and that review sessions will be held during the regular class time that day. It also notes that the professor will not have office hours on February 13.
This document describes a proposed study to produce insect-resistant transgenic plants through chloroplast transformation. Researchers will construct a chloroplast transformation vector containing insecticidal genes and a selectable marker gene driven by a chloroplast-specific promoter. This will allow expression of the insecticidal proteins to be confined to the green parts of plants. Explants will be biolistically transformed with the vector and transgenic lines containing and expressing the insecticidal genes will be selected and analyzed. The goal is to develop transplastomic plants for use in integrated pest management programs to control major insect pests in an environmentally sustainable way.
This document discusses the topic of pathogenomics in plant pathology. It begins with an introduction to key terms and techniques used in pathogenomics such as marker genes, effectors, and high throughput gene sequencing. It then discusses the role of effectors in pathogenesis and host-pathogen interactions. It provides examples of pathogenomic studies on various pathogens such as Puccinia graminis f. sp. tritici (wheat rust) and Xanthomonas axonopodis pv. manihotis (cassava bacterial blight). It discusses how pathogenomics can help develop diagnostic tools, provide durable resistance to plants, and uncover plant processes through analysis of pathogen genomes and effectors.
This summary analyzes the mRNA expression levels of the Gmhsp17.6-L gene in soybean genotypes that are resistant or susceptible to the root-knot nematode Meloidogyne javanica. Previous research identified a microsatellite marker, 176 Soy HSP, that strongly correlates with resistance to M. javanica. Sequencing of this marker revealed similarity to the promoter region of the Gmhsp17.6-L gene. The study examines levels of Gmhsp17.6-L mRNA transcripts in resistant and susceptible genotypes using ribonuclease protection assay and quantitative PCR. Results indicate higher mRNA levels in resistant genotypes, which had larger AT(n) insertions in the Gmhsp17
This document describes a microarray study that analyzed gene expression changes in Nicotiana benthamiana in response to infection by South African cassava mosaic virus (SACMV). The microarray identified over 600 genes whose expression was altered at 21 days post infection, including genes involved in transcription, defense responses, and hormone signaling. Notable changes were seen in genes related to sucrose and starch metabolism, as well as genes associated with intracellular movement and the cytoskeleton. The results provide insight into the complex molecular interactions between SACMV and its host plant during the infection process.
A transplastomic plant is a genetically modified plant in which the new genes have not been inserted in the nuclear DNA but in the DNA of the chloroplasts.
This document discusses Agrobacterium-mediated gene transfer. Agrobacterium is a genus of bacteria that can transfer DNA between itself and plants, causing tumors. The most commonly studied species is A. tumefaciens, which causes crown gall disease in plants. A. tumefaciens contains a Ti plasmid that can transfer a segment of DNA (T-DNA) into the host plant genome. The T-DNA contains oncogenes that cause tumor formation and opine synthesis genes. Virulence genes on the Ti plasmid (Vir genes) are required for T-DNA transfer.
Functional Genomics of Plant Pathogen interactions in Wheat Rust PathosystemSenthil Natesan
Cereal rust fungi are pathogens of major importance to agriculture, threatening cereal production worldwide. Targeted breeding for resistance, based on information from fungal surveys and population structure analyses of virulence, has been effective. Nevertheless, breakdown of resistance occurs frequently and continued efforts are needed to understand how these fungi overcome resistance and to determine the range of available resistance genes. The development of genomic resources for these fungi and their comparison has released a torrent of new ideas and approaches to use this information to assist pathologists and agriculture in general. The sequencing of gene transcripts and the analysis of proteins from haustoria has yielded candidate virulence factors among which could be defence-triggering avirulence genes. Genome-wide computational analyses, including genetic mapping and transcript analyses by RNA sequencing of many fungal isolates, will predict many more candidates (Bakkeren et al., 2012)
Dissecting the mechanisms of host-pathogen systems like wheat-rust, including pathogen counter-defenses will ensure a step ahead towards understanding current outcomes of interactions from a co-evolutionary point of view, and eventually move a step forward in building more durable strategies for management of diseases caused by fungi (Hadrami et al.,2012)
Genome of Athelia rolfsii genome of ~65Mb having 20290 contigs. Annotation analysis revealed 16000 genes involved in fungicide resistance, virulence and pathogenicity along with and lethal genes.Genome have GC content 46.4%
