BAC & YAC are artificially prepared chromosomes to clone DNA sequences.yeast artificial chromosome is capable of carrying upto 1000 kbp of inserted DNA sequence
BAC & YAC are artificially prepared chromosomes to clone DNA sequences.yeast artificial chromosome is capable of carrying upto 1000 kbp of inserted DNA sequence
This presentation covers a general introduction to expression vector, its components, types, and its application. Then it covers some of the expression system with examples.
MBB 501 PLANT BIOTECHNOLOGY
INFORMATION ABOUT DIFFERENT DNA MODIFYING ENZYMES
WHAT IS AN ENZYME?
Alkaline Phosphatase
Polynucleotide kinase
Terminal deoxyneucleotidyl transferase
Nucleases
Exonuclease
Bal31 Exonuclease III
Endonuclease
S1 endonulease
Deoxyribonuclease 1 (Dnase 1)
RNase A
RNase H
Restriction Endonuclease
PvuI
PvuII
Different types of endonuclease enzymes
The recognition sequences for some of the most frequently used restriction endonucleases.
Categorization of enzymes
Isoschizomers
Neoschizomers
Isocaudomers
General and molecular genetics.
cDNA Library ,Introduction,Discovery of cDNA library,Preparation ,construction,Enzymes used in cDNA library,uses ,advantages and disadvantages of cDNA library.
This presentation covers a general introduction to expression vector, its components, types, and its application. Then it covers some of the expression system with examples.
MBB 501 PLANT BIOTECHNOLOGY
INFORMATION ABOUT DIFFERENT DNA MODIFYING ENZYMES
WHAT IS AN ENZYME?
Alkaline Phosphatase
Polynucleotide kinase
Terminal deoxyneucleotidyl transferase
Nucleases
Exonuclease
Bal31 Exonuclease III
Endonuclease
S1 endonulease
Deoxyribonuclease 1 (Dnase 1)
RNase A
RNase H
Restriction Endonuclease
PvuI
PvuII
Different types of endonuclease enzymes
The recognition sequences for some of the most frequently used restriction endonucleases.
Categorization of enzymes
Isoschizomers
Neoschizomers
Isocaudomers
General and molecular genetics.
cDNA Library ,Introduction,Discovery of cDNA library,Preparation ,construction,Enzymes used in cDNA library,uses ,advantages and disadvantages of cDNA library.
A DNA library is a collection of cloned restriction fragments of the DNA of an organism.
Two kinds of libraries will be discussed: genomic libraries and complementary DNA (cDNA) libraries.
Genomic libraries ideally contain a copy of every DNA nucleotide sequence in the genome.
In contrast, cDNA libraries contain those DNA sequences that appear as mRNA molecules, and these differ from one cell type to another.
As a pioneer biotechnology company in the world, Creative Biogene can provide high quality cDNA libraries construction service to customers worldwide.
https://www.creative-biogene.com/Services/cDNA-Library-Construction-Service
Creation of a cDNA library starts with mRNA instead of DNA. Messenger RNA carries encoded information from DNA to ribosomes for translation into protein. To create a cDNA library, these mRNA molecules are treated with the enzyme reverse transcriptase, which is used to make a DNA copy of an mRNA (i.e., cDNA). A cDNA library represents a sampling of the transcribed genes, but a genomic library includes untranscribed regions.
The complete genome sequences of a number of organisms, including mammals, have recently become available because of rapid advances in DNA sequencing technology. Nevertheless, the analysis of transcripts still plays a crucial role in bridging the gap between the genome and the proteome, particularly in mammals. Therefore, as a method for the analysis of transcripts, cDNA library construction is crucial, even in the post-genome sequencing era.
