title: Adaptive evolution of vertebrate-type cryptochrome in the ancestors of Hymenoptera.
abstract: One of the most mysterious aspects of insect clock mechanisms is that some insects, including Hymenoptera and Tribolium, only express a vertebrate-type cryptochrome (cry2). It is unknown whether or not cry2 underwent adaptive evolution in these insects. In the present study, we cloned and sequenced the full-length cry2 from a fig pollinator species, Ceratosolen solmsi (Hymenoptera: Chalcidoidea: Agaonidae), and examined the molecular evolution and daily expression of this gene. Our results suggest that cry2 underwent positive selection in the branch leading to hymenopteran insects. The function of CRY2 might have been fixed since undergoing natural selection in the ancestor of Hymenoptera. Male pollinators showed stronger rhythmicity in the host figs, which reflect an adaptation to their life cycles.
authors.affiliation: Key Laboratory of Zoological Systematics and Evolution, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, People's Republic of China.
authors.forename: Bo
authors.initials: B
authors.lastname: Wang
authors.forename: Jin-Hua
authors.initials: JH
authors.lastname: Xiao
authors.forename: Sheng-Nan
authors.initials: SN
authors.lastname: Bian
authors.forename: Hai-Feng
authors.initials: HF
authors.lastname: Gu
authors.forename: Da-Wei
authors.initials: DW
authors.lastname: Huang
mesh_terms: D000818:Animals; D002681:China; D002940:Circadian Rhythm; D056931:Cryptochromes / Q000235:genetics* / Q000378:metabolism*; D019143:Evolution, Molecular; D005260:Female; D030681:Ficus; D005786:Gene Expression Regulation; D006927:Hymenoptera / Q000235:genetics* / Q000378:metabolism*; D008297:Male; D008969:Molecular Sequence Data; D010802:Phylogeny; D054817:Pollination; D016133:Polymerase Chain Reaction; D017422:Sequence Analysis, DNA
chemical_list: D056931:Cryptochromes