Genetic Association between Swine Leukocyte antigen Class II Haplotypes and Reproduction Traits in Microminipigs

Abstract

The effects of swine leukocyte antigen (SLA) molecules on numerous production and reproduction performance traits have been mainly reported as associations with specific SLA haplotypes that were assigned using serological typing methods. In this study, we intended to clarify the association between SLA class II genes and reproductive traits in a highly inbred population of 187 Microminipigs (MMP), that have eight different types of SLA class II haplotypes. In doing so, we compared the reproductive performances, such as fertility index, gestation period, litter size, and number of stillbirth among SLA class II low resolution haplotypes (Lrs) that were assigned by a polymerase chain reaction-sequence specific primers (PCR-SSP) typing method. Only low resolution haplotypes were used in this study because the eight SLA class II high-resolution haplotypes had been assigned to the 14 parents or the progenitors of the highly inbred MMP herd in a previous publication. The fertility index of dams with Lr-0.13 was significantly lower than that of dams with Lr-0.16, Lr-0.17, Lr-0.18, or Lr-0.37. Dams with Lr-0.23 had significantly smaller litter size at birth than those with Lr-0.17, Lr-0.18, or Lr-0.37. Furthermore, litter size at weaning of dams with Lr-0.23 was also significantly smaller than those dams with Lr-0.16, Lr-0.17, Lr-0.18, or Lr-0.37. The small litter size of dams with Lr-0.23 correlated with the smaller body sizes of these MMPs. These results suggest that SLA class II haplotypes are useful differential genetic markers for further haplotypic and epistatic studies of reproductive traits, selective breeding programs, and improvements in the production and reproduction performances of MMPs.

Genomic Diversity of the Major Histocompatibility Complex in Health and Disease

“…Some controversial aspects of the role of the MHC sexual selection and reproduction in primates [17], birds [18] and fish [19] are reviewed in this Special Issue. Three research papers specifically report on the MHC association with reproductive traits and kin selection (MHC-based mate choice) and fitness [30,31,32]. Ando and co-authors examined the association between Class II haplotypes and reproductive performances such as fertility index, gestation period, litter size, and number of stillbirths in the highly inbred population of Microminipigs [30].…”

“…Three research papers specifically report on the MHC association with reproductive traits and kin selection (MHC-based mate choice) and fitness [30,31,32]. Ando and co-authors examined the association between Class II haplotypes and reproductive performances such as fertility index, gestation period, litter size, and number of stillbirths in the highly inbred population of Microminipigs [30]. They found statistically significant differences between haplotypes and the fertility index of dams, litter size at birth, litter size at weaning of dams, and body sizes of adult animals.…”

“…They concluded from their long-term field, behavioural and genetic study that the MHC genes of giant pandas should be included when studying MHC-dependent reproductive studies. In this regard, the giant pandas [32] and the minimicropigs [30] appear to be two unique inbred mammalian models for investigating the correlation between the MHC and reproduction.…”

“…In regard to the research articles, Farina and co-workers highlighted the importance of analysing the coordinated haplotypic expression of HLA-DQA and -DQB to better understand susceptibility to the autoimmune diseases T1D and CD [25]. Ando and colleagues used the MHC Class II haplotypes determined from breeding records of highly inbred Microminipigs to investigate their association with reproductive traits [30]. Lan and co-workers described the use of MHC haplotypes as adaptive markers in their study of the relative roles of selection and genetic drift in seven populations of the endangered crested ibis [31].…”

“…This Special Issue on the “Genomic Diversity of the MHC in Health and Disease” consists of eighteen papers with one commentary [16], five reviews [17,18,19,20,21], eleven research articles [22,23,24,25,26,27,28,29,30,31,32] and one communication [33]. These papers cover a broad range of topics on the genomic diversity of the MHC regulatory system in various vertebrate species in health and disease including structure and function; MHC Class I, II and III genes; antigen presentation; innate and adaptive immunity; neurology; transplantation; haplotypes; alleles; infectious and autoimmune diseases; fecundity; conservation; lineage; and evolution.…”