Da Lage J L, Renard E, Chartois F, Lemeunier F, Cariou M L
Populations, Génétique et Evolution, Centre National de la Recherche Scientifique, 91198 Gif sur Yvette cedex, France.
Proc Natl Acad Sci U S A. 1998 Jun 9;95(12):6848-53. doi: 10.1073/pnas.95.12.6848.
We describe a gene from Drosophila melanogaster related to the alpha-amylase gene Amy. This gene, which exists as a single copy, was named Amyrel. It is strikingly divergent from Amy because the amino acid divergence is 40%. The coding sequence is interrupted by a short intron at position 655, which is unusual in amylase genes. Amyrel has also been cloned in Drosophila ananassae, Drosophila pseudoobscura, and Drosophila subobscura and is likely to be present throughout the Sophophora subgenus, but, to our knowledge, it has not been detected outside. Unexpectedly, there is a strong conservation of 5' and 3' flanking regions between Amyrel genes from different species, which is not the case for Amy and which suggests that selection acts on these regions. In contrast to the Amy genes, Amyrel is transcribed in larvae of D. melanogaster but not in adults. However, the protein has not been detected yet. Amyrel evolves about twice as fast as Amy in the several species studied. We suggest that this gene could result from a duplication of Amy followed by accelerated and selected divergence toward a new adaptation.
我们描述了一种来自黑腹果蝇的与α-淀粉酶基因Amy相关的基因。这个基因以单拷贝形式存在，被命名为Amyrel。它与Amy有显著差异，因为氨基酸差异为40%。编码序列在第655位被一个短内含子打断，这在淀粉酶基因中是不寻常的。Amyrel也已在拟果蝇、伪暗果蝇和黑果蝇中克隆出来，并且可能存在于整个Sophophora亚属中，但据我们所知，在其他地方尚未检测到。出乎意料的是，不同物种的Amyrel基因之间的5'和3'侧翼区域存在很强的保守性，而Amy基因并非如此，这表明选择作用于这些区域。与Amy基因不同，Amyrel在黑腹果蝇的幼虫中表达，但在成虫中不表达。然而，尚未检测到该蛋白质。在研究的几个物种中，Amyrel的进化速度大约是Amy的两倍。我们认为这个基因可能是由Amy复制后，朝着新的适应性方向加速并经过选择而产生的分化结果。
