Cellular distribution of HLA-G mRNA in transgenic mouse placentas.
The human MHC class I gene, HLA-G, is unique among members of the class I gene family in that it is nonpolymorphic, and expression is primarily restricted to extraembryonic tissues. To examine regulatory elements that direct tissue- and cell lineage-specific expression of this gene, transgenic mice expressing HLA-G have been established. In this study, in situ hybridization was used to evaluate the cellular distribution of HLA-G mRNA in transgenic placentas. Extraembryonic tissues were obtained at gestation day 12.5 from embryos that had been microinjected with either 6.0 or 5.7 kb of HLA-G genomic DNA and had been transferred into pseudopregnant HLA-G transgenic mice or Swiss mice. The 6.0 kb transgene contained an additional 250 bp at the extreme 5'-end of the upstream region. Genotype of the recipient had no discernable effect on the cellular distribution of HLA-G mRNA. HLA-G mRNA was present in both trophoblast and mesenchymal cells in transgenic placentas carrying 6.0 kb of genomic HLA-G, a pattern strikingly similar to that of HLA-G message distribution in early gestation human placentas. By contrast, in placentas from embryos carrying 5.7 kb HLA-G DNA, specific mRNA was found primarily in mesenchymal cells at the base of the placenta. Thus, the 6.0 genomic fragment contains elements capable of directing HLA-G expression in placentas, and is particularly influential in the trophoblastic cell lineage.
Yelavarthi
K K
KK
Department of Anatomy and Cell Biology, University of Kansas Medical Center, Kansas City 66160-7400.
Schmidt
C M
CM
Ehlenfeldt
R G
RG
Orr
H T
HT
Hunt
J S
JS
D000818:Animals; D002460:Cell Line; D004622:Embryo, Mammalian / Q000737:chemistry; D005260:Female; D006680:HLA Antigens / Q000235:genetics*; D059951:HLA-G Antigens; D015395:Histocompatibility Antigens Class I / Q000235:genetics*; D051379:Mice; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D010920:Placenta / Q000737:chemistry*; D011247:Pregnancy; D012333:RNA, Messenger / Q000032:analysis / Q000235:genetics
D006680:HLA Antigens; D059951:HLA-G Antigens; D015395:Histocompatibility Antigens Class I; D012333:RNA, Messenger