Sunkin S M, Stringer S L, Stringer J R
Department of Molecular Genetics, Biochemistry and Microbiology, University of Cincinnati, College of Medicine, Ohio 45267-0524.
J Eukaryot Microbiol. 1994 May-Jun;41(3):292-300. doi: 10.1111/j.1550-7408.1994.tb01509.x.
A fragment from the genome of rat-derived Pneumocystis carinii was found to contain two MSG genes arranged as a direct repeat. The sequences from one gene (MSG B), the region between the two genes, and part of the second gene (MSG A) were determined. The two MSG genes were not identical in sequence. The open reading frames of MSG A and MSG B encode non-identical proteins, both of which are similar to that encoded by a previously published cDNA. The MSG B gene sequence showed no evidence of introns. The 5' and 3' untranslated regions of the MSG gene pair were highly conserved, but the regions immediately upstream of the open reading frames of MSG A and B were different from the region upstream of a previously characterized MSG cDNA. Primers designed to extend upstream of the 5' end of MSG and downstream of the 3' end of MSG were used in a polymerase chain reaction with total genomic P. carinii DNA as template. Presumptive intergenic amplification products from this reaction were cloned and sequenced. The sequences of these regions were similar but distinct, indicating that tandem arrangement of MSG genes is a common organizational motif.
从大鼠源性卡氏肺孢子虫的基因组中发现一个片段，其中包含两个以正向重复排列的MS基因。确定了一个基因（MSGB）的序列、两个基因之间的区域以及第二个基因（MSGA）的部分序列。这两个MS基因在序列上并不相同。MSGA和MSGB的开放阅读框编码不同的蛋白质，二者均与先前发表的cDNA所编码的蛋白质相似。MSGB基因序列未显示出内含子的证据。MS基因对的5'和3'非翻译区高度保守，但MSGA和MSGB开放阅读框紧邻的上游区域与先前鉴定的MS cDNA的上游区域不同。以卡氏肺孢子虫全基因组DNA为模板，在聚合酶链反应中使用设计用于在MS的5'端上游和3'端下游延伸的引物。将该反应中推测的基因间扩增产物进行克隆和测序。这些区域的序列相似但不同，表明MS基因的串联排列是一种常见的组织模式。
