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A cell contains host chromosome (large loop of DNA), F plasmid (small loop of DNA) and a pilus (projection out of the cell). The F plasmid is inserted into the host chromosome to become Hfr male (donor). When the plasmid is removed from the host chromosome, genes from the chromosome (such as lac) may move from the chromosome to the plasmid. In this case the cell becomes an F’ cell.
(a) The F plasmid can occasionally integrate into the bacterial chromosome, producing an Hfr cell. (b) Imprecise excision of the F plasmid from the chromosome of an Hfr cell may lead to the production of an F’ plasmid that carries chromosomal DNA adjacent to the integration site. This F’ plasmid can be transferred to an F cell by conjugation.
a) Diagram showing one cell with multiple genes on its chromosome as well as an integrated F plasmid. This cell begins copying and transferring its entire genome but conjugation ends before the entire chromosome is transferred. B) A sample plasmid showing the variety of genes on the plasmid. Some sample genes include: argG, pabB, metA, argR, polA, and oriC. Numbers in the center of the plasmid indicate the location of genes; these numbers show a plasmid of 1000bp total.
(a) An Hfr cell may attempt to transfer the entire bacterial chromosome to an F cell, treating the chromosome like an extremely large F plasmid. However, contact between cells during conjugation is temporary. Chromosomal genes closest to the integration site (gene 1) that are first displaced during rolling circle replication will be transferred more quickly than genes far away from the integration site (gene 4). Hence, they are more likely to be recombined into the recipient F cell’s chromosome. (b) The time it takes for a gene to be transferred, as detected by recombination into the F cell’s chromosome, can be used to generate a map of the bacterial genome, such as this genomic map of E. coli . Note that it takes approximately 100 minutes for the entire genome (4.6 Mbp) of an Hfr strain of E. coli to be transferred by conjugation.

Consequences and applications of conjugation

Plasmids are an important type of extrachromosomal DNA element in bacteria and, in those cells that harbor them, are considered to be part of the bacterial genome. From a clinical perspective, plasmid s often code for genes involved in virulence. For example, genes encoding proteins that make a bacterial cell resistant to a particular antibiotic are encoded on R plasmids . R plasmids, in addition to their genes for antimicrobial resistance, contain genes that control conjugation and transfer of the plasmid. R plasmids are able to transfer between cells of the same species and between cells of different species. Single R plasmids commonly contain multiple genes conferring resistance to multiple antibiotics.

Genes required for the production of various toxins and molecules important for colonization during infection may also be found encoded on plasmids. For example, verotoxin-producing strains of E. coli ( VTEC ) appear to have acquired the genes encoding the Shiga toxin from its gram-negative relative Shigella dysenteriae through the acquisition of a large plasmid encoding this toxin. VTEC causes severe diarrheal disease that may result in hemolytic uremic syndrome (HUS), which may be lead to kidney failure and death.

In nonclinical settings, bacterial genes that encode metabolic enzymes needed to degrade specialized atypical compounds like polycyclic aromatic hydrocarbons (PAHs) are also frequently encoded on plasmids. Additionally, certain plasmids have the ability to move from bacterial cells to other cell types, like those of plants and animals, through mechanisms distinct from conjugation. Such mechanisms and their use in genetic engineering are covered in Modern Applications of Microbial Genetics .

