Ang H L, Ungefroren H, De Bree F, Foo N C, Carter D, Burbach J P, Ivell R, Murphy D
Neuropeptide Laboratory, National University of Singapore.
Endocrinology. 1991 Apr;128(4):2110-7. doi: 10.1210/endo-128-4-2110.
We are using transgenic mice to study the regulation of the bovine vasopressin (VP) and oxytocin (OT) genes. Prompted by the observation that mice bearing a bovine OT transgene express bovine OT RNA in their testes, we investigated the expression of the VP-OT locus in normal mice and cattle. Normal wild-type mice do not have detectable levels of either VP or OT RNA in their testes. Normal cattle are also devoid of detectable VP transcripts, but have relatively high levels of testicular OT RNA. Additionally, OT, but not VP, peptide is detectable by HPLC. In situ hybridization to RNA in bovine testicular tissue sections localized OT transcripts to seminiferous tubules, with a distribution similar to that of alpha-inhibin, suggesting expression in Sertoli cells. Interestingly, the bovine OT RNAs in the transgenic mouse testes were also shown by in situ hybridization to have the same distribution. These data suggest that the cis-acting regulatory sequences responsible for expression of the OT gene in bovine Sertoli testis reside within the limits of the transgene used in this study. Further, the trans-acting factors present in murine testicular cells are able to recognize these elements, although they do not express the endogenous mouse OT gene in this tissue.
我们正在利用转基因小鼠研究牛血管加压素（VP）和催产素（OT）基因的调控。鉴于携带牛OT转基因的小鼠在其睾丸中表达牛OT RNA这一观察结果，我们研究了正常小鼠和牛中VP-OT基因座的表达。正常野生型小鼠睾丸中检测不到VP或OT RNA。正常牛也没有可检测到的VP转录本，但睾丸中OT RNA水平相对较高。此外，通过高效液相色谱法可检测到OT肽，但检测不到VP肽。对牛睾丸组织切片中的RNA进行原位杂交，将OT转录本定位到生精小管，其分布与α-抑制素相似，表明在支持细胞中表达。有趣的是，原位杂交也显示转基因小鼠睾丸中的牛OT RNA具有相同的分布。这些数据表明，负责牛睾丸支持细胞中OT基因表达的顺式作用调控序列位于本研究中所用转基因的范围内。此外，小鼠睾丸细胞中存在的反式作用因子能够识别这些元件，尽管它们在该组织中不表达内源性小鼠OT基因。
