■在软体动物神经系统的结构和发育中观察到的显着多样性提出了有关软体动物神经发生的分子机制的有趣问题。SoxB家族转录因子的表达在神经元发育中起着举足轻重的作用,从而为神经发生的策略提供有价值的见解。
■在这项研究中,我们进行了基因表达分析,重点是在腹足纲lymnaeastagnalis早期神经发生过程中SoxB家族转录因子。我们采用了杂交链式反应原位杂交(HCR-ISH)的组合,免疫细胞化学,共聚焦显微镜,和细胞增殖测定,以研究LsSoxB1和LsSoxB2从胃发育期到孵化的时空表达模式,特别注意中央环状神经节的形成。
■我们的研究表明,LsSoxB1表现出从胃到孵化阶段的外胚层表达扩大,而LsSoxB2在外胚层中的表达在veliger阶段停止。LsSoxB1在头部的外胚层中表达,脚,和内脏复合体,以及形成神经节和感觉细胞。相反,LsSoxB2主要限于上皮下层,并在变态过程中形成神经节细胞。增殖试验表明,在所有发育阶段,外胚层中分裂的细胞分布均匀,表明腹足类动物中没有明显的神经源性区域,增殖增加。
■我们的发现揭示了在腹足纲动物中SoxB1表达的空间和时间上扩展的模式,与其他lophrochozoan物种相比。SoxB基因的这种延长和广泛表达可以解释为转录新生的一种形式。代表对延长神经发生的预适应。因此,它可能有助于腹足类动物神经系统的多样化,并导致软体动物中枢神经系统复杂性的增加。
UNASSIGNED: The remarkable diversity observed in the structure and development of the molluscan nervous system raises intriguing questions regarding the molecular mechanisms underlying neurogenesis in Mollusca. The expression of SoxB family transcription factors plays a pivotal role in neuronal development, thereby offering valuable insights into the strategies of neurogenesis.
UNASSIGNED: In this study, we conducted gene expression analysis focusing on SoxB-family transcription factors during early neurogenesis in the gastropod Lymnaea stagnalis. We employed a combination of hybridization chain reaction in situ hybridization (HCR-ISH), immunocytochemistry, confocal microscopy, and cell proliferation assays to investigate the spatial and temporal expression patterns of LsSoxB1 and LsSoxB2 from the gastrula stage to hatching, with particular attention to the formation of central ring ganglia.
UNASSIGNED: Our investigation reveals that LsSoxB1 demonstrates expanded ectodermal expression from the gastrula to the hatching stage, whereas expression of LsSoxB2 in the ectoderm ceases by the veliger stage. LsSoxB1 is expressed in the ectoderm of the head, foot, and visceral complex, as well as in forming ganglia and sensory cells. Conversely, LsSoxB2 is mostly restricted to the subepithelial layer and forming ganglia cells during metamorphosis. Proliferation assays indicate a uniform distribution of dividing cells in the ectoderm across all developmental stages, suggesting the absence of distinct neurogenic zones with increased proliferation in gastropods.
UNASSIGNED: Our findings reveal a spatially and temporally extended pattern of
SoxB1 expression in a gastropod representative compared to other lophotrochozoan species. This prolonged and widespread expression of SoxB genes may be interpreted as a form of transcriptional neoteny, representing a preadaptation to prolonged neurogenesis. Consequently, it could contribute to the diversification of nervous systems in gastropods and lead to an increase in the complexity of the central nervous system in Mollusca.