What is the role of the micronucleus in ciliates?

The micronucleus in ciliates plays a crucial role in controlling sexual reproduction. In these organisms, ciliates have two types of nuclei: the macronucleus and the micronucleus. The macronucleus is primarily responsible for the day-to-day metabolic processes and the expression of the organism’s phenotype, while the micronucleus serves a different function.

During sexual reproduction, specifically in processes such as conjugation, the micronucleus is responsible for undergoing processes like meiosis and producing gametic nuclei. This genetic exchange is essential for increasing genetic diversity in ciliate populations. After this exchange, the micronuclei can also fuse, contributing to the genetic recombination that characterizes sexual reproduction in these organisms.

This specialization of functions between the macronucleus and micronucleus ensures that the organism can efficiently manage reproductive processes while maintaining its metabolic functions separately.