Research Article

Analysis of skin color change and related gene expression after crossing of Dongxiang black chicken and ISA layer

Published: September 28, 2015
Genet. Mol. Res. 14 (3) : 11551-11561 DOI: 10.4238/2015.September.28.7

Abstract

This study evaluated the effects of the autosomal domi­nant Fm gene in conjunction with the sex-linked Id gene on skin color and related gene expression. Ten Dongxiang black cocks were selected to build ten families by mating 60 individuals of ISA B-line layers. The skin color of the F1 generation was observed at different time points. At 126 days, 36 chickens were slaughtered, and gene expression of TYRP1, TYRP2, MC1R, and EDNRB in breast skin was assessed by quantitative RT-PCR. The ratio of Dongxiang black chickens with white skin chicks in the F1 generation to that of non-white was 3:7 (HoFF: HeFf). At 126 days, all F1 generation cocks showed white skin (115/115), while the percentages of hens with black skin were 100% (HoFF, 27/27) and 53.75% (HeFf, 43/80). The change in skin color peaked between 42 and 84 days. The offspring of HoFF displayed significantly higher expres­sion of MC1R, compared with those of HeFf (P < 0.05). The “L” value of hen’s skin was significantly lower, and TYRP1 and TYRP2 expres­sion was significantly higher (P < 0.05) than in cocks with the same Fm/fm genotype. These findings indicate the presence of homozygous and heterozygous Fm in Dongxiang black chickens, with the offspring of homozygous birds showing a higher percentage of black skin percentage. The expression of the four genes studied was correlated with skin color, with TYRP1 and TYRP2 representing the most suitable molecular markers.

This study evaluated the effects of the autosomal domi­nant Fm gene in conjunction with the sex-linked Id gene on skin color and related gene expression. Ten Dongxiang black cocks were selected to build ten families by mating 60 individuals of ISA B-line layers. The skin color of the F1 generation was observed at different time points. At 126 days, 36 chickens were slaughtered, and gene expression of TYRP1, TYRP2, MC1R, and EDNRB in breast skin was assessed by quantitative RT-PCR. The ratio of Dongxiang black chickens with white skin chicks in the F1 generation to that of non-white was 3:7 (HoFF: HeFf). At 126 days, all F1 generation cocks showed white skin (115/115), while the percentages of hens with black skin were 100% (HoFF, 27/27) and 53.75% (HeFf, 43/80). The change in skin color peaked between 42 and 84 days. The offspring of HoFF displayed significantly higher expres­sion of MC1R, compared with those of HeFf (P < 0.05). The “L” value of hen’s skin was significantly lower, and TYRP1 and TYRP2 expres­sion was significantly higher (P < 0.05) than in cocks with the same Fm/fm genotype. These findings indicate the presence of homozygous and heterozygous Fm in Dongxiang black chickens, with the offspring of homozygous birds showing a higher percentage of black skin percentage. The expression of the four genes studied was correlated with skin color, with TYRP1 and TYRP2 representing the most suitable molecular markers.