Stricklett Peter K, Taylor Deborah, Nelson Raoul D, Kohan Donald E
Division of Adult, University of Utah School of Medicine, Salt Lake City 84132, USA.
Am J Physiol Renal Physiol. 2003 Jul;285(1):F33-9. doi: 10.1152/ajprenal.00366.2002. Epub 2003 Mar 18.
Evaluation of thick ascending limb (TAL) function has been hindered by the limited ability to selectively examine the function of this nephron segment in vivo. To address this, a Cre/loxP strategy was employed whereby the Tamm-Horsfall (THP) promoter was used to drive Cre recombinase expression in transgenic mice. The THP gene was cloned from a mouse genomic library, and 3.7 kb of the mouse THP 5'-flanking region containing the first noncoding exon of the THP gene were inserted upstream of an epitope-tagged Cre recombinase (THP-CreTag). THP-CreTag transgenic mice were bred with ROSA26-enhanced yellow fluorescent protein (eYFP) mice (contain a loxP-flanked "STOP" sequence 5' to eYFP), and doubly heterozygous offspring were analyzed. THP and eYFP were expressed in an identical pattern with predominant localization to the renal outer medulla without expression in nonrenal tissues. eYFP did not colocalize with thiazide-sensitive cotransporter (distal tubule) or neuronal nitric oxide synthase (macula densa) expression. THP mRNA expression was detected only in kidney, whereas CreTag mRNA was also present in testes. These data indicate that THP-CreTag transgenic mice can be used for TAL-specific gene recombination in the kidney.
对厚壁升支（TAL）功能的评估一直受到体内选择性检测该肾单位节段功能能力有限的阻碍。为了解决这个问题，采用了一种Cre/loxP策略，即利用Tamm-Horsfall（THP）启动子驱动转基因小鼠中Cre重组酶的表达。从小鼠基因组文库中克隆了THP基因，并将包含THP基因第一个非编码外显子的3.7 kb小鼠THP 5'侧翼区域插入到一个表位标记的Cre重组酶（THP-CreTag）的上游。将THP-CreTag转基因小鼠与ROSA26增强型黄色荧光蛋白（eYFP）小鼠（在eYFP的5'端含有一个loxP侧翼的“STOP”序列）杂交，并对双杂合子后代进行分析。THP和eYFP以相同的模式表达，主要定位于肾外髓质，在非肾组织中不表达。eYFP与噻嗪敏感共转运体（远端小管）或神经元型一氧化氮合酶（致密斑）的表达不共定位。THP mRNA仅在肾脏中检测到，而CreTag mRNA也存在于睾丸中。这些数据表明，THP-CreTag转基因小鼠可用于肾脏中TAL特异性基因重组。
