Sequence Clonging Of Telomerase Component Genes And The Correlation Between Their Expression And Telomerase Activity In Cashmere Goat

Telomerase is a nucleotide-protein complex enzyme mainly composed of the telomerase RNA component(TERC) and the telomerase reverse transcriptase(TERT), which catalyzes the addition of repeat sequence to telomeric DNA modulating the division and proliferation of cell. In this study the two components of cashmere goat telomerase were clonged and sequenced, and their expression as well as the status of telomerase activity was detected in adult goat tissues. Based on the analysis of homology of the TERC and TERT sequences among cattle, human, mouse and rat, different sets of primers were designed to amplify the corresponding unknown region of cashmere goat. Using cashmere goat genomic DNA and cDNA sample as template respectively, the 474bp DNA sequence and 289bp cDNA sequence of TERC and 4842bp partial DNA sequence and 2712bp partial cDNA sequence of TERT were obtained by PCR technology. The PCR products were ligased into pGEM-T easy vector and sequenced. The sequence information was compared with bovine corresponding sequences using BLAST software on the NCBI website, which showed the sequence homology is above 94ï¼…between goat and cattle, and is also much high compared to human, mouse and rat. As the gene sequence information obtained, the transcriptional state of telomerase components, TERT and TERC, were examined in heart, kidney, liver and testis of cashmere goat. Results shorted that TERC is expressed in all the tissues examined, while TERT is only expressed in the kidney and testis with different expression level, which is high in testis and low in kidney, and not detected in the heart and liver. The activity status of telomerase was also examined in the above tissues by telomeric repeat amplification protocol (TRAP). Result showed the telomerase activity is not detected in the heart and liver, kidney showed weak activity, testis had strong activity, which was according with the TERT ggene expression state in tissues. These results demonstrate that kidney and testis have telomerase activity which is repressed in most of cashmere goat somatic tissues. The transcription of two components of telomerase is independent in cashmere goats, and the TERT is the limiting component of telomerase activity.