Annette,
One principle may be "methylation" -- ie, the modifying of methyl groups
varyingly attached to DNA. At least one study has focused upon this
combination of factors:
Guillaudeux T et al. Am J Repro Immunol 30.228-38 1993. Differences
between human sperm and somatic cell DNA in CpG methylation within the
class I chromosomal region.
from the abstract:
"Unmethylated CpG sites were detected in the 3'... fragments of HLA-F
and HLA-G genes in sperm... In contrast, no difference was observed in the
methylation status of the HLA-B, HLA-C, and HLA-E genes between germ and
somatic cells..."
Teresa
On 6 May 1997, Annette I Niestroy wrote:
> What is (are) the principle antigen(s) that mediate maternal tolerance
> of an embryo? Recent studies implicate HLA-G. How is implantation
> permited if the zygote contains seemingly foreign (paternal) material?