1. What is pathogen variability?
2. Significance of pathogen Variability
3. Stages of variation
4. Mechanism of Variability in fungi
5. Characterization of variability among plant pathogens
This document summarizes a study that analyzed gene expression in barley and Arabidopsis plants infected with powdery mildew and Turnip mosaic virus, respectively. The researchers extracted total RNA and polysome-associated (actively translated) RNA from infected and uninfected plants. Microarray analysis identified genes differentially expressed in total and polysomal RNA in response to infection. In barley, 3505 genes were differentially expressed in resistant plants infected with powdery mildew, but no genes were differentially expressed in susceptible plants. In Arabidopsis, 958 genes were differentially expressed in response to Turnip mosaic virus infection. Gene ontology analysis showed that differentially expressed genes were enriched for specific biological functions.
The document discusses the origin and evolution of class 1 integrons, which are genetic elements that play a key role in the spread of antibiotic resistance. It finds that class 1 integrons were originally present in the chromosomes of non-pathogenic soil and freshwater bacteria. Exposure to antibiotics through human activities exerted strong selective pressure that led to the transfer and fixation of class 1 integrons in human pathogens, driving the global rise of antibiotic resistance.
PREVALENCE AND CHARACTERIZATION OF VIRULENCE PROPERTIES OF PSEUDOMONAS AERUGI...SUS GROUP OF INSTITUTIONS
Pseudomonas aeruginosa is the epitome of an opportunistic pathogen of humans that cause urinary tract infections, respiratory system infection, particularly in victim of severe burns, cancer and AIDS patient who are immunocompromised. Most Pseudomonas infections are both invasive and toxigenic. The particular bacterial determinants of virulence mediate different stages of infection and are ultimately responsible for the characteristic syndromes that accompany the disease. In the present study P. aeruginosa was found to be more prevalent in burn patients (100%) followed by urinary tract infection samples (71%), sputum samples (66%) and wound samples (59%). 85% isolates recovered from clinical samples were mucoid. A total of 35% isolates were strong siderophore producers, 19% isolates were strong protease producers while 52% were strong phospholipase producers. Isolates from burns, sputum and environment sample were strong rhamnolipid producers. Elevated level of hemolysin production was observed in burn, urine and wound isolates. The prominence of haemagglutination ability in environmental isolates followed by burns isolates provided evidence for its being a nosocomial pathogen. The association between virulence determinants and disease can indicate the precise role played by the determinant in estabilishing the disease. Isolates were maximally sensitive towards lactam antibiotics.
This document summarizes Sudhir Navathe's presentation on genome analysis of fungal pathogens of cereal crops. It provides an overview of fungal genome resources and sequencing workflows. It then discusses key findings from comparative genomic analyses of several major fungal pathogens, including the identification of effector genes and accessory chromosomes. The document also presents a case study on the discovery of the ToxA virulence gene in the wheat pathogen Bipolaris sorokiniana through research from multiple countries.
This study analyzed the occurrence and diversity of integrons in bacteria isolated from an urban wastewater treatment plant. A total of 697 isolates of Enterobacteriaceae and Aeromonas were screened for integrons. Three new gene cassettes were identified, including a novel aadA variant and genes involved in cell signaling and unknown functions. Thirteen different gene cassette arrays were detected, with four representing novel integrons. Approximately 80% of isolates were resistant to at least 3 antibiotic classes. The presence of novel integron structures in treated effluent suggests wastewater treatment plants may facilitate the formation and spread of antibiotic resistance genes.
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The Milky Way’s (MW) inner stellar halo contains an [Fe/H]-rich component with highly eccentric orbits, often referred to as the
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the last few Gyr, consistent with the body of work surrounding the VRM.
Microbial interaction
Microorganisms interacts with each other and can be physically associated with another organisms in a variety of ways.
One organism can be located on the surface of another organism as an ectobiont or located within another organism as endobiont.
