内蒙古白绒山羊端粒酶在不同组织中的表达与活性

Expression of Telomerase Component Genes and Activity of Telomerase in Cashmere Goat

真核生物体内的端粒酶(Telomerase)是一种逆转录酶,能够特异地延长端粒DNA长度,从而调节细胞的分裂与增殖,端粒酶主要包括RNA组分(Telomerase RNA Component,TERC)和逆转录酶组分(Telomerase ReverseTranscriptase,TERT)。本研究利用RT-PCR技术对绒山羊端粒酶这两种组分在心脏、肾脏、肝脏、睾丸组织中的mRNA转录水平进行了检测,结果表明,TERC基因在以上四种组织中均有表达,而TERT基因则仅在肾脏和睾丸中有表达,且睾丸中的转录水平明显高于肾脏,而在心脏和肝脏中未检测到。同时,通过端粒重复序列扩增法(Telomeric Repeat Amplification Protocol,TRAP)对四种组织中的端粒酶活性状态进行了检测,在心脏和肝脏未检测到端粒酶活性,肾脏显示有较弱的活性,睾丸则表现出较强的活性,这与TERT基因的转录情况一致。由此可见绒山羊端粒酶的活性与不同组织的细胞增殖特性相关;端粒酶两种组分的转录是相互独立的,逆转录酶TERT组分是端粒酶活性的限速成分。

Objective Telomerase,a nucleotide-protein complex enzyme,is composed of a telomerase RNA component（TERC） and a telomerase reverse transcriptase（TERT）,which catalyzes the addition of repeat sequences to telomeric DNA modulating the division and proliferation of cell.In this study,transcription of the telomerase components,TERT and TERC,was examined in heart,kidney,liver and testis of the cashmere goat.Results showed that TERC was expressed in all the tissues examined,while TERT was only expressed in kidney and testis.Expression of TERT in testis was higher than that in kidney,and not detected in heart and liver.Telomerase activity was also examined by the telomere repeat amplification protocol（TRAP）.Telomerase activity was not detected in heart and liver.Weak activity was detected in kidney,and strong was found in testis,which was in accordance with expression of the TERT gene.These results demonstrate that kidney and testis have telomerase activity which is repressed in most somatic tissues of the cashmere goat.Transcription of the two telomerase components is independent,and TERT is the limiting component of telomerase activity.