Molecular cloning and expression of pheromone-binding protein1 from the diamondback moth, Plutella xylostella

We report on the identification and characterization of a new cDNA encoding the pheromone-binding protein1 (PxylPBP1) from male antennae of the diamondback moth, Plutella xylostella (L.) (Lepidoptera: Plutellidae). The deduced amino acid sequences of PxylPBP1 revealed a mature protein of 164 amino acids, with six cysteine residues in conserved positions relative to other known PBP. The alignment of the mature PxylPBP1 with other Lepidoptera PBP showed high sequence similarity (70-80%) with other full-length sequences from GenBank. Reverse transcription polymerase chain reaction (PCR) analysis revealed that the PxylPBP1 gene is only expressed in antennae. Real-time PCR further indicated that the expression of PxylPBP1 gene is higher in male moths, and higher in mated moths regardless of gender. The transcription levels of PxylPBP1 gene of unmated male moths reduced with age, and peaked in 4-h-old female moths.