Questions & Answers

please what is the topic today.
Anafure Reply
I hope u are doing good
Anafure
Yes ooo u
Daniel
what is immunoglobulin specifications
hop Reply
what if she is having stomach pain ND also running temprature
Samuel Reply
i wante to study medicine in university so how i should prepare my self
Lissa Reply
microorganism functions
NUHU Reply
how does the helicobacteri pylori affect the stomach walls?
Erick Reply
hi
Allan
Hlo
SUMIT
hi
Umar
hi
Umar
when the stomach is been affected with helicobacteria what are the preventive measure to be considered to ensure specific outcome?
Umar
yeah
Ayan
proper alimentation( feed properly),avoid eating lot of pepper but the main point is nutrition if you feed well the bacteria won't cause digestion of the stomach wall and thus you will be fine
Nanjoh
what is microbiology
vijay Reply
microbiology is the scientific study of microorganisms .microorganisms are those organisms that are too small to see with the naked eye ex-bacteria fungi
Yashkin
a branch of biological science concerned with organisms that can not be observed with a naked eye
Mooya
what are the types of granulocytes and explain
lord
polymorpho nuclear leukocyte, known as granulocyte are divide into three,1-polymorpho eosinophil 2-polymorpho basophil 3-polymorpho neutrophil
Musa
microbiology is scientific study of microorganism which can nt be seen by naked eye,for example bacteria,viruses, protozoa ad fungi.
Emma
microbiology is the scientific study of microorganisms
Atia
good
Samuel
microbiology is the study of micro organisms by the use of microscope to know how they react and respire to it environments
Daniel
microbiology is a branch of science which studies microbe
Ivy
microbiology is the study of microoganism
paul
microbiology is the study of tiny organisms which are difficult to be seen by naked eyes
hop
I want to know more about sample collection on the field
Ama Reply
blood collection and urinarysis
Lizzy
2143
Lizzy
yes
Lizzy
In the periodic table the number on the upper left hand side is what
Aurelia Reply
Hydrogen
Tob
am not talking about the elements
Aurelia
Is it the atomic number or the mass number
Aurelia
hologen
Usman
differences between acid fast and non acid fast bacilli
ANTHONY Reply
acid fast have cell wall that holds to carbol fuschin stain while non acid fast doesn't have. it readily releases out the primary stain the carbol fuschin.
LAFIA
where do I post a question that isn't related to that topic
eklectc
hi everyone
kennedy
hello
Olivia
for sure, this question is not related to the topic.
LAFIA
can someone explain the process of glycolysis and the electron transport chain? I'm so freakin lost. it loses carbons, gains hydroxyls, gains, loses Hydrogens....ugh it's like a foreign language to me! or direct me to a youTube video or something that will make this seem easier to concept?
eklectc
it's a loaded question, sorry!
eklectc
why is DNA a genetic material
Mcbeth Reply
DNA is genetic material because it contains chromosome contains the traits which includes characters and behavioral characteristics
chima
why is it difficulty to classfy protista
Tanaka
Good
Eddy
what is infection prevention
Muhammed Reply
good hygiene
Dhaqan
way of preventing disease causing germs
henry
maintenance of sterilization
Pooja
h
Faustina
describe the components of the epidemiology triangle
Muhammed Reply
Hai
Nantongo
hii
Md
where from you
Md
i am Indian
Md
you
Md
Hello friend
effiong
How are you people doing
effiong
أ‌) Host factor ب) pathogen ج) environment
Widad
Hello
Kofi
Hi
Widad
hey hi
kalai
The epidemiologic triangle is made up of three parts: agent, host and environment
Princess
please can a microbiologist will work at hospital
Usman
yes but some state whose have deficiency of medical laboratories practictioners
jamilu
yes, as a lab scientists
kehinde
pls what are the layers of the skin
Jenny
Epidermis and Dermis
Nantongo
EPIDERMIS is the outer layer of the skin and it made up of three layers. Cornified, Granular and Malpighian layer. DERMIS is composed mainly of connection tissues, sweat glands, sebaceous glands, sensory nerves endings and fat cells.
MASA
what are the fluids used in biochemistry Lab used to diagnose diseases
Jb Reply
fadumo qule a gemil3
fadumo Reply
Faadum mahamud disease micro biology
fadumo
makuway diinkaraan suaalo
fadumo
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Source:  OpenStax, Microbiology. OpenStax CNX. Nov 01, 2016 Download for free at http://cnx.org/content/col12087/1.4
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