Transduction is a method of transferring genes among bacteria via virus particles, which can be divided into two categories known as generalized and specialized transduction. During the lytic cycle, which quickly replicates phages and eventually releases them, ultimately killing the host cell, generalized transduction occurs. In generalized transduction, bacterial DNA is transferred from one cell to another by means of a bacteriophage. The phage first attaches to the bacterial host cell, and releases its nucleic acid in to the host cell, where host DNA is broken down. Phage protein coats (capsids) are formed in the cell, containing not only phage DNA, but mistakenly the bacterial host cells DNA as well. After the newly formed phages are released, the bacterial DNA …show more content…
In specialized transduction only a few specific genes are transferred from bacterial cells. This begins with a bacteriophage attaching and releasing its nucleic acids into the bacterial host cell, and integrates to a specific site in the host cells chromosome. Transducing particles are now produced, although these particles are defective, as they do not contain the entire phage genome. However they can still infect other cells. The transducing particles containing bacterial and phage DNA, once again find a new bacterial host cell as a recipient and integrate this new DNA into the recipient cell. Both methods involve the transfer of information via a bacteriophage from cell to cell, and result in a recombinant cell, which has a different genotype than the recipient cell. Also, the transducing particles formed in both methods are defective and must find a new host cell. Although generalized and specialized transductions have similarities they do also have key differences. In generalized transduction any part of the bacterial DNA (random fragments) may be misplaced into the newly formed transducing
The purpose of this experiment was to determine the reversion rate and recombination rate of two mutant T4 bacteriophages, rII 29 and rII 31. Through recombination rate, the map unit between the two mutants was calculated.
Titer of the Bacterial virus, the Measurement of the Recombination and the Reversion Rate, and the Gene Map Distance (Phage Recombination)
Some phages infect bacteria to destroy them, which is called lysic lifestyle, while other phages infect bacteria and stay dormant inside them for a while, which is referred to as a lysogenic lifestyle. A phage infects the bacteria cell by injecting its genetic material into the bacteria’s cytoplasm. This allows the bacteria synthesis process to start making the phage’s genetic code instead of its own. Once the bacteria have made enough phages to handle, the walls will break and release all of the phage that was created. The phages that were made are now resetting the process and beginning again by infecting the other near bacteria by injecting their genetic material once again. Those phages that stay within the bacteria and not burst the bacteria will continue to reproduce the phages own genetic code. (Griffiths,
The virus fuses with the cell’s plasma membrane. The capsid proteins are removed, releasing the viral proteins and RNA. Reverse transcriptase catalyzes the synthesis of a DNA strand complementary to the viral RNA. Reverse transcriptase catalyzes the synthesis of a second DNA strand complementary to the first. The double-stranded DNA is incorporated as a provirus into the cell’s DNA. Proviral genes are transcribed into RNA molecules, which serve as genomes for the next viral generation and as mRNAs for translation into viral proteins. The viral proteins include capsid proteins and reverse transcriptase (made in the cytosol) and envelope glycoproteins (made in the ER). Vesicles transport the glycoproteins from the ER to the cell’s plasma membrane. Capsids are assembled around viral genomes and reverse transcriptase molecules. New viruses bud off from the host cell.
The main objectives of this experiment included making dilutions of solutions, plating phage or bacteria, and determining the number of bacterial viruses or phage in a suspension. It was also conducted to demonstrate that two different mutants of phage T4 can exchange genetic material to give rise to wild-type phage. The experiment was used to distinguish mutants from wild-type by their host specificity. The recombination in bacteriophage was performed to determine the concentration of unadsorbed phage from the U series plates, total concentration from B series, and concentration of
Transformation is the transfers of virulence from one cell to another, through the transferring of genetic material. It was originally postulated in 1928 through the works of Federick Griffith, a British microbiologist. Griffith observed that the mutant form, non-virulent form, of the bacteria Streptococcus Pnumoniae could be transformed into the normal, virulent form, when injected into mice along with heat killed normal forms. He concluded that somehow the information the dead virulent form had transformed the mutant form into a virulent form.
The transposon in this experiment is contains kanR in between the inverted repeats on either end, which will be transposed from the plasmid pVJT128 to the chromosome of the recipient bacteria.
