• Korean Journal of Poultry Science
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• v.41 no.3
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• pp.191-196
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• 2014

The identification and utilization of potential candidate genes with significant effects on economically important traits have become increasingly important in poultry breeding programs. The ovocalyxin-32 (OCX-32) gene is located chromosome 9 in chicken, plays an important role in eggshell formation. This study was performed to assess the association between single nucleotide polymorphisms (SNPs) of OCX-32 gene and egg production traits in the Korean native chicken. Four Korean native chicken population (n = 181; including 46 females of Ogol, 46 females of white, 43 females of gray and 46 females of black) were used to analyze two SNPs (c.494A>C and c.267T>G) in the OCX-32 gene by PCR-RFLP (Polymerase Chain Reaction-Restricted Fragment Length Polymorphism). We measured egg production traits of age at first egg, first egg weight, egg production ratio and egg weight. The SNP c.494A>C was significantly associated with egg production ratio in Korean Ogol chickens (p<0.001) and egg weight in Korean white chickens (p<0.05). SNP c.267T>C was significantly associated with egg weight in Korean Ogol chickens (p<0.05). But there was no significant association in Korean gray and black chickens. Results suggest the possibility of using molecular markers in OCX-32 gene as a tool for performance and egg production traits in Korean native chicken breeding program.

• Korean Journal of Poultry Science
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• v.44 no.1
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• pp.19-28
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• 2017

The eggshell is an intricate and highly ordered structure composed of multiple layers and a calcified matrix. The eggshell is formed at the uterine segment of the chicken oviduct. In this study, histological changes in the uterine endometrium and the expression of the eggshell-related genes were investigated according to hen age. We analyzed the expression of eggshell protein-related genes, such as OCX-32, OCX-36, OC-17, OC-116, and eggshell-ion-related genes, such as CABL-1, SPP1, SCNN1G, ATP2A2, CA2, and CALM1. In chicken uterine endometrium, histological deformation, fibrosis, atrophy and elimination of micro-villi were found with increasing hen age. The concentration of blood-ion components did not significantly change with age. The amount of telomeric DNA in uterine endometrial cells decreased with increasing hen age. The expression of most of the eggshell-related genes changed significantly with increasing hen age. The expression of some ovo-proteins, which play a role in eggshell formation, increased with increasing hen age; however, there were no significant correlations among eggshell protein genes. Eggshell ion-related genes, such as ATP2A2, SCNN1G, CA2, and CALM1, were closely related to each other. The OCX-32 and OCX-36 genes were closely related to some of the eggshell ion genes. Eggshell protein-related genes, such as the OCX-32, OCX-36 genes and ion-related genes such as CALB-1, ATP2A2, SCNN1G, CA2, CALM1, affected eggshell formation, mutually or independently. This study shows that, uterine although endometrial cell damage occurs with increasing hen age, normal eggshells can be formed in old hens. This suggests that eggshell protein-and eggshell ion-related genes also control the homeostasis of eggshell formation.