painEP2251 mutant adults have no difference in spiking of mechanosensory neurons of the labellar taste bristles or labellar taste pegs in response to mechanical stimuli, compared to controls.
painEP2251 mutant adults do not show any defects in sensing food hardness and like the wild-type flies prefer softer food with lower sugar content (0.5mM sucrose, 0.2% agarose) to a hard food with higher sugar content (1mM sucrose, 2% agarose) in a binary choice assay.
The number of times painEP2251 females reject males is significantly lower than that of wild-type females.
painEP2251 homozygous and heterozygous adults are defective in courtship long term memory (reduction in courtship activity 5 days after 7-hours conditioning) when compared to controls. painEP2251 homozygous adults exhibit normal courtship short term memory (reduction in courtship activity 30 minutes after 1-hour conditioning) when compared to controls.
Mutant third instar larvae show significant defects in nociception, having a significant reduction in the response frequency to noxious mechanical stimuli compared to control larvae. However, the navigational behaviours of the mutant larvae in response to gentle touch are not significantly different from wild type.
painEP2251 mutant larvae show a significant delay in response to noxious heat compared to control flies. These flies also exhibit a delay in their jump response to noxious heat of 11 seconds.
Mutant larvae do not show the cardiac pauses during motion which are seen in wild-type larvae.
Basal cardiac activity (measured in anaesthetised animals) is increased in mutant larvae compared to wild-type controls.
The action potential recordings from semi-dissected heart tubes of mutant larvae are abnormal, showing a slightly more positive maximum diastolic potential and reduced amplitude of depolarisation than recordings from wild type.
Semi-dissected heart tubes in which local pressure is applied to segment A6 do not show cardiac arrest after the pressure is applied, in contrast to wild-type heart tubes, which under these conditions undergo cardiac arrest of an average duration of 25.8 +/- 1.6 seconds.
The cardiac rhythm of mutant semi-dissected heart tubes is not modified by hypo-osmotic shock (in contrast to wild-type larvae).
The mating success rate, defined as the percentage of pairs that copulate, is significantly higher in painEP2251 homozygous females than wild-type. The time to copulation of painEP2251 mutant females is significantly shorter than that of controls. No significant difference is detected in the courtship latency or courtship index (defined as the percentage of time spent courting in a given observation period). These results show that painEP2251 mutant females do not elicit increased courtship behavior than control females, and that the rapid copulation of virgin painEP2251 mutant females is because of their enhanced receptivity.
No significant difference is observed in locomotion of painEP2251 mutant females compared to controls.
Larvae show normal thermotactic behaviour in a thermal preference assay.