DFCI shivdasani SAGE
Mammalian Fetal Gut Development

Studying the development of a relatively simple organ like the vertebrate intestine affords unique opportunities to acquire fundamental insights into general mechanisms of organogenesis. The Shivdasani Laboratory is focused on investigating molecular mechanisms of mouse intestine development.

The developing intestine has two major embryonic origins: the absorptive and secretory epithelium (mucosa) is entirely derived from the endodermal germ layer, whereas the surrounding stroma and smooth muscle originate from a mesodermal cell compartment. Decades of incisive cell and developmental research has established that proper formation of the whole organ depends critically on epithelial-mesenchymal interactions both during fetal life and for homeostasis of the mature organ. Other cell sub-populations, including vascular endothelium and neuronal cells, provide additional layers of regulation and complexity. Using a systematic approach of mRNA expression profiling, we are attempting to obtain first a general overview of developmental gene expression in the fetal mouse intestine and subsequently to identify candidate mediators of critical developmental cellular transitions.

We have constructed SAGE (Serial Analysis of Gene Expresion) libraries from three discrete stages in development of the mouse small intestine: post-coital days (E) 12.5, 13.5, and 15.5. The period between E13.5 and E15.5 is especially important because it witnesses the onset of epithelial cell differentiation, with a crucial transition from a poorly differentiated, pseudostratified squamous epithelium (see figure below) into a primitive columnar epithelium characterized by rudimentary villi. It is the gene expression profile associated with this important cellular transition that is cataloged and searchable in these pages. To see a comparison between mRNA expression in the fetal (E12.5) mouse stomach and intestine, please visit http://genome.dfci.harvard.edu/StomSAGE.

An analysis of the intestine expression data is published in the following report: Lepourcelet M, Tou L, Cai L, Sawada J, Lazar AJF, Glickman JN, Williamson J, Everett AD, Redston M, Fox EA, Nakatani Y, Shivdasani RA. Insights into developmental mechanisms and cancers in the mammalian intestine derived from SAGE and study of the hepatoma-derived growth factor (HDGF). Development 2005; 132:415-427.

Fetal (post-coital) age E12.5 E13.5 E15.5
Fetal mouse intestine
SAGE tags sequenced 65585 69040 67522
Unique SAGE tags 12168 12920 12574

These SAGE libraries are available for queries and comparisons

Click Here to Download the Whole Dataset!

Please send comments to: ramesh_shivdasani@dfci.harvard.edu