Wen J, Kawamata Y, Tojo H, Tanaka S, Tachi C
Laboratory of Applied Genetics, Graduate School of Agriculture and Life Science, University of Tokyo, Japan.
Mol Reprod Dev. 1995 Aug;41(4):399-406. doi: 10.1002/mrd.1080410402.
Whey acidic protein (WAP) is a major whey protein secreted in rodents' milk. Murine WAP (mWAP) genes have been assumed to be expressed solely in the mammary gland. However, several heterologous genes fused with the mWAP promoter and artificially introduced into animal genomes as transgene were expressed not only in the mammary gland but also in other tissues as well. In the present study, we investigated, by means of the reverse transcription polymerase chain reaction (RT-PCR), the patterns of expression of endogenous WAP genes in tissues of normal mice and in transgenic mice carrying hGH gene coupled to the mWAP promoter sequence. The results revealed that the genes driven by the mWAP promoter, regardless of whether they are endogenous genes or transgenes, were transcribed in a variety of tissues other than the mammary gland of lactating normal female mice, although the expression levels are generally low. The expression of WAP genes in the cerebrum and the liver is regulated, as in the mammary gland, according to the reproductive stages. However, the tissue distribution of endogenous WAP gene expression in mature virgin transgenic female mice was the same as that in lactating normal female mice.
乳清酸性蛋白（WAP）是啮齿动物乳汁中分泌的一种主要乳清蛋白。小鼠WAP（mWAP）基因一直被认为仅在乳腺中表达。然而，几个与mWAP启动子融合并作为转基因人工导入动物基因组的异源基因不仅在乳腺中表达，也在其他组织中表达。在本研究中，我们通过逆转录聚合酶链反应（RT-PCR），研究了正常小鼠组织以及携带与mWAP启动子序列相连的hGH基因的转基因小鼠中内源性WAP基因的表达模式。结果显示，由mWAP启动子驱动的基因，无论它们是内源性基因还是转基因，在泌乳正常雌性小鼠乳腺以外的多种组织中都有转录，尽管表达水平通常较低。与乳腺一样，大脑和肝脏中WAP基因的表达根据生殖阶段受到调控。然而，成熟处女转基因雌性小鼠中内源性WAP基因表达的组织分布与泌乳正常雌性小鼠相同。
