Preliminary evidence of segregation distortion in the SLA system

Abstract

SummaryThe segregation of 11 well‐defined SLA haplotypes was investigated in 40 Land‐race and 48 Large White Danish and Swiss litters. Among the 11 haplotypes, the segregation of one (SLA 20–8.2.11) deviated significantly from the expected 1: 1 segregation ratio in back‐cross families. Tests indicated that these families were homogeneous with respect to segregation distortion, although the distortion was more pronounced in litters sired by heterozygous Danish boars than by heterozygous Swiss boars and Danish and Swiss sows. The data presented do not allow any definite conclusion about the cause of the segregation distortion. The possibility of the distortion being caused either by a complex similar to the T/t‐complex found in mouse and contemplated in man or directly by the SLA region is discussed.

Maternal Transmission Ratio Distortion in Two Iberian Pig Varieties

“…No significant common TRDLs were found between this previous study and our results. Neither TRDLs were found in the IGF2 locus (also described in humans) and the histocompatibility antigen loci [20,21,53]. Even though these results were in other pig breeds, it is important to consider that our study has analyzed datasets from dams but not sires.…”

“…In pigs, there is a lack of information about the TRD phenomenon, although it could induce bias in genetic mapping studies [16][17][18][19]. The few references about pigs are mainly related to a specific locus in genes or other kinds of segregation distortions [20][21][22]. So far, the greatest TRD study in pigs is the mapping of TRD loci (TDRLs) in boars and part of their offspring using a Bayesian approach to detect paternal TRDLs in the pig genome, but no maternal TRDLs [23].…”

Bypassing Mendel’s First Law: Transmission Ratio Distortion in Mammals

“…Transmission ratio distortion has been extensively studied among a variety of taxa in insects [ 82 , 83 , 84 , 85 ], birds [ 86 , 87 , 88 ], fish [ 89 , 90 ] and crustaceans [ 91 ], but very few mammalian species have been investigated beyond man and mouse. Despite the significant scientific interest in studying TRD phenomenon in species with higher genetic proximity to humans, most species documented to date, except for the common shrew [ 1 , 92 , 93 ], are livestock species, such as cattle [ 5 , 16 , 94 , 95 , 96 , 97 ], pig [ 4 , 98 , 99 , 100 , 101 , 102 ], horse [ 103 , 104 ], goat [ 105 ] and sheep [ 106 ]. The interest in these taxa originates mainly from the agricultural industry for whom any genetic factor, such as TRD that can influence the reproductive success of animals, is of major interest in terms of production objectives [ 107 ].…”

“…Preliminary evidence of TRD in livestock was reported as early as 1985 with the segregation study of eleven swine leukocyte antigen (SLA) haplotypes in two breeds of pigs [ 98 ]. Inspired by this report, as well as others on mice and humans [ 109 ], excess male transmission of a major histocompatibility complex haplotype was quickly identified in horses [ 104 ].…”

Effect of genetic variation in the MHC Class II DRB region on resistance and susceptibility to Johne’s disease in endangered Indian Jamunapari goats

“…, 1989; Sheikh et al. , 2006) and reproduction traits (Philipsen & Kristensen, 1985; Renord & Vaiman, 1989) in various species suggesting potential utility as candidate gene marker.…”