Analysis of spatiotemporal expression and function of the single-minded homolog in the branchiopod crustacean Daphnia magna.
Analysis of spatiotemporal expression and function of the single-minded homolog in the branchiopod crustacean Daphnia magna.
复制标题
鳃足类甲壳动物大型溞中单一同源物的时空表达和功能分析。
DOI：
10.1016/j.gene.2014.11.028
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发表时间：
2015
期刊：
影响因子：
3.5
通讯作者：
and Ohta,
中科院分区：
文献类型：
--
作者：
Morita;S.;Shiga;Y.;Tokishita;S.;and Ohta,
在昆虫黑腹果蝇中，腹中线细胞对中枢神经系统(CNS)的形成至关重要，并在外胚层神经母细胞的指定中发挥作用。值得注意的是，中线细胞在甲状旁腺腹轴的形成中也起着最近被认识到的作用。一心一意是腹侧中线细胞的主要调节者，是这些功能所必需的。最近，SIMP在各种节肢动物中的表达模式已有报道。这些结果表明，中线前体是从共同祖先下颌纲的腹侧神经外胚层进化而来的。然而，简单功能只在少数生物体中被分析过。为了研究编码单一结构基因sim的这些功能在昆虫和甲壳类动物中是否保守，我们检测了低等甲壳动物Daphniasimhomolog(Dma Sim)的胚胎表达模式，并分析了OFDMA sim在胚胎发育过程中的功能。DMA Sim蛋白在腹侧神经外胚层(如甲藻和海龟)和中线(如下颌骨)表达。除了这种保守的腹侧神经外胚层和中线表达，DMA Sim在腹中线外表达；它在上颌骨2、假定的壳腺和其他组织中表达。为了研究单核细胞的功能，我们使用了RNA干扰技术(RNAi)来抑制单核细胞的发育。经dma simRNAi处理的胚胎表现出轴索形成异常，肢体和腹部发育异常。此外，RNAi介导的敲除OFDMA Sit，一个可能的DMA Sim靶基因，导致了相似的胚胎表型。这些结果表明，除了在腹中线起到保守的作用外，dma也可能是由适当的缝隙介导的腹侧发育所必需的。我们的发现表明，在后生动物进化过程中，同源基因可能为腹侧中线细胞提供了不同的发育功能。
In insect Drosophila melanogaster, ventral midline cells are crucial to formation of the central nervous system (CNS) and have roles in the specification of ectodermal neuroblasts. Notably, midline cells also have more recently recognized roles in the formation of the higher crustaceanParhyaledorso-ventral axis. The single-minded is a master regulator of ventral midline cells and is required for these functions. Recentlysimexpression patterns have been reported in various arthropods. These results suggest that the midline precursors evolved from ventral neuroectoderm of common ancestor Mandibulata. However,simfunction has been only analyzed in few organisms. To investigate whether these functions ofsim, the gene encoding Single-minded, are conserved among insects and crustaceans, we examined the embryonic expression pattern of a lower crustacean Daphniasimhomolog (dma sim) and analyzed the function ofdma simduring embryonic development. The Dma Sim protein was expressed in the ventral neuroectoderm (like in onychophoran and chelicerate) and midline (like in mandibulatan). In addition to this conserved ventral neuroectoderm and midline expression, Dma Sim was expressed outside the ventral midline; it was expressed in maxilla 2, presumptive shell glands, and other tissues. To investigatedma simfunction, we used RNA interference (RNAi) to inhibitdma siminDaphniaembryos. Embryos subjected todma simRNAi exhibited improper axon tract formation and abnormal limb and ventral development. Furthermore, RNAi-mediated knockdown ofdma slit, a putative Dma Sim target gene, resulted in similar embryonic phenotypes. These results indicated thatdma simmight be required for properdma slit-mediated ventral development in addition to being required for a conserved role in the ventral midline. Our findings indicated thatsimhomologs might have provided different developmental functions to ventral midline cells during metazoan evolution.