DOI: 10.5061/dryad.jh8j7
title: Data from: Albinism in phylogenetically and geographically distinct populations of Astyanax cavefish arises through the same loss-of-function Oca2 allele

description: The Mexican tetra, Astyanax mexicanus, comprises 29 populations of
 cave-adapted fish distributed across a vast karst region in northeastern
 Mexico. These populations have a complex evolutionary history, having
 descended from "old" and "young" ancestral
 surface-dwelling stocks that invaded the region ~8 MYa and ~2.1 MYa,
 respectively. This study investigates a set of captive, pigmented Astyanax
 cavefish collected from the Micos cave locality in 1970, in which albinism
 appeared over the last two decades. We combined novel coloration analyses,
 coding sequence comparisons, and mRNA expression level studies to
 investigate the origin of albinism in captive-bred Micos cavefish. We
 discovered albino Micos cavefish harbor two copies of a loss-of-function
 Oca2 allele previously identified in the geographically distant Pachón
 cave population. This result suggests that phylogenetically young Micos
 cavefish and phylogenetically old Pachón fish inherited this Oca2 allele
 from the ancestral surface-dwelling taxon. This likely resulted from the
 presence of the loss-of-function Oca2 haplotype in the "young"
 ancestral surface-dwelling stock that colonized the Micos cave, and also
 introgressed into the ancient Pachón cave population. The appearance of
 albinism in captive Micos cavefish, caused by the same loss-of-function
 allele present in Pachón cavefish, implies that geographically and
 phylogenetically distinct cave populations can evolve the same
 troglomorphic phenotype from standing genetic variation present in the
 ancestral taxon.
description: Raw Quantitative PCR
 MeasurementsThis file contains raw
 cycling threshold (C(t)) data collected for quantitative PCR measurements
 of Oca2 (experimental gene) expression and GAPDH (control gene)
 expression. These data were collected using a Bio-Rad MiniOpticon
 real-time PCR instrument.Raw qPCR
 measures.xlsxRaw Filter Coloration
 MeasurementsThe first tab of this
 data file contains the raw "eye dropper" values collected for
 each of 13 concentric circular grid points in the CMYK color mode. Each
 "area" measurement describes which of 13 grid points was
 measured. Data was collected from each of seven different individuals from
 five different groups. The second tab of this data file contains the raw
 triplicate and averaged measures of darkness for the same seven
 individuals from five different groups indicated above.Descriptive Statistics
 Coloration MeasurementsThis data file contains
 the descriptive statistics for all raw coloration and greyscale
 measurements collected from each of seven individuals from five groups of
 fish.Raw filter
 ImagesThis folder contains
 raw, high-resolution filter images from which coloration measurements were
 collected.Raw filter
 images.zipRaw filter Images +
 GridsThese are the
 high-resolution filter images overlain with a "digital"
 grid". This grid was used to determine the position from which
 coloration measurements were collected from each of seven individuals from
 five different groups.Raw filter images +
 grids.zipRaw fin clip
 PhotographsThese are the raw images
 of caudal fin clips collected from a representative albino Micos cavefish
 and a representative pigmented Micos cavefish.Raw fin clip
 photographs.zip