Abandoning sex: multiple origins of asexuality in the ciliate Tetrahymena.

ABSTRACT:

Background

By segregating somatic and germinal functions into large, compound macronuclei and small diploid micronuclei, respectively, ciliates can explore sexuality in ways other eukaryotes cannot. Sex, for instance, is not for reproduction but for nuclear replacement in the two cells temporarily joined in conjugation. With equal contributions from both conjugants, there is no cost of sex which theory predicts should favor asexuality. Yet ciliate asexuality is rare. The exceptional Tetrahymena has abandoned sex through loss of the micronucleus; its amicronucleates are abundant in nature where they reproduce by binary fission but never form conjugating pairs. A possible reason for their abundance is that the Tetrahymena macronucleus does not accumulate mutations as proposed by Mull

SUBMITTER: Doerder FP 

PROVIDER: S-EPMC4045964 | biostudies-literature | 2014 May

REPOSITORIES: biostudies-literature