This document discusses different concepts of genes including classical concepts like alleles and modern concepts like jumping genes, overlapping genes, split genes, nested genes, and fusion genes. It then focuses on jumping genes or transposons, providing details on their discovery by Barbara McClintock in maize in the 1940s. Transposons are able to move from one location in the chromosome to another. The document discusses types of transposons like IS-elements, P-elements, and retrotransposons. It also discusses the significance of transposons and examples of transposon systems in maize like the Ac-Ds system.
despite of the enormous genomic diversity, the phage genome mapping is being done using a plethora of techniques,which includes both genetic mapping and physical mapping
Molecular Marker and It's ApplicationsSuresh Antre
Molecular (DNA) markers are segments of DNA that can be detected through specific laboratory techniques. With the advent of marker-assisted selection (MAS), a new breeding tool is now available to make more accurate and useful selections in breeding populations.
Gene regulation in eukaryotes in a nutshell covering all the important stages of gene regulation in eukaryotes at transcriptional level, translation level and post-translational level.
despite of the enormous genomic diversity, the phage genome mapping is being done using a plethora of techniques,which includes both genetic mapping and physical mapping
Molecular Marker and It's ApplicationsSuresh Antre
Molecular (DNA) markers are segments of DNA that can be detected through specific laboratory techniques. With the advent of marker-assisted selection (MAS), a new breeding tool is now available to make more accurate and useful selections in breeding populations.
Gene regulation in eukaryotes in a nutshell covering all the important stages of gene regulation in eukaryotes at transcriptional level, translation level and post-translational level.
Transposable elements (TEs), also known as "jumping genes" or transposons, are sequences of DNA OR Mobile DNA elements that move (or jump) from one location in the genome to another. They are also known as jumping gene.
Presentation contents: Discovery and Definition of Transposon, Simple transposon and Composite transposons. Here I have explained Barbara McClintock Study of Transposable elements in Corn(Ac and Ds elements). After that Types of Transposable Elements. Then In Simple Transposons or IS elements introduction and how they mediate recombination between two different Plasmids. Introduction of Composite Transposons and their organization (Tn 5 and Tn 10). Introduction of Non-Composite Transposons(Tn 3) and Replicative Transposons.
The Role of Introns in Genetic Regulation
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Introns are sequences that interrupt open reading frames (ORFs) in RNA.
Spliceosomal introns are exclusive of eukaryotic nuclear gene transcripts, are a complex of small nuclear RNAs (snRNAs) and proteins .
Introns are crucial because the protein variety is greatly enhanced by alternative splicing in which introns take partly important roles.
Changes in the exon-intron structure of a gene can also occur, including the loss or/and gain of introns. Intron loss is important aspect of gene structural variation and plays a vital role in gene evolution.
This report focuses on the intron, its origin, classification, evolution, loss and gain, function, and the diverse roles of splicing and alternative splicing in human disease.
A transposable element (TE or transposon) is a DNA sequence that can change its position within a genome, sometimes creating or reversing mutations and altering the cell's genome size.
Transposition often results in duplication of the TE.
Barbara McClintock's discovery of these jumping genes earned her a Nobel Prize in 1983.
Transposable elements make up a large fraction of the genome and are responsible for much of the C-value of eukaryotic cells.
Professional air quality monitoring systems provide immediate, on-site data for analysis, compliance, and decision-making.
Monitor common gases, weather parameters, particulates.
Richard's entangled aventures in wonderlandRichard Gill
Since the loophole-free Bell experiments of 2020 and the Nobel prizes in physics of 2022, critics of Bell's work have retreated to the fortress of super-determinism. Now, super-determinism is a derogatory word - it just means "determinism". Palmer, Hance and Hossenfelder argue that quantum mechanics and determinism are not incompatible, using a sophisticated mathematical construction based on a subtle thinning of allowed states and measurements in quantum mechanics, such that what is left appears to make Bell's argument fail, without altering the empirical predictions of quantum mechanics. I think however that it is a smoke screen, and the slogan "lost in math" comes to my mind. I will discuss some other recent disproofs of Bell's theorem using the language of causality based on causal graphs. Causal thinking is also central to law and justice. I will mention surprising connections to my work on serial killer nurse cases, in particular the Dutch case of Lucia de Berk and the current UK case of Lucy Letby.
