Ungefroren H, Davidoff M, Ivell R
Department of Molecular Biology, University of Hamburg, Germany.
J Endocrinol. 1994 Jan;140(1):63-72. doi: 10.1677/joe.0.1400063.
Northern blot hybridization showed that bovine and sheep testis, unlike testes from other mammals, contain moderate levels of an apparently normal oxytocin gene transcript. In situ hybridization localized this mRNA to within the seminiferous tubules, possibly in the Sertoli cells. Conflicting with this result, immunohistochemistry showed that both oxytocin and the syngeneic neurophysin I epitopes are both clearly restricted to the Leydig cells, being expressed here at a low level. Since illegitimate transcription from spurious start sites can lead to a lack of translation product, the integrity of the major ruminant testicular transcripts of the oxytocin gene was checked using differential hybridization. RNase protection and multiple polymerase chain reaction assays. All tests showed the transcripts to have a normal, translatable composition and to be transcribed from the conventional 5' initiation site. Therefore, the block in oxytocin gene expression within the tubules is probably due to a lesion at the post-transcriptional level. The low level peptide expression in the Leydig cells can probably be attributed to the presence of functional transcripts in these cells, which are below the level of significant detection for the in situ hybridization assay.
Northern印迹杂交显示，与其他哺乳动物的睾丸不同，牛和羊的睾丸含有中等水平的明显正常的催产素基因转录本。原位杂交将这种mRNA定位在生精小管内，可能位于支持细胞中。与此结果相矛盾的是，免疫组织化学显示催产素和同基因神经垂体素I表位都明显局限于睾丸间质细胞，且在该细胞中低水平表达。由于来自假起始位点的异常转录可导致缺乏翻译产物，因此使用差异杂交、RNA酶保护和多重聚合酶链反应分析来检查催产素基因主要反刍动物睾丸转录本的完整性。所有测试均表明转录本具有正常的、可翻译的组成，并从常规的5'起始位点转录。因此，小管内催产素基因表达的阻断可能是由于转录后水平的损伤。睾丸间质细胞中低水平的肽表达可能归因于这些细胞中存在功能性转录本，但其水平低于原位杂交检测的显著检测水平。
