Expression of cytochrome c oxidase subunit 1 gene in the brain at an early stage in the termination of pupal diapause in the sweet potato hornworm, Agrius convolvuli.

Suppression-subtractive hybridization was used to isolate cDNAs specifically expressed in the brain at the termination of pupal diapause in Agrius convolvuli. One of the isolated clones shows similarity to the cytochrome c oxidase subunit 1 (COX1) gene. The full-length cDNA was obtained from brain mRNA by rapid amplification of cDNA ends (RACE). The insert is 1.65 kb in length and has an open reading frame of 1.46 kb which encodes a putative protein of 486 amino acid residues. RT-PCR reveals that the mRNA increases dramatically at an early stage of diapause termination. Activity of cytochrome c oxidase in the brain also increases at the same time. The up-regulation of this gene suggests that expression of the COX1 gene and ATP synthesis are initiated in the brain in association with diapause termination.