Abstract
Although intercellular communication is essential for proper development in multicellular organisms, it is mostly unexplored how it controls the cell reprogramming process. To investigate the role of cellular interaction in determining the cell fates during the reprogramming process, we performed laser ablation experiments in the differentiated leaf cells of the moss Physcomitrella patens from which apical stem cells are directly initiated by excision. Even a singly isolated leaf cell initiated an apical stem cell with great frequency at a rate about 80%, suggesting that leaf cells are equipotent cells and can be regarded as an equivalence group. On the other hand, when the two-adjacent cells were isolated, they adopted distinct fates. One cell became an apical stem cell fate while neighboring cell did not. Furthermore, when we isolated two cells separated by one dead cell, both cells adopted stem cell fates. These results suggest that presumptive stem cell inhibits the stem cell initiation of neighboring cell during reprogramming process and the regulation occurs within a single cell range.
