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The expression of the human chorionic gonadotropin beta subunit gene depends on negative control
Author(s) -
Chen YenHui,
Chen TzerMing,
Hsieh ChangYao
Publication year - 1996
Publication title -
cell biochemistry and function
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.933
H-Index - 61
eISSN - 1099-0844
pISSN - 0263-6484
DOI - 10.1002/cbf.686
Subject(s) - microbiology and biotechnology , human chorionic gonadotropin , protein subunit , biology , gene , fusion gene , transcription (linguistics) , gene expression , beta (programming language) , hela , embryo , g alpha subunit , cell culture , genetics , endocrinology , hormone , linguistics , philosophy , computer science , programming language
Abstract 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.