Fig 1.
Dominant Red (DRDR/DR+, MC1RD/-), Dominant Black (DR+/DR+, MC1RD/-) and Recessive Red (DR+/DR+, MC1Re/MC1Re) phenotypes.
(A) The first animal to display the Dominant Red phenotype was SURINAM SHEIK ROSABEL-RED (HOCANF3541221), born in 1980 in Ontario Canada. (B) A Dominant Black Holstein female. (C) A Recessive Red Holstein female. (D) A Dominant Red Holstein female. Reprinted under a CC BY license, with permission from (A) Canadian Livestock Photography Inc., original copyright 1985 and (B, C and D) Cybil Fisher Photography, original copyright 2014.
Table 1.
Hair pigment content and composition.
Fig 2.
Linkage and genome-wide association mapping of Dominant Red.
(A) Whole genome linkage mapping using a single half-sib family of 15 DR and 17 WT animals shows Dominant Red is located on BTA3. The black line is a cubic spline smoother with a lambda of 0.05. (B) Linkage mapping shows eight contiguous SNPs on BTA3 in complete association with Dominant Red across a 10.7 Mb region. (C) Genome-wide association analysis in 95 DR and more than 500 WT animals identifies a significant association on BTA3 within the 10.7 Mb region identified by linkage mapping. The most significant marker is ARS-BFGL-NGS-94819 @ 9,722,400 bp. The black line is a cubic spline smoother with a lambda of 0.05.
Fig 3.
Evolutionary conservation of Dominant Red associated COPA mutation.
Multiple sequence alignment using MUSCLE [16] of COPA and orthologues indicates high conservation across 17 species from mammals to yeast. The arginine (R) to cysteine (C) amino acid substitution caused by the Dominant Red SNP is indicated with the arrow and is completely conserved in all species with available sequences. The WD40 repeat motif is highlighted in yellow.
Fig 4.
Differential expression results comparing Dominant Red (DRDR/DR+, MC1RD/MC1RD) and Dominant Black (DR+/DR+, MC1RD/-) skin samples.
Gene expression levels (normalized gene counts averaged across the six analyzed samples) are represented as a function of log2-fold changes of Dominant Red versus Dominant Black samples. Genes that are significantly overexpressed in Dominant Black skin samples are depicted in black, those overexpressed in Dominant Red samples are illustrated in red, while non-significant changes are illustrated in gray. Genes previously implicated in melanocyte biology and/or pigment type-switching are annotated (selected genes that do not exhibit a significant difference at FDR<0.1 are highlighted in blue while the ones showing significant expression changes are marked additionally with an asterisk associated to the gene symbol).
Table 2.
KEGG pathways significantly enriched in genes that are overexpressed in Dominant Red skin samples.