The association of H-2 haplotype with implantation, survival, and growth of murine embryos.

Using three congenic strains, C57BL/10Sn(H-2b), B10.A/SnSg(H-2a), and B10.D2/nSn(H-2d), we sought to investigate the possible association of H-2 haplotype with the number of implants, fetal survival, and fetal weight, as well as to analyze the possible effects of hybrid vigor and maternal-fetal histoincompatibility in primigravidae mice. The results of this study indicate a significant association between genes at or near the H-2 complex and both fetal loss and fetal weight, but not the number of implants. Haplotype variation accounted for 14 percent of the variation in fetal loss and 20 percent of the variation in fetal weight. With the exception of fetal loss, there was no evidence of a maternal effect. There was also no clear evidence of hybrid vigor or histoincompatibility effects for any of the three variables studied. In summary, the data suggests that particular allelic variants at or near the H-2 complex confer some selective advantage as measured by differential fetal survival and fetal growth.