Little skate genome provides insights into genetic programs essential for limb-based locomotion.
Little skate genome provides insights into genetic programs essential for limb-based locomotion.
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作者：
Yoo D;Park J;Lee C;Song I;Lee YH;Yun T;Lee H;Heguy A;Han JY;Dasen JS;Kim H;Baek M
小溜冰鱼Leucoraja erinacea是一种软骨鱼，使用与陆地脊椎动物相似的遗传程序和神经元亚型，表现出骨盆鳍驱动的行走行为。然而，由于缺乏高质量的参考基因组，对小冰鞋运动回路发育的机制研究一直受到限制。在这里，我们生成了一个小溜冰基因组的组装，具有精确的基因注释和结构，这使得对运动所必需的脊髓运动神经元(MN)的后基因组分析成为可能。通过小鼠、滑冰和鸡的MN转录本的种间比较，鉴定了共享和不同的基因表达谱。通过比较小鼠和溜冰MN的染色质可及性区域，可以预测到不同的转录因子(Tf)基序，这些基序可用于实现MN表达基因的差异性调控。在MN表达的基因中观察到比在小滑冰中更多的Tf基序预测。这些发现提示在进化过程中控制脊椎动物MN发育的保守和发散的分子机制，这可能有助于在四足动物中出现更复杂的运动系统的复杂的基因调控网络。
The little skate Leucoraja erinacea, a cartilaginous fish, displays pelvic fin driven walking-like behavior using genetic programs and neuronal subtypes similar to those of land vertebrates. However, mechanistic studies on little skate motor circuit development have been limited, due to a lack of high-quality reference genome. Here, we generated an assembly of the little skate genome, with precise gene annotation and structures, which allowed post-genome analysis of spinal motor neurons (MNs) essential for locomotion. Through interspecies comparison of mouse, skate and chicken MN transcriptomes, shared and divergent gene expression profiles were identified. Comparison of accessible chromatin regions between mouse and skate MNs predicted shared transcription factor (TF) motifs with divergent ones, which could be used for achieving differential regulation of MN-expressed genes. A greater number of TF motif predictions were observed in MN-expressed genes in mouse than in little skate. These findings suggest conserved and divergent molecular mechanisms controlling MN development of vertebrates during evolution, which might contribute to intricate gene regulatory networks in the emergence of a more sophisticated motor system in tetrapods.