Morphological and molecular characteristics of living human fetuses between Carnegi stages 7 and 23: localization of inhibin mRNA {alpha} and {beta}a subunits by in-situ hybridization

Localization of the mRNA and ßa subunits of inhibinhas previously been reported in the human gonads during thesecond trimester. Adrenal inhibin has also been reported inthe second trimester for the ßa and ßbsubunits. Investigations showing localization by in-situ hybridizationduring the first trimester have not been reported. The resultshave shown hybridization of the and ßa subunits,throughout the period of development studied, in a variety oftissues including the dorsal and thoracic aortas and pericardiumstages 13-22 (ßa subunit); liver stages 19-21 (ßa)and stages 21-22 (); mesonephros stages 21 and 22 (ßa);gonad stages ( and ßa); adrenal stages 19-22 (); surfaceectoderm stages 16-22 (ßa); mesenchyme stages 16-22(ßa); amnion stages 13-16 (ßa); yolk sacstage 12 ( and ßa); cartilage stages 19-22 (ßa);and nasal proliferation stages 21 and 22 (ßa). Whencompared with distribution of the protein subunits it was notedthat more immunostaining activity was found, suggesting thatprobes were not sufficiently sensitive enough to detect alllevels of mRNA expressed. It can be surmised, therefore, thatthe lack of visual hybridization of the mRNA cannot precludethe possibility that it is not being translated within the tissueeven though hybridization was not apparent.