Microbial interaction may be positive such as mutualism, proto-cooperation, commensalism or may be negative such as parasitism, predation or competition
Types of microbial interaction
Positive interaction: mutualism, proto-cooperation, commensalism
Negative interaction: Ammensalism (antagonism), parasitism, predation, competition
I. Mutualism:
It is defined as the relationship in which each organism in interaction gets benefits from association. It is an obligatory relationship in which mutualist and host are metabolically dependent on each other.
Mutualistic relationship is very specific where one member of association cannot be replaced by another species.
Mutualism require close physical contact between interacting organisms.
Relationship of mutualism allows organisms to exist in habitat that could not occupied by either species alone.
Mutualistic relationship between organisms allows them to act as a single organism.
Examples of mutualism:
i. Lichens:
Lichens are excellent example of mutualism.
They are the association of specific fungi and certain genus of algae. In lichen, fungal partner is called mycobiont and algal partner is called
II. Syntrophism:
It is an association in which the growth of one organism either depends on or improved by the substrate provided by another organism.
In syntrophism both organism in association gets benefits.
Compound A
Utilized by population 1
Compound B
Utilized by population 2
Compound C
utilized by both Population 1+2
Products
In this theoretical example of syntrophism, population 1 is able to utilize and metabolize compound A, forming compound B but cannot metabolize beyond compound B without co-operation of population 2. Population 2is unable to utilize compound A but it can metabolize compound B forming compound C. Then both population 1 and 2 are able to carry out metabolic reaction which leads to formation of end product that neither population could produce alone.
Examples of syntrophism:
i. Methanogenic ecosystem in sludge digester
Methane produced by methanogenic bacteria depends upon interspecies hydrogen transfer by other fermentative bacteria.
Anaerobic fermentative bacteria generate CO2 and H2 utilizing carbohydrates which is then utilized by methanogenic bacteria (Methanobacter) to produce methane.
ii. Lactobacillus arobinosus and Enterococcus faecalis:
In the minimal media, Lactobacillus arobinosus and Enterococcus faecalis are able to grow together but not alone.
The synergistic relationship between E. faecalis and L. arobinosus occurs in which E. faecalis require folic acid
Karyotype variability in plant pathogenic fungi palm7016
1.
2. Karyotype Variability in Plant Pathogenic Fungi
Seminar on
Chaithra,M.
PALM 7016
Department of Plant Pathology
3. Flow of Seminar
Introduction
Types of Variability in plant pathogenic fungi
Mechanism in a Chromosomal rearrangement
Consequences of Chromosomal rearrangement
Case studies
conclusion
4. • Karyotype is the number and appearance of chromosome in the nucleus
of an organism
• Variability: it is the property of an organism to change its characters from one
generation to theother
1Karyotype variability in plant pathogenic fungi, PALM7016; 2018-2019,ACM, UASB
5. 2Karyotype variability in plant pathogenic fungi, PALM7016 ;2018-2019,ACM, UASB
Importance of karyotype variability
Many fungus are smaller in size and have a weak morphological differentiation of
chromosome among the different species
To understand the various mechanism of creation of variability in fungi during its
life cycle
To know the evolution of new virulence strains against resistance varieties
To identify the arrangement of pathogenicity gene on the chromosome
