Data from: Recombination in the eggs and sperm in a simultaneously hermaphroditic vertebrate

When there is no recombination (achiasmy) in one sex, it is in the
heterogametic one. This observation is so consistent that it constitutes
one of the few patterns in biology that may be regarded as a ‘rule’ and
Haldane (Haldane 1922 J. Genet. 12, 101–109. (doi:10.1007/BF02983075))
proposed that it might be driven by selection against recombination in the
sex chromosomes. Yet differences in recombination rates between the sexes
(heterochiasmy) have also been reported in hermaphroditic species that
lack sex chromosomes. In plants—the vast majority of which are
hermaphroditic—selection at the haploid stage has been proposed to drive
heterochiasmy. Yet few data are available for hermaphroditic animals, and
barely any for hermaphroditic vertebrates. Here, we leverage reciprocal
crosses between two black hamlets (Hypoplectrus nigricans, Serranidae),
simultaneously hermaphroditic reef fishes from the wider Caribbean, to
generate high-density egg- and sperm-specific linkage maps for each
parent. We find globally higher recombination rates in the eggs, with
dramatically pronounced heterochiasmy at the chromosome peripheries. We
suggest that this pattern may be due to female meiotic drive, and that
this process may be an important source of heterochiasmy in animals. We
also identify a large non-recombining region that may play a role in
speciation and local adaptation in Hypoplectrus.