Up-regulation of cryptochrome 1 gene expression in cotton bollworm () during migration over the Bohai Sea.

Cryptochromes (CRYs) are flavoproteins and play a pivotal role in circadian clocks which mediate behavior of organisms such as feeding, mating and migrating navigation. Herein, we identified novel transcripts in of six isoforms of and seven isoforms of by Sanger sequencing. Phylogenetic analysis showed that the transcripts of and align closely with other insect , indicating within-species divergence of . A analysis revealed that the encoding sequence of the was under purifying selection by a strong negative selection pressure whereas the was less constraint and showed a less strong purification selection than . In general, were more abundantly transcribed in wild migrating populations than that in laboratory maintained populations, and expression of the was lower than in all samples tested. Moreover, when compared with the migrating parental population, offspring reared in laboratory conditions showed a significant reduction on transcription of the but not . These results strongly suggest that was more related to the migration behavior of than .