Relationship between individual DNA methylation percentage differences and carcass traits in pigs

Abstract

AbstractIn order to investigate the effects of DNA methylation on pig carcass traits, the methylation-sensitive amplified polymorphism technique (MSAP) was adopted to amplify DNA from blood samples taken from 77 F1hybrids of Large White×Meishan crosses. A total of 15 carcass traits were tested. Results showed that means of internal fat rate (IFR), lean meat percentage (LMP) and ratio of lean meat versus fat meat (RLF) were significantly different (P<0.05) among five levels of general individual methylation difference (GIMDP); means of carcass weight (CW), IFR, backfat thickness at buttock (BFT3), average backfat thickness (ABF), carcass length to the first rib (CLR) and carcass length to the first neck vertebra (CLN) were also significantly different (P<0.05) among five levels of special individual methylation percentage difference (SIMDP), while means of 15 carcass traits were not significantly different (P>0.05) among five levels of neutral individual methylation percentage difference (NIMDP). Of all traits that were significantly affected by SIMPD, CW, ABF and BFT3increased, IFR and backfat thickness at shoulder (BFT1) decreased, while CLR and bone percentage (BP) fluctuated with the SIMDP increase. The regressions between SIMDP and IFR, BFT1, BFT3and ABF were significant (P<0.05). It is concluded that DNA methylation can be applied as a marker to related studies in pigs; positive methylation sites were superior to negative methylation sites in predicting hybrid performance, and methylation differences should be maintained at specific levels for different traits to improve the productivity of pigs.