Description
Krppel-like factor 9 (Klf9), a zinc-finger transcription factor, is implicated in the control of cell proliferation, cell differentiation and cell fate in brain and uterus. Using Klf9 null mutant mice, we have investigated the involvement of Klf9 in small intestine crypt-villus cell renewal and lineage determination. We report the predominant expression of Klf9 gene in small intestine smooth muscle (muscularis externa). Jejunums null for Klf9 have shorter villi, reduced crypt stem/transit cell proliferation, and altered lineage determination as indicated by decreased and increased numbers of Goblet and Paneth cells, respectively. A stimulatory role for Klf9 in villus cell migration was demonstrated by BrdU labeling. Results suggest that Klf9 controls the elaboration, from small intestine smooth muscle, of molecular mediator(s) of crypt cell proliferation and lineage determination, and of villus cell migration.