Pan L, Chen J, Chen C
Shanghai Institute of Cell Biology, Chinese Academy of Sciences, China.
Chin J Biotechnol. 1997;13(2):79-83.
We were the first to report 5'-flanking sequences of goat beta-lactoglobulin (beta LG) gene (867 bp) including a promoter (770 bp) and part of the first exon (97 bp). The fragment was isolated from Chinese goat tissue with PCR, and then cloned and sequenced. Sequence comparison showed 94.6% homology with sheep and 88% homology with cattle, respectively. There are highly conserved transcription factor binding sites as well. It suggested that the proximal 406 bp of 5'-flanking sequences of sheep beta LG possess strong tissue-specific DNAaseI-hypersensitive sites. Sheep beta LG transgenes containing only the 406-bp 5'-flanking sequences were efficiently expressed in the mouse mammary gland at a high level. These goat beta LG 5'-flanking sequences could possibly direct heterologous protein expression in the milk of transgenic animals.
我们首次报道了山羊β-乳球蛋白（β-LG）基因的5'侧翼序列（867 bp），包括一个启动子（770 bp）和第一个外显子的一部分（97 bp）。该片段通过PCR从中国山羊组织中分离出来，然后进行克隆和测序。序列比较显示，与绵羊的同源性分别为94.6%，与牛的同源性为88%。也存在高度保守的转录因子结合位点。这表明绵羊β-LG 5'侧翼序列近端的406 bp具有很强的组织特异性DNA酶I超敏位点。仅包含406 bp 5'侧翼序列的绵羊β-LG转基因在小鼠乳腺中高效高水平表达。这些山羊β-LG 5'侧翼序列可能指导转基因动物乳汁中异源蛋白的表达。
