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

This study evaluated the effects of the autosomal domi-nant 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 expres-sion of MC1R, compared with those of HeFf (P < 0.05). The "L" value of hen's skin was significantly lower, and TYRP1 and TYRP2 expres-sion 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.

High-resolution melting curve analysis of the ADSL and LPL genes and their correlation with meat quality and blood parameters in chickens.

Adenylosuccinate lyase (ADSL) and lipoprotein lipase (LPL) are key enzymes in the metabolism of inosine monophosphate (IMP) and fat mass, which are important factors in meat quality evaluation. In this study, we selected 50 hens from the ISA B-line layers and Guangxi Yellow chickens, slaughtered the chickens at 120 days old, and analyzed polymorphisms in the ADSL and LPL genes using the high-resolution melting curve method. Blood lipid parameters, intramuscular fat (IMF), and IMP content were higher (P < 0.05) in Guangxi Yellow chickens than in ISA B-line layers, while LPL activity was lower (P < 0.05). In exon 2 of the ADSL gene, a C3484T mutation was identified. In both breeds, the CC genotype showed the highest IMP, and IMP was the lowest in the TT genotype. In the 5ꞌ regulatory region of the LPL gene, a C293T mutation was identified. In both breeds, the CC genotype showed the lowest LPL and IMF, while IMF was the highest in the TT genotype. The percentages of individuals with the TT type in the ADSL gene, which was associated with the lowest IMP, were 16.0 and 52.0% in Guangxi chickens and ISA layers, respectively. The percentages of individuals with the CC type of the LPL gene, which was associated with the lowest LPL and IMF, were 28.0 and 44.0%, respectively. The ADSL and LPL gene mutations are correlated with differences in meat quality in different chicken breeds, and high-resolution melting curve is an effective prediction technology for these mutations.