cDNA fingerprinting of osteoprogenitor cells to isolate differentiation stage-specific genes

A cDNA fingerprinting strategy was developed to identify genes based on the ir differential expression pattern during osteoblast development. Prelimina ry biological and molecular staging of cDNA pools prepared by global amplif ication PCR allowed discriminating choices to be made in selection of expre ssed sequence tags (ESTs) to be isolated. Sequencing of selected ESTs confi rmed that both known and novel genes can be isolated from any developmental stage of interest, e.g, from primitive progenitors, intermediate precursor s or mature osteoblasts. EST expression provides insight into possible inte rrelated physiological functions and putative interacting molecules during differentiation. This method offers a functional genomics approach to isola te differentiation stage-specific genes in samples as small as a single cel l.