Wright W E, Piatyszek M A, Rainey W E, Byrd W, Shay J W
Department of Cell Biology and Neuroscience, University of Texas Southwestern Medical Center at Dallas 75235-9039, USA.
Dev Genet. 1996;18(2):173-9. doi: 10.1002/(SICI)1520-6408(1996)18:2<173::AID-DVG10>3.0.CO;2-3.
Telomerase is a ribonucleoprotein that synthesizes telomere repeats onto chromosome ends and is involved in maintaining telomere length in germline tissues and in immortal and cancer cells. In the present study, the temporal regulation of expression of telomerase activity was examined in human germline and somatic tissues and cells during development. Telomerase activity was detected in fetal, newborn, and adult testes and ovaries, but not in mature spermatozoa or oocytes. Blastocysts expressed high levels of telomerase activity as did most human somatic tissues at 16-20 weeks of development with the exception of human brain tissue. This activity could no longer be detected in the somatic tissues examined from the neonatal period onward. Neither placenta nor cultured fetal amniocytes contained detectable telomerase activity. Fetal tissues explanted into primary cell culture showed a dramatic decline in telomerase activity which became undetectable after the first passage in vitro. Elucidation of the regulatory pathways involved in the repression of telomerase activity during development may lead to the ability to manipulate telomerase levels and explore the consequences both for cellular aging and for the survival of cancer cells.
端粒酶是一种核糖核蛋白，可在染色体末端合成端粒重复序列，并参与维持生殖系组织以及永生细胞和癌细胞中端粒的长度。在本研究中，我们检测了人类生殖系和体细胞组织以及发育过程中的细胞中端粒酶活性表达的时间调控。在胎儿、新生儿及成人的睾丸和卵巢中检测到了端粒酶活性，但在成熟精子或卵母细胞中未检测到。囊胚表达高水平的端粒酶活性，与发育16 - 20周时的大多数人类体细胞组织一样，但人类脑组织除外。从新生儿期开始，在所检测的体细胞组织中均未再检测到这种活性。胎盘和培养的胎儿羊膜细胞均未检测到可检测到的端粒酶活性。植入原代细胞培养的胎儿组织显示端粒酶活性急剧下降，在体外首次传代后就无法检测到。阐明发育过程中端粒酶活性抑制所涉及的调控途径，可能会使人们有能力操纵端粒酶水平，并探索其对细胞衰老和癌细胞存活的影响。
