The advancement of sequencing technology and molecular breeding methods has provided technical support and assurance for accurate breeding. Genomic Selection (GS) utilizes genomic information to improve livestock breeding, and it is more accurate and more efficient than traditional selection methods. GS has been widely applied in domestic animal breeding, especially in cattle. However, there are still limited studies on the application and research of GS in sheep and goats. This paper outlines the principles, analysis methods, and influential factors of GS and elaborates on the research progress, challenges, and prospects of applying GS in sheep and goat breeding. Through the review of these aspects, this paper is expected to provide valuable references for the implementation of GS in the field of sheep and goat breeding.

Intramuscular fat (IMF) is an important indicator affecting chicken quality. However, there are few studies on IMF in aged chickens. Nanchuan chicken is an excellent local egg and meat dual-purpose breed in Southwest China, renowned for its delicious flavor and fresh meat. In this study, biochemical characteristics and regulation mechanism of IMF deposition in aged Nanchuan chickens were systematically clarified. Slaughter performance, the IMF, triglyceride (TG), phospholipid (PLIP), total cholesterol (TCHO) and Fatty acids (FA) content in the breast muscle of 55-week-old Nanchuan chicken was measured, and RNA sequencing was integrated to explore the regulatory genes of IMF deposition. The results showed that the IMF content and whole net carcass yield in the high IMF group were significantly higher than those in the low IMF group (P < 0.01), while the shear force showed the opposite pattern. And, TG content in the high IMF group was significantly higher than that of the low IMF group (P < 0.05), and it was significantly positively correlated with the IMF content (P < 0.01). Meanwhile, we detected four FAs (C20:1n10, C20:4n6, C22:5n6, C22:6n3) in the high IMF group were significantly higher than those in the low IMF group (P < 0.05). In addition, the RNA sequencing results showed 469 up-regulated differentially expressed genes (DEGs) were identified, and these up-regulated DEGs were significantly enriched in ECM-receptor interaction, actin cytoskeleton regulation and focal adhesion pathways (P < 0.05). Among these DEGs, THBS1, THBS2, ITGA2, ITGA9, ITGAV and LUM were confirmed to be related to IMF deposition by protein-protein interaction (PPI) network, correlation analysis and gene expression level analysis, and these genes were hardly reported in researches of chicken IMF deposition. Our findings will help fully elucidate the mechanism of IMF formation of chickens and provide a theoretical foundation for the protection and utilization and the genetic improvement of Nanchuan chicken.

The local goat breeds of Chongqing represent the typical goat populations of Southwestern China and play a significant role in global goat research. However, studies on these goats remain limited. Chongqing goats exhibit diverse coat colors, a crucial economic trait essential for individual and breed identification. In this study, we performed genome-wide association analysis (GWAS) of Chongqing goats to identify candidate genes associated with coat color. The results of the GWAS revealed that the ASIP, AHCY, and ITCH genes on chromosome 13 are significantly associated with coat color variation in Chongqing goats. Furthermore, haplotype analysis, gene function annotation, and pathway analysis enrichment further confirmed that a significant region on chromosome 13 is associated with coat color in local Chongqing goats, and that ASIP and AHCY are related to black coat color, whereas ITCH is potentially associated with white coat expression. Additionally, we also identified TPK1 as being associated with coat color in goats, which has hardly been reported. The newly identified genes expand our understanding of the complex genetic architecture underlying pigmentation traits in livestock. Our study identifies the genes related to coat color in local goats, which enriches the genetic resource pool of goats and contributes to a deeper understanding of the genetic mechanisms underlying coat color in these breeds.

The advancement of sequencing technology and molecular breeding methods have provided technical support and assurance for accurate breeding. Genomic Selection (GS) utilizes genomic information to improve livestock breeding and, it is more accurate and more efficient than traditional selection methods. GS has been widely applied in domestic animals breeding, especially in cattle. However, there is still limited study on the application and research of GS in sheep and goat. In this paper, we outlined the principle, analysis methods, the influential factors of GS, and elaborated on the research progress, challenges, and prospects of applying GS in sheep and goat breeding. Through the review of these aspects this paper is expected to provide valuable references for the implementation of GS in the field of sheep and goat breeding.