Ken-ichiro Tatematsu

Learn More
To construct an efficient system for the production of recombinant proteins in silkworm (Bombyx mori), we investigated the promoter activity of the silkworm sericin 1, 2, and 3 genes (Ser1, Ser2, and Ser3) using a GAL4/UAS binary gene expression system in transgenic silkworm. The promoter activity of the upstream region of Ser1 was strong, yielding high(More)
Transgenic silkworms can be useful for investigating the functions of genes in the post-genomic era. However, the common method of using a transposon as an insertion tool may result in the random integration of a foreign gene into the genome and suffer from a strong position effect. To overcome these problems, it is necessary to develop a site-specific(More)
A binary gene expression system using the yeast GAL4 DNA-binding protein and the upstream activating sequence (UAS) of galactose-driven yeast genes is an established and powerful tool for the analysis of gene function. However, in the domesticated silkworm, Bombyx mori, this system has been limited in its utility by the relatively low transcriptional(More)
The white, scarlet and brown genes of Drosophila melanogaster encode three half-type ATP-binding cassette (ABC) transporters. In Drosophila, precursors of ommochromes and pteridines are transported by White/Scarlet and White/Brown heterodimers, respectively. The white egg 2 (w-2) mutant of the silkworm, Bombyx mori, has white eggs and eyes because of lack(More)
Ommochromes are one of the major pigments involved in coloration of eggs, eyes, and body surface of insects. However, the molecular mechanisms of the final steps of ommochrome pigment synthesis have been largely unknown. The eggs of the silkworm Bombyx mori contain a mixture of ommochrome pigments, and exhibit a brownish lilac color. The recessive(More)
Enhancer trapping and insertional mutagenesis are powerful tools for analyzing genetic function. To construct an enhancer trap system in the silkworm Bombyx mori, we developed efficient jumpstarter strains by inserting the piggyBac transposase gene under the control of Bombyx cytoplasmic actin gene (BmA3) promoter into the genome. To stabilize the inserted(More)
The context sequence motif surrounding the ATG initiation codon influences mRNA translation efficiency and affects protein production; however, the optimal sequence differs among species. To determine the optimal sequence for production of recombinant proteins in a transgenic silkworm, we compared 14-nucleotide context motifs around the ATG (ATG-context) in(More)
In response to the successful use of monoclonal antibodies (mAbs) in the treatment of various diseases, systems for expressing recombinant mAbs using transgenic animals or plants have been widely developed. The silkworm (Bombyx mori) is a highly domesticated insect that has recently been used for the production of recombinant proteins. Because of their(More)
We established a transgenic silkworm strain expressing the human insulin receptor (hIR) using the GAL4/UAS system. Administration of human insulin to transgenic silkworms expressing hIR decreased hemolymph sugar levels and facilitated Akt phosphorylation in the fat body. The decrease in hemolymph sugar levels induced by injection of human insulin in the(More)