10. 7Karyotype variability in plant pathogenic fungi, PALM7016; 2018-2019,ACM, UASB
Chromosomal rearrangement
Fierro etal.,2017
“DNA shuffling throughout the genome and is a naturally occurring
heritable event in eukaryotic organisms”
Source of genetic variation within and between individual species
Role in the evolution of fungi
Main cause of karyotype variability in populations
12. Meiotic recombination
DNA repair Machinery
Parasexual recombination
Transposon – Associated Chromosomal rearrangement
Lateral DNA transfer
9Karyotype variability in plant pathogenic fungi, PALM7016; 2018-2019,ACM, UASB
13. 10Karyotype variability in plant pathogenic fungi, PALM7016; 2018-2019,ACM, UASB
1. Meioticrecombination
Alexanderetal.,20091
Karyogamy
Failureto separate
(nondisjunction)
14. 11Karyotype variability in plant pathogenic fungi, PALM7016; 2018-2019,ACM, UASB
Meiotic transmission of unequal chromosome number in Mycosphaerella graminicola
Alexander et al., 2009
Parental isolates : IPO323, IPO94269 and IPO95052
Construct the linkage map of the both the hybrid and also construct bridge map by
using DArT and SSR marker
Linkage group 8
Genotyping of LG8 DArT markers
PCR confirmation
15. 12Karyotype variability in plant pathogenic fungi, PALM7016,;2018-2019,ACM, UASB
Nondisjunctionresultsin lossofchromosomes
Graphicalgenotypingof LG8
Alexander et al., 2009
16. 13Karyotype variability in plant pathogenic fungi, PALM7016,; 2018-2019,ACM, UASB
Nondisjunctionresultsin disomy
Graphicalgenotypingof LG1 Alexander et al., 2009
17. 14Karyotype variability in plant pathogenic fungi, PALM7016; 2018-2019,ACM, UASB
2. DNARepairMachinery
Double strand breaks
repairing pathways
Homologous
recombination repairing
pathway (HRR)
Non-homologous DNA
end joining
pathway(NHEJ)
19. 16Karyotype variability in plant pathogenic fungi, PALM7016; 2018-2019,ACM, UASB
3. Parasexual recombination
Parasexuality is a mechanism described in fungi that results in recombination in the absence of meiosis
Guido Pontecorvo (1956): on Aspergillus nidulans (Emericella nidulans)
Parasexual cycle is initiated by fusion of hyphae (anastomosis) during which nuclei and other
cytoplasmic components occupy the same cell (Heterokaryosis)
Alternative source of recombination in imperfect fungi
eg: Colletotrichum acutatum, Cryphonectria parasitica : alternative source of genetic variability
Also helps to transfer the pathogenicity chromosomes among asexual lineage of the fungi
Milgroom etal.,2017
20. 17Karyotype variability in plant pathogenic fungi, PALM7016; 2018-2019,ACM, UASB
Schoustraet al.,2007
Parasexual cycle in the filamentous fungus : Aspergillus nidulans
Anastomosis
21. Karyotype variability in plant pathogenic fungi, PALM7016; 2018-2019,ACM, UASB
Schoustra et al., 2007
18
To study the specific advantages of haploidy or diploidy in the fungus
Aspergillus nidulans
Evolving strains of Aspergillus nidulans
Comparing the rate Relative fitness between
haploid and isogenic diploid strains based on
Mycelial Growth Rate
22. Karyotype variability in plant pathogenic fungi, PALM7016; 2018-2019,ACM, UASB
FitnessTrajectoriesof EvolvingStrains
(A) haploid strains (B)diploid strains
Eachline- one singleevolvingstrain
Haploidizeddiploidsare indicatedwith a red dashedline
Rate of adaptation of individual populations is estimated by the slope of the
fitness Schoustraetal.,2007
19
23. Karyotype variability in plant pathogenic fungi, PALM7016; 2018-2019,ACM, UASB
Mean of all strains with respect to relative fitness
Fourreverted to haploidyin
the courseof the experiment
Diploidstrains
Haploidstrains
Mean rate of adaptation is given by the slope
Schoustraetal.,2007
20
