GENE REARRANGEMENTS IN CHLAMYDOMONAS CHLOROPLAST DNAS ARE ACCOUNTED FOR BY INVERSIONS AND BY THE EXPANSION/CONTRACTION OF THE INVERTED REPEAT
GENE REARRANGEMENTS IN CHLAMYDOMONAS CHLOROPLAST DNAS ARE ACCOUNTED FOR BY INVERSIONS AND BY THE EXPANSION/CONTRACTION OF THE INVERTED REPEAT
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DOI：
10.1007/bf00020189
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发表时间：
1995-01-01
影响因子：
5.1
通讯作者：
TURMEL, M
中科院分区：
文献类型：
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作者：
BOUDREAU, E;TURMEL, M
为了深入了解导致衣藻属内叶绿体DNA(CpDNA)广泛变异的突变事件，我们研究了衣藻属衣藻的叶绿体基因组织，该衣藻是干扰种优格米托斯和莫氏衣藻的近亲，其cpDNA已被很好地描述。Pitschmannii环状cpDNA全长187kb，是迄今报道的最小的衣藻cpDNA，分别比同种衣藻cpDNA小56kb和105kb。尽管有这种显著的大小差异，但Pitschmannii cpDNA上的77个基因的排列与共线的C.eugametos和C.moewusii cpDNA上的相应基因的组织只有三个明显的差异。基因顺序的这些变化是由反向重复序列的扩张/收缩以及单复制区中的一个或两个倒置来解释的。在陆地植物的cpDNA中，这类事件也与基因重排有关。Pitschmannii和C.eugametos/C.moewusii cpDNA之间的巨大大小差异主要归因于多个缺失/添加事件，而不是通常在陆地植物cpDNA中观察到的反向重复序列的扩张/收缩。我们还发现，松材线虫线粒体基因组是一个16.5kb的环状DNA分子，分别比Moewusii和C.eugametos小5.5kb和7.5kb。
To gain insight into the mutational events responsible for the extensive variation of chloroplast DNA (cpDNA) within the green algal genus Chlamydomonas, we have investigated the chloroplast gene organization of Chlamydomonas pitschmannii, a close relative of the interfertile species C. eugametos and C. moewusii whose cpDNAs have been well characterized. At 187 kb, the circular cpDNA of C. pitschmannii is the smallest Chlamydomonas cpDNA yet reported; it is 56 and 105 kb smaller than those of its C. eugametos and C. moewusii counterparts, respectively. Despite this substantial size difference, the arrangement of 77 genes on the C. pitschmannii cpDNA displays only three noticeable differences from the organization of the corresponding genes on the collinear C. eugametos and C. moewusii cpDNAs. These changes in gene order are accounted for by the expansion/contraction of the inverted repeat and one or two inversions in a single-copy region. In land plant cpDNAs, these kinds of events are also responsible for gene rearrangements. The large size difference between the C. pitschmannii and C. eugametos/C. moewusii cpDNAs is mainly attributed to multiple events of deletions/additions as opposed to the usually observed expansion/contraction of the inverted repeat in land plant cpDNAs. We also found that the mitochondrial genome of C. pitschmannii is a circular DNA molecule of 16.5 kb which is 5.5 and 7.5 kb smaller than its C. moewusii and C. eugametos counterparts, respectively.