Entrainment of circadian locomotor activity rhythm in the onion fly, Delia antiqua

摘要

In the onion fly, Delia antiqua, the phase of locomotor activity in LD cycle occurred progressively lat er with age and the τ in DD also changed with age, suggesting that the age dependent　Ψ　RL　change in D. antiqua would be attributed to the increase in τ.When D.antiqua drank D2O in LD cycles, the phase of locomotor activity delayed toward the late photophase in a dose-dependent manner. The τ with D2O increased in a dose-dependent manner in DD, Suggesting that the phase delay of locomotor activity in LD cycles was caused by the increase in τ. The phase of locomotor activity of D.antiqua, in cycles of L(400lux) Ldim (1.0lux) delayed as compared with that in LD cycles. The τ in constant dim light(LdimLdim) was longer than that in DD, suggesting that the phase delay of locomotor activity in LLdim cycle was caused by increase in τ.The phase of locomotor activity of D.antiqua in LD12:12 advanced at a low temperature(20℃) as compared with that at a high temperature(25℃). The τ in DD at 20℃ became short er than that at 25℃, suggesting again that the phase advance of locomotor activity in LD cycles at 20℃ was caused by decrease in τ.A 1 h light pulse falling in early night in LD ll:13 at 20℃ caused a phase delay of locomotor activity of D.antiqua and the pulse falling in late night a phase advance.The percentage of pupal diapause was decreased by these pulses in LD ll:13 at 20℃. However, further studies are necessary to determine whether the photoperiodictime measurement in this species is a function of the circadian system or not.