https://www.creative-biogene.com/Services/cDNA-Library-Construction-Service
Creative Biogene’s goal is to provide you with the most affordable and high-quality cDNA libraries construction service to ensure your satisfaction in a timely and professional manner. https://www.creative-biogene.com/Services/cDNA-Library-Construction-Service
Earliest Galaxies in the JADES Origins Field: Luminosity Function and Cosmic ...Sérgio Sacani
We characterize the earliest galaxy population in the JADES Origins Field (JOF), the deepest
imaging field observed with JWST. We make use of the ancillary Hubble optical images (5 filters
spanning 0.4−0.9µm) and novel JWST images with 14 filters spanning 0.8−5µm, including 7 mediumband filters, and reaching total exposure times of up to 46 hours per filter. We combine all our data
at > 2.3µm to construct an ultradeep image, reaching as deep as ≈ 31.4 AB mag in the stack and
30.3-31.0 AB mag (5σ, r = 0.1” circular aperture) in individual filters. We measure photometric
redshifts and use robust selection criteria to identify a sample of eight galaxy candidates at redshifts
z = 11.5 − 15. These objects show compact half-light radii of R1/2 ∼ 50 − 200pc, stellar masses of
M⋆ ∼ 107−108M⊙, and star-formation rates of SFR ∼ 0.1−1 M⊙ yr−1
. Our search finds no candidates
at 15 < z < 20, placing upper limits at these redshifts. We develop a forward modeling approach to
infer the properties of the evolving luminosity function without binning in redshift or luminosity that
marginalizes over the photometric redshift uncertainty of our candidate galaxies and incorporates the
impact of non-detections. We find a z = 12 luminosity function in good agreement with prior results,
and that the luminosity function normalization and UV luminosity density decline by a factor of ∼ 2.5
from z = 12 to z = 14. We discuss the possible implications of our results in the context of theoretical
models for evolution of the dark matter halo mass function.
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.
Richard's aventures in two entangled wonderlandsRichard 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.
DERIVATION OF MODIFIED BERNOULLI EQUATION WITH VISCOUS EFFECTS AND TERMINAL V...Wasswaderrick3
In this book, we use conservation of energy techniques on a fluid element to derive the Modified Bernoulli equation of flow with viscous or friction effects. We derive the general equation of flow/ velocity and then from this we derive the Pouiselle flow equation, the transition flow equation and the turbulent flow equation. In the situations where there are no viscous effects , the equation reduces to the Bernoulli equation. From experimental results, we are able to include other terms in the Bernoulli equation. We also look at cases where pressure gradients exist. We use the Modified Bernoulli equation to derive equations of flow rate for pipes of different cross sectional areas connected together. We also extend our techniques of energy conservation to a sphere falling in a viscous medium under the effect of gravity. We demonstrate Stokes equation of terminal velocity and turbulent flow equation. We look at a way of calculating the time taken for a body to fall in a viscous medium. We also look at the general equation of terminal velocity.
1. SYED MUHAMMAD KHAN (BS HONS. ZOOLOGY)
CDNA LIBRARY
“A cDNA library is defined as a collection of cDNA fragments. Complementary DNA
(cDNA) is DNA synthesized from a single-stranded RNA (e.g., messenger RNA) template in
a reaction catalyzed by the enzyme reverse transcriptase."
Principle of cDNA Library: To make cDNA libraries, DNA reverse transcripts of the RNA
sequences (usually the mRNA) of an organism are produced and then cloned. It is called a
cDNA library because all the DNA in this library is complementary to mRNA and is produced
by the reverse transcription. Much of eukaryotic DNA consists of repetitive sequences that
are not transcribed into mRNA and those sequences are not represented in a cDNA library.
Prokaryotes and lower eukaryotes do not contain introns (non-coding sequences), rendering
the preparation of cDNA unnecessary. Hence, cDNA libraries are produced only from higher
eukaryotes such as humans.
Vectors of cDNA Library: Vectors are used to mediate the cloning of the cDNA fragments,
two of the most important vectors used for this purpose are: (1) Bacterial Plasmid and (2)
Bacteriophages.
PROCEDURE IN THE CONSTRUCTION OF cDNA LIBRARY:
The steps involved in the construction of a cDNA library are as follows:
1. Extraction of mRNA (from a eukaryotic cell): Firstly, the mRNA is obtained and purified
from the rest of the RNAs. Several methods exist for purifying RNA such as trizol extraction
and column purification. The rest of the RNAs are discarded.
