Single Nucleotide Polymorphisms of Neurexophilin Gene are Unrelated to Chicken Sperm Storage

摘要

Neurexophilin 1 (Nxph1) is considered as a potential candidate marker for sperm storage in hens. Neurexophilin 3 (Nxph3) functions as Nxph1 in Nxph1 knockout mice. The objective of this study was to characterize polymorphisms of Nxph1 and Nxph3 gene in 137 Hyline hens and 122 Yangzhou hens and evaluate their genetic effects on sperm storage. The hens were inseminated with spermatozoa on 2 consecutive days. Eggs of each hen were collected and set daily following the latter of two inseminations until two consecutive clear eggs. Duration of fertility, fertile egg number and early live embryos were used for association analysis. In this study, three Single Nucleotide Polymorphisms (SNPs), T-1378C, C-2953T and C797A were found at Neurexophilin 1 gene and four SNPs, G236A, C507T, G564A and T612C were found at Neurexophilin 3 gene. SNPs, C507T, G564A and T612C of Nxph3 resulted in synonymous substitution. SNP, C797A, led to the change of 266th amino acid of Nxph1 from proline to histine. SNP, G236A, led to the change of 79th amino acid of Neurexophilin 3 from arginine to glutamine. SNPs, C-2953T, C797A, G236A did not influence characteristics of sperm storage in this study. The birds of Hyline hens with TT genotype at -1378 SNP had the lowest fertility duration, fertile egg number and early live embryos (p<0.01) while TT genotype birds of Yangzhou hens had the highest ones (p<0.01). There were only two TT genotype birds in Hyline hens and six in Yangzhou hens. The small number of TT genotype birds may be the cause of the contrary effect of SNP (T-1378C) on sperm storage in different chicken populations, suggesting that this SNP had no effect on chicken sperm storage.