Isolation and characterization of three diapause-associated transcripts from the Colorado potato beetle, Leptinotarsa decemlineata

Using suppressive subtractive hybridization, fragments of three diapause-associated transcripts (DAT-1, 2 and 3) were isolated from the Colorado potato beetle, Leptinotarsa decemlineata. Full-length clones were developed for the transcripts. DAT-1 encodes a deduced protein 286 amino acids in length with limited identity to several proteins with leucine-rich domains. DAT-2 encodes a deduced protein 229 amino acids in length with 27% identity, 40% similarity to the desiccation stress protein from Tenebrio molitor. DAT-3 encodes a deduced protein 97 amino acids in length with identity to no known protein. DAT-1 and 2 have similar expression patterns as determined by northern blot analysis. Trace levels of these two transcripts are first detected in 3-day-old diapause-programmed adults with a significant increase in expression on day 6. Expression of DAT-3 begins on day 12 in diapause-programmed adults and expression levels increase until the beetles enter diapause. Expression of DAT-1, 2 and 3 continues at least 60 days into diapause.