Leishmania major Friedlin chromosome 1 has an unusual distribution of protein-coding genes
Leishmania major Friedlin chromosome 1 has an unusual distribution of protein-coding genes
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DOI：
10.1073/pnas.96.6.2902
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发表时间：
1999-03-16
影响因子：
11.1
通讯作者：
Stuart, K
中科院分区：
文献类型：
--
作者：
Myler, PJ;Audleman, L;Stuart, K
利什曼原虫是进化上古老的原生动物（动质体科）和重要的人类病原体，可引起从无症状到致命的一系列疾病。利什曼原虫基因组相对较小[大约34兆碱基（Mb）]，缺乏大量的重复DNA，分布在36对染色体中，大小从0.3 Mb到2.5 Mb不等，使其成为确定完整基因组序列的有用候选者。我们在这里报告了最小的染色体chr1的核苷酸序列。chr1序列有一个257千碱基的区域，密集排列着79个蛋白质编码基因。该区域两侧是端粒和亚端粒重复元件，这些元件在chr1同源物中数量和含量不同，导致大约27.5千碱基大小的差异。引人注目的是，前29个基因都编码在一条DNA链上，而剩下的50个基因编码在另一条DNA链上。根据chr1的基因密度，我们预测利什曼原虫共有约9800个基因，其中40%可能编码未知蛋白质。
Leishmania are evolutionarily ancient protozoans (Kinetoplastidae) and important human pathogens that cause a spectrum of diseases ranging from the asymptomatic to the lethal. The Leishmania genome is relatively small [approximate to 34 megabases (Mb)], lacks substantial repetitive DNA, and is distributed among 36 chromosomes pairs ranging in size from 0.3 Mb to 2.5 Mb, making it a useful candidate for complete genome sequence determination. We report here the nucleotide sequence of the smallest chromosome, chr1. The sequence of chr1 has a 257-kilobase region that is densely packed with 79 protein-coding genes. This region is flanked by telomeric and subtelomeric repetitive elements that vary in number and content among the chr1 homologs, resulting in an approximate to 27.5-kilobase size difference. Strikingly, the first 29 genes are all encoded on one DNA strand, whereas the remaining 50 genes are encoded on the opposite strand. Based on the gene density of chr1, ne predict a total of approximate to 9,800 genes in Leishmania, of which 40% may encode unknown proteins.