Data from: High-density sex-specific linkage maps of a European tree frog (Hyla arborea) identify the sex chromosome without information on offspring sex

Identifying homology between sex chromosomes of different species is
essential to understanding the evolution of sex determination. Here, we
show that the identity of a homomorphic sex chromosome pair can be
established using a linkage map, without information on offspring sex. By
comparing sex-specific maps of the European tree frog Hyla arborea, we
find that the sex chromosome (linkage group 1) shows a threefold
difference in marker number between the male and female maps. In contrast,
the number of markers on each autosome is similar between the two maps. We
also find strongly conserved synteny between H. arborea and Xenopus
tropicalis across 200 million years of evolution, suggesting that the rate
of chromosomal rearrangement in anurans is low. Finally, we show that
recombination in males is greatly reduced at the centers of large
chromosomes, consistent with previous cytogenetic findings. Our research
shows the importance of high-density linkage maps for studies of
recombination, chromosomal rearrangement and the genetic architecture of
ecologically or economically important traits.