EXPRESSION OF 2 AROMATASE CDNAS IN VARIOUS RABBIT-TISSUES

Aromatase is a steroidogenic enzyme complex which catalyses the conver sion of androgens to estrogens. In a previous study, we elucidated the structure of a 2.9 kb aromatase cDNA from ovarian rabbit tissue. We r eport here, the structure of another shorter aromatase cDNA (1.5 kb) f rom the same tissue. This cDNA is likely to encode for a nonfunctional aromatase which would lack an heme binding domain. We have shown usin g an RT-PCR technique that rabbit placental tissue, like the ovarian o ne, expresses both the 2.9 and 1.5 kb cDNA and that the adipose tissue expresses the 2.9 kb cDNA. Using a 5' RACE procedure, we obtained the 5' end of the placental transcripts. Comparison of its sequence with the 5' end of the ovarian one suggests the existence of distinct exon 1 sequences for each one of the two tissues as already described in th e human. These results point to the rabbit as a useful laboratory anim al for studying regulation of aromatase expression in adipose and plac ental tissues. (C) 1998 Elsevier Science Ltd. All rights reserved.