Why Do Sex Chromosomes Stop Recombining?

Publication date: July 2018Source: Trends in Genetics, Volume 34, Issue 7Author(s): Suvi Ponnikas, Hanna Sigeman, Jessica K. Abbott, Bengt HanssonIt is commonly assumed that sex chromosomes evolve recombination suppression because selection favours linkage between sex-determining and sexually antagonistic genes. However, although the role of sexual antagonism during sex chromosome evolution has attained strong support from theory, experimental and observational evidence is rare or equivocal. Here, we highlight alternative, often neglected, hypotheses for recombination suppression on sex chromosomes, which invoke meiotic drive, heterozygote advantage, and genetic drift, respectively. We contrast the hypotheses, the situations when they are likely to be of importance, and outline why it is surprisingly difficult to test them. Lastly, we discuss future research directions (including modelling, population genomics, comparative approaches, and experiments) to disentangle the different hypotheses of sex chromosome evolution.

Source: Trends in Genetics - July 10, 2018 Category: Genetics & Stem Cells Source Type: research