Effects of altitude on circadian rhythm of adult locomotor activity in Himalayan strains of Drosophila helvetica

Abstract

BackgroundWe recently reported that the altitude of origin altered the photic and thermal sensitivity of the circadian pacemaker controlling eclosion and oviposition rhythms of high altitude Himalayan strains of Drosophila ananassae. The present study was aimed at investigating the effects of altitude of origin on the pacemaker controlling the adult locomotor activity rhythm of D. helvetica.MethodsLocomotor activity rhythms of the high altitude Himalayan (haH) strain (Hemkund-Sahib, 4,121 m above sea level) and the low altitude Himalayan (laH) strain (Birahi, 1,132 m a.s.l.) of D. helvetica were assayed by two experiments. The first experiment examined the natural entrainment pattern in light-dark (LD) cycles at the breeding site of each strain. The second experiment examined the entrainment parameters in LD 12:12 cycles and the period of free-running rhythm in constant darkness (DD) under controlled laboratory conditions.ResultsWhen entrained by natural or artificial LD cycles, the haH strain had an unimodal activity pattern with a single peak that commenced in the forenoon and continued till evening, while the laH strain had a bimodal activity pattern in which the morning peak occurred before lights-on and was separated by about 4 h from the evening peak. Unimodality of the haH strain was retained in DD; however, bimodality of the laH strain was abolished in DD since the evening peak disappeared immediately after the trasfer from LD 12:12 to DD. The period of the free-running rhythm of the haH strain was ~26.1 h, whereas that of the laH strain was ~21.7 h.ConclusionParameters of entrainment and free-running rhythm of the adult locomotor activity of the haH strain of D. helvetica were strikingly different from those of the laH strain and were likely due to ecological adaptations to the prevailing environmental conditions at the altitude where the species evolved.

Circadian Rhythms Differ between Sexes and Closely Related Species of Nasonia Wasps

“…Circadian rhythms dynamics are readily affected by adaptation to local climatic conditions, such as latitude, altitude or humidity [10], [42], [43] and may explain differences in τ and CoG observed among Nasonia species, as discussed above, but also among strains. A trait related to circadian rhythms in Nasonia is photoperiodism, apparent in the form of diapause induction in short days [15], [44], [45].…”

Flies as models for circadian clock adaptation to environmental challenges

“…Within the main Drosophila groups, clade II is again the sister group of the remaining six clades. Clade II coincides with the subgenus Sophophora and contains the “model” species D. melanogaster and other species that have been investigated from the chronobiological point of view such as D. suzukii , D. yakuba , D. simulans , D. pseudoobscura , D. helvetica , D.ananassae , D. willistoni , D. auraria, and D. triauraria (Gleason & Powell, ; Hamby, Kwok, Zalom, & Chiu, ; Hermann et al., ; Joshi, ; Low, Lim, Ko, & Edery, ;Nishinokubi et al., ; Nishinokubi, Shimoda, & Ishida, ; Ousley et al., ; Pittendrigh, ; Pittendrigh & Takamura, ; Prabhakaran, De, & Sheeba, ; Prabhakaran & Sheeba, , , ; Vanlalhriatpuia et al., ; Wheeler et al., ; Yamada & Yamamoto, ). Important for the present review is that the subgenus Sophophora has separated from the remaining groups (clades III–VIII), among which is the Drosophila subgenus (clade VI), about 30 million years ago.…”

Adaptive significance of circadian rhythms ofmontiuma subgroup ofDrosophila: I – locomotor behaviour

“…There are reports that there is persistence of circadian rhythm in eclosion in the fruit fly D. melanogaster, which was maintained in constant light for more than 600 generations (Sheeba et al 1999). The results showed that there is difference in the activity pattern at different light regimes; similarly, other reports showed that high altitude Himalayan strain had unimodal activity pattern with a single delayed peak that commenced in the forenoon and continued till evening while the low altitude Himalayan strain had bimodal activity pattern with early morning peak that was separated by the evening peak by a period of inactivity of 4 h (Vanlalhriatpuia et al 2007). D. melanogaster showed bimodal activity both in DD 15 and DD 30 and also reduction in the amount of activity and fitness compared to laboratory population (Shereen et al Forthcoming 2011).…”

“…times selected for activity in an open field (Joshi and Vanlalnghaka 2005;Palaksha et al 2011) differed in baseline activity but the changes in activity over time following introduction to a novel environment. Further, locomotor behaviour in Drosophila melanogaster (Wheeler et al 1993) and its mutants (Konopka and Benzer 1971), Drosophila ananassae (Joshi 1999), three sympatric Drosophila parasitoids (Fleury et al 2000), altitudinal variation in locomotor behaviour of D. ananassae (Vanlalhriatpuia et al 2007), Drosophila bipectinata and Drosophila malerkotliana ) was well studied. Locomotor activity variation was also observed in 11 species of Drosophila originating across the United States (Simunovic and Jaenike 2006).…”