title: The evolution and expression of the moth visual opsin family.
abstract: Because visual genes likely evolved in response to their ambient photic environment, the dichotomy between closely related nocturnal moths and diurnal butterflies forms an ideal basis for investigating their evolution. To investigate whether the visual genes of moths are associated with nocturnal dim-light environments or not, we cloned long-wavelength (R), blue (B) and ultraviolet (UV) opsin genes from 12 species of wild-captured moths and examined their evolutionary functions. Strong purifying selection appeared to constrain the functions of the genes. Dark-treatment altered the levels of mRNA expression in Helicoverpa armigera such that R and UV opsins were up-regulated after dark-treatment, the latter faster than the former. In contrast, B opsins were not significantly up-regulated. Diel changes of opsin mRNA levels in both wild-captured and lab-reared individuals showed no significant fluctuation within the same group. However, the former group had significantly elevated levels of expression compared with the latter. Consequently, environmental conditions appeared to affect the patterns of expression. These findings and the proportional expression of opsins suggested that moths potentially possessed color vision and the visual system played a more important role in the ecology of moths than previously appreciated. This aspect did not differ much from that of diurnal butterflies.
authors.affiliation: State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, P.R. China.
authors.forename: Pengjun
authors.initials: P
authors.lastname: Xu
authors.forename: Bin
authors.initials: B
authors.lastname: Lu
authors.forename: Haijun
authors.initials: H
authors.lastname: Xiao
authors.forename: Xiaowei
authors.initials: X
authors.lastname: Fu
authors.forename: Robert W
authors.initials: RW
authors.lastname: Murphy
authors.forename: Kongming
authors.initials: K
authors.lastname: Wu
mesh_terms: D000818:Animals; D019143:Evolution, Molecular; D009036:Moths / Q000145:classification / Q000235:genetics*; D055355:Opsins / Q000145:classification / Q000235:genetics*; D010802:Phylogeny; D012333:RNA, Messenger / Q000235:genetics
chemical_list: D055355:Opsins; D012333:RNA, Messenger