ISSN:
0263-6484
Keywords:
human chorionic gonadotropin
;
choriocarcinoma
;
gene transcription
;
Life Sciences
;
Molecular Cell Biology
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Biology
,
Medicine
Notes:
Transcription of the human chorionic gonadotropin (hCG) genes begins in the very early embryo stage and decreases or even disappears in nonplacental tissues. We have studied the regulation of hCG-beta genes by cell fusion and by the reverse transcription-polymerase chain reaction (RT-PCR). The choriocarcinoma cell lines, JAR and JEG-3, express high levels of the hCG-beta subunit while HeLa cells express extremely low levels of it. Most HeLa × JAR and HeLa × JEG-3 fusion clones expressed only a trace of the hCG-beta subunit mRNA, while JAR × JEG-3 fusion clones still expressed high levels of the hCG-beta subunit. Most transcripts of the hCG-beta subunit genes in JAR and JEG-3 came from the hCG-beta 5 subunit. Even the trace amount of hCG-beta transcripts from fusion clones came mainly from the beta-5 gene. The results suggest that the expression of the hCG-beta subunit genes depends on negative control. Probably when embryonic cells differentiate to form nonplacental tissues, specific inhibitors may appear and inhibit the expression of the hCG-beta subunit genes.
Additional Material:
3 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/cbf.686
