Chorionic Gonadotropin Beta Polypeptide (CGb)

By restriction digest analysis, Talmadge et al. (1983) determined that the 7 CGB genes are extremely similar but not identical. Otani et al. (1988) found that CGB3 and CBG8 were expressed at 2-fold lower levels than CGB5 following transfection into a mouse adrenocortical cell line. Bo and Boime (1992) determined that most of the sequence variation among the CGB genes occurs in the nontranslated region of exon 1. They further found that CGB3 was expressed at about the same levels at CGB8 in first trimester placenta and in a choriocarcinoma cell line, and both were expressed at a lower level than CGB5. Jameson and Lindell (1988) determined that each of the CGB genes contains 3 exons. Otani et al. (1988) determined that the promoter regions contain no CAAT or TATAA boxes.