25. Karyotype variability in plant pathogenic fungi, PALM7016; 2018-2019,ACM, UASB
Intra-chromosomal mitotic recombination between repeats
Mehrabi etal.,2017
22
26. Karyotype variability in plant pathogenic fungi, PALM7016; 2018-2019,ACM, UASB
Length of the spacer
sequence between the
repeated elements
Rate of intra-chomosomal recombination depends on:
Length of
the repeats
Orientation of the
two homologous
region
Eg: Cladosporium fulvum and Dothistroma septosporum : Intra-chromosomal
rearrangements by excision of transposons from chromosomes followed by inappropriate
NHEJ repair, significantly decreases the synteny between closely related species
Ohm et al., 2012
23
27. Karyotype variability in plant pathogenic fungi, PALM7016; 2018-2019,ACM, UASB
5. LateralDNAtransfer(LDT)
Mehrabi etal.,2017
Cytoplasmicfusionof two
different fungalspecies
An entire chromosome of a donar
species is transferred to the nucleus
of another species and proliferates
throughmitosis
Stable integration of a small
DNA segment from a
chromosome of one individual
to another
B
A
C
23
Donar
chromosome
24
28. Karyotype variability in plant pathogenic fungi, PALM7016; 2018-2019,ACM, UASB
Lateral DNA transfer = Horizontal gene and chromosome transfer
Transfer of (DNA segment) Pathotoxin producing genes
eg: T- toxin producing gene in Cochliobolous heterostrophus
HC-toxin producing gene in Cochliobolous carbonum
ToxA toxin producing gene in Pyrenophora tritici –repentis
Transfer of entire chromosomes which is mainly responsible for pathogenicity
eg: Alternaria alternata
Walton etal.,2017
25
29. Karyotype variability in plant pathogenic fungi, PALM7016; 2018-2019,ACM, UASB
Akagi et al., 2009
Horizontal transfer of an entire pathogenicity chromosome among the
Alternaria alternata strains
26
Alternaria alternata : Alternaria stem canker on tomato
Host specific toxin : AAL toxin
Pathogenicity genes : ALT genes, Polyketide synthetase genes.
Improper horizontal chromosome transformation : loss of chromosome
This loosed chromosome called as conditional dispensable chromosome.
30. 27Karyotype variability in plant pathogenic fungi, PALM7016; 2018-2019,ACM, UASB
Dispensable chromosome / accessory chromosome
One of the type of special chromosomes
Randolph : coined this extra chromosome known as B chromosome
It was first observed as extra chromosome in the hemipteran insect.
It is unnecessary for survival and reproduction of an organism but involved in
pathogenicity or virulence on a specific host plants during the infection process
This extra chromosome are known as B chromosomes, supernumerary
chromosomes, accessary chromosomes, (conditionally) dispensable chromosomes or
lineage specific chromosome or pathogenicity chromosome
Covert al.,2017
31. 28Karyotype variability in plant pathogenic fungi, PALM7016; 2018-2019,ACM, UASB
Alternaria alternata : Alternaria blotch in apple
Isolates :O-210(original isolate) , O-210∆C(sub-culture strain)
Identify the AMT and cyclic peptide synthetase gene in
original isolate and sub-culture strains of A. alternata by using
(RT)- PCR and leaf necrosis bioassay method
The effect of loss of dispensable chromosome on the
pathogenicity of Alternaria alternata
Johnson et al., 2001
32. 29Karyotype variability in plant pathogenic fungi, PALM7016; 2018-2019,ACM, UASB
(RT)-PCR on Alternaria alternata strains
using AMT- specific primer to study
AMT gene expression
Leaf necrosis bioassay on susceptible apple laves using
culture filtrates of A. alternata strains to test for AM-
toxic production
Johnson et al., 2001
33. 30Karyotype variability in plant pathogenic fungi, PALM7016; 2018-2019,ACM, UASB
Colony morphology of A. alternata O-210
and 0-210∆c.
Pulsed –field gel electrophoresis of A.
