- 著者
- Nomoto Hiroshi Kondo Takuma Miyoshi Hideaki Nakamura Akinobu Hida Yoko Yamashita Ken-ichiro Sharma Arun J. Atsumi Tatsuya
- 出版者
- Endocrine Society
- 雑誌
- Endocrinology (ISSN:00137227)
- 巻号頁・発行日
- vol.156, no.10, pp.3570-3580, 2015-10
- 被引用文献数
- 13
The large-Maf transcription factor v-maf musculoaponeurotic fibrosarcoma oncogene homolog A (MafA) has been found to be crucial for insulin transcription and synthesis and for pancreatic beta-cell function and maturation. However, insights about the effects of small Maf factors on beta-cells are limited. Our goal was to elucidate the function of small-Maf factors on beta-cells using an animal model of endogenous small-Maf dysfunction. Transgenic (Tg) mice with beta-cell-specific expression of dominant-negative MafK (DN-MafK) experiments, which can suppress the function of all endogenous small-Mafs, were fed a high-fat diet, and their in vivo phenotypes were evaluated. Phenotypic analysis, glucose tolerance tests, morphologic examination of beta-cells, and islet experiments were performed. DN-MafK-expressed MIN6 cells were also used for in vitro analysis. The results showed that DN-MafK expression inhibited endogenous small-Maf binding to insulin promoter while increasing MafA binding. DN-MafK Tg mice under high-fat diet conditions showed improved glucose metabolism compared with control mice via incremental insulin secretion, without causing changes in insulin sensitivity or MafA expression. Moreover, up-regulation of insulin and glucokinase gene expression was observed both in vivo and in vitro under DN-MafK expression. We concluded that endogenous small-Maf factors negatively regulates beta-cell function by competing for MafA binding, and thus, the inhibition of small-Maf activity can improve beta-cell function.
- 著者
- Tsukazaki Hikaru Honjo Masanori Yamashita Ken-ichiro Ohara Takayoshi Kojima Akio Ohsawa Ryo Wako Tadayuki
- 出版者
- Japanese Society of Breeding
- 雑誌
- Breeding science (ISSN:13447610)
- 巻号頁・発行日
- vol.60, no.2, pp.139-152, 2010
- 被引用文献数
- 11
We investigated the correspondence between classifications based on simple sequence repeat (SSR) markers and on morphological traits for 30 bunching onion (Allium fistulosum L.) varieties. We also examined applicability of an assignment test for variety identification in bunching onion. Cluster analysis based on the allele frequency data at 29 SSR loci classified most of the varieties except for ‘Iwatsuki-2’ into the predicted variety groups, ‘Kaga’, ‘Senju’ or ‘Kujo’, which were categorized based on morphological traits. Although ‘Iwatsuki-2’ has been regarded as a member of ‘Kaga’ group, molecular data suggested the variety belonging to ‘Kujo’ rather than ‘Kaga’. In the assignment test at the individual level, 89.1% of the individuals were assigned to their original variety. When the assignment was conducted based on groups each consisting of four individuals, the percentage of correct assignments was considerably improved (99.3%). These results suggested that the assignment test approach will be useful for variety identification in allogamous bunching onions, which have large within-variety genetic diversity. On the other hand, it was also suggested that sampling of true source varieties will be fundamental to avoid misjudgment.