Kobayashi Kenji, Yamada Lixy, Satou Yutaka, Satoh Nori
Department of Zoology, Graduate School of Science, Kyoto University, Sakyo-Ku, Kyoto, Japan.
Genesis. 2013 Sep;51(9):647-59. doi: 10.1002/dvg.22413. Epub 2013 Aug 12.
During early embryogenesis, embryonic cells gradually restrict their developmental potential and are eventually destined to give rise to one type of cells. Molecular mechanisms underlying developmental fate restriction are one of the major research subjects within developmental biology. In this article, this subject was addressed by combining blastomere isolation with microarray analysis. During the 6th cleavage of the Ciona intestinalis embryo, from the 32-cell to the 64-cell stage, four mother cells divide into daughter cells with two distinct fates, one giving rise to notochord precursor cells and the other to nerve cord precursors. Approximately 2,200 each of notochord and nerve cord precursor cells were isolated, and their mRNA expression profiles were compared by microarray. This analysis identified 106 and 68 genes, respectively, that are differentially expressed in notochord and nerve cord precursor cells. These included not only genes for transcription factors and signaling molecules but also those with generalized functions observed in many types of cells. In addition, whole-mount in situ hybridization showed dynamic spatial expression profiles of these genes during segregation of the two fates: partitioning of transcripts present in the mother cells into either type of daughter cells, and initiation of preferential gene expression in either type of cells.
在胚胎发育早期，胚胎细胞逐渐限制其发育潜能，最终注定会产生一种类型的细胞。发育命运限制的分子机制是发育生物学的主要研究课题之一。在本文中，通过将卵裂球分离与微阵列分析相结合来探讨这一课题。在玻璃海鞘胚胎的第6次卵裂期间，从32细胞期到64细胞期，四个母细胞分裂为具有两种不同命运的子细胞，一种产生脊索前体细胞，另一种产生神经索前体细胞。分别分离出约2200个脊索和神经索前体细胞，并通过微阵列比较它们的mRNA表达谱。该分析分别鉴定出106个和68个在脊索和神经索前体细胞中差异表达的基因。这些基因不仅包括转录因子和信号分子的基因，还包括在许多类型细胞中观察到的具有一般功能的基因。此外，全胚胎原位杂交显示了这些基因在两种命运分离过程中的动态空间表达谱：母细胞中存在的转录本在两种子细胞类型中的分配，以及在两种细胞类型中优先基因表达的起始。
