Abstract
The feather rate phenotype in chicks, including early-feathering and late-feathering phenotypes, are widely used as a sexing system in the poultry industry. The objective of this study was to obtain candidate genes associated with the feather rate in Shouguang chickens. In the present study, we collected 56 blood samples and 12 hair follicle samples of flight feathers from female Shouguang chickens. Then we identified the chromosome region associated with the feather rate by genome-wide association analysis (GWAS). We also performed RNA sequencing and analyzed differentially expressed genes between the early-feathering and late-feathering phenotypes using HISAT2, StringTie, and DESeq2. We identified a genomic region of 10.0–13.0 Mb of chromosome Z, which is statistically associated with the feather rate of Shouguang chickens at one-day old. After RNA sequencing analysis, 342 differentially expressed known genes between the early-feathering (EF) and late-feathering (LF) phenotypes were screened out, which were involved in epithelial cell differentiation, intermediate filament organization, protein serine kinase activity, peptidyl-serine phosphorylation, retinoic acid binding, and so on. The sperm flagellar 2 gene (SPEF2) and prolactin receptor (PRLR) gene were the only two overlapping genes between the results of GWAS and differential expression analysis, which implies that SPEF2 and PRLR are possible candidate genes for the formation of the chicken feathering phenotype in the present study. Our findings help to elucidate the molecular mechanism of the feather rate in chicks.
Highlights
The feather rate phenotype in newborn chicks can be observed within 24 h after hatching, based on the relative length of the primary feathers and primary-covert feathers
prolactin receptor (PRLR) was proposed as the late-feathering gene, and the duplication sequence containing part of the PRLR gene was regarded as the causative mutation of the LF phenotype in chicken (Elferink et al, 2008; Luo et al, 2012; Bu et al, 2013)
Combined with the results of RNA sequencing analysis, we found that sperm flagellar 2 gene (SPEF2) and PRLR were the only two overlapping genes between the results of genome-wide association analysis (GWAS) and differential expression analysis, which implied that SPEF2 and PRLR were the only two possible candidate genes for the formation of the chicken feathering phenotype in the present study
Summary
The feather rate phenotype in newborn chicks can be observed within 24 h after hatching, based on the relative length of the primary feathers and primary-covert feathers. A chick with its primary feathers longer than its primary-covert feathers by more than 2 mm is caused by the earlyfeathering (EF) phenotype; otherwise, it would be caused by the late-feathering (LF) phenotype. Candidate Genes for Feather Rate and contributes to the LF phenotype, relatively the k+ allele is recessive and promotes the EF phenotype (Warren, 1925). The relationship between the feather rate phenotype and production performances were investigated. Goger et al (2017) observed that the EF groups generally had higher egg production and hatching performances except for egg weight. Compared to yellow-feathered broilers with the EF phenotype, yellow-feathered broilers with the LF phenotype had significantly higher breast muscle weight, breast muscle rate, abdominal fat weight, and abdominal fat rate (Hu et al, 1995)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
