Mosquito genomes are frequently invaded by transposable elements through horizontal transfer.
Mosquito genomes are frequently invaded by transposable elements through horizontal transfer.
复制标题
DOI：
10.1371/journal.pgen.1008946
复制
发表时间：
2020-11
期刊：
影响因子：
4.5
通讯作者：
Wallau GL
中科院分区：
文献类型：
--
作者：
Melo ES;Wallau GL
转座因子是一类移动的遗传因子，基本上寄生在所有真核生物的基因组中。由于其复杂性，深入的TE表征仅适用于少数模式生物。在本研究中，我们进行了从头和同源性为基础的表征TE的基因组中的24种蚊子，并调查其遗传方式。埃及伊蚊、白纹伊蚊和致乏库蚊的基因组中超过40%由TE组成，而按蚊物种之间的基因组差异很大（0.13%-19.55%）。在过去的3000万年里，蚊子之间通过水平转移（16个不同的超家族的172个TE家族）进行了广泛的TE交换。水平转移的TE占伊蚊物种基因组的7%左右，占按蚊基因组的一小部分。这些水平转移的TE大多来自三个普遍存在的LTR超家族：Gypsy，Bel-Pao和Copia。通过搜索超过32，000个基因组，我们还发现了蚊子和两个不同门-刺胞纲和线虫纲-以及两个亚门-螯肢纲和甲壳纲之间的转移，确定了一种载体，蠕虫Wuchereria bancrofti，它使Tc 1-mariner元素在各种按蚊物种之间水平传播。这些数据也使我们能够重建这个TE的水平转移网络，涉及40多个物种。总之，我们的研究结果表明，TE经常通过蚊子之间的水平转移进行交换，影响蚊子的基因组大小和变异性。大多数真核生物基因组的很大一部分来自DNA片段，这些DNA片段可以通过插入基因组的其他区域而繁殖，从而产生基因组的不稳定性和变异性。这些片段被称为转座因子（TE）。由于它们是真核生物基因组的组成部分，这些DNA片段通常与其他基因一起沿着垂直遗传给宿主后代。宿主基因组具有一系列分子机制，这些机制被自然选择来控制TE复制，避免对基因组的最有害损伤，从而导致长期的TE失活和变性。然而，TE有时会失控，通过水平转移入侵其他物种，通过性交以外的其他方式转移遗传信息。这种现象在蚊子中的研究很少，蚊子是传播许多人类病原体的非常重要的昆虫分类群。我们对24种蚊子基因组的TE含量进行了分析，并研究了TE遗传模式，揭示了这些物种之间以及远亲之间的数百个水平转移事件。我们还确定了一种蚊子寄生丝虫，这是作为许多种蚊子之间的转移载体，水平转移的TE对蚊子的基因组扩增和变异有显着贡献。
Transposable elements (TEs) are mobile genetic elements that parasitize basically all eukaryotic species genomes. Due to their complexity, an in-depth TE characterization is only available for a handful of model organisms. In the present study, we performed a de novo and homology-based characterization of TEs in the genomes of 24 mosquito species and investigated their mode of inheritance. More than 40% of the genome of Aedes aegypti, Aedes albopictus, and Culex quinquefasciatus is composed of TEs, while it varied substantially among Anopheles species (0.13%–19.55%). Class I TEs are the most abundant among mosquitoes and at least 24 TE superfamilies were found. Interestingly, TEs have been extensively exchanged by horizontal transfer (172 TE families of 16 different superfamilies) among mosquitoes in the last 30 million years. Horizontally transferred TEs represents around 7% of the genome in Aedes species and a small fraction in Anopheles genomes. Most of these horizontally transferred TEs are from the three ubiquitous LTR superfamilies: Gypsy, Bel-Pao and Copia. Searching more than 32,000 genomes, we also uncovered transfers between mosquitoes and two different Phyla—Cnidaria and Nematoda—and two subphyla—Chelicerata and Crustacea, identifying a vector, the worm Wuchereria bancrofti, that enabled the horizontal spread of a Tc1-mariner element among various Anopheles species. These data also allowed us to reconstruct the horizontal transfer network of this TE involving more than 40 species. In summary, our results suggest that TEs are frequently exchanged by horizontal transfers among mosquitoes, influencing mosquito's genome size and variability. A large fraction of most eukaryotic genomes is derived from DNA fragments that can multiply by inserting themselves in other regions of the genome, generating genomic instability and variability. These fragments are called Transposable Elements (TEs). Since they are a constituent part of the eukaryote genomes, these DNA pieces are normally inherited vertically along with other genes to the host offspring. Host genomes have an arsenal of molecular mechanisms that were naturally selected to control TEs replication avoiding most deleterious damage to the genome and hence leading to long-term TEs inactivation and degeneration. However, TEs sometimes get out of control and invade other species through horizontal transfer, the transfer of genetic information through other means than sexual intercourse. This phenomenon is poorly studied in mosquitoes, a highly important insect taxon that transmit many human pathogens. We characterized the whole TE content of 24 mosquito genomes and investigated the TE inheritance mode uncovering hundreds of horizontal transfer events among these species and distantly related ones. We also identify a mosquito parasitic filarial worm, that is involved as a transfer vector between many species of mosquitoes and that horizontally transferred TEs contributed significantly to mosquito's genome expansion and variation.
登录
查看更多内容
影响因子：
4.9
作者：
Bao W;Kojima KK;Kohany O
通讯作者：
Kohany O
影响因子：
3.3
作者：
Biedler, James K.;Sha, Hongguang;Tu, Zhijian
通讯作者：
Tu, Zhijian
影响因子：
9.6
作者：
Bonizzoni M;Gasperi G;Chen X;James AA
通讯作者：
James AA
影响因子：
7
作者：
El Baidouri M;Carpentier MC;Cooke R;Gao D;Lasserre E;Llauro C;Mirouze M;Picault N;Jackson SA;Panaud O
通讯作者：
Panaud O
影响因子：
5.8
作者：
Edgar, RC;Myers, EW
通讯作者：
Myers, EW