Red and blond Mangalitza pigs display a signature of divergent directional selection in the SLC45A2 gene

The Mangalitza lard-type
pig breed is well known for its fatty appearance and curly hair, and it is
mainly distributed in Eastern Europe. Four main varieties were created in the
19th century by artificial selection: Blond Mangalitza, Black
Mangalitza, Swallow Belly Mangalitza, and Red Mangalitza. The Swallow Belly
variety has a black coat combined with yellow blond throat and underbelly. In
the current work, we aimed to investigate if the colourations of Mangalitza pigs are genetically determined by one
or a few loci which frequencies have been modified by artificial selection.
Performance of selection scans, with hapFLK and BayeScan, and of a genome-wide association study
for coat colour in Red, Swallow Belly and
Blond Mangalitza pigs, highlighted the existence of one region on SSC16 (18-20
Mb) with potential effects on hair pigmentation. The analysis of the gene
content of this region allowed us to detect the solute carrier family 45 member
2 (SLC45A2) gene. The polymorphisms of
this gene has been associated with reduced levels or absence of melanin in several
mammalian species. The genotyping of four missense polymorphisms evidenced that
rs341599992:G>A and rs693695020:G>A SNPs are strongly but not fully
associated with the red and blond coat colours of Mangalitza pigs, a result
that was confirmed by performing a haplotype association test. The near
fixation of alternative SLC45A2 genotypes
in Red and Blond Mangalitza pigs provides a compelling example of the
consequences of a divergent directional selection for coat colour in a domestic species.