This presentation explores a brief idea about the structural and functional attributes of nucleotides, the structure and function of genetic materials along with the impact of UV rays and pH upon them.
Slide 1: Title Slide
Extrachromosomal Inheritance
Slide 2: Introduction to Extrachromosomal Inheritance
Definition: Extrachromosomal inheritance refers to the transmission of genetic material that is not found within the nucleus.
Key Components: Involves genes located in mitochondria, chloroplasts, and plasmids.
Slide 3: Mitochondrial Inheritance
Mitochondria: Organelles responsible for energy production.
Mitochondrial DNA (mtDNA): Circular DNA molecule found in mitochondria.
Inheritance Pattern: Maternally inherited, meaning it is passed from mothers to all their offspring.
Diseases: Examples include Leber’s hereditary optic neuropathy (LHON) and mitochondrial myopathy.
Slide 4: Chloroplast Inheritance
Chloroplasts: Organelles responsible for photosynthesis in plants.
Chloroplast DNA (cpDNA): Circular DNA molecule found in chloroplasts.
Inheritance Pattern: Often maternally inherited in most plants, but can vary in some species.
Examples: Variegation in plants, where leaf color patterns are determined by chloroplast DNA.
Slide 5: Plasmid Inheritance
Plasmids: Small, circular DNA molecules found in bacteria and some eukaryotes.
Features: Can carry antibiotic resistance genes and can be transferred between cells through processes like conjugation.
Significance: Important in biotechnology for gene cloning and genetic engineering.
Slide 6: Mechanisms of Extrachromosomal Inheritance
Non-Mendelian Patterns: Do not follow Mendel’s laws of inheritance.
Cytoplasmic Segregation: During cell division, organelles like mitochondria and chloroplasts are randomly distributed to daughter cells.
Heteroplasmy: Presence of more than one type of organellar genome within a cell, leading to variation in expression.
Slide 7: Examples of Extrachromosomal Inheritance
Four O’clock Plant (Mirabilis jalapa): Shows variegated leaves due to different cpDNA in leaf cells.
Petite Mutants in Yeast: Result from mutations in mitochondrial DNA affecting respiration.
Slide 8: Importance of Extrachromosomal Inheritance
Evolution: Provides insight into the evolution of eukaryotic cells.
Medicine: Understanding mitochondrial inheritance helps in diagnosing and treating mitochondrial diseases.
Agriculture: Chloroplast inheritance can be used in plant breeding and genetic modification.
Slide 9: Recent Research and Advances
Gene Editing: Techniques like CRISPR-Cas9 are being used to edit mitochondrial and chloroplast DNA.
Therapies: Development of mitochondrial replacement therapy (MRT) for preventing mitochondrial diseases.
Slide 10: Conclusion
Summary: Extrachromosomal inheritance involves the transmission of genetic material outside the nucleus and plays a crucial role in genetics, medicine, and biotechnology.
Future Directions: Continued research and technological advancements hold promise for new treatments and applications.
Slide 11: Questions and Discussion
Invite Audience: Open the floor for any questions or further discussion on the topic.
Introduction:
RNA interference (RNAi) or Post-Transcriptional Gene Silencing (PTGS) is an important biological process for modulating eukaryotic gene expression.
It is highly conserved process of posttranscriptional gene silencing by which double stranded RNA (dsRNA) causes sequence-specific degradation of mRNA sequences.
dsRNA-induced gene silencing (RNAi) is reported in a wide range of eukaryotes ranging from worms, insects, mammals and plants.
This process mediates resistance to both endogenous parasitic and exogenous pathogenic nucleic acids, and regulates the expression of protein-coding genes.
What are small ncRNAs?
micro RNA (miRNA)
short interfering RNA (siRNA)
Properties of small non-coding RNA:
Involved in silencing mRNA transcripts.
Called “small” because they are usually only about 21-24 nucleotides long.
Synthesized by first cutting up longer precursor sequences (like the 61nt one that Lee discovered).
Silence an mRNA by base pairing with some sequence on the mRNA.
