Vectors are DNA molecules that can carry foreign genes into host cells. There are several types of vectors including plasmids, bacteriophages, cosmids, bacterial artificial chromosomes (BACs), and yeast artificial chromosomes (YACs). Plasmids are the most commonly used cloning vectors and can accept DNA inserts ranging from a few base pairs to 10kb. Larger DNA fragments can be cloned using vectors based on bacteriophages, cosmids, BACs, or YACs.
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
What are an expression vector? Detailed description of plant gene structure. Plant expression vector systems are generally consists of Ri and Ti plasmids.
The other vectors which are generally used are DNA and RNA viruses.
What are an expression vector? Detailed description of plant gene structure. Plant expression vector systems are generally consists of Ri and Ti plasmids.
The other vectors which are generally used are DNA and RNA viruses.
description of plasmids and types and importance of plasmids and artificial plasmids(PBR322,cosmids,phagemids) and selection of the recombinants and uses and advantages and disadvantages of the plasmids
“The technique in which a DNA fragment carrying a gene inserted into the cloning vector, this vector is introduced in the living cell and subsequent propagation of this recombination DNA molecule into many copies is known as gene cloning.
It is the basics of vector cloning which necessary for every and each student who is intrested in biotechnology. It is only starting, if you want to more than this then please comment on it.
Cancer cell metabolism: special Reference to Lactate PathwayAADYARAJPANDEY1
Normal Cell Metabolism:
Cellular respiration describes the series of steps that cells use to break down sugar and other chemicals to get the energy we need to function.
Energy is stored in the bonds of glucose and when glucose is broken down, much of that energy is released.
Cell utilize energy in the form of ATP.
The first step of respiration is called glycolysis. In a series of steps, glycolysis breaks glucose into two smaller molecules - a chemical called pyruvate. A small amount of ATP is formed during this process.
Most healthy cells continue the breakdown in a second process, called the Kreb's cycle. The Kreb's cycle allows cells to “burn” the pyruvates made in glycolysis to get more ATP.
The last step in the breakdown of glucose is called oxidative phosphorylation (Ox-Phos).
It takes place in specialized cell structures called mitochondria. This process produces a large amount of ATP. Importantly, cells need oxygen to complete oxidative phosphorylation.
If a cell completes only glycolysis, only 2 molecules of ATP are made per glucose. However, if the cell completes the entire respiration process (glycolysis - Kreb's - oxidative phosphorylation), about 36 molecules of ATP are created, giving it much more energy to use.
IN CANCER CELL:
Unlike healthy cells that "burn" the entire molecule of sugar to capture a large amount of energy as ATP, cancer cells are wasteful.
Cancer cells only partially break down sugar molecules. They overuse the first step of respiration, glycolysis. They frequently do not complete the second step, oxidative phosphorylation.
This results in only 2 molecules of ATP per each glucose molecule instead of the 36 or so ATPs healthy cells gain. As a result, cancer cells need to use a lot more sugar molecules to get enough energy to survive.
Unlike healthy cells that "burn" the entire molecule of sugar to capture a large amount of energy as ATP, cancer cells are wasteful.
Cancer cells only partially break down sugar molecules. They overuse the first step of respiration, glycolysis. They frequently do not complete the second step, oxidative phosphorylation.
This results in only 2 molecules of ATP per each glucose molecule instead of the 36 or so ATPs healthy cells gain. As a result, cancer cells need to use a lot more sugar molecules to get enough energy to survive.
introduction to WARBERG PHENOMENA:
WARBURG EFFECT Usually, cancer cells are highly glycolytic (glucose addiction) and take up more glucose than do normal cells from outside.
Otto Heinrich Warburg (; 8 October 1883 – 1 August 1970) In 1931 was awarded the Nobel Prize in Physiology for his "discovery of the nature and mode of action of the respiratory enzyme.
WARNBURG EFFECT : cancer cells under aerobic (well-oxygenated) conditions to metabolize glucose to lactate (aerobic glycolysis) is known as the Warburg effect. Warburg made the observation that tumor slices consume glucose and secrete lactate at a higher rate than normal tissues.
