Journal of Animal Science and Technology 53(3) 195~202, 2011 DOI:10.5187/JAST.2011.53.3.195 － － 195 * Corresponding author : Ki-Ho Lee, Ph.D. Department of Biochemistry and Molecular Biology and Medical Sciences Research Institute, Eulji University, Daejeon 301-746, Korea. Tel: +82-42-259-1643, Fax: +82-42-259-1649, E-mail: kiholee@eulji. ac.kr Expressional Profiling of Telomerase and Telomere-Associated Molecules in the Rat Testis and Seminal Vesicle during Postnatal Developmental Period Hee Jung Seo 1 , Seong Kyu Lee 1 , Haing Woon Baik 1 , Yong-Pil Cheon 2 , Taehoon Chun 3 , Inho Choi 4 and Ki-Ho Lee 1 * 1 Department of Biochemistry and Molecular Biology, Eulji University, Daejeon, Korea 301-746, 2 Department of Biology, Sungshin Women’s University, Seoul 136-742, Korea, 3 School of Life Sciences and Biotechnology, Korea University, Seoul 136-701, Korea, 4 School of Biotechnology, Yeugnam University and Bovine Genome Resources Bank, Gyeongsan 712-749, Korea ABSTRACT Maintenance of adequate telomere length in developing cells is the most important concern to preserve the integrity of the genome. The length of telomere is strictly regulated by numerous telomere-binding proteins and/or interacting factors. Even though the expression of telomerase in the male reproductive tract has been characterized, developmental expressional profiling of telomerase and other telomere-associated proteins has not been determined in detail. The present study was attempted to examine expression patterns of catalytic subunit (Tert) and RNA component (Terc) of telomerase and two telomerase associated factors, telomerase associated protein 1 (Tep1) and TERF1 (TRF1) interacting nuclear factor 2 (Tinf2) in the testis and seminal vesicle of male rat during postnatal development. The real-time PCR analysis was utilized to quantify mRNA expression of molecules. The abundance of Tep1 mRNA in the testis and seminal vesicle was the highest at 5 months of age. Expressional fluctuation of Tinf2 during postnatal development was found in the testis, while expression of Tinf2 in the seminal vesicle was gradually increased until 5 months of age and then significantly decreased later. mRNA level of Tert gene in the testis was significantly increased at the adult and the elder, while the highest expression of Tert gene in the seminal vesicle was found at 5 months of age. Expression of Terc transcript in the testis and seminal vesicle was the highest at 5 months of age, followed by significant reduction at 1 and 2 years of ages. Such differential gene expression of telomere-associated factors and telomerase components in different male reproductive tissues during postnatal development indicates that maintenance of telomere length would be regulated in tissue- and/or age-specific manners. (Key words : Telomerase, Testis, Seminal vesicle, Development, Telomerase-associated molecule) INTRODUCTION Telomeres are specialized DNA-protein structures which are present at the ends of eukaryotic linear chromosomes and function to protect from chromosomal degradation and fusion, leading cells to apoptosis or growth arrest (Siderakis and Tarsounas, 2007). Telomeric DNA is consisted of tandem G-rich repetitive DNA sequences at which a large number of proteins are bound (Palm and de Lange, 2008). Even though the telomeric DNA sequences do not encode specific proteins, the telomeric repeats are crucial to preserve genome integrity (Bekaert et al., 2004). Interestingly, the number of telomeric repeats among tissues within an organism is not always same, but is dramatically changed during development (Bekaert et al., 2004). In addition, it is well characterized that length of telomere is species- and cell type-specific (Walmsley and Petes, 1985). Thus, it is important to maintain adequate length of telomeric DNA repeats in each tissue and/or cell type. Based on conventional DNA replication procedure, a portion of telomeric end sequences becomes lost during each round of DNA replication (Bekaert et al., 2004). A specific DNA polymerase, called telomerase, resolves such shortening of telomere length for DNA replication. Telomerase is a complex of two essential components, telomerase reverse transcriptase (TERT), and its RNA component (TERC) (Bekaert et al., 2004). TERT is the catalytic domain of the telomerase, and TERC provides the template for telomere extension. A number of researches have demonstrated a strong relationship between activity of telomerase and protection against telomere erosion during each round of cell replication (Morin, 1989). In most mammalian somatic cells,