Question

Compare and contrast horizontal gene transfer in prokaryotes with vertical gene transfer that occurs during sexual reproduction in eukaryotes.

How is horizontal gene transfer a plausible mechanism for diversification of prokaryotes? Use the steps for speciation that we discussed in class for your explanation.

Answer 1

1. Horizontal gene transfer in prokaryotes:

a. Horizontal gene transfer is the transfer of genetic material from one bacteria to the other bacteria which is not it's offspring.

b. It can occur through conjugation, transformation, transduction or through gene transfer agents.

c. Horizontal gene transfer induces genetic variation in the recipient bacteria, thus helps in evolution in prokaryotes.

Vertical gene transfer in eukaryotes:

a. It is the transfer of genetic information from parents to offsprings

b. It occurs through sexual means of reproduction involving the fusion of gametes.

c. In sexual reproduction, variation is induced through crossing over events during meiosis, thus helping the organisms to evolve and adapt to changing environmental conditions.

2. Horizontal gene transfer in prokaryotes involves the sharing of different/new genes with a recipient bacterial cell, leading to variation.

The variation introduced in the recipient cell along with mutations allows for adaptation and natural selection of the bacterium under specific environmental conditions. This ultimately leads to diversification of the bacteria from its original species.