Insights into the evolution of mammalian telomerase: platypus TERT shares similarities with genes of birds and other reptiles and localizes on sex chromosomes.
Insights into the evolution of mammalian telomerase: platypus TERT shares similarities with genes of birds and other reptiles and localizes on sex chromosomes.
复制标题
DOI：
10.1186/1471-2164-13-216
复制
发表时间：
2012-06-01
期刊：
影响因子：
4.4
通讯作者：
Bose HR Jr
中科院分区：
文献类型：
--
作者：
Hrdličková R;Nehyba J;Lim SL;Grützner F;Bose HR Jr
TERT 基因编码端粒酶复合物的催化亚基，负责维持端粒长度。脊椎动物端粒酶已在真兽类哺乳动物、鱼类和鸡中进行了研究，但对其他脊椎动物的关注较少。鸭嘴兽占据着重要的进化地位，为哺乳动物基因的进化提供了独特的见解。我们报告了鸭嘴兽 TERT (OanTERT) 直系同源物的克隆，并提供了与其他脊椎动物基因的比较。 OanTERT 编码的蛋白质与有袋动物 TERT 和鸟类 TERT 具有高度序列相似性。与蜥脚类动物和有袋动物以及鲨鱼和棘皮动物的 TERT 一样，OanTERT 在 N 末端区域含有扩展的可变接头，表明它们已经存在于基础脊椎动物中，但在射线鳍鱼和真兽类哺乳动物中独立丢失。鉴定出几种选择性剪接的 OanTERT 变体，其结构与禽类 TERT 变体相似。端粒酶活性在所有鸭嘴兽组织中都表达，如冷血动物和鼠科啮齿动物。 OanTERT 位于性染色体 X3/Y2 的假常染色体区域，扩大了人类 5 号染色体和鸭嘴兽性染色体之间的同源性。同线性分析表明，TERT 与最后一个共同哺乳动物祖先中的性连锁基因共定位。有趣的是，雌性鸭嘴兽在心脏和肝脏组织中比雄性鸭嘴兽表达更高水平的端粒酶。 OanTERT 与爬行动物外群的 TERT 具有许多特征，表明 OanTERT 代表了哺乳动物的祖先 TERT。因此，真兽类哺乳动物的 TERT 特有特征是在单孔类动物分化之后才进化出来的。
The TERT gene encodes the catalytic subunit of the telomerase complex and is responsible for maintaining telomere length. Vertebrate telomerase has been studied in eutherian mammals, fish, and the chicken, but less attention has been paid to other vertebrates. The platypus occupies an important evolutionary position, providing unique insight into the evolution of mammalian genes. We report the cloning of a platypus TERT (OanTERT) ortholog, and provide a comparison with genes of other vertebrates. The OanTERT encodes a protein with a high sequence similarity to marsupial TERT and avian TERT. Like the TERT of sauropsids and marsupials, as well as that of sharks and echinoderms, OanTERT contains extended variable linkers in the N-terminal region suggesting that they were present already in basal vertebrates and lost independently in ray-finned fish and eutherian mammals. Several alternatively spliced OanTERT variants structurally similar to avian TERT variants were identified. Telomerase activity is expressed in all platypus tissues like that of cold-blooded animals and murine rodents. OanTERT was localized on pseudoautosomal regions of sex chromosomes X3/Y2, expanding the homology between human chromosome 5 and platypus sex chromosomes. Synteny analysis suggests that TERT co-localized with sex-linked genes in the last common mammalian ancestor. Interestingly, female platypuses express higher levels of telomerase in heart and liver tissues than do males. OanTERT shares many features with TERT of the reptilian outgroup, suggesting that OanTERT represents the ancestral mammalian TERT. Features specific to TERT of eutherian mammals have, therefore, evolved more recently after the divergence of monotremes.
登录
查看更多内容
DOI：
10.1073/pnas.95.15.8479
发表时间：
1998-07-21
影响因子：
11.1
作者：
Bryan, TM;Sperger, JM;Cech, TR
通讯作者：
Cech, TR
影响因子：
4.4
作者：
Delany, ME;Daniels, LM;Taylor, HA
通讯作者：
Taylor, HA
影响因子：
10.7
作者：
Brunet, Frederic G.;Roest Crollius, Hugues;Robinson-Rechavi, Marc
通讯作者：
Robinson-Rechavi, Marc
影响因子：
4.8
作者：
Bosoy, D;Peng, Y;Lue, NF
通讯作者：
Lue, NF
影响因子：
14.9
作者：
CovielloMcLaughlin, GM;Prowse, KR
通讯作者：
Prowse, KR