Albertin Caroline B, Medina-Ruiz Sofia, Mitros Therese, Schmidbaur Hannah, Sanchez Gustavo, Wang Z Yan, Grimwood Jane, Rosenthal Joshua J C, Ragsdale Clifton W, Simakov Oleg, Rokhsar Daniel S
The Eugene Bell Center for Regenerative Biology and Tissue Engineering, Marine Biological Laboratory, Woods Hole, MA, USA.
Department of Molecular and Cell Biology, University of California, Berkeley, CA, USA.
Nat Commun. 2022 May 4;13(1):2427. doi: 10.1038/s41467-022-29748-w.
Cephalopods are known for their large nervous systems, complex behaviors and morphological innovations. To investigate the genomic underpinnings of these features, we assembled the chromosomes of the Boston market squid, Doryteuthis (Loligo) pealeii, and the California two-spot octopus, Octopus bimaculoides, and compared them with those of the Hawaiian bobtail squid, Euprymna scolopes. The genomes of the soft-bodied (coleoid) cephalopods are highly rearranged relative to other extant molluscs, indicating an intense, early burst of genome restructuring. The coleoid genomes feature multi-megabase, tandem arrays of genes associated with brain development and cephalopod-specific innovations. We find that a known coleoid hallmark, extensive A-to-I mRNA editing, displays two fundamentally distinct patterns: one exclusive to the nervous system and concentrated in genic sequences, the other widespread and directed toward repetitive elements. We conclude that coleoid novelty is mediated in part by substantial genome reorganization, gene family expansion, and tissue-dependent mRNA editing.
头足类动物以其庞大的神经系统、复杂的行为和形态创新而闻名。为了研究这些特征的基因组基础，我们组装了波士顿市场鱿鱼（Doryteuthis (Loligo) pealeii）和加州双斑章鱼（Octopus bimaculoides）的染色体，并将它们与夏威夷短尾鱿鱼（Euprymna scolopes）的染色体进行比较。相对于其他现存的软体动物，软体（蛸亚纲）头足类动物的基因组高度重排，这表明在早期发生了强烈的基因组重组。蛸亚纲基因组具有与大脑发育和头足类动物特异性创新相关的多兆碱基串联基因阵列。我们发现，一种已知的蛸亚纲特征，即广泛的A到I mRNA编辑，表现出两种根本不同的模式：一种是神经系统特有的，集中在基因序列中，另一种是广泛存在的，针对重复元件。我们得出结论，蛸亚纲的新奇性部分是由大量的基因组重组、基因家族扩张和组织依赖性mRNA编辑介导的。