alternata O-210 and O-210∆c
Johnson et al., 2001
34. 31Karyotype variability in plant pathogenic fungi, PALM7016; 2018-2019,ACM, UASB
species Number
of DCs
Size range of
DCs
Functiona
l gene(s)
Biological significance
Nectria haematococca MPVI 3 0.45 to 1.6Mb PEP1.PEP2,
PEP5,PDA1
and PDA4
virulence on pea
Alternaria alternata 1 <2Mb Tox genes Pathogenicity on certain hosts
Fusarium oxysporum f. sp. Lycopersici 6 <3.5Mb Six genes Virulence on tomato
Colletotrichum gloeosporioides 1 2Mb Cyclic
homology
Unknown
Cochliobolus heterostrophus 1 1.2Mb Tox1 genes Virulence on maize
Cochliobolus carbonum 1 2.2 or 3.5Mb TOX2 genes Virulence on maize
Leptosphaeria maculans 1 0.73Mb AvrLm11 Virulence on oilseed rape
Zymoseptoria tritici 8 0.39 to 0.77Mb Unknown Quantitative virulence on
wheat
Magnoporthe oryzae 1 1.2Mb AVR-pita Virulence on rice
Gibberella fujikuroi MP A 1 0.7Mb unknown unknown
Known dispensable chromosomes (DCs) in filamentous fungi
Mehrabi etal.,2017
35. Karyotype variability in plant pathogenic fungi, PALM7016; 2018-2019,ACM, UASB
Transformation-mediated loss of the 1Mb CDC of the A. alternata tomato pathotype
Leaf necrosis bioassay
for AAL toxin
production by the wild
type and mutant strains
Electrophoretic
karyotypes of
the CDC
deficient
mutant (9-1) &
wild type(As-
27) strain of
the A. alternata
Pathogenisity
test of the wild-
type and mutant
strains
Akagi et al., 2009
32
36. Karyotype variability in plant pathogenic fungi, PALM7016; 2018-2019,ACM, UASB
Production of AAL and AF toxins and pathogenicity of the fusion strain EST6
Leaves of tomato and strawberry cultivar were
wounded Slightly, treated with culture filtrates of
the parent and fusion strain
Leaves were inoculated with mycelial pieces of the
strains incubate in a moist chamber at 250c for 3
days
Akagi et al.,2009
33
37. Karyotype variability in plant pathogenic fungi, PALM7016; 2018-2019,ACM, UASB
Electrophoretic karyotypes of parental and hybrid stains of A. alternata
34
Akagi et al.,2009
38. Karyotype variability in plant pathogenic fungi, PALM7016; 2018-2019,ACM, UASB
Menardo et al., 2016
Hybridof the two Powderymildewsspecializedontwo different hosts (Wheat andRye)caninfect
the hybridplant speciesoriginatingfrom those two hosts(Triticale)
Wheat Rye Triticale
35
hybridization
39. Karyotype variability in plant pathogenic fungi, PALM7016; 2018-2019,ACM, UASB
Wheat powdery mildew is caused by Blumria graminis f. sp. tritici
Rye-B. graminis f. sp. secalis
Triticale -B. g. f. sp. triticale
Triticale was initially resistant to powdery mildew; however, this pathogen
was first observed on triticale in 2001 and has since become a major disease in
Europe
36
40. Karyotype variability in plant pathogenic fungi, PALM7016; 2018-2019,ACM, UASB
The B.g. triticale genome consisted of genotype B. g. secalis
alternating with segments with a B. g. tritici genotype
In B. g. triticale, between 11.9 and 21.4% of the polymorphic
sites represented the B. g. secalis genotype
In contrast, over 80% of these genomes had the B. g. tritici
genotype
Thus, they conclude that B. g. triticale is a hybrid of B. g. tritici
and B. g. secalis.
Menardo et al.,2016
37
41. Karyotype variability in plant pathogenic fungi, PALM7016; 2018-2019,ACM, UASB
Hostspecificityofpowderymildewformae speciales
B. graminis f. sp.secalisXB.graminis f. sp.tritici
Wheat RyeB. graminis f. sp.triticale
triticale +wheat Menardo etal.,2016
38
42. Karyotype variability in plant pathogenic fungi, PALM7016; 2018-2019,ACM, UASB
Model for the evolution of specialized forms and host ranges in B. graminis
Menardo et al.,2016
39
43. Wheat stem rust
Wheat stem rust : Puccinia graminis f. sp. tritici
New race TTKSK : Ug99 – virulence on Sr13+17 gene
New variant of Ug99: TTTSK – virulence on Sr36 gene & Sr13+17gene
Abrahim et al., 2018
Karyotype variability in plant pathogenic fungi, PALM7016; 2018-2019,ACM, UASB 40
Ethiopia
44. Karyotype variability in plant pathogenic fungi, PALM7016; 2018-2019,ACM, UASB
Depotter et al., 2016
Hybridization mechanism
Genomic and transcriptomic consequences of hybridization
Pathogens on novel host through hybridization
Observed the naturally occurring interspecific hybrid pathogens and its importance on
genome evolution.
