Regulation of aromatase cytochrome P-450 (estrogen synthetase) transcripts in the quail brain by testosterone.
The aromatase cytochrome P-450 (P-450AROM) cDNA, which was identified by homologies in the DNA and in the deduced amino acid sequences with human P-450AROM cDNA, was isolated from a brain cDNA library of Japanese quail, demonstrating the presence of RNA transcripts of P-450AROM in the quail brain. To determine trace amounts of P-450AROM mRNA in the brain and to examine the effects of testosterone on its expression, a quantitative PCR method of RNA transcripts was developed. Brain total RNA was subjected to reverse transcription reaction and then quantitated by PCR from cDNA with a fluorescent dye-labeled primer. The quantity of P-450AROM mRNA was calculated by using an internal standard of modified P-450AROM (m-P-450AROM) RNA. The brain P-450AROM was primarily transcribed in the hypothalamus area (1.15 +/- 0.14 amol/micrograms of RNA) and traces of transcripts only were detected in the cerebellum (0.038 +/- 0.005 amol/micrograms of RNA). The P-450AROM mRNA in the hypothalamus of castrated quail was low (0.270 +/- 0.078 amol/micrograms of RNA) and increased 4- to 5-fold following treatment with testosterone. These results demonstrate, for the first time, that the increase in P-450AROM activity that is observed in the brain following treatment with testosterone results from a pretranslational regulation of the P-450AROM by androgens.
Harada
N
N
Division of Molecular Genetics, Fujita Health University, Aichi, Japan.
Yamada
K
K
Foidart
A
A
Balthazart
J
J
D000728:Androgens / Q000494:pharmacology; D000818:Animals; D001141:Aromatase / Q000096:biosynthesis*; D001483:Base Sequence; D001923:Brain Chemistry / Q000187:drug effects*; D002531:Cerebellum / Q000378:metabolism; D003370:Coturnix / Q000378:metabolism*; D003577:Cytochrome P-450 Enzyme System / Q000096:biosynthesis*; D015723:Gene Library; D007031:Hypothalamus / Q000378:metabolism; D008297:Male; D008969:Molecular Sequence Data; D009919:Orchiectomy; D016133:Polymerase Chain Reaction; D013739:Testosterone / Q000494:pharmacology*
D000728:Androgens; D013739:Testosterone; D003577:Cytochrome P-450 Enzyme System; D001141:Aromatase