Transcriptome expression profiling of fur color formation in domestic rabbits using Solexa sequencing

Fur color is an important, genetically determined characteristic of domestic rabbits, and rabbit furs are of great economic value. To investigate the molecular genetics associated with fur color determination in domestic rabbits, we used Solexa-sequencing technology to probe gene expression in dorsal skin tissues sampled from full-sibling Rex rabbits of different colors. The number of expressed genes in each sample was approximately 14,700. Among the top 30 genes and transcription factors with the highest reads per kilobase per million values, the elongation factor-alpha 1 gene was highly expressed in all samples, as were genes of the ribosomal protein and keratin gene families. Compared with the chinchilla (C) Rex rabbit control sample, the numbers of genes in the black (B) and white (W) rabbit samples were 1809 and 460, respectively, and the number of common differentially expressed genes was 257. Clustering analysis of these 257 genes revealed that 32 were up-regulated in sample B and down-regulated in sample W. Of these 32 genes, we identified some that are related to fur formation, including Tyrosinase-related protein 1 (TYRP1) and Tyrosinase (TYR), as well as genes with unknown functions. Quantitative real-time polymerase chain reaction was used to verify the expression patterns of those genes. The findings are expected to provide reference for the further study of fur color formation in rabbits.