More severe than elav²⁰. Flying/jumping ability and coordination are temperature-sensitive. ERG and optomotor responses are defective at 22^oC and 29^oC. Photoreceptor and optic lobe morphology are abnormal in flies raised at 29^oC.

Affect retinula cell physiology. At 20^oC electroretinograms (ERG) have a normal light coincident receptor potential (LCRP) but lack the on/ off transients. At 29^oC the amplitude and rates of depolarization and repolarization of the light coincident receptor potential (LCRP) are noticeably reduced.

Abnormalities of visual system rearing at 29^oC or high-temperature pulses delivered to pupae, raised otherwise at 20^oC, causes vacuolization of photoreceptors and disorganization of rhabdomeres; high-temperature rearing or pupal pulsing induces severe optic lobe defects (absence of size reduction); electroretinograms of this mutant, raised at high-temperature, are missing light-on and light-off transient spikes (also seen after low-temperature rearing) and have reduction of ERG photoreceptor potential; amplitude of this potential also deteriorates as does deep pseudopupil when adults treated at high-temperature after low-temperature rearing.

Temperature-sensitive period for aberrant wing posture in elav¹⁹ extends from larval to pupal period.

temperature-sensitive