Triosephosphate Isomerase Genes in Two Trophic Modes of Euglenoids (Euglenophyceae) and Their Phylogenetic Analysis
Triosephosphate Isomerase Genes in Two Trophic Modes of Euglenoids (Euglenophyceae) and Their Phylogenetic Analysis
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眼虫纲两种营养模式的磷酸丙糖异构酶基因及其系统发育分析
DOI：
10.1111/j.1550-7408.2008.00324.x
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发表时间：
2008-05
影响因子：
2.2
通讯作者：
中科院分区：
文献类型：
--
作者：
摘要。在两种营养模式的眼虫中鉴定了两种不同长度的编码磷酸丙糖异构酶（TIM）的cDNA，即光养型的纤细眼虫（Euglena gracilis）和中间眼虫（Euglena intermedia）和腐养型的长形裸藻（Astasia longa）。序列分析和前序列预测表明，较短的cDNA编码胞质TIM和较长的cDNA编码质体TIM（pTIM）。推测的A. longa pTIM和A. longa pTIM和E. gracilis pTIM提示A. longa pTIM靶向质体。因此，虽然A.虽然龙眼已经失去了光合作用的能力，但它们可能保留其他TIM相关的功能，如糖酵解和异戊烯基二磷酸或脂肪酸的合成。包括我们从绿藻和红藻中获得的TIM序列，我们的系统发育分析表明，裸藻的TIM组既不与动质体的TIM，这与裸藻共享最近的共同祖先，也不是密切相关的绿藻的TIM，这被认为是通过次生内共生的裸藻质体的供体。相反，它们与红藻的TIM组合在一起。此外，我们的氨基酸序列比对和结构建模表明，裸藻和红藻的TIM在其loop-4区域内共享独特的2-aa插入。因此，在裸藻与动质体分化后，裸藻与红藻之间可能发生了时间趋同进化或横向基因转移（更可能）。
ABSTRACT. Two different length cDNAs encoding triosephosphate isomerase (TIM) were identified in the two trophic modes of euglenoids, the phototrophic Euglena gracilis and Euglena intermedia and the saprotrophic Astasia longa. Sequence analyses and presequence prediction indicated that the shorter cDNA encodes a cytosolic TIM and the longer cDNA encodes a plastid TIM (pTIM). The typical presequence of the putative A. longa pTIM and the high sequence similarity between A. longa pTIM and E. gracilis pTIM imply that A. longa pTIM is targeted to plastids. Therefore, although the plastids of A. longa have lost the ability of photosynthesis, they might retain other TIM‐related function(s), such as glycolysis and the synthesis of isopentenyl diphosphate or fatty acids. Including the TIM sequences obtained by us from chlorophytes and rhodophytes, our phylogenetic analyses indicated that euglenoid TIMs group neither with TIMs of kinetoplastids, which share the nearest common ancestor with euglenoids, nor are closely related to TIMs of chlorophytes, which are considered to be the donors of euglenoid plastids through secondary endosymbiosis. Instead, they group with TIMs of rhodophytes. In addition, our amino acid sequence alignment and structure modeling showed that TIMs of euglenoids and rhodophytes share a unique 2‐aa insertion within their loop‐4 areas. Therefore, either tim convergent evolution or lateral gene transfer (more probably) might have occurred between euglenoids and rhodophytes after the divergence of euglenoids with kinetoplastids.
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影响因子：
10.7
作者：
Strimmer, K;vonHaeseler, A
通讯作者：
vonHaeseler, A
DOI：
10.1099/00207713-51-3-783
发表时间：
2001-05
影响因子：
2.8
作者：
A. N. Müllner;D. Angeler;R. Samuel;E. Linton;R. Triemer
通讯作者：
A. N. Müllner;D. Angeler;R. Samuel;E. Linton;R. Triemer
影响因子：
--
作者：
Borza, T;Popescu, CE;Lee, RW
通讯作者：
Lee, RW
影响因子：
64.8
作者：
Matsuzaki, M;Misumi, O;Kuroiwa, T
通讯作者：
Kuroiwa, T
DOI：
10.1016/0167-4781(95)00015-9
发表时间：
1995-04
期刊：
Biochimica et biophysica acta
影响因子：
--
作者：
Matthias Schmidt;I. Svendsen;J. Feierabend
通讯作者：
Matthias Schmidt;I. Svendsen;J. Feierabend