Chen X L, Hartzell D L, McGraw R A, Hausman G J, Dean R G
Animal and Dairy Science Department, The University of Georgia, USA.
Biochem Biophys Res Commun. 1999 Aug 19;262(1):187-92. doi: 10.1006/bbrc.1999.1176.
Transgenic (TG) mice expressing porcine GH receptor (pGHR) directed by a 762-bp proximal leptin promoter were used to analyze the capability of the promoter to drive and regulate pGHR expression in vivo. Transgene expression occurred in inguinal, retroperitoneal, and epididymal/parametrial fat depots in both male and female TG mice, but not in wild type (WT) mice. pGHR transgene was also expressed in liver, heart, kidney, muscle, lung, and brain. Levels of pGHR transgene mRNA were higher in tissues other than adipose tissue. Fasting reduced leptin mRNA levels in adipose; however, pGHR transgene expression was not affected in either adipose or muscle. These results suggest (1) the region between +3 and -759 bp of the leptin promoter is able to drive gene expression in vivo, (2) this region may not be responsible for adipose tissue specificity of leptin expression, and (3) this region may not be responsible for negative regulation of leptin gene expression during fasting.
利用由762个碱基对的瘦素近端启动子指导表达猪生长激素受体（pGHR）的转基因（TG）小鼠，分析该启动子在体内驱动和调节pGHR表达的能力。转基因表达在雄性和雌性TG小鼠的腹股沟、腹膜后以及附睾/子宫旁脂肪库中出现，但在野生型（WT）小鼠中未出现。pGHR转基因也在肝脏、心脏、肾脏、肌肉、肺和大脑中表达。pGHR转基因mRNA水平在脂肪组织以外的组织中更高。禁食降低了脂肪组织中瘦素mRNA水平；然而，pGHR转基因表达在脂肪组织或肌肉中均未受影响。这些结果表明：（1）瘦素启动子+3至-759碱基对之间的区域能够在体内驱动基因表达；（2）该区域可能与瘦素表达的脂肪组织特异性无关；（3）该区域可能与禁食期间瘦素基因表达的负调节无关。
