Data from: Exaggerated heterochiasmy in a fish with sex-linked male coloration polymorphisms

It is often stated that polymorphisms for mutations affecting fitness of
males and females in opposite directions [sexually antagonistic (SA)
polymorphisms] are the main selective force for the evolution of
recombination suppression between sex chromosomes. However, empirical
evidence to discriminate between different hypotheses is difficult to
obtain. We report genetic mapping results in laboratory-raised families of
the guppy (Poecilia reticulata), a sexually dimorphic fish with SA
polymorphisms for male coloration genes, mostly on the sex chromosomes.
Comparison of the genetic and physical maps shows that crossovers are
distributed very differently in the two sexes (heterochiasmy); in male
meiosis, they are restricted to the termini of all four chromosomes
studied, including chromosome 12, which carries the sex-determining locus.
Genome resequencing of male and female guppies from a population also
indicates sex linkage of variants across almost the entire chromosome 12.
More than 90% of the chromosome carrying the male-determining locus is
therefore transmitted largely through the male lineage. A lack of
heterochiasmy in a related fish species suggests that it originated
recently in the lineage leading to the guppy. Our findings do not support
the hypothesis that suppressed recombination evolved in response to the
presence of SA polymorphisms. Instead, a low frequency of recombination on
a chromosome that carries a male-determining locus and has not undergone
genetic degeneration has probably facilitated the establishment of
male-beneficial coloration polymorphisms.