2. Construction of cDNA from the extracted mRNA: There are different strategies for the
construction of a cDNA, two of them are as follows:
The RNase Method: In this method, a complementary DNA strand is synthesized using
reverse transcriptase to make an RNA: DNA duplex. The RNA strand is then nicked and
replaced by DNA. The first step is to add a primer to the 3’ end of the RNA. This primer is
extended into a DNA strand by reverse transcriptase. This leaves an RNA: DNA duplex. The
next step is to replace the RNA strand with a DNA strand. This is done by using RNase H
(RNA digesting enzyme) enzyme which removes the RNA from RNA: DNA duplex. A single
DNA strand is left behind which acts as a template. The second DNA strand is synthesized by
the action of DNA polymerase.
The Self-Priming method: A primer is attached at the polyadenylate tail (poly-A tail) of the
mRNA to prime the DNA strand synthesis against the mRNA. The cDNA that forms, as a
result, can fold back on itself, forming a hairpin loop, hence the cDNA self-primes itself for
2. SYED MUHAMMAD KHAN (BS HONS. ZOOLOGY)
the synthesis of the second strand. After the synthesis of the second DNA strand, this loop
must be cleaved with a single-strand-specific nuclease. This method has a flaw: there is a
risk of losing some of the nucleotide sequence of the DNA because of the nuclease.
3. Cloning the cDNA: The cDNA can be cloned by incorporating it into a vector (bacterial
plasmid, bacteriophage, etc.) and allowing the said vector to multiply with the copy of
the cDNA within. Following are some methods of incorporating the DNA fragment into
the vector genome:
Blunt End Ligation: The double-stranded, blunt-ended cDNA molecules can be attached to
the vector molecules by blunt-ended ligation, i.e. the blunt ends of the cDNA are
ligated/joined to the blunt ends of the vector DNA.
Addition of Linkers: The cDNA molecules can also be attached to the vector molecules by the
addition of linkers (small segments of DNA containing many restriction sites). The addition
of linkers is followed by digestion with the relevant enzyme and then ligation into a vector.
Incorporation of Restriction Sites: Another option is to modify the steps of the creation of
DNA strands to include restriction sites in the cDNA. The cDNA can incorporate into the
vector by these restriction sites.
Figure: Procedure for the construction of the cDNA library. First of all, mRNA is isolated from
a eukaryotic cell. Then, the mRNA is used as a template to produce DNA. This DNA is then
incorporated into a vector and cloned. (Source: Wikimedia, CC-BY-SA)
ADVANTAGES OF cDNA LIBRARY:
3. SYED MUHAMMAD KHAN (BS HONS. ZOOLOGY)
A cDNA library has two advantages over other genome libraries:
It is enriched with fragments from actively transcribed genes (the genes that are
transcribed a lot).
Introns do not interrupt the cloned sequences; introns would pose a problem when the
goal is to produce a eukaryotic protein in bacteria because most bacteria have no means
of removing the introns.
DISADVANTAGES OF cDNA LIBRARY:
The major disadvantage of a cDNA library is that it contains only sequences that are present
in a mature mRNA. Introns and any other sequences that are altered after transcription are
not present; sequences, such as promoters and enhancers, which are not transcribed into
RNA also are not present in a cDNA library.
It is also important to note that the cDNA library represents only those gene sequences ex-
pressed in the tissue from which the RNA was isolated. The frequency of a particular DNA
sequence in a cDNA library depends on the abundance of the corresponding mRNA in the
given tissue. In contrast, almost all genes are present at the same frequency in a genomic
DNA library.
APPLICATIONS OF cDNA LIBRARY:
Following are the applications of cDNA libraries:
Discovery of new genes.
Cloning of full-length cDNA molecules for in vitro study of gene function.
Study of various mRNAs expressed in different cells or tissues.
Study of alternative splicing in different cells or tissues.