Question

What is said to be the selfish property of the lac gene cluster?

Answer 1

Lac operon:

It is an operon required for the transport and metabolism of lactose in E. coli and many other enteric bacteria.

Selfish-gene theory:

1. Genes don't present themselves naked to the scrutiny of natural selection, instead they present their phenotypic effects.
2. In the case of lac genes, the lac I repressor gene can control the expression of the lac zya genes placed at any location in the chromosome, such a gene is placed directly upstream of lac zya.
3. The co-localization of the regulatory gene has been proposed to be a selfish property of the lac gene cluster as these can raise the fitness of such clusters of genes by permitting vertical and horizontal inheritance.