A telomere-to-telomere assembly of Oscheius tipulae and the evolution of rhabditid nematode chromosomes.
A telomere-to-telomere assembly of Oscheius tipulae and the evolution of rhabditid nematode chromosomes.
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DOI：
10.1093/g3journal/jkaa020
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发表时间：
2021-01-18
期刊：
影响因子：
--
通讯作者：
Blaxter M
中科院分区：
文献类型：
--
作者：
Gonzalez de la Rosa PM;Thomson M;Trivedi U;Tracey A;Tandonnet S;Blaxter M
在这里，González de la Rosa等人使用从纳米孔长读段产生的杆状线虫Oscheius tipulae的新端粒到端粒组装来探索线虫染色体的系统发育稳定性。作者将60 Mb的基因组分解为6个染色体分子，并发现了所有端粒特异性染色质减少的证据。他们提出了一个模型，通过重排和融合的七个祖先Nigon元素的线虫染色体的进化。真核染色体具有系统发育持久性。在许多分类群中，每条染色体都有一个单一的功能性着丝粒，在纺锤体附着和分离中起重要作用。融合和分裂可以产生没有或多个着丝粒的染色体，导致基因组不稳定。具有全着丝粒染色体的组（其中着丝粒功能沿沿着每条染色体分布）可能显示核型不稳定性。这通常不是这种情况，在秀丽隐杆线虫中，已经提出维持稳定核型的作用已经转移到减数分裂配对中心，它们位于每条染色体的一端。在这里，我们探讨了线虫染色体的系统发育稳定性，使用一个新的端粒端粒组装的杆状线虫Oscheius tipulae从纳米孔长读取。60 Mb O. tipulae基因组被分解为六个染色体分子。我们发现在所有的端粒特异性染色质减少的证据。比较这个O染色体。tipulae组装与染色体组装的不同的小杆线虫，我们确定了七个祖先的染色体元件（Nigon元件），并提出了一个模型的线虫染色体的进化，通过重排和融合这些元素。我们确定频繁的融合事件涉及NigonX，与小杆X染色体相关的元素，因此性染色体相关基因集在物种之间存在显着差异。尽管核型稳定，但由Nigon元件定义的染色体内的基因顺序是不保守的。我们的线虫染色体进化模型提供了一个平台，调查本地基因组重排和核型进化之间的紧张局势，在生成现存的基因组架构。
Here, González de la Rosa et al. explore the phylogenetic stability of nematode chromosomes using a new telomere-to-telomere assembly of the rhabditine nematode Oscheius tipulae generated from nanopore long reads. The authors resolve the 60 Mb genome into six chromosomal molecules and find evidence of specific chromatin diminution at all telomeres. They present a model for the evolution of nematode chromosomes through rearrangement and fusion of seven ancestral Nigon elements. Eukaryotic chromosomes have phylogenetic persistence. In many taxa, each chromosome has a single functional centromere with essential roles in spindle attachment and segregation. Fusion and fission can generate chromosomes with no or multiple centromeres, leading to genome instability. Groups with holocentric chromosomes (where centromeric function is distributed along each chromosome) might be expected to show karyotypic instability. This is generally not the case, and in Caenorhabditis elegans, it has been proposed that the role of maintenance of a stable karyotype has been transferred to the meiotic pairing centers, which are found at one end of each chromosome. Here, we explore the phylogenetic stability of nematode chromosomes using a new telomere-to-telomere assembly of the rhabditine nematode Oscheius tipulae generated from nanopore long reads. The 60-Mb O. tipulae genome is resolved into six chromosomal molecules. We find the evidence of specific chromatin diminution at all telomeres. Comparing this chromosomal O. tipulae assembly with chromosomal assemblies of diverse rhabditid nematodes, we identify seven ancestral chromosomal elements (Nigon elements) and present a model for the evolution of nematode chromosomes through rearrangement and fusion of these elements. We identify frequent fusion events involving NigonX, the element associated with the rhabditid X chromosome, and thus sex chromosome-associated gene sets differ markedly between species. Despite the karyotypic stability, gene order within chromosomes defined by Nigon elements is not conserved. Our model for nematode chromosome evolution provides a platform for investigation of the tensions between local genome rearrangement and karyotypic evolution in generating extant genome architectures.
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影响因子：
1.6
作者：
ALBERTSON, DG;THOMSON, JN
通讯作者：
THOMSON, JN
影响因子：
1.6
作者：
ALBERTSON, DG;NWAORGU, OC;SULSTON, JE
通讯作者：
SULSTON, JE
影响因子：
3.3
作者：
Besnard F;Koutsovoulos G;Dieudonné S;Blaxter M;Félix MA
通讯作者：
Félix MA
DOI：
10.1073/pnas.0910413107
发表时间：
2010-04-27
影响因子：
11.1
作者：
d'Alencon, E.;Sezutsu, H.;Feyereisen, R.
通讯作者：
Feyereisen, R.
影响因子：
16.6
作者：
Foster, Jeremy M.;Grote, Alexandra;Ghedin, Elodie
通讯作者：
Ghedin, Elodie