Ir25a2 mutant flies do not show significant changes in the expected avoidance response to food laced with different acids (5% acetic acid, 5% glycolic acid, 10% citric acid, 20% lactic acid, 5% tartaric acid, 2% propionic acid, 2% butyric acid, or 10mM HCl), as compared to controls. GRNs enervating S6 and S10 sensilla do not show changes in the responses (frequency of spikes) to acetic acid (1%), glycolic acid (1%), tartaric acid (1%), citric acid (5%), propionic acid (1%), butyric acid (1%), HCl (10mM), and lactic acid (20%), as compared to controls.
Ir25a2/Ir25a2 adult females have significantly reduced preference for oviposition on acid-containing medium, compared to controls.
Ir25a2/Ir25a2 mutant females do not exhibit a significant reduction in feeding preference index for 1% yeast extract versus 5mM sucrose solution, as compared to wild type.
Ir25a2 homozygous mutant larvae do not have any alteration in amino acid preference, compared to controls.
In olfactory preference assays for polyamines, Ir25a2/Ir25a2 flies do not show any significant difference in their attraction to putrescine or cadaverine, as compared to wild type, and females do not show any significant difference in their aversion to oviposit on polyamine-rich substrate (plain, sugar-free 1% agarose supplemented with either putrescine or cadaverine) versus non-supplemented substrate, as compared to wild type.
Ir25a2 mutant larvae have significantly decreased bitter avoidance, compared to controls.
Ir25a2 homozygous adults are able to synchronize circadian locomotor activity to high amplitude (4[o]C) temperature cycles under constant light (LL) or constant dark (DD) conditions, similar to controls; at a range of smaller (2[o]C) temperature intervals, Ir25a2 adults fail to synchronize to temperature cycles under LL; they also have a significantly reduced phase-shift in circadian locomotor activity, compared to controls, when shallow (2[o]C) temperature cycles are advanced or delayed under LL or DD; they have similar circadian locomotor rhythms to controls under light-dark (LD) and when shifted to DD conditions with no circadian temperature cycle; sensory activity in the hind leg nerve in response to temperature changes is lost, compared to controls, with no alteration in motor activity or spontaneous leg movement.
Ir25a2/Ir25a1 adults have a reduced phase-shift in circadian locomotor activity, compared to controls, when light-dark entrained flies are moved to dark-dark with 7 h advanced 25[o] C:27 [o]C temperature cycles.
Ir25a2/Df(2L)Exel6010 adults have a significantly lower circadian clock entrainment index for locomotor activity rhythms following a 7 h delay under 25[o] C:27 [o]C temperature cycles in constant light conditions, compared to controls.
Mutant flies show normal responses to both low salt (50mM NaCl) and high salt (500mM NaCl) in a two-way choice test.
Homozygous Ir25a2 mutant animals are viable and fertile.
Ir25a2 mutant class 4 (ac4) coeloconic sensilla lack electrophysiological responsiveness to phenylethyl amine, while phenylacetaldehyde responses are unchanged.
Ir25a2 mutant class 3 (ac3) coeloconic sensilla exhibit normal electrophysiological responsiveness to propionic acid.
Electrophysiological responses to γ-hexalactone persist in Ir25a2 mutant class 3 (ac3) coeloconic sensilla.
Electrophysiological responses to 1,4-diaminobutane, but not to acetic acid, are abolished in Ir25a2 mutant class 2 (ac2) coeloconic sensilla.
Electrophysiological responses to ammonia are retained in Ir25a2 mutant class 1 (ac1) coeloconic sensilla.