Multiple functionally divergent and conserved copies of alpha tubulin in bdelloid rotifers.
Multiple functionally divergent and conserved copies of alpha tubulin in bdelloid rotifers.
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DOI：
10.1186/1471-2148-12-148
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发表时间：
2012-08-17
影响因子：
3.4
通讯作者：
Barraclough TG
中科院分区：
文献类型：
--
作者：
Eyres I;Frangedakis E;Fontaneto D;Herniou EA;Boschetti C;Carr A;Micklem G;Tunnacliffe A;Barraclough TG
蛭形轮虫是一种微小的动物，它们显然在没有性生活的情况下存活了数百万年，并且能够通过一种称为无水共生的过程在所有生命阶段的干燥中存活下来。这两个特征被认为在塑造近年来发现的蛭形基因组的几个不寻常的特征中发挥了作用。无性恋和无水对蛭体基因组影响的研究主要集中在了解基因拷贝数上。本文研究了α微管蛋白的拷贝数和序列分化。α微管蛋白是保守的，在动物中通常拷贝数较少，但在适应极端环境的动物中也发生了α微管蛋白拷贝的增殖，例如适应寒冷环境的南极鱼类。通过克隆和测序，我们比较了4种兼性轮虫和4种单性轮虫的α微管蛋白拷贝变异。利用一种蛭形动物Adineta ricciae的转录组数据验证了结果。与动物的典型模式一样，单纲轮虫含有一个或两个α微管蛋白副本，但蛭形物种含有11到13个不同的副本，分布在五个纲中。大约一半的拷贝形成一个高度保守的群体，彼此之间和与单基因拷贝之间的氨基酸配对差异仅为1.1%。其他副本具有不同的氨基酸序列，相对于同义的变化，这些序列在类之间的进化速度明显快于类内的进化速度，并且在预测的生化特性上有所不同。每个类的拷贝在实验室条件下表达，用于构建转录组。我们的发现与最近的证据一致，即蛭形体是退化的四倍体，祖先基因拷贝的功能分化已经发生，但显示了蛭形体祖先的进一步复制事件如何导致该基因的保守拷贝和功能分化拷贝的增殖。
Bdelloid rotifers are microscopic animals that have apparently survived without sex for millions of years and are able to survive desiccation at all life stages through a process called anhydrobiosis. Both of these characteristics are believed to have played a role in shaping several unusual features of bdelloid genomes discovered in recent years. Studies into the impact of asexuality and anhydrobiosis on bdelloid genomes have focused on understanding gene copy number. Here we investigate copy number and sequence divergence in alpha tubulin. Alpha tubulin is conserved and normally present in low copy numbers in animals, but multiplication of alpha tubulin copies has occurred in animals adapted to extreme environments, such as cold-adapted Antarctic fish. Using cloning and sequencing we compared alpha tubulin copy variation in four species of bdelloid rotifers and four species of monogonont rotifers, which are facultatively sexual and cannot survive desiccation as adults. Results were verified using transcriptome data from one bdelloid species, Adineta ricciae. In common with the typical pattern for animals, monogonont rotifers contain either one or two copies of alpha tubulin, but bdelloid species contain between 11 and 13 different copies, distributed across five classes. Approximately half of the copies form a highly conserved group that vary by only 1.1% amino acid pairwise divergence with each other and with the monogonont copies. The other copies have divergent amino acid sequences that evolved significantly faster between classes than within them, relative to synonymous changes, and vary in predicted biochemical properties. Copies of each class were expressed under the laboratory conditions used to construct the transcriptome. Our findings are consistent with recent evidence that bdelloids are degenerate tetraploids and that functional divergence of ancestral copies of genes has occurred, but show how further duplication events in the ancestor of bdelloids led to proliferation in both conserved and functionally divergent copies of this gene.
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影响因子：
2.9
作者：
Bagniewska-Zadworna, Agnieszka
通讯作者：
Bagniewska-Zadworna, Agnieszka
影响因子：
3.1
作者：
Gladyshev, Eugene A.;Arkhipova, Irina R.
通讯作者：
Arkhipova, Irina R.
DOI：
10.1016/s0300-9629(97)00012-1
发表时间：
1997-11-01
期刊：
COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY A-PHYSIOLOGY
影响因子：
--
作者：
Detrich, HW
通讯作者：
Detrich, HW
DOI：
10.1098/rstb.2009.0034
发表时间：
2009-08-12
影响因子：
6.3
作者：
Foster, Peter G.;Cox, Cymon J.;Embley, T. Martin
通讯作者：
Embley, T. Martin
影响因子：
6.5
作者：
Foster, PG
通讯作者：
Foster, PG