Single nucleotide variations in the ANXA5 promoter regulated piglet weight in the Min pig

<i>ANXA5</i> is a pleiotropic candidate gene, however its effect on piglet production trait remains unclear. In this study, a novel SNP: g.-519 A > G was identified in ANXA5 promoter. In Min pigs, association analysis showed the birth weight of AA animals at g.-674 C > A was higher than that of the AC or CC piglets (<i>p</i> < 0.05), while the heterozygous of g.-519 A > G had a higher weight than the homozygote at day 3, 7, 14, 21 after birth (<i>p</i> < 0.05). Porcine <i>ANXA5</i> and <i>NR4A1</i> existed in piglets' gastrointestinal tract, and NR4A1 localized to the nucleus and cytoplasm which regulated the expression of <i>ANXA5</i>. Luciferase reporter analysis demonstrated that the deletion of predictive NR4A1 binding region decreased the luciferase activity of porcine <i>ANXA5</i> promoter (<i>p</i> < 0.05), and the A allele of g.-519 A > G within this region had significantly higher luciferase activity than the G allele (<i>p</i> < 0.01). In conclusion, this research suggested that g.-519 A > G was a piglet weight variant that regulated the transcription of <i>ANXA5</i> partially by NR4A1.