Kikuko Tamura

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A simple mathematical method is developed to estimate the number of nucleotide substitutions per site between two DNA sequences, by extending Kimura's (1980) two-parameter method to the case where a G+C-content bias exists. This method will be useful when there are strong transition-transversion and G+C-content biases, as in the case of Drosophila(More)
The handedness of visceral organs is conserved among vertebrates and is regulated by asymmetric signals relayed by molecules such as Shh, Nodal and activin. The gene Pitx2 is expressed in the left lateral plate mesoderm and, subsequently, in the left heart and gut of mouse, chick and Xenopus embryos. Misexpression of Shh and Nodal induces Pitx2 expression,(More)
Recently a point mutation of guanine to thymine at nucleotide position 1917 in the endothelial nitric oxide synthase (eNOS) gene has been reported to be associated with coronary artery spasm. In addition, a significant association of the 4a/b polymorphism in intron 4 of the eNOS gene with coronary artery disease has been reported. However, the implications(More)
Plant alkaloids, one of the largest groups of natural products, provide many pharmacologically active compounds. Several genes in the biosynthetic pathways for scopolamine, nicotine, and berberine have been cloned, making the metabolic engineering of these alkaloids possible. Expression of two branching-point enzymes was engineered: putrescine(More)
Notch is involved in the cell fate determination of many cell lineages. The intracellular region (RAMIC) of Notch1 transactivates genes by interaction with a DNA binding protein RBP-J. We have compared the activities of mouse RAMIC and its derivatives in transactivation and differentiation suppression of myogenic precursor cells. RAMIC comprises two(More)
2,4-Dichlorophenoxyacetic acid (2,4-D)-degrading bacteria were isolated from pristine environments which had no history of 2,4-D exposure. By using 2,4-D dye indicator medium or 14C-labeled 2,4-D medium, six strains were isolated from eight enrichment cultures capable of degrading 2,4-D. Phylogenetic analyses based on 16S ribosomal DNA (rDNA) sequencing and(More)
During embryonic development, initially similar fields can develop into distinct structures, such as the vertebrate fore- and hindlimbs. Although considerable progress has been made in our understanding of the genetic control underlying the establishment of the different limb axes, the molecular cues that specify the differential development of the fore-(More)
Xenopus laevis can regenerate an amputated limb completely at early limb bud stages, but the metamorphosed froglet gradually loses this capacity and can regenerate only a spike-like structure. We show that the spike formation in a Xenopus froglet is nerve dependent as is limb regeneration in urodeles, since denervation concomitant with amputation is(More)
Tumor cells often express phenotypic markers that are specific to the cells from which they originated. A neural RNA-binding protein, Musashil, is an evolutionarily well-conserved marker for neural stem cells/ progenitor cells. To examine the origin of gliomas, we examined the expression of the human Musashil homolog, MSI1, in human glioma tissues and in(More)
Signaling induced by interaction between the receptor Notch and its ligand Delta plays an important role in cell fate determination in vertebrates as well as invertebrates. Vertebrate Notch signaling has been investigated using its constitutively active form, i.e. the truncated intracellular region which is believed to mimic Notch-Delta signaling by(More)