The Effect of BSCL2 Gene on Fat Deposition Traits in Pigs

Abstract

BSCL2 encodes seipin, a transmembrane endoplasmic reticulum protein associated with lipodystrophy and severe metabolic complications, including diabetes and hepatic steatosis. In pigs, BSCL2 expression increases during adipocyte differentiation. In the present study, we identified significant gene variants associated with fat deposition (FD)-related processes based on subcutaneous fat tissue RNA-seq data. In the association study, to prove our hypothesis, three Polish pig breeds were included: Złotnicka White (ZW, n = 72), Polish Landrace (PL, n = 201), and Polish Large White (PLW, n = 169). Based on variant calling analysis and χ2 tests, BSCL2 mutations showing significantly different genotype/allele distribution between high- and low-fat pigs were selected for a comprehensive association study. Four interesting BSCL2 variants (rs346079334, rs341493267, rs330154033, and rs81333153) belonging to downstream and missense mutations were investigated. Our study showed a significant decrease in minor allele frequency for two BSCL2 variants (rs346079334 and rs341493267) in PL pigs in 2020–2021. In ZW, BSCL2 mutations significantly affected loin and ham fats, meat redness, and growth performance traits, such as feed conversion and daily feed intake. Similar observations were noted for PLW and PL, where BSCL2 mutations influenced fat depositions and meat traits, such as loin eye area, loin mass and fat, carcass yield, and growth performance traits. Based on the observation in pigs, our study supports the theory that BSCL2 expressed in subcutaneous fat is involved in the FD process.

Expression genome-wide association study identifies key regulatory variants enriched with metabolic and immune functions in four porcine tissues

“…To identify other interesting regulated genes per tissue, the focus was placed on cis -eQTLs that presented the highest ratio of significant variants after correcting for eQTL length. Genes identified included BSCL2 in spleen, mutations in BSCL2 have been associated with fat deposition in pigs [ 80 ], TRAPPC9 in the liver, which has been implicated in porcine backfat thickness [ 81 ] as well as nutrient absorption and body size [ 82 ], and in in muscle, CLCA2 , which is involved in mediating the calcium contraction response [ 83 ]. CLCA2 has been earlier found in a haplotype region subject to strong opposite selection between Duroc (a sire line) and Large White (a sow line) pigs [ 84 ].…”