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.

Sex chromosomes are deeply conserved in some organisms but remarkably labile in others. Here we describe a novel, female-hemizygous ZW sex chromosome system in the nematode Bunonema JU3390. We propose this neo-sex chromosome evolved from an autosome to escape mutational meltdown…