Structure and evolution of the U2 small nuclear RNA multigene family in primates: gene amplification under natural selection?
Structure and evolution of the U2 small nuclear RNA multigene family in primates: gene amplification under natural selection?
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灵长类U2小核RNA多基因家族的结构和进化：自然选择下的基因扩增？
DOI：
10.1128/mcb.10.11.5876-5882.1990
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发表时间：
1990
影响因子：
5.3
通讯作者：
Schmid,CW
中科院分区：
文献类型：
--
作者：
Matera,AG;Weiner,AM;Schmid,CW
U2基因的组织在类人猿、东半球猴子和原猴星系中进行了比较。在人类和所有的类人猿(长臂猿、猩猩、大猩猩和黑猩猩)中，U2基因被组织成6kb元件的串联重复；然而，这些不同物种中6kb元件的限制图略有不同，这表明在这个串联阵列中必须存在保持序列同源性的机制。在东半球的猕猴中，U2基因被组织成一个11kb元件的串联重复；在恒河猴和两只密切相关的猕猴中，11kb元件的限制性内切酶图谱也略有不同，证实了有效的序列同质化是U2串联阵列的固有特性。有趣的是，11kb的猴子重复单位与6kb的人类重复单位不同，只有5kb的猴子特有的序列块。最后，我们发现原猴的U2基因是分散的，而不是随机重复的，这表明原始人和东半球猴子的U2串联阵列是由共同的祖先U2基因的独立扩增产生的。或者，在原始人和东半球猴子血统分化后不久，5kb的猴子特异序列可能被插入到6kb的阵列中或从11kb的阵列中删除。
The organization of U2 genes was compared in apes, Old World monkeys, and the prosimian galago. In humans and all apes (gibbon, orangutan, gorilla, and chimpanzee), the U2 genes were organized as a tandem repeat of a 6-kb element; however, the restriction maps of the 6-kb elements in these divergent species differed slightly, demonstrating that mechanisms must exist for maintaining sequence homogeneity within this tandem array. In Old World monkeys, the U2 genes were organized as a tandem repeat of an 11-kb element; the restriction maps of the 11-kb elements in baboon and two closely related macaques, bonnet and rhesus monkeys, also differed slightly, confirming that efficient sequence homogenization is an intrinsic property of the U2 tandem array. Interestingly, the 11-kb monkey repeat unit differed from the 6-kb hominid repeat unit by a 5-kb block of monkey-specific sequence. Finally, we found that the U2 genes of the prosimian galago were dispersed rather than tandemly repeated, suggesting that the hominid and Old World monkey U2 tandem arrays resulted from independent amplifications of a common ancestral U2 gene. Alternatively, the 5-kb monkey-specific sequence could have been inserted into the 6-kb array or deleted from the 11-kb array soon after divergence of the hominid and Old World monkey lineages.