Hypomethylation in the promoter region of <i>ZPBP</i> as a potential litter size indicator in Berkshire pigs

Abstract

In pigs, litter size is typically defined as the total number of piglets born (TNB) or the number of piglets born alive (NBA). Increasing pig litter size is of great economic interest as a means to increase productivity. The capacity of the uterus is a critical component of litter size and may play a central role in prolificacy. In this study, we investigated litter-size-related epigenetic markers in uterine tissue from Berkshire pigs with smaller litter size groups (SLGs) and larger litter size groups (LLGs) using genome-wide bisulfite sequencing (GWBS). A total of 3269 differentially methylated regions (DMRs) were identified: 1566 were hypermethylated and 1703 hypomethylated in LLG compared to SLG. The zona pellucida binding protein (ZPBP) gene was significantly hypomethylated in the LLG promoter region, and its expression was significantly upregulated in uterine tissue. Thus, the methylation status of ZPBP gene was identified as a potential indicator of litter size. Furthermore, we verified its negative correlation with litter size traits (TNB and NBA) in whole blood samples from 172 Berkshire sows as a blood-based biomarker by a porcine methylation-specific restriction enzyme polymerase chain reaction (PMP) assay. The results suggest that the methylation status of the ZPBP gene can serve as a valuable epigenetic biomarker for hyperprolific sows.

Association of IL-4 and IL-4R Polymorphisms with Litter Size Traits in Pigs

“…Increasing litter size is of significant economic interest in the pig industry [ 1 , 2 , 3 ]. Embryonic survival is the main factor in determining litter size in pigs and depends on maternal recognition of pregnancy, embryo attachment, implantation, placental development, uterine capacity, and the maintenance of pregnancy [ 4 , 39 ].…”

“…Litter size traits are among the most important traits for breeding in commercial pig production. Increasing litter size is of great economic interest as a means of enhancing the productivity of the pig industry [ 1 , 2 , 3 ]. Major limitations to increasing litter size in pigs are embryonic mortality and fetal losses during the pregnancy period [ 4 , 5 ].…”

“…Genotypic and allelic frequencies of porcine IL-4 and IL-4R genes in Landrace sows. Allele A represents wild type alleles of the IL-4 g.134993898T and IL-4R c.1577A for each locus, and allele B represents mutate alleles of IL-4 g.134993898C and IL-4R c.1577T 2. The p-value is considered a significant level of the chi-square (χ 2 ) test for Hardy-Weinberg equilibrium of each locus.…”

“…n: number of investigated litters, TNB: total number born, NBA: number born alive, NWA: number of piglets weaned alive, MBW: mean birth weight of the piglets, MWW: mean weight of piglets at weaning. MBW and MWW traits are presented in kg 2. Means ± SE represents least square means ± standard error.…”

Novel polymorphisms in GPX5 gene and their association with reproductive and productive traits in Lumsniang (Hampshire x Niang Megha) pigs under subtropical hilly region of Meghalaya

“…Improvements in sow reproductive performance are slow in porcine production due to low heritability of reproductive traits (Goddard and Hayes, 2009;Bidanel, 2011). Litter size is one of the important reproductive traits in pig production, as an increase in the number of pigs weaned per sow will increase economic returns for the swine farming sector (Sato et al, 2016;Metodev et al, 2019;An et al, 2019). Genetic selection is employed in conjunction with traditional selection methods using suitable markers for improving reproductive traits in swine, therefore, it is necessary to identify and test suitable genetic markers.…”