Transdução

Transdução is a biological process by which DNA is transferred from one bacterium to another by a virus. Specifically, a bacteriophage, which is a virus that infects bacteria, can accidentally package bacterial DNA into its capsid during the replication process. When this phage then infects a new bacterium, it injects the foreign bacterial DNA along with its own viral DNA. This foreign DNA can then be incorporated into the recipient bacterium's genome.

There are two main types of transduction: generalized and specialized. Generalized transduction occurs when any piece of bacterial DNA can be packaged into the phage capsid. This happens randomly during the lytic cycle of phage replication, where the bacterial DNA is fragmented and then some fragments are mistakenly packaged into new phages. Specialized transduction, on the other hand, involves the transfer of specific bacterial genes. This occurs when a temperate phage, which integrates its DNA into the bacterial chromosome (forming a prophage), excises itself imprecisely. During this imprecise excision, it can pull adjacent bacterial DNA along with its own viral DNA. When this phage infects a new bacterium, it delivers these specific bacterial genes. Transduction is a significant mechanism for horizontal gene transfer in bacteria, contributing to genetic diversity and the spread of traits such as antibiotic resistance.