Discovery of siRNA?
The first small RNA:
In 1993 Rosalind Lee (Victor Ambros lab) was studying a non- coding gene in C. elegans, lin-4, that was involved in silencing of another gene, lin-14, at the appropriate time in the
development of the worm C. elegans.
Two small transcripts of lin-4 (22nt and 61nt) were found to be complementary to a sequence in the 3' UTR of lin-14.
Because lin-4 encoded no protein, she deduced that it must be these transcripts that are causing the silencing by RNA-RNA interactions.
Types of RNAi ( non coding RNA)
MiRNA
Length (23-25 nt)
Trans acting
Binds with target MRNA in mismatch
Translation inhibition
Si RNA
Length 21 nt.
Cis acting
Bind with target Mrna in perfect complementary sequence
Piwi-RNA
Length ; 25 to 36 nt.
Expressed in Germ Cells
Regulates trnasposomes activity
MECHANISM OF RNAI:
First the double-stranded RNA teams up with a protein complex named Dicer, which cuts the long RNA into short pieces.
Then another protein complex called RISC (RNA-induced silencing complex) discards one of the two RNA strands.
The RISC-docked, single-stranded RNA then pairs with the homologous mRNA and destroys it.
THE RISC COMPLEX:
RISC is large(>500kD) RNA multi- protein Binding complex which triggers MRNA degradation in response to MRNA
Unwinding of double stranded Si RNA by ATP independent Helicase
Active component of RISC is Ago proteins( ENDONUCLEASE) which cleave target MRNA.
DICER: endonuclease (RNase Family III)
Argonaute: Central Component of the RNA-Induced Silencing Complex (RISC)
One strand of the dsRNA produced by Dicer is retained in the RISC complex in association with Argonaute
ARGONAUTE PROTEIN :
1.PAZ(PIWI/Argonaute/ Zwille)- Recognition of target MRNA
2.PIWI (p-element induced wimpy Testis)- breaks Phosphodiester bond of mRNA.)RNAse H activity.
MiRNA:
The Double-stranded RNAs are naturally produced in eukaryotic cells during development, and they have a key role in regulating gene expression .
Nutraceutical market, scope and growth: Herbal drug technologyLokesh Patil
As consumer awareness of health and wellness rises, the nutraceutical market—which includes goods like functional meals, drinks, and dietary supplements that provide health advantages beyond basic nutrition—is growing significantly. As healthcare expenses rise, the population ages, and people want natural and preventative health solutions more and more, this industry is increasing quickly. Further driving market expansion are product formulation innovations and the use of cutting-edge technology for customized nutrition. With its worldwide reach, the nutraceutical industry is expected to keep growing and provide significant chances for research and investment in a number of categories, including vitamins, minerals, probiotics, and herbal supplements.
Unveiling the Energy Potential of Marshmallow Deposits.pdf
Modern gene concept
1. CONCEPT OF THE GENE
CLASSICAL
Alleles,
Multiple Alleles,
Pseudoalleles,
Complementation Test,
Experiments On Rii Locus
And Lozenge Locus.
2. CONCEPT OF THE GENE
MODERN
Jumping Genes,
Overlapping,
Split Genes,
Nested Genes,
and Fusion Genes.
3. JUMPING GENES OR TRANSPOSONS
• Earlier it was thought that genes were static and had
definite and fixed locus.
• Barbara McClintock in maize (corn) in late 1940s first
predicted by certain genetic elements were moving from
one site to an entirely different site in the chromosome.
• She discovered that in Indian maize corn have cobs
with kernels of different colours.
• Alexander Brink. In late 1960s this phenomenon was
also discovered in bacteria. These controlling elements
were later on called as transposable elements.
• “a DNA sequence that is able to move or insert itself
at a new location in the genome.”
• They constitute a fairly accountable fraction of genome
of organisms like fungi, bacteria, plants, animals and
humans.
The reddish streaks on
these corn grains are
caused by transposons
4. All of them are characterized by
(i) The presence of inverted terminal repeats required for
transposition;
(ii) The ability to create duplication of flanking DNA at the site
of insertion, target site duplications; and
(iii) Presence of open reading frames coding for enzyme
transposase, which catalyzes transposition.