Viruses are microscopic particles that invade and take over both eukaryotic and prokaryotic cells. They consist of two structures, which are the nucleic acid and capsid. The nucleic acid contains all genetic material in the form of DNA or RNA, and is enclosed in the capsid, which is the protein coating that helps the virus attach to and penetrate the host cell. In some cases, certain viruses have a membrane surrounding the capsid, called an envelope. This structure allows viruses to become more stealthy and protected. There are two cycles in which a virus can go into: lytic and lysogenic. The lytic cycle consists of the virus attaching to a cell, injecting its DNA, and creating more viruses, which proceed to destroy the host. On the other hand, the lysogenic cycle includes the virus attaching to the cell, injecting its DNA, which combines with the cell’s DNA in order for it to become provirus. Then, the provirus DNA may eventually switch to the lytic cycle and destroy the host.
The DNA fragment is the blueprint for every piece of the bacteria. The information in the DNA and RNA can be copied and translated into proteins. Depending on roles the proteins move to various part of the bacteria, which transport the proteins around the cells. There are many different ways in which bacteria obtain foreign DNA, involving the procedures of transformation. In transformation, bacteria carry their DNA from the environment through their cell wall. Frederick Griffith discovers the process of transformation in 1928 while examining virulent bacteria that cause pneumonia in mice. Griffith used two strains of pneumococcus bacteria: a virulent, smooth strain (S-strain) and a non-virulent rough-strain. When mice were injected with smooth strain it killed the mice and the non- virulent rough strain, mice were healthy and alive. The mice that are exposed to r-strain cells stayed healthy and good, and those exposed to dead smooth cells stay healthy and good when r-strain
The oldest war on earth is one not between nations or tribes, humans and animals, but the one between bacteria and viruses. Bacterial phages have been attacking bacteria for millions of years. This process happens when a phage (virus) attaches onto the bacteria and inserts its DNA to take over the cell and use it as a factory to produce more viruses. Nearly 40 percent of all bacteria die every single day because of this, but sometimes a bacteria will endure the attack and are able to use their most effective attack, CRISPER. This DNA archive is used to store a genetic copy of the attacking virus, when the virus makes an appearance again the bacteria is able to use its very own super power, a protein called CAS9. It is then able to extremely accurately compare its DNA with the stored copy of the virus DNA and look for an identical match. When found it is able to precisely “cut out” the virus DNA making it ineffective and protecting the cell. Bit this revolution into CRISPER genetic modification didn’t happen until scientist realized that it was programmable.
1. Viruses have genetic material enclosed in a capsid. They are an intercellular parasite. They are also extremely small in size. Their infections can be prevented by vaccines. The virus’s head is the capsid holding the DNA meanwhile its body is called a tail sheath and the tail fibers are the legs coming out of it. The two strategies for viral reproduction are through the lysogenic and lytic cycle. The purpose of the lysogenic cycle is to “build up” the virus. The original virus injects its DNA into the host cell, as the cell undergoes mitosis, the DNA that was from the virus will be replicated as well as the hosts regular DNA. At first the bacteria is known
The protective capsid helps the virus escape detection and destruction during the invasion of the host. When the virus reaches the target cell, biochemical reactions between the capsid and cell wall allow the virus to latch on and inject its genome into the cell’s interior. Once inside, the viral genetic material insinuates itself into the host’s DNA or RNA. In an efficient feat of natural bioengineering, the host cell’s genetic machinery now does the rest of the work for the virus. The cell, which had already been making copies of its own genome, now also replicates that of the virus. Coded within the viral material is the blueprint for making more copies of the viral genome. Further instructions command the production of capsids and directions for assembly of new viruses. After the host cell becomes engorged with viruses, it explodes, sending the new
We all know that bacteria moves around the body and multiplies to the point where it gets us sick but how does this process work. The process of transduction is our answer to the how this all works. Transduction is a process that introduces non native DNA into a cell by a virus. An example of Transduction is the process having to do with DNA, the viral transfer of DNA from one bacterium to another bacterium.
Microbiologists believe that Mycobacterium tuberculosis becomes antibiotic resistant when it exchanges genes with other already resistant bacteria because bacteria mutate and spread rapidly within hours. There are three forms of gene mutations categorized as conjugation, transformation, and transduction. Conjugation permits the transfer of DNA from one cell to another whereas transformation occurs when a cell decays. While its cell wall falls apart, the inner genetic makeup becomes available to other
One reason why I agree and disagree with specialized transduction because the people who are doing genetic engineering know what they are dealing with and know what to do with specialized transduction. Another reason why I agree and disagree with specialized transduction because they are creating antibiotic for specific bacteria but also making the bacteria more resistant. The last reason why I agree and disagree with specialized transduction because it can spot mutated genes and create genes.