The increased availability of biomedical data, particularly in the public domain, offers the opportunity to better understand human health and to develop effective therapeutics for a wide range of unmet medical needs. However, data scientists remain stymied by the fact that data remain hard to find and to productively reuse because data and their metadata i) are wholly inaccessible, ii) are in non-standard or incompatible representations, iii) do not conform to community standards, and iv) have unclear or highly restricted terms and conditions that preclude legitimate reuse. These limitations require a rethink on data can be made machine and AI-ready - the key motivation behind the FAIR Guiding Principles. Concurrently, while recent efforts have explored the use of deep learning to fuse disparate data into predictive models for a wide range of biomedical applications, these models often fail even when the correct answer is already known, and fail to explain individual predictions in terms that data scientists can appreciate. These limitations suggest that new methods to produce practical artificial intelligence are still needed.
In this talk, I will discuss our work in (1) building an integrative knowledge infrastructure to prepare FAIR and "AI-ready" data and services along with (2) neurosymbolic AI methods to improve the quality of predictions and to generate plausible explanations. Attention is given to standards, platforms, and methods to wrangle knowledge into simple, but effective semantic and latent representations, and to make these available into standards-compliant and discoverable interfaces that can be used in model building, validation, and explanation. Our work, and those of others in the field, creates a baseline for building trustworthy and easy to deploy AI models in biomedicine.
Bio
Dr. Michel Dumontier is the Distinguished Professor of Data Science at Maastricht University, founder and executive director of the Institute of Data Science, and co-founder of the FAIR (Findable, Accessible, Interoperable and Reusable) data principles. His research explores socio-technological approaches for responsible discovery science, which includes collaborative multi-modal knowledge graphs, privacy-preserving distributed data mining, and AI methods for drug discovery and personalized medicine. His work is supported through the Dutch National Research Agenda, the Netherlands Organisation for Scientific Research, Horizon Europe, the European Open Science Cloud, the US National Institutes of Health, and a Marie-Curie Innovative Training Network. He is the editor-in-chief for the journal Data Science and is internationally recognized for his contributions in bioinformatics, biomedical informatics, and semantic technologies including ontologies and linked data.
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.
Observation of Io’s Resurfacing via Plume Deposition Using Ground-based Adapt...Sérgio Sacani
Since volcanic activity was first discovered on Io from Voyager images in 1979, changes
on Io’s surface have been monitored from both spacecraft and ground-based telescopes.
Here, we present the highest spatial resolution images of Io ever obtained from a groundbased telescope. These images, acquired by the SHARK-VIS instrument on the Large
Binocular Telescope, show evidence of a major resurfacing event on Io’s trailing hemisphere. When compared to the most recent spacecraft images, the SHARK-VIS images
show that a plume deposit from a powerful eruption at Pillan Patera has covered part
of the long-lived Pele plume deposit. Although this type of resurfacing event may be common on Io, few have been detected due to the rarity of spacecraft visits and the previously low spatial resolution available from Earth-based telescopes. The SHARK-VIS instrument ushers in a new era of high resolution imaging of Io’s surface using adaptive
optics at visible wavelengths.
A brief information about the SCOP protein database used in bioinformatics.
The Structural Classification of Proteins (SCOP) database is a comprehensive and authoritative resource for the structural and evolutionary relationships of proteins. It provides a detailed and curated classification of protein structures, grouping them into families, superfamilies, and folds based on their structural and sequence similarities.
2. Vectors are self- replicating DNA molecules . that serves
as the carrier for the transfer or insertion of foreign gene(s)
into another cell, where it can be replicated and/or
expressed.
Vector is a latin word derived from ‘vehere’ means carrier
Examples
Plasmid
Phage
Hybrid vector
Artificial Chromosomes.
3. Cloning vector
A cloning vector is a genome
that can accept the target
DNA and increase the number
of copies through its own
autonomous replication.
These vectors are only useful
for storing a genetic
sequence.
Expression Vector
A vector that is used for
expressing a gene contained
within the cloned DNA. For a
gene to give rise to a protein
product, an expression vector
must be used that contains the
necessary elements for a host
cell to transcribe and translate
the gene.
4.
5.
6. Major types of cloning Vectors
Plasmid. Circular extrachromosomal DNA that autonomously replicates inside
the bacterial cell. Plasmids generally have a high copy number, such
as pUC19 which has a copy number of 500-700 copies per cell.
Phage. Linear DNA molecules derived of bacteriophage lambda. Can be
replaced with foreign DNA without disrupting its life cycle.
Cosmids. Another circular extrachromosomal DNA molecule that combines
features of plasmids and phage.
Bacterial Artificial Chromosomes. Based on bacterial mini-F plasmids.
