Oudejans C B, Krimpenfort P, Ploegh H L, Meijer C J
Department of Obstetrics/Gynecology, Free University Amsterdam, The Netherlands.
J Exp Med. 1989 Feb 1;169(2):447-56. doi: 10.1084/jem.169.2.447.
The mechanisms that regulate developmental control of the expression of MHC class I genes during generation of extra-embryonic tissues are largely unknown. In the present study, we studied the levels of transcripts of the human HLA-B27 gene in extra-embryonic tissues of transgenic mice containing the HLA-B27 (heavy chain) gene by in situ hybridization with biotinylated single-stranded RNA probes. In contrast to extra-embryonic stromal cells and embryonic tissues which contain (varying levels of) messenger RNA coding for HLA-B27, specific transcripts were not detected in labyrintho-, or spongiotrophoblast, nor in trophoblastic giant cells. These cells are devoid of HLA A and B locus class I transcripts in man. Regulation of expression of human MHC class I genes in extra-embryonic trophoblast in transgenic animals is thus under conserved selective pressure that is retained across a species barrier. Thus, in extra-embryonic tissues, regulation of expression of MHC class I genes is distinct from the mechanisms operating in developing embryonic cells.
在胚外组织生成过程中调节MHC I类基因表达的发育控制机制在很大程度上尚不清楚。在本研究中，我们通过用生物素化的单链RNA探针进行原位杂交，研究了含有HLA - B27（重链）基因的转基因小鼠胚外组织中人HLA - B27基因的转录本水平。与含有（不同水平）编码HLA - B27信使RNA的胚外基质细胞和胚胎组织不同，在迷路滋养层、海绵滋养层或滋养层巨细胞中未检测到特异性转录本。在人类中，这些细胞缺乏HLA A和B位点的I类转录本。因此，转基因动物胚外滋养层中人MHC I类基因的表达调控处于保守的选择压力之下，这种压力跨越物种屏障得以保留。因此，在胚外组织中，MHC I类基因的表达调控不同于发育中的胚胎细胞中起作用的机制。
