Considering the role of Notch and Wnt signaling pathways in epithelial cell differentiation in the mammalian intestine, indicate whether each of the following changes in "minigut" organoids in culture is expected to lead to a higher (H) or lower (L) number of stem cells. Your answer would be a two-letter string composed of letters H and L only, e.g. HH.
( ) RNA interference knockdown of Hes1, an essential downstream effector of the Notch signaling pathway
( ) Deletion of the gene encoding Apc, a gene that is mutated in many colorectal cancers

Question

Considering the role of Notch and Wnt signaling pathways in epithelial cell differentiation in the mammalian intestine, indicate whether each of the following changes in "minigut" organoids in culture is expected to lead to a higher (H) or lower (L) number of stem cells. Your answer would be a two-letter string composed of letters H and L only, e.g. HH.
( )	RNA interference knockdown of Hes1, an essential downstream effector of the Notch signaling pathway
( )	Deletion of the gene encoding Apc, a gene that is mutated in many colorectal cancers

Quizplus · Accepted Answer

Notch signaling originating from Paneth cells inhibits differentiation of the gut epithelial stem cells. Inhibition of Notch signaling will therefore lead to differentiation. By allowing activation of the Wnt signaling pathway, Apc deletion interferes with stem-cell differentiation, producing more stem cells.

Considering the Role of Notch and Wnt Signaling Pathways in Epithelial