Sequence analysis of the mitochondrial genome of Sarcophyton glaucum:: Conserved gene order among octocorals
Sequence analysis of the mitochondrial genome of Sarcophyton glaucum:: Conserved gene order among octocorals
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DOI：
10.1007/pl00006429
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发表时间：
1998-12-01
影响因子：
3.9
通讯作者：
Cavalier-Smith, T
中科院分区：
文献类型：
--
作者：
Beaten, MJ;Roger, AJ;Cavalier-Smith, T
提出了八珊瑚肉藻线粒体基因组 11,715 bp 片段的核苷酸序列，完成了对这种刺胞动物门动物成员的整个基因组的分析。该基因组包含与其他动物相同的 13 个蛋白质编码基因和 2 个核糖体 RNA 基因。然而，它还包括先前报道的不寻常的错配修复基因同源物，并且仅编码单个 tRNA 基因。与其他两种刺胞动物（17,443 和 18,911 bp）相比，该细胞器基因组的长度处于中等水平，包含最少数量的非编码 DNA（428 个，而分别为 1283 和 781 bp），使其成为迄今为止在该门中发现的最紧凑的基因组。 S. glaucum 的线粒体基因表现出与另一种八珊瑚海肾 (Renilla kolikeri) 中发现的相同排列，其中五个蛋白质编码基因的顺序与昆虫和脊椎动物线粒体基因组中发现的顺序相同。尽管八珊瑚的基因顺序似乎高度保守，但与六珊瑚（Metridium senile）相比，几乎没有发现相似之处。与其他后生动物线粒体基因组一样，A + T 组成升高，并且观察到对以 G 或 C 结尾的密码子的普遍偏向。然而，一个例外是与 TGG 相比，很少使用 TGA 来编码色氨酸。这种不同的密码子偏好是不寻常的，但似乎是两种关系较远的昆虫动物中的保守特征。
The nucleotide sequence for an 11,715-bp segment of the mitochondrial genome of the octocoral Sarcophyton glaucum is presented, completing the analysis of the entire genome for this anthozoan member of the phylum Cnidaria. The genome contained the same 13 protein-coding and 2 ribosomal RNA genes as in other animals. However, it also included an unusual mismatch repair gene homologue reported previously and codes for only a single tRNA gene. Intermediate in length compared to two other cnidarians (17,443 and 18,911 bp), this organellar genome contained the smallest amount of noncoding DNA (428, compared to 1283 and 781 nt, respectively), making it the most compact one found for the phylum to date. The mitochondrial genes of S. glaucum exhibited an identical arrangement to that found in another octocoral, Renilla kolikeri, with five protein-coding genes in the same order as has been found in insect and vertebrate mitochondrial genomes. Although gene order appears to be highly conserved among octocorals, compared to the hexacoral, Metridium senile, few similarities were found. Like other metazoan mitochoadrial genomes, the A + T composition was elevated and a general bias against codons ending in G or C was observed. However, an exception to this was the infrequent use of TGA compared to TGG to code for tryptophan. This divergent codon bias is unusual but appears to be a conserved feature among two rather distantly related anthozoans.