Objective To screen and identify differentially expressed genes in the dorsal root ganglion （DRG） in early experimental diabetic rats. Methods Diabetic model rats were induced by single intraperitoneal injection of streptozotocin （STZ）. At the second week after STZ injection, the sensory nerve conduction velocities （SNCV） of sciatic nerve were measured as an indicator of neuropathy. The technique of silver-staining mRNA differential display polymerase chain reaction （DD-PCR） was used to detect the levels of differentially expressed genes in rat DRG. The cDNA fragments that displayed differentially were identified by reverse-hybridization, cloned and sequenced subsequently, and then confirmed by Northern blot. Results The SNCV in the diabetic model group [n = 9, （45.25±10.38） m/s] reduced obviously compared with the control group [n = 8, （60.10± 11.92） m/s] （P 〈 0.05）. Seven distinct cDNA clones, one was up-regulated gene and the others were downregulated ones, were isolated by silver-staining mRNA differential display method and confirmed by Northern blot. According to the results of sequence alignment with GenBank data, majority of the clones had no significant sequence similarity to previously reported genes except only one that showed high homology to 6-pyruvoyl-tetrahydropterin synthase mRNA （accession No., BC059140）, which had not been reported to relate to diabetic neuropathy. Conclusion These differentially expressed genes in the diabetic DRG may contribute to the pathogenesis of diabetic peripheral neuropathy.
