Takuya Minokawa

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Development of the body plan is controlled by large networks of regulatory genes. A gene regulatory network that controls the specification of endoderm and mesoderm in the sea urchin embryo is summarized here. The network was derived from large-scale perturbation analyses, in combination with computational methodologies, genomic data, cis-regulatory(More)
We present the current form of a provisional DNA sequence-based regulatory gene network that explains in outline how endomesodermal specification in the sea urchin embryo is controlled. The model of the network is in a continuous process of revision and growth as new genes are added and new experimental results become available; see(More)
Genes that are upregulated by LiCl treatment of sea urchin embryos and/or downregulated by injection into the egg of mRNA encoding an internal fragment of cadherin (Cad) were detected in a differential macroarray screen. The method was that recently described by J. P. Rast et al. (2000, Dev. Biol. 228, 270-296). Almost 10(5) clones from a 12-h cDNA library(More)
Expression of the wnt8 gene is the key transcriptional motivator of an intercellular signaling loop which drives endomesoderm specification forward early in sea urchin embryogenesis. This gene was predicted by network perturbation analysis to be activated by inputs from the blimp1/krox gene, itself expressed zygotically in the endomesoderm during cleavage;(More)
In the ascidian embryo, the nerve cord and notochord of the tail of tadpole larvae originate from the precursor blastomeres for both tissues in the 32-cell-stage embryo. Each fate is separated into two daughter blastomeres at the next cleavage. We have examined mechanisms that are responsible for nerve cord and notochord specification through experiments(More)
The Strongylocentrotus purpuratus hnf6 (Sphnf6) gene encodes a new member of the ONECUT family of transcription factors. The expression of hnf6 in the developing embryo is triphasic, and loss-of-function analysis shows that the Hnf6 protein is a transcription factor that has multiple distinct roles in sea urchin development. hnf6 is expressed maternally,(More)
The spatial and temporal expression patterns of Strongylocentrotus purpuratus genes encoding four different transcription factors, viz. SpFoxb, SpHes, SpKrl, and SpNk1, have been examined, using a recently developed, highly sensitive whole mount in situ hybridization procedure, and quantitative real time PCR. Two of the genes studied, SpHes and SpNk1, are(More)
The nanos genes play important roles in the development of primordial germ cells in animal species. In the sea urchin, Hemicentrotus pulcherrimus, small micromere descendants specifically express HpNanos mRNA and this expression continues in the left coelomic pouch, which produces the major component of the adult rudiment. In this study, we showed that(More)
The expression patterns of Brachyury (Bra) orthologs in the development of four species of sand dollars (order: Clypeasteroida), including a direct-developing species, and of a sea urchin species (order: Echinoida) were investigated during the period from blastula to the pluteus stage, with special attention paid to the relationship between the expression(More)
A gene regulatory network (GRN) controls the process by which the endomesoderm of the sea urchin embryo is specified. In this GRN, the program of gene expression unique to the skeletogenic micromere lineage is set in train by activation of the pmar1 gene. Through a double repression system, this gene is responsible for localization of expression of(More)