Microarray analysis of perichondral and reserve growth plate zones

In the growth plate, the reserve and perichondral zones have been hypothesized to have similar functions, but their exact functions are poorly understood. Our hypothesis was that significant differential gene expression exists between perichondral and reserve chondrocytes that may differentiate the respective functions of these two zones. Normal Sprague-Dawley rat growth plate chondrocytes from the perichondral zone (PC), reserve zone (RZ), proliferative zone (PZ), and hypertrophic zone (HZ) were isolated by laser microdissection and then subjected to microarray analysis. In order to most comprehensively capture the unique features of the two zones, we analyzed both the most highly expressed genes and those that were most significantly different from the proliferative zone (PZ) as a single comparator. Keywords: cell specific expression profiles 2 microarray replicates were obtained for each zone, using pooled quantities of RNA from 3 rats each at 42 and 46 days of age.