Yeast Artificial Chromosomes. This is an artificial chromosome that contains
telomeres (disposable buffers at the ends of chromosomes which are cut off
during cell division) with origins of replication, a yeast centromere (part of a
chromosome that links sister chromatids or a dyad), and a selectable marker for
identification in yeast cells.
7. Plasmids
• Plasmid vectors are used to clone DNA ranging in size from
several base pairs to several thousands of base pairs (100bp -
10kb).
• The term plasmid was first introduced by the American molecular
biologist Joshua Lederberg in 1952.
8. Some plasmids may integrate into the bacterial chromosome. They are
called episome or integrative plasmids. At this stage they replicate along
with the bacterial chromosome.
The plasmids in this way are classified into 2 types
Stringent & Relaxed plasmid
• Some plasmids, especially the larger ones, are stringent and have a low
copy number of perhaps just one or two per cell. stringent plasmids
encode protein factors that are necessary for their own replication,
• Relaxed plasmids, are present in multiple copies of 50 or more per cell.
relaxed plasmids replicate using host derived proteins
9. • One way of grouping plasmids is by their ability to transfer to
other bacteria. Conjugative plasmids contain tra genes, which
perform the complex process of conjugation, the transfer of
plasmids to another bacterium.
• Non-conjugative plasmids are incapable of initiating
conjugation, hence they can be transferred only with the
assistance of conjugative plasmids.
10. Another way to classify plasmids is by function. There are
five main classes:
•Fertility F-plasmids: which contain tra genes. They are
capable of conjugation and result in the expression of sex
pilli.
•Resistance plasmids: which contain genes that provide
resistance against antibiotics or poisons. They were
historically known as R-factors.
•Col plasmids: which contain genes that code for
bacteriocins, proteins that can kill other bacteria.
•Degradative plasmids: which contains genes for the
digestion of unusual substances, e.g. toluene and salicylic
acid.
•Virulence plasmids: which turn the bacterium into a
pathogen.
11. First vetors to develop was pBR322
“P” indicates plasmid
“BR” identifies the laboratory in which vector
was originally constructed.
(BR stands for Bolivar and Rodriguez, the two
researchers who develop pBR322)
“322” distinguishes the plasmid from others
developed in the same laboratory.
12. Cloning Vectors based on E. coli Plasmids
pBR322
• The plasmid pBR322 was the first widely used plasmid vector. It is a
small plasmid (4363 bp). pBR322 contains the following
components.
• Origin of replication: carries the Col EI replication origin and rop
gene to ensure reasonably high plasmid copy number (15–20 copies
per cell)
• Antibiotic resistance genes. as selectable markers. The ampicillin
resistance gene (termed bla or, more commonly, AMPr), and the
tetracycline resistance gene (termed tet or TETr)
• Cloning sites. The plasmid carries a number of unique restriction
enzyme recognition sites. Some of these are located in one or other of
the antibiotic resistance genes. For example, sites for PstI, PvuI and
SacI are found within AMPR, and sites for BamHI and HindIII are
located within TETR
13.
14. • The antibiotic resistance genes in pBR322 allow for the direct selection of
recombinants in a process called insertional inactivation. For example, if we
want to clone a DNA fragment into the BamHI site of pBR322
• The insert DNA will interrupt the gene responsible for tetracycline
resistance, but the gene for ampicillin resistance will not be altered.
• Transformed cells are first grown on bacterial plates containing ampicillin to
kill all the cells that do not contain a plasmid.
• Those cells that grow on ampicillin are then replica plated onto medium
containing both ampicillin and tetracycline.
• Those cells that grow in the presence of the ampicillin, but die under
tetracycline selection, contain plasmids that have foreign DNA inserts
In other words, the insertion of a foreign DNA fragment into an antibiotic
resistance gene inactivates the gene product and leads to antibiotic
sensitivity
17. • Blue-white screening is a rapid and efficient technique for the identification of
recombinant bacteria. It relies on the activity of β-galactosidase, an enzyme occurring
in E. coli, which cleaves lactose into glucose and galactose.
• The presence of lactose in the surrounding environment triggers the lacZ operon in E.
coli. The operon activity results in the production of β-galactoisdase enzyme that
metabolizes the lactose. Most plasmid vectors carry a short segment of lacZ gene that
contains coding information for the first 146 amino acids of β-galactosisdase. The
host E. coli strains used are competent cells containing lacZΔM15 deletion mutation.
