Novel biflagellate TKB055 as a possible early-branch in the global eukaryotic phylogeny : studies on its morphology, transcriptome, and mitochondrial genome

新型双鞭毛虫 TKB055 作为全球真核系统发育中可能的早期分支：对其形态、转录组和线粒体基因组的研究

• 批准号: 22657025
• 负责人: INAGAKI Yuji
• 金额: $ 2.19万
• 依托单位: University of Tsukuba
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Challenging Exploratory Research
• 财政年份: 2010
• 资助国家: 日本
• 起止时间: 2010 至 2011
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-22657025/
• 关键词: ミトコンドリア; 真核生物系統; 原始真核生物; 細胞内微細構造; EST解析

Discoba (Excavata) is a unicellular eukaryotic assemblage that comprises four subgroups: Heterolobosea, Euglenozoa, Jakobida and Tsukubamonadida. This clade is especially important for understanding the early evolution of mitochondrial (mt) genomes, as the jakobid Reclinomonas americana retains the most ancestral (i.e. gene-rich) genome of any mt genomes determined to date. Amongst discobids, the Tsukubamonadida is the most recently established group and contains a single representative species (Tsukubamonas globosa; formerly known as the biflagellate strain TKB055) whose precise phylogenetic position within the Discoba has not yet been resolved. We conducted a pyrosequencing-based transcriptomic survey of T globosa and, based on these data, we assembled a phylogenomic alignment of 157 proteins. Our phylogenomic analyses show that T. globosa branches at the base of the union of Euglenozoa and Heterolobosea. In addition, we completely sequenced the mt genome of T. globosa (48,463 bp in length and A+T content of 66.2%). The mt genome of T. globosa can be mapped as circular, and encodes 52 putative protein-coding and 29 RNA genes, indicating that T. globosa is second only to R. americana in terms of its coding capacity. The relationships amongst the majormembers of the Discoba clade inferred from the 157-protein phylogeny and their mt genome data enalbe us to elucidate the evolution of mt gene repertoires in this protist clade.

Discoba(Exavata)是一种单细胞真核生物组合，由异形藻、裸眼藻目、雅各布亚纲和Tsukubamonadida亚群组成。这一分支对于理解线粒体(Mt)基因组的早期进化尤其重要，因为jakobid Reclinomonas americana保留了迄今为止确定的任何mt基因组中最原始的(即富含基因的)基因组。在Discoba中，Tsukubamonadida是最新建立的类群，包含一个具有代表性的物种(Tsukubamonas lobosa；以前被称为双鞭毛菌株TKB055)，其在Discoba中的确切系统发育位置尚未确定。我们进行了一项基于焦磷酸测序的转录组调查，并在这些数据的基础上，我们组装了157个蛋白质的系统发育序列。我们的系统发育分析表明，球囊毛虫在裸体动物和异叶藻的结合部的底部分枝。此外，我们还对球形毛滴虫的mt基因组进行了全序列测定(全长48463bp，A+T含量为66.2%)。球囊原虫的mt基因组为环状，编码52个蛋白质编码基因和29个RNA基因，其编码能力仅次于美洲锥虫。从157个蛋白质的系统发育和它们的mt基因组数据推断的Discoba分支的主要成员之间的关系可以用来阐明这个原生生物分支中mt基因库的进化。

项目成果

ミトコンドリアをもたないプロティスト分類群'Fomicata'の分子系統:複数遺伝子に基づく解析

线粒体原生生物分类群“Fomicata”的分子系统发育：基于多基因的分析

• 发表时间: 2011
• 作者: 小松崎洋志;瀧下清貴;Marin Kolisko;矢吹彬憲;雪吹直史;稲垣祐司;橋本哲男;Andrew J Roger;Alastair GB Simpson
• 通讯作者: Alastair GB Simpson

Tsukubamonas globosa is a deep-branching member in the Discoba clade : Morphology, phylogenomics, and mitochondrial genome(国際・招待講演)

Tsukubamonas globosa 是 Discoba clade 中的深分支成员：形态学、系统发育组学和线粒体基因组（国际/邀请报告）

• 发表时间: 2011
• 作者: Akinori Yabuki;Ryoma Kamikawa;Martin Kolisko;Sohta A. Ishikawa;Ken-ichiro Ishida;Alastair G. B. Simpson;Andrew J. Roger;Yuji Inagaki
• 通讯作者: Yuji Inagaki

Difference in transcriptional regulation between two genes encoding plastid-targeted GAPDH in the dinoflagellate Karenia mikimotoi

甲藻 Karenia mikimotoi 中编码质体靶向 GAPDH 的两个基因之间转录调控的差异

• 发表时间: 2011
• 作者: Yazaki Y;Kamikawa R;Matsumoto T;Hashimoto T;Inagaki Y
• 通讯作者: Inagaki Y

Tsukubamonas globosa is a deep-branching member in the Discoba clade : Morphology, phylogenomics, and mitochondrial genome

Tsukubamonas globosa 是 Discoba 分支的深分支成员：形态学、系统发育学和线粒体基因组

• 发表时间: 2011
• 作者: Yabuki A;Kamikawa R;Kolisko M;Ishikawa SA;Ishida K;Simpson AGB;Roger AJ;Inagaki Y
• 通讯作者: Inagaki Y

A simulation study for assessing phylogenetic inference attracted by inclusion of sequences with compositional bias and extraordinary substitution rate

一项模拟研究，用于评估因包含具有组成偏差和异常替代率的序列而引起的系统发育推断

• 发表时间: 2010
• 作者: Ishikawa S;Inagaki Y;Tanabe AS;Kamikawa R;Hashimoto T
• 通讯作者: Hashimoto T