Polymorphisms in an obesity-related gene (PCSK1) are associated with fat deposition and production traits in Italian heavy pigs

Abstract

The proprotein convertase subtilisin/kexin type 1 (PCSK1) gene encodes the prohormone convertase 1/3 enzyme that processes prohormones into functional hormones that, in turn, regulate central and peripheral energy metabolism. Mutations in the human PCSK1 gene cause severe monogenic obesity or confer risk of obesity. We herein investigated the porcine PCSK1 gene with the aim of identifying polymorphisms associated with fat deposition and production traits in Italian heavy pigs. By re-sequencing about 5.1 kb of this gene in 21 pigs of different breeds, we discovered 14 polymorphisms that were organized in nine haplotypes, clearly distributed in two clades of putative European and Asian origin. Then we re-mapped this gene on porcine chromosome 2 and analysed its expression in several tissues including gastric oxyntic mucosa of weanling pigs in which PCSK1 processes the pre-pro-ghrelin into ghrelin, which in turn is involved in the control of feed intake and energy metabolism. Association analyses between PCSK1 single-nucleotide polymorphisms (SNPs) and production, carcass and several other traits were conducted on five groups of pigs from three different experimental designs, for a total of 1221 animals. Results indicated that the analysed SNPs were associated (P , 0.01 or P , 0.05) with several traits including backfat thickness and visible intermuscular fat in Italian Duroc (ID) and growth performances in Italian Large White (ILW) and in ILW 3 Italian Landrace pigs. However, the effects estimated in the ILW were opposite to the effects reported in the ID pigs. Suggestive association (P , 0.10) was observed with muscle cathepsin B activity, opening, if confirmed, potential applications to reduce the excessive softness defect of the green hams that is of particular concern for the processing industry. The results obtained supported the need to further investigate the PCSK1 gene to fully exploit the value of its variability and apply this information in pig breeding programmes.

Metabolomics evidences plasma and serum biomarkers differentiating two heavy pig breeds

“…Pigs of both breeds were performance-tested during the same period and in the same batch at the Test Station of the National Pig Breeder Association (ANAS). Performance evaluation started when the pigs were 30 to 45 days of age and ended when the animals reached about 155 ± 5 kg live weight (Fontanesi et al, 2012). All animals were fed and handled in the same ways.…”

Analysis of Association Between a Microsatellite at Intron 1 of the Insulin-Like Growth Factor 1 (IGF1) Gene and Fat Deposition, Meat Production and Quality Traits in Italian Large White and Italian Duroc Pigs

“…Depending on the trait, models included the fixed effects of sex, batch on trial, inbreeding coefficient of the animal, interaction of sex by age at slaughtering, date of slaughtering and the random effects of litter and animal. Random Residuals (RRs) were calculated for all considered traits using linear fixed models including the same factors used for each trait in the BLUP-Multiple Trait Animal Model (Fontanesi et al, 2010;2012a). Reasons for using both EBVs and RRs in association analyses has been discussed in details in Fontanesi et al (2012a).…”

“…Random Residuals (RRs) were calculated for all considered traits using linear fixed models including the same factors used for each trait in the BLUP-Multiple Trait Animal Model (Fontanesi et al, 2010;2012a). Reasons for using both EBVs and RRs in association analyses has been discussed in details in Fontanesi et al (2012a).…”

“…Analysis of association in the Italian Duroc pigs for BFT, ADG, LC, HW and FGR was carried out merging the random group and the animals from the selective genotyping approach based on extreme and divergent VIF EBV. This was possible because these animals were normally distributed for the traits indicated above, which were not used as criterion in the selection of the extreme animals (Fontanesi et al, 2012a). A total of 312 Italian Duroc pigs was used in these analyses.…”

“…Performance test of the animals included in this study was carried out at the Test Station of ANAS as already described 2012a). Feed intake was recorded daily and body weight was measured bimonthly.…”