期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：2002
卷号：99
期号：6
页码：3591-3596
DOI：10.1073/pnas.012549799
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：Telomeres are usually maintained about an equilibrium length, and the set point for this equilibrium differs between species and between strains of a given species. To examine the requirement for telomerase in mediating establishment of a new telomere length equilibrium, we generated interspecies crosses with telomerase mTR knockout mice. In crosses between C57BL/6J (B6) and either of two unrelated mouse species, CAST/Ei and SPRET/Ei, telomerase mediated establishment of a new telomere length equilibrium in wild-type mTR+/+ mice. This new equilibrium was characterized by elongation of the short telomeres of CAST/Ei or SPRET/Ei origin. In contrast, mTR-/- offspring of interspecies crosses failed to elongate telomeres. Unexpectedly, haploinsufficiency was observed in mTR+/- heterozygous interspecies mice, which had an impaired ability to elongate short SPRET/Ei or CAST/Ei telomeres to the new equilibrium set point that was achieved in wild-type mTR+/+ mice. These results demonstrate that elongation of telomeres to a new telomere set point requires telomerase and indicate that telomerase RNA may be limiting in vivo.