5. Types of Transposons
Examples :
IS-elements,
P-elements in maize,
hobo-elements in
Drosophila etc.
Tn3-elements found in bacteria
may be viral or non-viral.
Retrovirus like elements:
They carry long terminal repeats
(LTR).
Eg:copia, gypsy elements in
Drosophila.
Retroposons:
LTR are absent.
Eg: LINEs and SINEs in humans.
6. Transposons in Maize:
Ac-Ds system:
o by Barbara Mc. Clintock.
o Ac stands for Activator and Ds for Dissociation.
o Barbara found that Ds and Ac genes were sometimes
mobile and moved to different chromosomal locations
thus resulting in different kernel phenotypes.
o Ac and Ds, both exhibit inter-chromosomal as well as
intra-chromosomal movements (transposition).
o Ds element is activated by Ac and on activation it serves
as the site provider for breakage in chromosome. Ac can
move autonomously(the ability of their own excision)
while Ds can move only in the presence of Ac (Fig. 6).
The transposition involving this Ac-Ds system produces
altered kernel phenotypes.
• Other transposable elements of maize are:
i. spm (suppressor mutator) system,
ii. dt (dotted) system,
iii. Mu (Mutator) system, etc.
7.
8.
9. Significance of Transposable Elements:
• 1. Transposons may change the structural and functional characteristics of genome
by changing their position in the genome.
• 2. Transposable elements cause mutation by insertion, deletion, etc.
• 3. Transposons make positive contribution in evolution as they have tremendous
impact on the alteration of genetic organisation of organisms.
• 4. They are useful as cloning vectors also, in gene cloning.
For example, P-elements are frequently used as vector for introducing transgenes into
Drosophila.
• 5. Transposons may also be used as genetic markers while mapping the genomes.
• 6. Transposon-mediated gene tagging is done for searching and isolation of a
particular gene.
10. OVERLAPPING GENES
• Genes which can be read or translated in two different ways to
produce two different proteins.
• In the genome of φ x 174 ,
-The actual number of nucleotide - 5400.
- The estimate of number of nucleotides -exceeds 6000 .
• How these proteins could be coded from a DNA segment which is
not long enough to code the required number of amino acids?.
-----Number of base pairs should be 3 times the number of amino
acids in protein.
11. • In 1976 Barnell and his co-workers discovered
that the genome of φ x 174 consists of 9 cistrons
(A, B, C, D, E, F, G, H, J).
• Cistron E is present between C and J, and that
cistron E overlaps cistron D.
• Again stop codon of gene D is overlapping with
the start codon of gene J (Fig. 14.18).
• Gene B also overlaps with gene A.
• In the base sequence TAATG, the first triplet code
TAA, is the stop codon of gene D and last three
(ATG) is the start codon of gene J (Fig. 14.19).
• Here the middle base (third from left) is the base
where both codons meet.
12. SPLIT GENES
• generally believed that a gene is a
continuous, uninterrupted sequence
of nucleotides which codes for a
single polypeptide chain.
• The sequences of some eukaryotic
genes (globin, ovalbumin) are found
to be interrupted (introns) by
nucleotides that are not represented
within the amino acid sequence of
the protein but present in the same
order in the genome as in the mRNA.
• Intervening sequences were
unequivocally demonstrated for the
first time in the gene for β-globin in
mouse and rabbit and then in chick
ovalbumin.
13. 1. RNA Splicing:
2. Ribozyme:
For the first time Thomas Cech (1986)
discovered that pre-rRNA isolated from
a ciliated protozoa,
Tetrahymena thermophila, is self
splicing.
14. NESTED GENES
• A situation in which one gene
resides within an intron of
another gene.
• Was first demonstrated in
the Gart locus of Drosophila
melanogaster by Steven
Henikoff et al.
• The existence of nested
genes is in contradiction to
the central hypothesis ,that
genes are located in linear
order on the chromosome.
15. FUSION GENE
• A fusion gene is a
hybrid gene formed
from two previously
separate genes.
• It can occur as a
result
of: translocation, inter
stitial deletion,
or chromosomal
inversion.