日本冲绳科学技术大学Daniel S. Rokhsar等研究人员合作揭示盲鳗的基因组与脊椎动物的演化。2024年1月23日，《自然》杂志在线发表了这项成果。

研究人员根据褐盲鳗（Eptatretus atami）的染色体级基因组序列，揭示了脊椎动物全基因组复制和程序性DNA消除的复杂历史、时间和功能作用。结合同源分析和系统发育分析的证据，研究人员建立了脊椎动物基因组演化的全面图景，包括寒武纪早期圆口动物-有颌动物分裂之前的自发四倍体化（1RV），随后有颌动物经历了寒武纪中晚期异四倍体化（2RJV），而圆口动物经历了漫长的寒武纪-奥陶纪六倍化（2RCY）。随后，盲鳗经历了广泛的基因组变化，染色体融合伴随着器官系统（眼睛、破骨细胞）重要基因的缺失，这在一定程度上导致了盲鳗体型的简化。

最后，研究人员描述了盲鳗的程序性DNA消除，确定了在早期发育过程中从体细胞系中删除的蛋白编码基因和重复元件。这些种系特异基因的消除提供了一种机制，通过抑制种系/多能性功能来解决体细胞和种系之间的遗传冲突，这与七鳃鳗的发现类似。脊椎动物早期基因组历史的重建为进一步探索圆口动物和有颌脊椎动物的演化提供了一个宝贵的框架。

据介绍，作为唯一幸存的无颌鱼类，盲鳗和七鳃鳗为早期脊椎动物的演化提供了一个重要的窗口。

附：英文原文

Title: The hagfish genome and the evolution of vertebrates

Author: Marltaz, Ferdinand, Timoshevskaya, Nataliya, Timoshevskiy, Vladimir A., Parey, Elise, Simakov, Oleg, Gavriouchkina, Daria, Suzuki, Masakazu, Kubokawa, Kaoru, Brenner, Sydney, Smith, Jeramiah J., Rokhsar, Daniel S.

Issue&Volume: 2024-01-23

Abstract: As the only surviving lineages of jawless fishes, hagfishes and lampreys provide a critical window into early vertebrate evolution1–3. Here, we investigate the complex history, timing, and functional role of genome-wide duplications4–7 and programmed DNA elimination8,9 in vertebrates in the light of a chromosome-scale genome sequence for the brown hagfish Eptatretus atami. Combining evidence from syntenic and phylogenetic analyses, we establish a comprehensive picture of vertebrate genome evolution including an auto-tetraploidisation (1RV) predating the Early Cambrian cyclostome-gnathostome split, followed by a Mid-Late Cambrian allo-tetraploidisation (2RJV) in gnathostomes and a prolonged Cambrian-Ordovician hexaploidisation (2RCY) in cyclostomes. Subsequently, hagfishes underwent extensive genomic changes with chromosomal fusions accompanied by the loss of genes essential for organ systems (eyes, osteoclasts), accounting in part for the simplification of their body plan1,2. Finally, we characterise programmed DNA elimination in hagfish, identifying protein-coding genes and repetitive elements that are deleted from somatic cell lineages during early development. The elimination of these germline-specific genes provides a mechanism for resolving genetic conflict between soma and germline by repressing germline/pluripotency functions, paralleling findings in lampreys10,11. Reconstruction of the early genomic history of vertebrates provides a valuable framework for further exploration of cyclostome and jawed vertebrate evolution.

DOI: 10.1038/s41586-024-07070-3

Source: https://www.nature.com/articles/s41586-024-07070-3

期刊信息

Nature：《自然》，创刊于1869年。隶属于施普林格·自然出版集团，最新IF：69.504

官方网址：http://www.nature.com

投稿链接：http://www.nature.com/authors/submit_manuscript.html