Golovine Konstantin, Schwerin Manfred, Vanselow Jens
Research Unit Molecular Biology, Research Institute for the Biology of Farm Animals, 18196 Dummerstorf, Germany.
Biol Reprod. 2003 Mar;68(3):978-84. doi: 10.1095/biolreprod.102.008037.
Aromatase cytochrome P450, the key enzyme of estrogen biosynthesis, is encoded by Cyp19. To elucidate the complex regulation of this gene in mouse gonads (ovary and testis) and brain (thalamic/hypothalamic areas), Cyp19 transcripts were isolated using rapid amplification of cDNA 5' ends and transcript concentrations were estimated in juveniles at different postnatal days (P0, P7, and P14) and in adult animals by real time polymerase chain reaction (PCR). In addition, the murine Cyp19 locus including all known exons and promoters was reconstructed from a recently published sequence of a mouse bacterial artificial chromosome. From each of the tissues investigated, Cyp19 transcripts with a specific 5' untranslated region (5' UTR) were isolated: T(ov) from ovary, T(br) from brain, and T(tes) from testis. T(tes) included a novel 5' UTR that did not show sequence similarities to other Cyp19 transcripts. Real time PCR experiments revealed similar levels of Cyp19 transcript concentrations in neonatal gonads of both sexes. The majority of transcripts were T(ov) in ovaries and T(tes) in testes. During further postnatal development, testicular Cyp19 transcript concentrations transiently decreased, but the contributions of different transcript variants basically remained unchanged. However, ovarian Cyp19 transcript concentrations increased by about 100 times, and almost 100% of all Cyp19 transcripts were identified as T(ov) in adult ovaries. Brains of both sexes showed highest transcript concentrations at P0. However, concentrations in female brains were reduced to adult levels earlier than in male brains. In brains of both sexes, T(br) was found to predominate throughout postnatal life. The results suggest that the mouse Cyp19 gene includes three different promoters that specifically direct expression in ovary, testis, and brain.
芳香化酶细胞色素P450是雌激素生物合成的关键酶，由Cyp19编码。为阐明该基因在小鼠性腺（卵巢和睾丸）及脑（丘脑/下丘脑区域）中的复杂调控机制，利用cDNA 5'末端快速扩增技术分离Cyp19转录本，并通过实时聚合酶链反应（PCR）对不同出生后天数（P0、P7和P14）的幼鼠及成年动物的转录本浓度进行估算。此外，从小鼠细菌人工染色体的最新公布序列中重建了包含所有已知外显子和启动子的小鼠Cyp19基因座。从每个研究组织中分离出具有特定5'非翻译区（5'UTR）的Cyp19转录本：卵巢中的T(ov)、脑中的T(br)和睾丸中的T(tes)。T(tes)包含一个与其他Cyp19转录本无序列相似性的新型5'UTR。实时PCR实验显示，两性新生性腺中Cyp19转录本浓度相似。卵巢中的大多数转录本为T(ov)，睾丸中的为T(tes)。在出生后的进一步发育过程中，睾丸Cyp19转录本浓度短暂下降，但不同转录变体的占比基本保持不变。然而，卵巢Cyp19转录本浓度增加了约100倍，成年卵巢中几乎100%的Cyp19转录本被鉴定为T(ov)。两性的脑在P0时转录本浓度最高。然而，雌性脑中的浓度比雄性脑更早降至成年水平。在两性的脑中，发现T(br)在整个出生后生命过程中占主导地位。结果表明，小鼠Cyp19基因包含三个不同的启动子，分别特异性地指导在卵巢、睾丸和脑中的表达。
