PANCREATIC-DUODENAL HOMEOBOX-1-ROLE IN GASTRIC ENDOCRINE PATTERNING

The gastrointestinal tract is subdivided into regions with different r oles in digestion and absorption. How this patterning is established i s unknown. We now report that the pancreatic-duodenal homeobox 1 gene (pdx1) is also expressed in cells of the distal stomach. Positive cell s include subpopulations of the three main endocrine (gastrin, somatos tatin and serotonin) cell types of this region. Pdx1 deficient mice we re virtually devoid of gastrin cells, had normal numbers of somatostat in cells and increased numbers of serotonin cells. Pdx1 is thus import ant for development of the gastrin cells of the antropyloric mucosa of the stomach and probably acts by controlling the fate of gastrin/sero tonin precursor cells.