LAUSR

Cryptochrome1 (CRY1) functions as a light-responsive photoreceptor, which is crucial for circadian rhythms. The identity and function of CRY1 in Plutella xylostella remain unknown. In the study, cry1 was cloned and identified in P. xylostella. Then, a cry1-knockout strain (Cry1-KO) of P. xylostella with a 2-bp deletion was established from the strain G88 by using the CRISPR/Cas9 technology. No daily temporal oscillation of cry1 was observed in G88 and Cry1-KO, and cry1 mean daily transcription of Cry1-KO was lower than that of G88. Both G88 and Cry1-KO demonstrated rhythmic locomotion under the light/dark condition with Cry1-KO being more active than G88 in the daytime, while Cry1-KO completely lost rhythmicity under constant darkness. The developmental period of pre-adult of Cry1-KO was longer than that of G88; the life span of Cry1-KO male adult was shorter than that of G88; the fecundity of Cry1-KO was lower than that of G88, and Cry1-KO showed lower intrinsic rate of increase (r), net reproduction rate (R0 ) and finite increase rate (λ), and longer mean generation time (T) than G88. Our results indicate that cry1 is involved in the regulation of locomotor circadian rhythm and development in P. xylostella, providing a potential target gene for controlling the pest and a basis for further investigation on circadian rhythms in lepidopterans. This article is protected by copyright. All rights reserved.