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Updated: Oct 16, 2026

Primary Endodermal Epithelial Cell Culture from the Yolk Sac Membrane of Japanese Quail Embryos
Published on: March 10, 2016
Multi-trait GWAS and comparative genomics identify candidate genes associated with egg weight and yolk lipid
Qianyun Ji1, Xiao Wang1, Jiajia Shi1
1Anhui Agriculture University, Hefei, China.
Objective:
Yolk lipids support embryonic and post-hatch development in poultry, while egg weight serves as a crucial selection trait regulated by polygenes. Understanding the genetic mechanisms underlying egg weight and yolk weight helps improve chicken breeding. This research aimed to explore key genomic regions and candidate genes potentially associated with these traits in indigenous chickens, to provide theoretical basis and genetic resources for genomic selection and precision breeding.
Methods:
Phenotypic and genetic correlation analyses were performed on indigenous chicken populations. Single-trait and multi-trait genome-wide association studies (GWAS) were used to screen trait-related SNPs. Selective sweep and runs of homozygosity (ROH) island analyses across chicken breeds were implemented to verify candidate regions. Upstream transcription factors and signaling pathways of candidate genes were further investigated for molecular mechanism validation.
Results:
Egg weight was strongly positively correlated with yolk weight in indigenous chickens. Integrated analyses of GWAS, MTAG, ROH, and selection signatures highlighted FASN and FAR1 as candidate genes potentially associated with egg and yolk weight. Functional verification demonstrated that transcription factor Sp1 activates the expression of FASN. This interaction promotes lipid metabolism and lipid droplet synthesis in chicken hepatocytes, suggesting a potential regulatory mechanism that may contribute to egg weight and yolk weight variation.
Conclusion:
This study highlights candidate loci and genes associated with egg and yolk weight in indigenous chickens and provides in vitro evidence supporting the involvement of the Sp1-FASN axis in hepatic lipid metabolism. These findings provide insights into the potential molecular mechanisms underlying yolk lipid deposition and provide candidate loci for further validation in genetic improvement of egg weight.
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