A MUP PROMOTER-THYMIDINE KINASE REPORTER GENE SHOWS RELAXED TISSUE-SPECIFIC EXPRESSION AND CONFERS MALE-STERILITY UPON TRANSGENIC MICE
A MUP PROMOTER-THYMIDINE KINASE REPORTER GENE SHOWS RELAXED TISSUE-SPECIFIC EXPRESSION AND CONFERS MALE-STERILITY UPON TRANSGENIC MICE
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DOI：
10.1128/mcb.8.11.4821
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发表时间：
1988-11-01
影响因子：
5.3
通讯作者：
BISHOP, JO
中科院分区：
文献类型：
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作者：
ALSHAWI, R;BURKE, J;BISHOP, JO
通过将小鼠1型主要尿蛋白（Mup）基因的2.2-kilobase 5''启动子区域与单纯疱疹病毒1型胸苷激酶基因（HSV tk）的编码区域融合来制备杂合基因，并通过显微注射将其引入小鼠基因组中。转基因Go雄性是不育的，或者在可育时不传递外源基因，并且Go雌性的转基因雄性后代也是不育的。通过雌性 Go 及其转基因雌性后代的繁殖建立了七个“品系”。六个细胞系在肝脏中表达 HSV 胸苷激酶活性，并且该活性与 HSV tk RNA 的存在完全相关。在检查的四个品系中的三个中，雌性肝脏中的表达低于雄性肝脏中的表达，并且在这些品系中，在肝细胞核中外源基因的连续转录率方面观察到相同的性别差异。当用睾酮处理其中一种性二态性品系的雌性时，HSV tk RNA 和胸苷激酶活性的水平有所增加，但未达到雄性水平。在肝脏表达方面，以及在其他七个组织中缺乏表达方面，该杂合基因表现出内源1型Mup基因的许多特征。然而，该基因也在包皮腺和睾丸中表达（高水平），这两种组织中 Mup 基因不表达。当该基因被引入七个品系中的五个时，携带了一个大肠杆菌supF基因的拷贝，该基因附着在HSV tk基因的3''末端之外，但这并不影响整体表达模式。所有品系都是雄性不育的，并且在睾丸中表达HSV胸苷激酶，但是一个品系在肝脏中没有显示活性，而另一个品系在包皮腺中没有显示活性。因此，睾丸表达可能是不育的原因。描述的数据表明包皮腺和睾丸中错误表达的原因是不同的。由于每个组织中的表达发生在多个系中，因此杂交基因的结构必须对每种情况负责。五个经过深入研究的品系显示出包皮腺、睾丸、男性肝脏和女性肝脏中至少有四种一致不同的相对表达模式。这些差异与不同品系中外源基因的拷贝数没有任何关系，并且一定是由于品系特异性整合的其他方面造成的。
A hybrid gene was made by fusing the 2.2-kilobase 5'' promoter region of a mouse group 1 major urinary protein (Mup) gene to the coding region of the herpes simplex virus type 1 thymidine kinase gene (HSV tk) and introduced into the genomes of mice by microinjection. Transgenic Go males were sterile, or when fertile did not transmit the foreign gene, and the transgenic male descendants of Go females were also sterile. Seven "lines" were established by breeding from Go females and their transgenic female descendants. Six lines expressed HSV thymidine kinase activity in the liver, and activity correlated perfectly with the presence of HSV tk RNA. In three of four lines examined, expression was lower in female than in male liver, and in these lines the same sex difference was observed in the rate of run-on transcription of the foreign genes in liver nuclei. When females of one of the sexually dimorphic lines were treated with testosterone, the levels of HSV tk RNA and thymidine kinase activity were increased, although not to male levels. In the aspects of liver expression, and also in a lack of expression in seven other tissues, the hybrid gene exhibits many of the characteristics of and endogenous group 1 Mup gene. However, the gene was also expressed (at high levels) in the preputial gland and testis, two tissues in which Mup genes are not expressed. The gene, when introduced into five of the seven lines, carried a copy of the Escherichia coli supF gene attached beyond the 3'' end of the HSV tk gene, but this did not affect the overall expression pattern. All of the lines were male sterile and expressed HSV thymidine kinase in the testis, but one line showed no activity in the liver, and another showed none in the preputial gland. Testicular expression is therefore the likely cause of sterility. Data are described which suggest that the causes of misexpression in the preputial gland and testis are different. Since expression in each tissue occurred in several lines, the structure of the hybrid gene must be responsible in each case. Five intensively studied lines showed at least four consistently different patterns of relative expression in preputial gland, testis, male liver, and female liver. These differences do not correlate in any way with the copy number of the foreign gene in the different lines and must be due to some other aspect of line-specific integration.