Khare P V, Satralkar M K, Vanlalnghaka C, Keny V L, Kasture M S, Shivagaje A J, Barnabas R J, Joshi D S
Zoology Department, Ahmednagar College, Ahmednagar, M.S., India.
Chronobiol Int. 2005;22(1):45-57. doi: 10.1081/cbi-200030508.
The effect of altitude on four basic properties of the pacemaker controlling the circadian rhythm of oviposition in two strains of Drosophila ananassae was determined. The high altitude (HA) strain from Badrinath (5123 m above sea level) had a low amplitude peak in the forenoon while the low altitude (LA) strain from Firozpur (179 m a.s.l.) had a high amplitude peak after the lights-off of LD 12:12 cycles. Free running periods in continuous darkness were about 22.6 and 27.4 h in the HA and LA strains, respectively. The light pulse phase response curve (PRC) for the HA strain showed a low amplitude and a dead zone of 8h; the ratio for the advance to delay region (A/D) was less than 1, while the PRC for the LA strain had a high amplitude, which was devoid of a dead zone and showed a ratio of A/D > 1. The magnitude of the delay phase shifts at CT 18 evoked by light pulses of 1 h duration, but varying light intensity was significantly different in the HA and LA strain, which suggests that the photic sensitivity of the clock photoreceptors mediating the phase shifts had been affected by the altitude.
研究了海拔高度对两种拟果蝇品系中控制产卵昼夜节律的起搏器的四个基本特性的影响。来自巴特那（海拔5123米）的高海拔（HA）品系在上午有一个低振幅峰值，而来自菲罗兹布尔（海拔179米）的低海拔（LA）品系在LD 12:12周期熄灯后有一个高振幅峰值。在持续黑暗中，HA和LA品系的自由运行周期分别约为22.6小时和27.4小时。HA品系的光脉冲相位响应曲线（PRC）显示振幅较低且有8小时的死区；提前与延迟区域的比值（A/D）小于1，而LA品系的PRC振幅较高，没有死区且A/D比值>1。持续1小时但光强度不同的光脉冲在CT 18引起的延迟相移幅度在HA和LA品系中有显著差异，这表明介导相移的时钟光感受器的光敏感性受到了海拔高度的影响。
