EGR1 mRNA expression levels and polymorphisms are associated with slaughter performance in chickens

Mao Ye; Xiaohuan Chao; Chutian Ye; Lijin Guo; Zhexia Fan; Xuerong Ma; Aijun Liu; Weiming Liang; Shuya Chen; Cheng Fang; Xiquan Zhang; Qingbin Luo

doi:10.1016/j.psj.2024.104533

EGR1 mRNA expression levels and polymorphisms are associated with slaughter performance in chickens

Poult Sci. 2024 Nov 12;104(1):104533. doi: 10.1016/j.psj.2024.104533. Online ahead of print.

Authors

Mao Ye¹, Xiaohuan Chao², Chutian Ye¹, Lijin Guo¹, Zhexia Fan¹, Xuerong Ma¹, Aijun Liu¹, Weiming Liang¹, Shuya Chen¹, Cheng Fang¹, Xiquan Zhang¹, Qingbin Luo³

Affiliations

¹ College of Animal Science, South China Agricultural University, Guangzhou, PR China; State Key Laboratory of Livestock and Poultry Breeding, South China Agricultural University, Guangzhou, PR China; Guangdong Provincial Key Lab of Agro-Animal Genomics and Molecular Breeding and Key Lab of Chicken Genetics, Breeding and Reproduction, Ministry of Agriculture, Guangzhou, PR China.
² State Key Laboratory of Livestock and Poultry Breeding, South China Agricultural University, Guangzhou, PR China; Guangdong Provincial Key Lab of Agro-Animal Genomics and Molecular Breeding and Key Lab of Chicken Genetics, Breeding and Reproduction, Ministry of Agriculture, Guangzhou, PR China.
³ College of Animal Science, South China Agricultural University, Guangzhou, PR China; State Key Laboratory of Livestock and Poultry Breeding, South China Agricultural University, Guangzhou, PR China; Guangdong Provincial Key Lab of Agro-Animal Genomics and Molecular Breeding and Key Lab of Chicken Genetics, Breeding and Reproduction, Ministry of Agriculture, Guangzhou, PR China. Electronic address: qbluo@scau.edu.cn.

Abstract

With the implementation of the policy of "centralized slaughtering and chilled to market" and the development of the livestock processing industry, numerous researchers have begun to focus on the selection and breeding of broilers bred for slaughter. The selection of breeds with excellent slaughtering performance and high meat production performance has become one of the most important selective breeding goals. In our previous study, we conducted transcriptome sequencing on chicken breast tissues with high and low breast muscle rates and found higher early growth response protein 1 (EGR1) expression in breast tissues with a low breast muscle ratio, thus hypothesizing that the EGR1 gene is involved in the growth and development process of chicken muscle tissues. Therefore, we analyzed the gene functions and polymorphisms of EGR1 to investigate its association with slaughter traits. We used various experimental methods, including RT-qPCR, Cell Counting Kit 8, 5-ethynyl-2'-deoxyuridine, western blot, flow cytometry, and immunofluorescence, to validate EGR1's role in chicken primary myoblasts. The results of our functional validation experiments indicate that EGR1 is highly expressed in breast tissues with a low breast muscle content and plays a key role in regulating of muscle growth and development by promoting proliferation and inhibiting the differentiation of chicken primary myoblasts. In addition, we explored the relationship between the EGR1 gene polymorphisms and slaughter traits using mixed linear models for the first time. In a population of Jiangfeng M3 lineage partridge chickens, we identified 4 EGR1 single-nucleotide polymorphisms, 2 of which were significantly associated with slaughter traits, including live weight, slaughter weight, semi-eviscerated weight, eviscerated weight, leg weight, wing weight, and breast muscle rate. In summary, ectopic expression of EGR1 promotes the proliferation and differentiation of chicken primary myoblasts. In addition, polymorphisms in EGR1 were associated with slaughter performance, providing a potential basis for further utilization of EGR1 as a breeding marker.

Keywords: Association analysis; Early growth response protein 1 (EGR1); Polymorphism; Skeletal muscle; Slaughter performance.