When the plasmid vector is taken up by such cells, due to α-complementation process,
a functional β-galatosidase enzyme is produced.
• The plasmid vectors used in cloning are manipulated in such a way that this α-
complementation process serves as a marker for recombination. A multiple cloning
site (MCS) is present within the lacZ sequence in the plasmid vector. This sequence
can be nicked by restriction enzymes to insert the foreign DNA. When a plasmid
vector containing foreign DNA is taken up by the host E. coli, the α-complementation
does not occur, therefore, a functional β-galactosidase enzyme is not produced. If the
foreign DNA is not inserted into the vector or if it is inserted at a location other than
MCS, the lacZ gene in the plasmid vector complements the lacZ deletion mutation in
the host E. coli producing a functional enzyme.
18. • For screening the clones containing recombinant DNA, a chromogenic substrate
known as X-gal is added to the agar plate. If β-galactosidase is produced, X-gal is
hydrolyzed to form 5-bromo-4-chloro-indoxyl, which spontaneously dimerizes to
produce an insoluble blue pigment called 5,5’-dibromo-4,4’-dichloro-indigo. The
colonies formed by non-recombinant cells, therefore appear blue in color while the
recombinant ones appear white. The desired recombinant colonies can be easily
picked and cultured.
• Isopropyl β-D-1-thiogalactopyranoside (IPTG) is used along with X-gal for blue-
white screening. IPTG is a non-metabolizable analog of galactose that induces the
expression of lacZ gene. It should be noted that IPTG is not a substrate for β-
galactosidase but only an inducer. For visual screening purposes, chromogenic
substrate like X-gal is required.
19. Advantages and Disadvantages of using Plasmids
• pBR322 was a breakthrough for molecular biology as the first widely
used plasmid for molecular cloning, but the double screening procedure
required to identify recombinant clones was both time consuming and
error prone.
• The major cloning advantage of pUC plasmids over pBR322 is that
foreign DNA fragments can be cloned into a variety of restriction
enzyme sites and recombinants rapidly screened
• The efficiency at which the plasmid is transferred to a bacterial cell is
very low.
• The capacity of plasmids to carry large fragments of foreign DNA is
limited. Most plasmids become unstable if their overall size exceeds
about 15 kbp.
20. Bacteriophages
Bacteriophages, or phages as they are commonly known, are viruses
that specifically infect bacteria.
Like all viruses, phages are very simple in structure, consisting merely of a
DNA (or occasionally ribonucleic acid (RNA)) molecule carrying a number
of genes, including several genes for replication of the phage, and its
components protein coat and phage specific replicative enzymes. Alteration
in any of the gene can impair replicative ability of resultant molecule.
21. M13—a filamentous phage
The normal M13 genome is 6.4 kb in length, but most of this is taken up by ten
closely packed genes. Each essential for the replication of the phage.
There is only a single 507-nucleotide intergenic sequence into which new DNA
could be inserted without disrupting one of these genes, and this region includes
the replication origin which must itself remain intact. Clearly there is only limited
scope for modifying the M13 genome.
22. • The first step in construction of an M13 cloning vector was to
introduce the lacZ′ gene into the intergenic sequence. This gave
rise to M13mp1, which forms blue plaques on X-gal agar (Figure
a). M13mp1 does not possess any unique restriction sites in the
lacZ′ gene. It does, however, contain the hexanucleotide GGATTC
near the start of the gene. A single nucleotide change would make
this GAATTC, which is an EcoRI site. This alteration was carried
out using in vitro mutagenesis, resulting in M13mp2 (Figure b)
23. • The next step in the development of M13 vectors was to introduce additional
restriction sites into the lacZ′ gene. This was achieved by synthesizing in the
test tube a short oligonucleotide, called a polylinker, which consists of a
series of restriction sites and has EcoRI sticky ends (Figure a). This
polylinker was inserted into the EcoRI site of M13mp2, to give M13mp7
(Figure b), a more complex vector with four possible cloning sites (EcoRI,
BamHI, SalI, and PstI). The polylinker is designed so that it does not totally
disrupt the lacZ′ gene: a reading frame is maintained throughout the
polylinker, and a functional, though altered, b-galactosidase enzyme is still
produced.
24. Hybrid plasmid–M13 vectors
• Although M13 vectors are very useful for the production of single-stranded
versions of cloned genes, they do suffer from one disadvantage.
