Gene Expression Patterns in Different Wool Densities of Rex Rabbit Using cDNA Microarray

This study was carried out to identify gene expression patterns in different wool densities of rex rabbit. The mid-dorsal skin samples from 8 rex rabbits were studied. They were divided into two groups according to different wool densities. Total RNA was isolated and labeled by reverse transcription reaction with Cy5-dCTP and Cy3-dCTP for cDNA probe. The cDNA probe was hybridized with cDNA microarrays containing 14 601 rabbit's genes. The differently expressed genes were analysed with the Gene Ontology (GO) classification and the pathway analysis. Hierarchical clustering was performed to clarify genes in association with different wool densities. The 2 657 differentially expressed genes were identified. Among them, 1 103 genes were functionally known genes, 687 genes were up-regulated and 419 were down-regulated. GO analysis indicated that these altered genes were associated with metabolism, signal transduction, cell cycle, cell adhesion, cell proliferation, cell division, apoptosis, and other processes. KEGG analysis showed that 95 signal pathways associated with up-regulated genes and 87 signal pathways associated with down-regulated genes had changed significantly (P<0.05). Some important differentially expressed genes in different wool densities of rex rabbit were identified, such as MMP2, TGF-β1, TGF-β2, IGF-1, ITGB1, RPS6KB1, BMP2, ActRIIB, CDK2, and CCNA2. Hierarchical clustering analysis separated the differentially expressed genes into 5 main characteristic groups. Data from cDNA microarray experiments clearly distinguished between group A and group B. Some important genes were identified, which might be useful in further study on wool density markers of rex rabbit.