Latitude dependent lability of phase response curve for oviposition rhythm of Drosophila ananassae

Abstract

Parameters of light pulse induced phase response curves (PRCs) for the circadian rhythm of oviposition in three latitudinal strains of Drosophila ananassae originating from 0°N on the equator at Pontianak (the PK strain), 11.94°N at Kannur (the KR strain) and 22.29°N at Dwaraka (the DA strain) were variable and latitude dependent. The PRC for the PK strain had a low amplitude, dead zone of 8 h and the ratio for the advance to delay region (A/D) < 1, but the PRC for the DA strain had a high amplitude, absence of dead zone and ratio of A/D > 1, while the PRC for the KR strain had intermediate values for these parameters. Thus, the lower latitude was correlated with low amplitude and protracted dead zone in the PRC for oviposition rhythm of D. ananassae.

Keywords:

• Circadian
• Drosophila
• phase shifts
• latitude
• oviposition

Acknowledgements

This study was supported by the Research Grant No. SP/SO/AS-43/2004 from the Department of Science and Technology, New Delhi to DSJ.