果蝇、嗜尸果蝇和果实蝇中甘油-3-磷酸脱氢酶的不稳定进化。

Erratic evolution of glycerol-3-phosphate dehydrogenase in Drosophila, Chymomyza, and Ceratitis.

作者信息

Kwiatowski J, Krawczyk M, Jaworski M, Skarecky D, Ayala F J

机构信息

Department of Ecology and Evolutionary Biology, University of California, Irvine, CA 92717-2525, USA.

出版信息

J Mol Evol. 1997 Jan;44(1):9-22. doi: 10.1007/pl00006126.

DOI:10.1007/pl00006126

PMID:9010132

Abstract

We have studied the evolution of Gpdh in 18 fruitfly species by sequencing 1,077 nucleotides per species on average. The region sequenced includes four exons coding for 277 amino acids and three variable-length introns. Phylogenies derived by a variety of methods confirm that the nominal genus Zaprionus belongs within the genus Drosophila, whereas Scaptodrosophila and Chymomyza are outside. The rate of GPDH evolution is erratic. The rate of amino acid replacements in a lineage appears to be 1.0 x 10(-10)/site/year when Drosophila species are considered (diverged up to 55 million years ago), but becomes 2.3 x 10(-10) when they are compared to Chymomyza species (divergence around 60 My ago), and 4.6 x 10(-10) when species of those two genera are compared with the medfly Ceratitis capitata (divergence around 100 My ago). In order to account for these observations, the rate of amino acid replacement must have been 15 or more times greater in some lineages and at some times than in others. At the nucleotide level, however, Gpdh evolves in a fairly clockwise fashion.

摘要

我们通过对18种果蝇的甘油磷酸脱氢酶（Gpdh）进行研究，平均每个物种测序1077个核苷酸。测序区域包括编码277个氨基酸的四个外显子和三个长度可变的内含子。通过多种方法得出的系统发育树证实，名义上的扎普里果蝇属（Zaprionus）属于果蝇属（Drosophila），而裂果蝇属（Scaptodrosophila）和酪果蝇属（Chymomyza）则不在此列。GPDH的进化速率不稳定。当考虑果蝇物种时（分歧时间可达5500万年前），一个谱系中氨基酸替换的速率似乎是1.0×10⁻¹⁰/位点/年，但与酪果蝇属物种相比时（分歧时间约6000万年前），该速率变为2.3×10⁻¹⁰，而当将这两个属的物种与地中海实蝇（Ceratitis capitata）相比时（分歧时间约1亿年前），该速率为4.6×10⁻¹⁰。为了解释这些观察结果，在某些谱系和某些时期，氨基酸替换的速率必定比其他谱系和时期大15倍或更多。然而，在核苷酸水平上，Gpdh以相当顺时针的方式进化。