A post-genome-wide association study validating the association of the glycophorin C gene with serum hemoglobin level in pig

OBJECTIVE: This study aimed to validate the statistical evidence from the genome-wide association study (GWAS) as true-positive and to better understand the effects of the glycophorin C (GYPC) gene on serum hemoglobin traits. METHODS: Our initial GWAS revealed the presence of two single nucleotide polymorphisms (SNPs) (ASGA0069038 and ALGA0084612) for the hemoglobin concentration trait (HGB) in the 2.48 Mb region of SSC15. From this target region, GYPC was selected as a promising gene that associated with serum HGB traits in pigs. SNPs within the GYPC gene were detected by sequencing. Thereafter, we performed association analysis of the variant with the serum hemoglobin level in three pig populations. RESULTS: We identified one SNP (g.29625094 T>C) in exon 3 of the GYPC gene. Statistical analysis showed a significant association of the SNP with the serum hemoglobin level on day 20 (p<0.05). By quantitative real-time polymerase chain reaction, the GYPC gene was expressed in eight different tissues. CONCLUSION: These results might improve our understanding of GYPC function and provide evidence for its association with serum hemoglobin traits in the pig. These results also indicate that the GYPC gene might serve as a useful marker in pig breeding programs.