Characterization and histologic localization of human growth hormone-variant gene expression in the placenta.
The human growth hormone-variant (hGH-V) gene is one of five highly similar growth hormone-related genes clustered on the short arm of chromosome 17. Although the pattern of expression of the adjacent normal growth hormone (hGH-N) and chorionic somatomammotropin (hCS) genes in this cluster are well characterized, the expression of the hGH-V gene remains to be defined. In previous studies, we have demonstrated that the hGH-V gene is transcribed in the term placenta and expressed as two alternatively spliced mRNAs: one is predicted to encode a 22-kD hormone (hGH-V), the other retains intron 4 in its sequence resulting in the predicted synthesis of a novel 26-kD hGH-V-related protein (hGH-V2). In the present report, we document the expression of both of these hGH-V mRNA species in the villi of the term placenta, demonstrate an increase in their concentrations during gestation, and directly sublocalize hGH-V gene expression to the syncytiotrophoblastic epithelium of the term placenta by in situ cDNA-mRNA histohybridization. The demonstrated similarity in the developmental and tissue-specific expression of the hGH-V gene with that of the related hCS gene suggests that these two genes may share common regulatory elements.
Liebhaber
S A
SA
Department of Medicine, University of Pennsylvania, Philadelphia 19104.
Urbanek
M
M
Ray
J
J
Tuan
R S
RS
Cooke
N E
NE
D000818:Animals; D015152:Blotting, Northern; D002824:Chorionic Villi / Q000032:analysis; D004848:Epithelium / Q000032:analysis; D005784:Gene Amplification; D005786:Gene Expression Regulation; D005796:Genes; D014644:Genetic Variation; D013006:Growth Hormone / Q000032:analysis / Q000235:genetics*; D006801:Humans; D051379:Mice; D009693:Nucleic Acid Hybridization; D010920:Placenta / Q000032:analysis / Q000166:cytology*; D011257:Pregnancy Proteins / Q000032:analysis / Q000235:genetics*; D012333:RNA, Messenger / Q000032:analysis; D014327:Trophoblasts / Q000032:analysis
D011257:Pregnancy Proteins; D012333:RNA, Messenger; D013006:Growth Hormone