Differential distribution of mRNA for the α- and β-subunits of chorionic gonadotrophin in the implantation stage blastocyst of the marmoset monkey
Date
1995
Authors
Lopata, A.
Berka, J.
Simula, A.
Norman, R.
Otani, T.
Editors
Advisors
Journal Title
Journal ISSN
Volume Title
Type:
Journal article
Citation
Placenta, 1995; 16(4):335-346
Statement of Responsibility
Lopata, A. ; Berka, J. ; Simula, A. ; Norman, R. ; Otani, T.
Conference Name
Abstract
We studied the expression of mRNA encoding the alpha- and beta-subunits of marmoset chorionic gonadotrophin (mCG) in implantation stage blastocysts and in a trophoblastic cell line derived from such blastocysts. In this investigation in situ hybridization was carried out using digoxygenin-labelled riboprobes to localize the subunit transcripts. The trophoblastic cell line, known to secrete bioactive mCG, was used as a positive control. Marmoset uterine embryos were cultured to hatched blastocysts and following growth on Matrigel or plastic were processed for in situ hybridization at developmental stages ranging from 13-15 days post-conception. In serial sections mCG-beta mRNA was detected mainly in polar trophoblast. The mRNA for mCG-alpha was expressed more uniformly in polar and mural trophoblast. Transcripts for the beta-subunit were not expressed, or present as weak signals, in the inner cell mass (ICM) and endoderm. However, low levels of mRNA for mCG-alpha were detected in the ICM and visceral endoderm. We have concluded that mRNA for mCG-beta was primarily localized to patches of syncytiotrophoblast at the embryonic pole and sparsely distributed in mural trophoblast, while the transcripts for mCG-alpha were distributed more uniformly in differentiating cytotrophoblast and syncytium, and at much lower levels in ICM and early endoderm.