Genome-wide epistatic interactions of litter size at birth in Chinese indigenous pigs

Improving
litter size at birth (TNB) and the number of
piglets born alive (NBA)
are the main breeding goals related to litter traits, which are economically
important. A better understanding of genetic
architecture underlying TNB and NBA traits could increase pig production
efficiency. However, most previous studies on these
traits focus on additive genetic effects, while epistatic interactions underlying TNB and
NBA traits has not yet been
well investigated, which are essential to understand how traits-related genes
interact. Herein, we conducted genome scans of epistatic interactions underlying
TNB and NBA traits in a total of 150 Chinese indigenous pigs (75 Jinhua and 75
Shengxian Plotted pigs) with high throughput genomic data. Based on SNPs with
high interaction values and connectivity scores, we identified eight promising
candidate genes, namely AKT2, TSC1, MTOR, PIK3R5, TIAM1, FGF14, RALB, and ROR2, potentially associated with litter
traits in pigs. Moreover, the underlying pathways, e.g., calcium ion transport,
pointed out their roles in litter size related-traits. Our findings provide new
insight into genetic architecture of litter traits in
pigs and will benefit economic profits in pig production.