The mitochondrial genomes of the human hookworms, Ancylostoma duodenale and Necator americanus (Nematoda: Secernentea)
The mitochondrial genomes of the human hookworms, Ancylostoma duodenale and Necator americanus (Nematoda: Secernentea)
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DOI：
10.1016/s0020-7519(01)00316-2
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发表时间：
2002-02-01
影响因子：
4
通讯作者：
Gasser, RB
中科院分区：
文献类型：
--
作者：
Hu, M;Chilton, NB;Gasser, RB
确定了两种人类钩虫的完整线粒体基因组序列，钩虫钩虫（13，721 bp）和美洲钩虫（13，604 bp）。圆形钩虫的基因组是迄今为止报道的任何后生动物生物体中最小的。它们相对较小的尺寸主要与AT富集区的长度减少有关。两种钩虫基因组均编码12种蛋白质。两个核糖体RNA和22个转运RNA基因，但缺乏ATP合成酶亚基8基因，这与迄今为止研究的其他三种Secernentea一致。所有基因都以相同的方向转录，并且具有高A和T，但低G和C的核苷酸组成。AT偏倚对密码子使用模式和蛋白质氨基酸组成都有显著影响。两种钩虫都有。除了基因nad 3和nad 5之间存在非编码区之外，基因以与秀丽隐杆线虫相同的顺序排列。以.然而，该非编码区被预测形成N中不存在的茎环结构。美国人这两种钩虫的线粒体基因组结构与猪蛔虫的不同之处仅在于AT富集区的位置，而与盘尾丝虫相比则存在实质性差异，包括4个基因或基因块易位以及一些转运RNA基因和AT富集区的位置。基于基因组结构和氨基酸序列的一致性，A. Alzaale和N. americanus与C. elegans比A. suum或O.扭转（所有secernentean线虫），与以前的系统发育研究使用核糖体DNA序列数据一致。两种人类钩虫线粒体基因组全序列的测定为系统学研究奠定了基础。这些线虫和其他具有社会经济重要性的线虫的种群遗传学和生态学。(C)2002年澳大利亚寄生虫学会由爱思唯尔科技有限公司出版。保留所有权利。
The complete mitochondrial genome sequences were determined for two species of human hookworms, Ancylostoma duodenale ( 13,721 bp) and Necator americanus (13,604 bp). The circular hookworm genomes are amongst the smallest reported to date for any metazoan organism. Their relatively small size relates mainly to a reduced length in the AT-rich region. Both hookworm genomes encode 12 protein. two ribosomal RNA and 22 transfer RNA genes, but lack the ATP synthetase subunit 8 gene, which is consistent with three other species of Secernentea studied to date. All genes are transcribed in the same direction and have a nucleotide composition high in A and T, but low in G and C. The AT bias had a significant effect on both the codon usage pattern and amino acid composition of proteins. For both hookworm species. genes were arranged in the same order as for Caenorhabditis elegans, except for the presence of a non-coding region between genes nad3 and nad5. In A. duodenale, this non-coding region is predicted to form a stem-and-loop structure which is not present in N. americanus. The mitochondrial genome structure for both hookworms differs from Ascaris suum only in the location of the AT-rich region, whereas there are substantial differences when compared with Onchocerca volvulus, including four gene or gene-block translocations and the positions of some transfer RNA genes and the AT-rich region. Based on genome organisation and amino acid sequence identity, A. duodenale and N. americanus were more closely related to C. elegans than to A. suum or O. volvulus (all secernentean nematodes), consistent with a previous phylogenetic study using ribosomal DNA sequence data. Determination of the complete mitochondrial genome sequences for two human hookworms (the first members of the order Strongylida ever sequenced) provides a foundation for studying the systematics. population genetics and ecology of these and other nematodes of socio-economic importance. (C) 2002 Australian Society for Parasitology Inc. Published by Elsevier Science Ltd. All rights reserved.