for^s/for^s third instar larvae display a significantly shorter travel path during feeding and increased food intake compared to for^R/for^R larvae.

for^R homozygous larvae show significant increase in travel path length during feeding and food search compared to for^s homozygotes, while the path length of for^R/for^s transheterozygotes is not significantly different from for^R homozygotes. However, the food intake of for^R larvae is significantly lower than that of both for^s and for^R/for^s mutants. for⁰/for^R transheterozygotes display longer travel path and reduced food intake compared to for⁰/for^s.

for^R/for^s have a similar foraging success to flies homozygous for for^R which is significantly higher than for^s homozygotes.

Expressing for^{dsRNA.UAS.pr4} under the control of Scer\GAL4^da.PU in a for^s homozygous background results in increased foraging success, but no difference in total distance travelled when compared to for^s homozygous controls.

Expressing for^{dsRNA.UAS.pr4} under the control of Scer\GAL4^da.PU in a for^R/for^s background has no effect on foraging success or distance travelled when compared to for^R/for^s controls.

The 'food leaving' behaviour score for for^s flies is low for flies raised in food-deprived conditions and high for flies raised in well-fed conditions. However, the increase in the score from FD to FED is greater for for^R than for^s or for^s2 flies.

In well-fed conditions, adult for^R flies have almost twice as much energy stored in whole-body lipid and about half the energy stored in carbohydrates compared to adult for^s or for^s2 flies.

for^s and for^s2 flies exhibit less food-related plasticity than for^R flies for a large majority of behavioural, metabolic and gene expression traits.

Homozygous for^s and trans-heterozygous for^R/for^s mutants show impaired visual pattern memory.

Similarly to wild-type flies, homozygous for^s flies are able to recognise different patterns. The thermotolerance of homozygous for^s mutants is similar to that of wild-type flies.

for^s flies exhibit a reduced sucrose responsiveness.

Fifteen minutes after a single conditioning cycle or a spaced (five conditioning cycles separated by 20-minute intervals) protocol, for^R homozygous mutants show stronger avoidance of the odor previously associated with shock than for^s or for^s2 homozygous mutants .

24 hours after a spaced (five conditioning cycles separated by 20-minute intervals) protocol, the for^R homozygous mutants show weaker memory of the association between an odor and shock than for^s or for^s2 homozygous mutants.

24 hours after a massed (five conditioning cycles immediately after one another) protocol, there is no difference between for^R, for^s and for^s2 homozygous mutants.

In for^s homozygous mutants, expression of for^UAS.T2 under the control of either Scer\GAL4^30Y,

Scer\GAL4^c739 or Scer\GAL4^Tab2-201Y leads to higher fifteen-minute memory scores after a single conditioning cycle (similar to those observed in for^R homozygous mutants) and lower 24 hour memory scores after a spaced protocol (similar to or below those observed in for^R homozygous mutants) when compared to controls.

Learning performance of for^s2 homozygous mutants is indistinguishable from that of for^s homozygous mutants.

for^R adults are significantly more active compared to for^s adults in a locomotor activity assay.

A significant increase in capa-stimulated fluid transport is observed at 50 and 60 minutes in Malpighian tubules from for^s animals, compared to those from for^R animals. This difference is especially pronounced at 60 minutes. There is no difference in basal fluid transport rates between the two lines.

for^s flies show a more rapid response decrement of the long-latency giant fiber response induced by electrical stimulation than for^R flies. for^R/for^s flies show a rate of response decrement intermediate between that of for^s and that of for^R.

for^s and for^R/for^s flies show full recovery from decrement to five-failure criterion of the long-latency electrically induced giant fiber response after 5 seconds of rest.

for^s larvae do not show "scribbler" behaviour (significantly more turning behaviour than wild-type larvae) on non-nutritive agar.

In the giant neuron culture system spontaneous nerve firing occurred in 36% of neurons examined. Supernumerary aftershock nerve spikes are evident after cessation of current injections in 18% of neurons. In voltage clamp studies, for^s neurons show significantly lower levels of both peak and sustained outward currents compared with for^R. Half-activation voltages of the peak (but not sustained) K⁺ currents in for^s and for^s2 are shifted towards positive potentials compared with for^R. Slopes of voltage dependent activation are similar for the three alleles for both peak and sustained currents. Large amplitude (up to 5nA) spontaneous ejcs occur at high frequency, evoked ejcs that are time-locked to the stimulus show significantly greater amplitude. Motor terminal projections on the larval muscles show ectopic nerve entry points on the muscle surface. The number of ectopic nerve points in the muscles of for^s, for^s2 and for^lsR92 correlates with excitability levels of both central neurons and motor axons.

The initial response to 1% oxygen hypoxia, cessation of feeding and movement to the surface of the yeast, occurs similarly in for^R and for^s, though the for^s larvae move more slowly. However significantly fewer for^s than for^R (13% as opposed to 49%) go on the next phase of the behavioral response, migrating away from the yeast. While for^s embryos survive 12 hrs of hypoxia poorly, for^R embryos survive well. for^s larvae also recover less well from hypoxia than do for^R larvae. Hypoxia blocks BrdU incorporation in cultured CNS of for^R, but not for^s larvae. for^s embryos retain the ability to block S phase under hypoxia. for^s larvae have less frequent and shorter terminal ramifications in their tracheal system than wild type.

Overexpression of four copies of P{hs-dg2} in larvae changes foraging behaviour to the rover phenotype.

for^s/for^s; Csr³/+ larvae show "rover-like" foraging behaviour.

Homozygous for^s larvae have shorter crawling paths than homozygous for^R larvae, and are parisitised less often by A.tabida than homozygous for^R larvae. Homozygous third instar larvae have shorter crawling paths than homozygous second instar larvae.

Larvae have shorter locomotory trails than larvae for for^R.

Adults carrying the R allele walk farther from food source after feeding than do adults with the S strain. Unlike in larval tests, the rover behavior of adults is not dominant over the sitter behavior.

Larvae homozygous for the "sitter" alleles for^s or for^lsR92 move equally as well as larvae homozygous for the "rover" for^R allele on non-nutritive substrates. Larvae homozygous for the for^R allele take more strides, not longer ones, than larvae carrying for^s or for^lsR92 on foraging substrates.

sitter allele

G9a^DD1, for^s has abnormal starvation stress response | female phenotype

G9a^DD1, for^s has abnormal feeding behavior | female phenotype

for^s, lilli^189Y/lilli[+] has abnormal memory phenotype