Supporting data for "Chromosome-level genome assembly of <i>Plazaster borealis</i>: shed light on the morphogenesis of multi-armed starfish and its regenerative capacity"

<i>Plazaster borealis</i> has a unique morphology, multiple arms with clear distinction between disk and arms, that does not follow remarkable characteristic of Echinoderm, penta-radial symmetry. Though it seems to be related with accelerated evolutionary rate at the morphological level, the lack of a reference genome has limited further research in-depth. Herein we report the first chromosome-level reference genome of <i>P. borealis</i>. <br>High coverage of long and short read data was used to assemble <i>de novo</i> 561Mb reference genome of <i>P. borealis</i> and Hi-C sequencing data was used to scaffold into 22 chromosomal scaffolds comprising 92.38% of the genome. The genome showed the presence of 98.1% of complete eukaryote BUSCO and 97.1% of complete metazoan BUSCO, indicating high quality assembly. Through the comparative genome analysis, we identified evolutionary accelerated genes related with morphogenesis and regeneration, suggesting their potential role in shaping body pattern and capacity of regeneration. <br>This first chromosome-level genome assembly of <i>P. borealis</i> provides fundamental insights into echinoderm biology, as well as the genomic mechanism underlying its unique morphology and regeneration.

北方盘海星（Plazaster borealis）具有独特的形态特征：拥有多条腕足，且体盘与腕足间界限分明，这与棘皮动物（Echinoderm）典型的五辐射对称特征显著不符。尽管该物种在形态层面似乎存在演化速率加速的现象，但由于缺乏参考基因组，其深入研究受到了极大限制。本研究首次报道了北方盘海星的染色体级参考基因组。
本研究利用高覆盖度的长读长与短读长测序数据，对北方盘海星进行从头（de novo）组装，获得了561Mb的参考基因组；并通过Hi-C测序数据将其挂载为22条染色体级支架，覆盖全基因组的92.38%。该基因组的完整真核生物BUSCO（Benchmarking Universal Single-Copy Orthologs）占比达98.1%，完整后生动物BUSCO占比达97.1%，表明本次基因组组装质量优异。
通过比较基因组学分析，本研究鉴定出与形态发生及再生相关的演化加速基因，提示这些基因在塑造该物种的身体构型与再生能力中发挥潜在作用。
本次北方盘海星的首个染色体级基因组组装结果，为棘皮动物生物学研究提供了基础性见解，同时也为解析其独特形态与再生能力背后的基因组机制提供了关键支撑。