アクティブボード・２００９年　８月
　　　　　・・・・・２００９年　８月　３日更新・・・・・

研究発表を行った学会；
・42nd Annual Meeting for the Japanese Society of Developmental Biologists.
　２００９年５月２８日〜３１日（新潟）

タイトル；Analysis of origin of the pancreatic precursors and the mechanism of endoderm regionalization in the chick embryos.
　
発表者；　勝本　恵一　氏
　　　（熊本大学　発生医学研究所　多能性幹細胞分野）
Abstract；
The aim of this study is to elucidate the pancreas development in the early chick endoderm. Recently, lineage tracing study using DiI solution have shown that dorsal pancreas precursor cells reside at the level of somite 4-7 in endoderm layer at 10 somite stage (ss), however, the origin of the pre-pancreatic endoderm prior to 10 ss has not yet been studied. Determination of the origin of the pancreas progenitor cells and trace the position of there descendants might provide information on when and where these cells might receive pancreas inducing signals from the adjacent tissues.
Using DiI crystal to mark endoderm cells, the correlations between specific endoderm sites and the positions of their descendants were studied. The endoderm precursor cells for the stomach, the pancreas or the intestine segregate right after the completion of gastrulation at HH5 stages. Transplantation experiments showed that the fates of the regional specific endoderm are determined in the order of the stomach, the intestine and then the pancreas. Moreover, insulin and glucagon expressing ectopic pancreas was generated in the stomach region in which non pancreatic endoderm were transplanted. Transplantation experiments also showed that the endoderm responding to the pancreatic inducing signals lies within the pre-pancreatic region and extends caudally beyond the intestinal endoderm region. These results indicate that the pancreatic fate is determined in the overlapping region of these two regions.