Abstract: The present invention provides a transgenic mouse retaining a DNA that encodes an exogenous GPR40 in an expressible state, wherein (1) the insulin secretion capacity has been increased, and/or (2) the glucose tolerance has been improved, compared with the corresponding non-transgenic mouse, or a portion of the living body thereof, a screening method for a prophylactic/therapeutic drug for diabetes mellitus and metabolic syndrome using the transgenic mouse, and the like.

Abstract: Disclosed are (1) a polypeptide (I) including the following amino acid sequence (II) in a molecule thereof: TyrAlaGluHisLysSerHisArgGlyGluTyrSerValCys (II) AspSerGluSerLeuTrpValThrAspLysSerSerAlaIle spIleArgGlyHisGlnValThrValLeuGlyGluIleLys ThrGlyAsnSerProValLysGlnTyrPheTyrGluThrArg CysLysGluAlaArgProValLysAsnGlyCysArgGlyIle AspAspLysHisTrpAsnSerGlnCysLysThrSerGlnThr TyrValArgAlaLeuThrSerGluAsnAsnLysLeuValGly TrpArgTrpIleArgIleAspThrSerCysValCysAlaLeu SerArgLysIleGlyArg (2) a DNA sequence coding for the polypeptide described in (1), (3) a vector including the DNA described in (2), (4) a transformant transformed by the vector described in (3), and (5) a process for producing the polypeptide (I) which comprises cultivating the transformant described in (4) in a culture medium to produce and accumulate the polypeptide described in (1) in a culture.

Abstract: A transformant, which harbors a recombinant vector containing a DNA which codes for human nerve growth factor 2 and a DNA which codes for the pro-region of a nerve growth factor at 5'-terminal of said DNA, produces human nerve factor 2 in stable and large amount in a culture medium.

Abstract: The present invention provides mouse embryonic stem cells and homozygous mutant mice carrying disruptions in the neurotrophin-3 (NT-3) gene generated by homologous recombination which results in the insertion of a reporter gene or a drug-resistance gene into an exon of the neurotrophin-3 gene. The mice harboring such homozygous mutations have a reduced number of sensory neurons compared with the number of sensory neurons present in a mouse lacking such mutations. These mice may be used to screen for substances that enhance the transcriptional activity of the NT-3 gene.

Abstract: Disclosed are respiratory-deficient yeast except Saccharomyces cerevisiae AH22R.sup.-, said respiratory-deficient yeast being transformed with a DNA containing a gene encoding a protein foreign to yeast and a method for preparing a protein foreign to yeast described above, which comprises culturing the yeast, and producing and accumulating the protein in a culture. The respiratory-deficient yeast of the present invention can produce a higher amount of protein than its parent strain.