Major histocompatibility complex (MHC)‐linked genes affecting development

Abstract

Genes affecting growth and development which are linked to the major histocompatibility complex have been found in the mouse (t-complex) and in the rat (growth and reproduction complex, grc), and there is some evidence that they also exist in humans. The genes of the t-complex have different effects depending upon the specific combinations involved: skeletal and fertility abnormalities, complete or partial embryonic mortality, high transmission ratios (segregation distortion) in males, high level of linkage disequilibrium with H-2, and suppression of recombination over the adjacent portion of the chromosome. The grc in the homozygous state causes small body size, sterility in the male and reduced fertility in the female, partial embryonic mortality, and a high level of linkage disequilibrium with RT1. It also interacts epistatically with the heterozygous Tal (tail anomaly lethal) gene to cause complete embryonic death. Mice carrying t-haplotypes and rats carrying the grc have an antigen in the male germ cells which cross-reacts very strongly (t-antigen). Suggestive evidence for such genes in humans comes from (1) studies on the relationship between skeletal defects and HLA haplotypes; (2) the association of specific HLA and complement haplotypes with a high transmission ratio in males, linkage disequilibrium among certain HLA and complement specificities and suppression of recombination in some MHC haplotypes; and (3) the lack of homozygotes in an isolated inbreeding population of desert nomads (Kel Kummer Tuaregs). In addition, immunogenetic studies on couples having chronic spontaneous abortions suggest that there is an unusually high incidence of homozygosity for the HLA-D/DR and HLA-A loci in these couples, and this finding is consistent with the presence of linked loci which behave like t or grc.

Tctex3, related to Drosophila Polycomblike, is expressed in male germ cells and mapped to the mouse t-complex Tctex3 have been deposited with the DDBJ database under Accession number AB011550.-->

“…Many of the disorders have a pathology in which an autoimmune response is implicated. However, other disease phenotypes such as skeletal abnormalities, recurrent spontaneous abortion (RSA), and infertility are known to be linked to HLA (Gill et al 1983;Jin et al 1995). In particular, RSA and infertility are more frequently found to be associated with the HLA class II region rather than with the class I region.…”

DRB3.2 gene polymorphism and its association with pashmina production in Changthangi goat

“…To date, many association studies were attempted between production traits and MHC polymorphism (Gavora et al ., 1983; Lamont et al ., 1987); however, whether these associations are due to the direct effect of MHC genes or the effect of genes in linkage disequilibrium with MHC genes is not yet clear. Moreover, genes influencing development and hormone levels are known to be linked with MHC in mice (Gill et al ., 1983). Nonetheless, these findings should be viewed as preliminary and further studies will be required to confirm the results.…”

Effect of Y chromosome and H-2 complex derived from Japanese wild mouse on sperm morphology

“…In this connexion we present data suggesting that one such gene controlling the high proportion of spermatozoa with deformed head is located close to the H-2 complex in the B10.MOL-OHM strain. The presence of genes affecting spermatogenesis and linked to the MHC (major histocompatibility complex) in the mouse is well known (Gill III et al 1983). They are mostly related to the T/t locus (Bennett, 1975).…”