• There is a limit to the size of DNA fragment that can be cloned with an M13
vector, with 1500 bp generally being looked on as the maximum capacity,
though fragments up to 3 kb have occasionally been cloned.
• To get around this problem a number of hybrid vectors (“phagemids”) have
been developed by combining a part of the M13 genome with plasmid DNA.
• An example is provided by pEMBL8, which was made by transferring into pUC8
a 1300 bp fragment of the M13 genome. (Figure a)
• This piece of M13 DNA contains the signal sequence recognized by the enzymes
that convert the normal double-stranded M13 molecule into single-stranded DNA
before secretion of new phage particles.
25.
26. • This signal sequence is still functional even though detached from the
rest of the M13 genome, so pEMBL8 molecules are also converted into
single-stranded DNA and secreted as defective phage particles (Figure
b).
• All that is necessary is that the E. coli cells used as hosts for a pEMBL8
cloning experiment are subsequently infected with normal M13 to act as
a helper phage, providing the necessary replicative enzymes and phage
coat proteins.
• pEMBL8, being derived from pUC8, has the polylinker cloning sites
within the lacZ′ gene, so recombinant plaques can be identified in the
standard way on agar containing X-gal.
27. Segments of the λ genome can be deleted without impairing viability
• The λ genetic map, showing the position of the main non-essential
region that can be deleted without affecting the ability of the phage to
follow the lytic infection cycle
• Removal of non-essential region decreases the size of the resulting λ
molecule by up to 15 kb. This means that as much as 18 kb of new
DNA can now be added.
28. Cosmid
Cosmids are hybrids between λ phage DNA molecule and a bacterial plasmid.
A cosmid is basically a plasmid that carries a cos site (Figure a). It also needs a
selectable marker, such as the ampicillin resistance gene, and a plasmid origin of
replication, as cosmids lack all the λ genes and so do not produce plaques. Instead
colonies are formed on selective media, just as with a plasmid vector.
Cosmids also possess a unique restriction enzyme recognition site into which
DNA fragments can be ligated. After the packaging reaction has occurred, the
newly formed λ particles are used to infect E. coli cells. The DNA is injected into
the bacterium like normal λ DNA and circularizes through complementation of the
cos ends.
Infected cells are plated onto a selective medium and antibiotic-resistant colonies
are grown.
29.
30. • A bacterial artificial chromosome is an engineered large
DNA molecule used to clone DNA segment in a bacterial
cell.
• Based on well known natural F1 plasmid (allows
conjugation between two bacterial cells).
• MCS present for insertion of foreign DNA.
• 150-300 kb can be inserted.
• Copy no is 2 per cell.
• Used in analysis of large genome.
• First BACs vector is pBAC108L.
BACs
31.
32.
33. Advantages:
◦ Useful for cloning up to 200 kb, but can be handled like
regular bacterial plasmid vectors.
◦ Useful for sequencing large stretches of chromosomal DNA;
frequently used in genome sequencing projects.
◦ More stable
◦ Easier to work with than the YACs.
Disadvantage:
◦ Difficult to transform bacteria.
34. Capable of carrying inserts of 200-2000 kbp in yeast
YACs Vector
35. Yeast artificial chromosome(YAC) vectors allow the
cloning, within yeast cells.
• A yeast centromere (CEN4): The yeast centromere is
specified by a 125 bp DNA segment.
• Yeast autonomously replicating sequence (ARS): Yeast
ARS elements are essentially origins of replication
• Yeast telomeres (TEL): Telomeres are the specific
sequences (5 - TGTGGGTGTGGTG-3) that are present
at the ends of chromosomes in multiple copies and are
necessary for replication and chromosome maintenance.
36. • YAC contains the telomere, centromere, and origin of
replication elements. If these elements are spliced into
DNA in the proper location and orientation, then a yeast
cell will replicate the artificial chromosome along with the
other, natural chromosomes. The target DNA is flanked by
the telomere regions that mark the ends of the
chromosome, and is interspersed with the centromere
region that is vital for replication. Finally, the start site for
the copying process is present. In essence, the yeast is
fooled into accepted genetic material that mimics a
chromosome.
37.
38.
39. Advantages:
• Very useful in mapping the human genome because
they could accommodate hundreds of thousands of
kilobases each.
• YACs containing a megabase or more are
known as “megaYACs.”
