Brady Seán G, Danforth Bryan N
Department of Entomology, Cornell University, Ithaca, New York, USA.
Mol Biol Evol. 2004 Apr;21(4):691-6. doi: 10.1093/molbev/msh062. Epub 2004 Jan 22.
We discovered the presence of a unique spliceosomal intron in the F1 copy of elongation factor-1alpha (EF-1alpha) restricted to the bee family Colletidae (Hymenoptera: Apoidae). The intron ranges in size from 101 to 1044 bp and shows no positional sliding. Our data also demonstrate the complete absence of this intron from exemplars representing all other bee families, as well as from close hymenopteran relatives. A review of the literature finds that this intron is likewise absent from all other arthropods for which data are available. This provides unambiguous evidence for a relatively recent intron insertion event in the colletid common ancestor and, at least in this specific instance, lends support to the introns-late hypothesis. The comparative distribution of this novel intron also supports the monophyly of Colletidae and the exclusion of the Stenotritidae from this family, providing an example of the potential of some introns to act as robust markers of shared descent.
我们发现在局限于蜜蜂科（膜翅目：准蜂科）的延伸因子-1α（EF-1α）的F1拷贝中存在一个独特的剪接体内含子。该内含子大小在101至1044碱基对之间，且无位置滑动现象。我们的数据还表明，代表所有其他蜜蜂科的样本以及膜翅目近亲中完全不存在这个内含子。文献综述发现，所有其他有数据可查的节肢动物中同样不存在这个内含子。这为在准蜂科共同祖先中相对近期发生的内含子插入事件提供了明确证据，并且至少在这个特定例子中，支持了内含子晚期假说。这个新内含子的比较分布也支持了蜜蜂科的单系性以及将澳蜂科排除在该科之外，提供了一些内含子作为共同祖先有力标记的潜力的一个例子。
