Mamluk R, Wolfenson D, Meidan R
Department of Animal Sciences, Faculty of Agriculture, Food and Environmental Quality Sciences, Hebrew University of Jerusalem, Rehovot, Israel.
Domest Anim Endocrinol. 1998 Mar;15(2):103-14. doi: 10.1016/s0739-7240(97)00085-4.
This study was undertaken to characterize the cDNA sequence encoding bovine LH receptor (LHR), and study the effect of different luteinization protocols on the steroidogenic capacity and LHR mRNA in bovine luteal cells. The bovine LHR cDNA sequence reported here showed high sequence identity with that of other species. Several mRNA splice variants were expressed in bovine corpus luteum (CL). Reverse transcription-polymerase chain reaction conducted with primers spanning exons 2-11 revealed, in addition to the full-length sequence, a shorter fragment homologous to splice variant B reported in porcine and ovine LHR cDNA sequences. Granulosa and theca cells derived from bovine preovulatory follicles were cultured with either forskolin (10 microM, for 8 d culture-Protocol 1) or LH (100 ng/ml, for 12 hr followed by a 7.5-d culture with 2 ng/ml-Protocol 2). LHR mRNA was not detected in luteal granulosa cells (LG); in contrast, luteal theca cells (LT) contained LHR mRNA at similar levels when cultured under Protocol 1 or 2. cAMP responses to a short challenge with LH were in good agreement with LHR mRNA levels. Cytochrome P450 side-chain-cleavage (P450scc) contents were lower in luteal cells cultured with LH as compared with cells cultured with forskolin; however, the difference between the two luteinization protocols was much larger in LT (P < 0.05) than in LG. This study suggests that a) LHR mRNA is mainly present in the theca-derived luteal cell and b) LHR mRNA and cytochrome P450scc expression in each of the luteal cell types seems to be under different control.
本研究旨在对编码牛促黄体素受体（LHR）的cDNA序列进行特征分析，并研究不同黄体化方案对牛黄体细胞类固醇生成能力和LHR mRNA的影响。本文报道的牛LHR cDNA序列与其他物种的序列具有高度的同源性。在牛黄体（CL）中表达了几种mRNA剪接变体。用跨越外显子2 - 11的引物进行逆转录 - 聚合酶链反应显示，除了全长序列外，还有一个与猪和羊LHR cDNA序列中报道的剪接变体B同源的较短片段。将来自牛排卵前卵泡的颗粒细胞和卵泡膜细胞分别用福司可林（10 μM，培养8天 - 方案1）或LH（100 ng/ml，培养12小时，随后用2 ng/ml培养7.5天 - 方案2）进行培养。在黄体颗粒细胞（LG）中未检测到LHR mRNA；相反，在方案1或方案2培养条件下，黄体卵泡膜细胞（LT）中LHR mRNA水平相似。对LH短时间刺激的cAMP反应与LHR mRNA水平高度一致。与用福司可林培养的细胞相比，用LH培养的黄体细胞中细胞色素P450侧链裂解酶（P450scc）含量较低；然而，两种黄体化方案之间的差异在LT中（P < 0.05）比在LG中更大。本研究表明：a）LHR mRNA主要存在于卵泡膜来源的黄体细胞中；b）每种黄体细胞类型中LHR mRNA和细胞色素P450scc的表达似乎受不同的调控。