Disadvantages:
• They are inefficient (not many clones are obtained per
microgram of DNA)
• Hard to isolate from yeast cells unstable
40. The TA cloning method takes advantage of the terminal
transferase activity of some DNA polymerases such as Taq
polymerase. This enzyme adds a single, 3'-A overhang to each
end of the PCR product. This makes it possible to clone this
PCR product directly into a linearized cloning vector with
single, 3'-T overhangs.
42. Ligase independent cloning (LIC) is a simple, fast and
relatively cheap method to produce expression constructs.
It makes use of the 3'--> 5'-activity of T4 DNA polymerase
to create very specific 10-15 base single overhangs in the
expression vector. PCR products with complementary
overhangs are created by building appropriate extensions
into the primers and treating them with T4 DNA
polymerase as well. The annealing of the insert and the
vector is performed in the absence of ligase by simple
mixing of the DNA fragments. This process is very
efficient because only the desired products can form.
Cloning vectors: By themselves, they are incapable of allowing for transcription and translation of the gene into a functional protein product.
In the case of a mammalian cell, a standard mammalian expression vector will contain an origin of replication, MCS, and selectable marker, as described above. However, the expression vector will also need a promoter found in mammalian cells that can drive the expression of the gene. The coding DNA needs other features to be transcribed and translated, such as the polyadenylation tail that normally appears at the end of transcribed pre-mRNA and a sequence that attracts the ribosome for translation.
Origin of replication (ORI)
This process marks autonomous replication in vector. ORI is a specific sequence of nucleotide in DNA from where replication starts. When foreign DNA is linked to this sequence then along with vector replication, foreign (desirable) DNA also starts replicating within host cell.
Selectable Marker
Besides ORI, a cloning vector should have selectable marker gene. This gene permits the selection of host cells which bear recombinant DNA (called transformants) from those which do not bear rDNA (non-transformants).
Restriction sites
It should have restriction sites, to allow cleavage of specific sequence by specific Restriction Endonuclease. Restriction sites in E.coli cloning vector pBR322 include HindIII , EcoRI , BamHI , SalI, PvuI, PstI, ClaI etc.
In nature, plasmids provide one or more functional benefits to the host such as resistance to antibiotics, degradative functions, and/or virulence. All natural plasmids contain an origin of replication (which controls the host range and copy number of the plasmid) and typically include a gene that is advantageous for survival, such as an antibiotic resistance gene. In contrast, plasmids utilized in the lab are usually artificial and designed to introduce foreign DNA into another cell. Minimally, lab-created plasmids have an origin of replication, selection marker, and cloning site. The ease of modifying plasmids and the ability of plasmids to self-replicate within a cell make them attractive tools for the life scientist or bioengineer.
Relaxed plasmids
They are the ones which are normally maintained at multiple copies per cell.
Stringent plasmids
They are the ones which have a limited number of copies per cell.
In this case of plasmid replication, the plasmid DNA is integrated in the bacterial chromosome and grows along with the cell. It uses the bacterial machinery for division A good example of this type of replication is Ti Plasmid, often used in agricultural genetic engineering experiments. It completely uses the cell genetic mechanism to grow.
acterial conjugation is the transfer of genetic material between bacterial cells by direct cell-to-cell contact or by a bridge-like connection between two cells.
The key to alpha-complementation is the fact that the lac-Z gene product (B-galactosidase) is a tetramer, and each monomer is made of two parts - lacZ-alpha, and lacZ-omega. Researchers determined that if the alpha fragment was deleted, the omega fragment is non-functional; however, alpha fragment functionality can be restored in-trans via plasmid. Hence, then name alpha-complementation.
Caternanes are the interlocked chromosomes which is one problem the replisome must fix while the other is dimerized chromosomes.
Telomeres function to protect the ends of chromosomes. They prevent one chromosome from binding to another (DNA is sticky). They also don't have any genetic information.
A shuttle vector is a vector (usually a plasmid) constructed so that it can propagate in two different host species. Therefore, DNA inserted into a shuttle vector can be tested or manipulated in two different cell types.
subcloning technique that avoids the use of restriction enzymes. he technique relies on the ability of adenine (A) and thymine (T) (complementary basepairs) on different DNA fragments to hybridize and, in the presence of ligase, become ligated together. PCR products are usually amplified using Taq DNA polymerase which preferentially adds an adenine to the 3' end of the product. Such PCR amplified inserts are cloned into linearized vectors that have complementary 3' thymine overhangs. he major downside of TA cloning is that directional cloning is not possible, so the gene has a 50% chance of getting cloned in the reverse direction.