Kroymann J, Zetsche K
Institut für Pflanzenphysiologie der Justus-Liebig-Universität Giessen, Heinrich-Buff-Ring 54-62, 35392 Giessen, Germany.
J Mol Evol. 1998 Oct;47(4):431-40. doi: 10.1007/pl00006400.
The 22,704-bp circular mitochondrial DNA (mtDNA) of the chlamydomonad alga Chlorogonium elongatum was completely cloned and sequenced. The genome encodes seven proteins of the respiratory electron transport chain, subunit 1 of the cytochrome oxidase complex (cox1), apocytochrome b (cob), five subunits of the NADH dehydrogenase complex (nad1, nad2, nad4, nad5, and nad6), a set of three tRNAs (Q, W, M), and the large (LSU)- and small (SSU)-subunit ribosomal RNAs. Six group-I introns were found, two each in the cox1, cob, and nad5 genes. In each intron an open reading frame (ORF) related to maturases or endonucleases was identified. Both the LSU and the SSU rRNA genes are split into fragments intermingled with each other and with other genes. Although the average A + T content is 62.2%, GC-rich clusters were detected in intergenic regions, in variable domains of the rRNA genes, and in introns and intron-encoded ORFs. A comparison of the genome maps reveals that C. elongatum and Chlamydomonas eugametos mtDNAs are more closely related to one another than either is to Chlamydomonas reinhardtii mtDNA.
对绿藻长绿梭藻22704碱基对的环状线粒体DNA（mtDNA）进行了全克隆和测序。该基因组编码呼吸电子传递链的七种蛋白质、细胞色素氧化酶复合体亚基1（cox1）、脱辅基细胞色素b（cob）、NADH脱氢酶复合体的五个亚基（nad1、nad2、nad4、nad5和nad6）、一组三个tRNA（Q、W、M）以及大（LSU）亚基和小（SSU）亚基核糖体RNA。发现了六个I类内含子，分别位于cox1、cob和nad5基因中，每个内含子中都鉴定出一个与成熟酶或内切核酸酶相关的开放阅读框（ORF）。LSU和SSU rRNA基因均被分割成相互交织且与其他基因交织的片段。尽管平均A+T含量为62.2%，但在基因间隔区、rRNA基因的可变结构域、内含子和内含子编码的ORF中检测到富含GC的簇。基因组图谱比较显示，长绿梭藻和真配子衣藻的mtDNA彼此之间的关系比它们与莱茵衣藻mtDNA的关系更为密切。
