The remarkable ability of rapid self-renewal makes the intestinal epithelium an ideal model for the study of adult stem cells. The intestinal epithelium is organized into villus and crypt, and a group of intestinal st...The remarkable ability of rapid self-renewal makes the intestinal epithelium an ideal model for the study of adult stem cells. The intestinal epithelium is organized into villus and crypt, and a group of intestinal stem cells located at the base of crypt are responsible for this constant self-renewal throughout the life. Identification of the intestinal stem cell marker Lgr5, isolation and in vitro culture of Lgr5+ intestinal stem cells and the use of transgenic mouse models have significantly facilitated the studies of intestinal stem cell homeostasis and differentiation, therefore greatly expanding our knowledge of the regulatory mechanisms underlying the intestinal stem cell fate determination. In this review, we summarize the current understanding of how signals of Wnt, BMP, Notch and EGF in the stem cell niche modulate the intestinal stem cell fate.展开更多
Impacts on growth of young trees of Pinus Koraiensis of 6 environmental factors of intensityof sunlight, direct sunlight, thickness of soil humus, neighboring trees, upper canopy species, herbs andshrubs were investig...Impacts on growth of young trees of Pinus Koraiensis of 6 environmental factors of intensityof sunlight, direct sunlight, thickness of soil humus, neighboring trees, upper canopy species, herbs andshrubs were investigated on young tree of Pinus Koraiensis and 4 neighboring trees which are consideredthe structural unit of the microenvironment. Results indicated that the 6 environmental factors underinvestigation had effects, to various extents, on growth of the young trees. Based on the findings, suitablegrowing conditions for regenerated young tree of Pinus Koraiensis under forest were identified andcorresponding silvicultural measures were proposed for operational practice.展开更多
基金supported by the National Natural Science Foundation of China(31330049,31221064)National Basic Research Program of China(2011CB943803,2011CBA01104,2010CB833706)to Chen Ye-Guang
文摘The remarkable ability of rapid self-renewal makes the intestinal epithelium an ideal model for the study of adult stem cells. The intestinal epithelium is organized into villus and crypt, and a group of intestinal stem cells located at the base of crypt are responsible for this constant self-renewal throughout the life. Identification of the intestinal stem cell marker Lgr5, isolation and in vitro culture of Lgr5+ intestinal stem cells and the use of transgenic mouse models have significantly facilitated the studies of intestinal stem cell homeostasis and differentiation, therefore greatly expanding our knowledge of the regulatory mechanisms underlying the intestinal stem cell fate determination. In this review, we summarize the current understanding of how signals of Wnt, BMP, Notch and EGF in the stem cell niche modulate the intestinal stem cell fate.
文摘Impacts on growth of young trees of Pinus Koraiensis of 6 environmental factors of intensityof sunlight, direct sunlight, thickness of soil humus, neighboring trees, upper canopy species, herbs andshrubs were investigated on young tree of Pinus Koraiensis and 4 neighboring trees which are consideredthe structural unit of the microenvironment. Results indicated that the 6 environmental factors underinvestigation had effects, to various extents, on growth of the young trees. Based on the findings, suitablegrowing conditions for regenerated young tree of Pinus Koraiensis under forest were identified andcorresponding silvicultural measures were proposed for operational practice.
