Populations of these cells undergo asymmetric or symmetric divisions and can be replenished when transit amplifying cells dedifferentiate.
The corkscrew model of these was described in a paper which aimed to discredit the histogen theory and was subtitled "lessons from the crypt". That population of these cells are surrounded by Paneth cells and intercalated columnar cells. Lineages of these cells can be traced by visualizing the polarity of the spectrosome or centrosome in Drosophila models. A theory of one type of these stem cells involves migration across an ovary while still retaining ring-canals between the lineage and is followed by a competitive selection mechanism. A series of high profile papers from the (*) Spradling lab brought into question the definition of these cells, especially their supposedly dependent role on niche cells. Populations of these cells undergo asymmetric or symmetric divisions and can be replenished when transit amplifying cells dedifferentiate. For 10 points each, name these undifferentiated progenitor cells which include the embryonic and induced pluripotent types.
The corkscrew model of these was described in a paper which aimed to discredit the histogen theory and was subtitled "lessons from the crypt".
stem cells