41
46. Karyotype variability in plant pathogenic fungi, PALM7016; 2018-2019,ACM, UASB
Interspecific hybridization
Depotter et al., 2016
43
47. Karyotype variability in plant pathogenic fungi, PALM7016; 2018-2019,ACM, UASB
Potential genomic and transcriptomic consequences of Allopolyploidy
44
Depotter et al., 2016
48. Karyotype variability in plant pathogenic fungi, PALM7016; 2018-2019,ACM, UASB
Functional consequences of chromosomal rearrangements
Mehrabi etal.,2017
45
Major evolutionary force for genetic diversity and adaptation to stressful
environments
Host range alteration
Disease outbreaks
Emergence of virulent strains
49. Light microscopy
Standard dyes such as giemsa or aceto-orceine
Used only for fungal species capable of sexual reproductions
Germ tube burst method (GTBM)
Better resolution
Condensed mitotic metaphase chromosomes
Magnification of chromosome size
Used with conventional dyes in light and fluorescent microscopy
Pulsed-field gel electrophoresis (PFGE)
Fungal Karyotyping
Enable the visualization of small chromosomes and is independent of meiosis
Used to estimate chromosome number and sizes of many fungal plant pathogen
Karyotype variability in plant pathogenic fungi, PALM7016; 2018-2019,ACM, UASB
Observation on karyotype variability
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50. Karyotype variability in plant pathogenic fungi, PALM7016; 2018-2019,ACM, UASB
Adavanced molecular cytogenetic techniques…
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Fluorescence in situ hybridization (FISH)
Enabled detection of small deletion and duplication events that could not be
visualized by standard microscopy
Comparative genomic hybridization (CGH)
Enables to compare two genomic DNA samples for gain or loss of entire
chromosomes or chromosomal segments
(Micro)array based CGH
Where DNA microarrays are used instead of the traditional metaphase chromosome
preparation
Detects very small alterations in chromosomes compare to FISH o traditional CGH
Editor's Notes
Main cause for CR and exchange of genetic materials.
Sexual process: breakage and fusion of dna strands occur as a result of crossing over between non sister chromatids of homologus chromosomes
It depend on distance.
R between HC of unequal length can result in new chromosome size variants….results in missing of dna stretches or dispensable portion of chromosome.
R b/w non-hc results in multivalents during meiosis that may lead to translocation
Each ascospore is genetically identical to one other ascospore with in the same ascus. Such pairs of identical ascospores =twins, genetically different ascospores as a result of R in the ascus =mirrors. Strains of descent lack of one or more chromosome , the twins originating from the first mitotic cell division after meiosis always appear to lack same chromosome. This indicate chromosome are stable during mitosis but loss during meiosis.
failure to separate hch meiosis1
failure of separation of sister chromatids during meiosis 2
Nondisjunction during meiosis in the haploid fungus M g reults in CNPdue to the loss or gain of specific chromosomes
Marker scores on all linkage groups were identical for these two isolates, we concluded that 2137 and 2139 are twins. Both isolates lack all markers located on LG8.this is a clear indication of absence of this linkage group from these 2 isolates bt present in parents. Further verified under pcr by Dart and SSR marker was used. Alll markers appeared to be absent .= nondisjunction uring meiosis
Nondisjunction not only loss of ch in onetwin bt also to disomy foor that chromosome in other twin in the same asus.
Results in double strand breaks(DSB) in vegetative cells during mitosis
Shotening or loss of chromosome
DSB occur simultaneously occur in two different chromosomes, NHEJ may produce chromosomal translocation by fusing dissimilar chromosomes, esulting in reciprocal translocation.
Chromosome –size DNA was separated by PFGE under conditions for <2Mb(a and b) and 1 to 6Mb(c and d)
Some tissues of certain organisms contain chromosomes, which differ significantly from normal chromosomes in terms of either morphology or function : such chromosomes are referred as special chromosome
Frequency of Spontaneous loss of DCs is more in laboratory condition (4.8%) compare to field condition (3.2%).