Identification of differentially expressed genes in epithelial stem/progenitor cells of fetal rat liver

Differentially expressed cDNA clones from fetal rat liver were isolated usi ng suppression subtractive hybridization, combined with an efficient screen ing strategy. Approximately 30,000 clones were screened, yielding 643 genes whose expression was induced, of which 201 clones were distinct and 68 rep resented ESTs or newly discovered genes of unknown function. Based on their expression patterns in different organs, fetal liver, liver regeneration m odels, and gut epithelial progenitor cell lines, the subtracted clones pres ented in this work were placed into four categories: (1) hepatoblast-specif ic genes; (2) hematopoietic cell-specific genes; (3) genes expressed in hep atoblasts, in hematopoietic cells, and at varying levels in other tissues; and (4) genes overexpressed in fetal liver, in models of activation of live r progenitor cells, and in epithelial progenitor cell lines. Hepatoblast-sp ecific clones and those reg resenting genes induced during liver regenerati on are under further study to define their specific function(s) in liver ce ll growth control and/or differentiation. (C) 2000 Academic Press.