F+ conjugation:
This results in the transfer of an F+ plasmid (coding only for a sex pilus) but not chromosomal DNA from a male donor bacterium to a female recipient bacterium. One plasmid strand enters the recipient bacterium while one strand remains in the donor. Each strand then makes a complementary copy. The recipient then becomes an F+ male and can make a sex pilus. Other plasmids present in the cytoplasm of the bacterium, such as those coding for antibiotic resistance, may also be transferred during this process.
Hfr (high-frequency recombinant) conjugation:
An F+ plasmid inserts or integrates into the nucleoid to form an Hfr male. The nucleoid then breaks in the middle of the inserted P plasmid and one DNA strand begins to enter the recipient bacterium. The bacterial connection usually breaks before the transfer of the entire chromosome is completed so the remainder of the F+ plasmid seldom enters the recipient. As a result, there is a transfer of some chromosomal DNA, that may be exchanged for a piece of the recipient's DNA, but not maleness.
Resistance plasmid conjugation:
This results in the transfer of a resistance plasmid (R-plasmid) from a donor bacterium to a recipient. One plasmid strand enters the recipient bacterium while one strand remains in the donor. Each strand then makes a complementary copy. The R-plasmid has genes coded for multiple antibiotic resistance and sex-pilus formation. The recipient becomes antibiotic resistant and male and is now able to transfer R-plasmids to other bacteria.
Tags: Bio Technology, Bio Genetix, Bacterial Conjugation
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