Functional validation of human pigmentation SNPs in zebrafish

Abstract

Pigmentation is a quantitative and polygenic trait with high diversity within and between human populations. Two coding single nucleotide polymorphisms (SNPs), A111T in SLC24A5 and L374F in SLC45A2 have been linked to normal pigmentation variation in European populations, and one SNP ‐ E272K in SLC45A2 has been potentially linked to the East Asian skin color. To directly test the effect of each of these polymorphisms on pigmentation, we used a direct functional assay based on mutant rescue in the zebrafish. For this assay, we first identified slc45a2 as the mutated gene in zebrafish albino mutants. Zebrafish mRNA containing mutant zebrafish allele did not rescue the mutant phenotype, while wild‐type slc45a2 mRNA did. In this study we describe how we were able to ascertain that A111T and L374F mutations appear to be hypomorphic mutations and that the E272K mutation is not. The method may also be applicable to the analysis of other polymorphisms linked to human phenotypes by genome‐wide association studies or DNA sequencing.NIH funding: 5R01 AR052535