MHC Class I antigen expression in rats. Only paternal class I antigens were expressed in the placenta of crosses between WF(u) and
DA(a) rat strains (Kanbour-Shakir A et al, 1990; Kanbour-
Shakir A et al, 1993; Kanbour-Shakir A et al, 1995). HLA class Ia genes do not
appear to be imprinted in human trophoblast cells, or in mouse placenta and horse placentas (see
Lenfant F et al, 1998).