In nature, ECB uses E/Z11 desaturase to make its species-specific pheromone and ACB uses Z14 desaturase. In order to study the desaturase evolution in these two species, we first cloned the full-length cDNAs encoding acyl-CoA desaturase from pheromone gland of European corn borer (ECB) by RACE RT-PCR and three full-length genes (ECBG1, ECBG2 and ECBG3) were obtained. The ORF of each cDNA was inserted into expression vector (YEpOLEX or pYES2) and the expressed protein was confirmed by GC/MS as Z/E 11 (ECBG1), Z9 (ECBG2) and Z14 (ECBG3) desaturase, respectively. The same method was used to clone the desaturase genes from the pheromone gland cDNA library of Asian corn borer (ACB). Three fragments of central region were obtained first (ACBG1-CR, ACBG2-CR and ACBG3-CR) Surprisingly, these three fragments were the same as those three central regions of ECB (ECBG1-CR, ECBG2-CR and ECBG3-CR). A full-length cDNA (ACBG1) was finally isolated and it was the same as ECBG1. ECBG2 and ECBG3 gene-specific primers were designed to amplify the corresponding ORFs of ECBG2 and ECBG3 with RT-PCR by using ACB cDNA library. Two ORFs (ACBG2-ORF and ACBG3-ORF) were successfully amplified and cloned, which were confirmed to be the same as the ORFs of ECBG2 and ECBG3, respectively. These preliminary results show that the same desaturase genes exist in both European and Asian corn borers, but each species uses a different one for its own specific pheromone.
Species 1: Lepidoptera Crambidae Ostrinia nubilalis (European corn borer)
Species 2: Lepidoptera Crambidae Ostrinia furnacalis (Asian corn borer)
Keywords: Asian corn borer, European corn borer, Z/E11-desaturase, Z14-desaturase, YEpOLEX, pYES2, functional assay, cDNA
The ESA 2001 Annual Meeting - 2001: An Entomological Odyssey of ESA