RAPID IDENTIFICATION OF A NOVEL CHONDROCYTE-SPECIFIC GENE BY RNA DIFFERENTIAL DISPLAY

Differential display or RNA fingerprinting is a novel approach for the isolation of differentially expressed genes. Here we describe the app lication of the RNA differential display technique to the analysis of the genes expressed in chick embryonic sternal chondrocytes, fibroblas ts and BrdU-treated chondrocytes, which dedifferentiate back to a mese nchymal-like phenotype. Parallel display among the genetags allowed us to isolate seven clones with differential expression patterns. Nucleo tide sequencing of one of these clones revealed that it is a novel dev elopmentally regulated gene with no significant homology to those repo rted previously. An RT-PCR analysis, using primers derived from this n ovel clone, confirmed the presence of the corresponding RNA only in th e untreated chondrocytes, and not in BrdU-treated chondrocytes or fibr oblasts. This confirmation of the expression pattern given by the diff erential display reinforces the reliability of this approach. These re sults indicate that the differential display analysis provides a rapid and effective way to identify novel differentially expressed genes du ring chondrogenesis. (C) 1996 Academic Press, Inc.