Fly photoreceptors and temperature: Relative UV-sensitivity is increased by cooling

Intracellular responses from blowfly photoreceptor cells were recorded at various temperatures in order to study the behaviour of the transduction system, with particular reference to spectral sensitivity. with decreased temperature the V-log I functions showed a reduction in amplitude and the responses showed a slowed time course. For double peaked spectral sensitivity function the UV or 350 nm peak was much less dependent on temperature than the peak in the visible region. The higher UV-sensitivity is interpreted in terms of the sensitizing pigment theory to indicate changes in the effectiveness of energy transfer between the two chromophores.