Re-inventing sex: A W chromosome and a path out of parthenogenesis for Bunonema nematodes
Sex chromosomes are deeply conserved in some organisms but remarkably labile in others. Here we describe the evolution of a novel sex chromosome in the nematode Bunonema JU3390, a species with an autosome-derived genomic segment currently functioning as a female-limited W chromosome. We propose this neo sex chromosome system evolved to escape lethal structural mutations accumulated during a period of parthenogenesis, demonstrating the role of evolutionary contingency in this rapid re-invention of sex.
evolutionary biology↗