Insulin-gene expression in extrafetal membranes of rats.
We quantified fetal rat extrapancreatic insulin-gene expression by measuring mRNA in the yolk sac and placenta. Yolk sac makes a significant contribution to the total fetal insulin stores. The placenta contains a much smaller amount of insulin mRNA. Yolk sac insulin mRNA is barely detectable at 16 days gestation but increases markedly to a maximum at 21 days, 1 day before birth. In contrast to the pancreatic 550-nucleotide (n) insulin mRNA, yolk sac has a 720-n mRNA. However, on removal of the terminal poly(A), both transcripts produce a 440-n RNA, the size predicted for a fully processed insulin mRNA.
Rau
K
K
Department of Pathology, University of Pittsburgh School of Medicine, Pennsylvania 15261.
Muglia
L
L
Locker
J
J
D000818:Animals; D005260:Female; D007328:Insulin / Q000235:genetics*; D008112:Liver Glycogen / Q000096:biosynthesis; D010920:Placenta / Q000032:analysis*; D011247:Pregnancy; D012333:RNA, Messenger / Q000032:analysis*; D051381:Rats; D014158:Transcription, Genetic; D015017:Yolk Sac / Q000032:analysis*
D007328:Insulin; D008112:Liver Glycogen; D012333:RNA, Messenger