Data for: Adaptive tail-length evolution in deer mice is associated with differential Hoxd13 expression in early development

Variation in the size and number of axial segments underlies much of the
diversity in animal body plans. Here, we investigate the evolutionary,
genetic, and developmental mechanisms driving tail-length differences
between forest and prairie ecotypes of deer mice (Peromyscus maniculatus).
We first show that long-tailed forest mice perform better in an arboreal
locomotion assay, consistent with tails being important for balance during
climbing. We then identify six genomic regions that contribute to
differences in tail length, three of which associate with caudal vertebra
length and the other three with vertebra number. For all six loci, the
forest allele increases tail length, indicative of the cumulative effect
of natural selection. Two of the genomic regions associated with variation
in vertebra number contain Hox gene clusters. Of those, we find an
allele-specific decrease in Hoxd13 expression in the embryonic tail bud of
long-tailed forest mice, consistent with its role in axial elongation.
Additionally, we find that forest embryos have more presomitic mesoderm
than prairie embryos, and that this correlates with an increase in the
number of neuromesodermal progenitors (NMPs), which are modulated by Hox13
paralogs. Together, these results suggest a role for Hoxd13 in the
development of natural variation in adaptive morphology on a
microevolutionary timescale.