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General Information
D. melanogaster
FlyBase ID
Feature type
Associated gene
Associated Insertion(s)
Carried in Construct
Also Known As
Allele class
    Nature of the Allele
    Allele class
    Mutations Mapped to the Genome
    Additional Notes
    point mutation
    Nucleotide change:


    Amino acid change:

    Y21term | Pdf-PA

    Reported amino acid change:



    Site of nucleotide substitution in mutant inferred by FlyBase based on reported amino acid change.

    Associated Sequence Data
    DNA sequence
    Protein sequence
    Progenitor genotype
    Nature of the lesion

    Amino acid replacement: Y21term.

    Expression Data
    Reporter Expression
    Additional Information
    Marker for
    Reflects expression of
    Reporter construct used in assay
    Human Disease Associations
    Disease Ontology (DO) Annotations
    Models Based on Experimental Evidence ( 0 )
    Modifiers Based on Experimental Evidence ( 0 )
    Comments on Models/Modifiers Based on Experimental Evidence ( 0 )
    Phenotypic Data
    Phenotypic Class
    Phenotype Manifest In
    Detailed Description

    Pdf01 mutant adults have advanced evening peak circadian locomotor activity under light-dark (LD) conditions, compared to controls.

    Pdf01 mutants show a relatively normal temperature preference during daytime, as compare to controls.

    Pdf01 mutant adults have significantly reduced strength of circadian locomotor rhythms under constant darkness, compared to heterozygous controls.

    Pdf[01] null mutants still display residual rhythmicity in emergence for the first two days after transfer to constant darkness, similar to controls; this is lost at later timepoints.

    Pdf01 homozygous mutant adults, reared under 12:12 light:dark zeitgeber cycle, present an advanced temperature preference rhythm phenotype and a significantly decreased night-time preferred temperature (zeitgeber times 16-24), but still display a similar day-time preferred temperature increase (between zeitgeber times 1-3 and 10-12) and a similar night-onset preferred temperature decrease (between zeitgeber times 10-12 and 13-15), as compared to controls.

    Pdf01 mutants exhibit light-dependent temperature preference similar to that of wild-type.

    In contrast to controls, which adjust their morning and evening activity peaks to align with seasonal dawn and dusk, Pdf01 mutant flies show defective morning behavior when exposed to either a winter light:dark cycle (10 hours day:14 hours night) or a summer cycle (14 hours day:10 hours night).

    Unlike wild-type, vast majority of Pdf01 mutant adults show a distinct ultradian rhythmicity in walking activity under constant dark conditions, with a mean ultradian period of about 50-60min. The period of this ultradian rhythmicity is highly temperature-dependent, with Q[10] coefficient of 2.68 for temperatures between 20-27.5oC.

    Mutant males show a dramatic reduction in the amount of (z)-7-Tricosene, (z)-5-Tricosene and (z)-7-Pentacosene at all circadian time points and a loss of the subjective day/night difference compared to wild type (measured on the sixth day of constant darkness).

    Pdf01 males mate more frequently than Canton-S males, regardless of the genotype of the females, but less often with Pdf01 females than with Canton-S females.

    Pdf01 mutants exhibit daytime temperature preference rhythms similar to those of wild-type flies during LD.

    Pdf01 flies under LD conditions show no increased morning activity before lights-on, with evening anticipatory activity becoming advanced and reduced in amplitude. Furthermore, they show decreased rhythmicity and a shortened circadian period under DD.

    Pdf01 mutants exhibit wild-type triglyceride levels.

    Mutant flies lack the normal morning peak of circadian locomotor activity under 12 hour light:12 hour dark conditions.

    Pdf01 mutant adult flies do not display any morning and evening anticipation behavior (and a corresponding peak in locomotor activity) when kept in constant darkness.

    Approximately 67% of mutant flies show arrhythmic or weakly rhythmic locomotor activity under constant darkness conditions.

    Pdf01 flies exhibit severe deficits in free-running locomotor rhythms, with ~50% arrythmicity in flies in constant darkness.

    Under light:dark (LD) conditions, mutant flies show increases in sleep during the late night. At the time when wild-type flies are waking up in advance of lights-on, the mutant flies fail to wake up.

    During the first day of constant darkness (DD) conditions, mutant flies show a significant increase in total sleep during the subjective day compared to control flies.

    Pdf01 mutants display reduced morning anticipation and an advanced evening peak under light/dark cycles, and high levels of arhythmicity and a shortened free-running period under constant darkness.

    Compared to controls, Pdf01 mutant flies show significantly more daytime sleep in light/dark or dark/dark conditions. The increase in daytime sleep is primarily due to a decrease in wake duration/consolidation during the day. Sleep latency is decreased in the light period of light/dark experiments, and in the subjective night period of dark/dark experiments compared to controls.

    Pdf01 mutants under 12h:12h light:dark cycles show a significantly advanced evening activity peak, which becomes more pronounced if in combination with synchronous 25[o] C:20 [o]C (or 20[o] C:10 [o]C) temperature cycles, as compared to controls; when the temperature cycle is advanced by 6h, the evening activity peak occurs even earlier and the activity gradually decreases toward lights-off.

    Under constant light conditions, about 55% of Pdf01 mutants display locomotor activity rhythms. Under the same conditions, only 10% of the wild-type controls show activity rhythms.

    Under constant darkness, 50% of Pdf01 mutants display rhythms of locomotor activity with a period of about 22.5h.

    Pdf01 mutant larvae show no significant differences from wild-type larvae in larval light avoidance assays. Pdf01 mutants, like wild-type larvae, display circadian modulation of photophobic behaviour.

    Pdf01 flies display an absence of lights-on anticipation and a phase advancement in the evening peak (lights-off anticipation).

    Approximately 44% of homozygous Pdf01 mutants display rhythmic locomotion.

    Approximately 83% of heterozygous Pdf01 mutants display rhythmic locomotion.

    Pdf01 homozygous flies display a strong negative geotaxis phenotype.

    Mutant flies are arrhythmic for locomotor activity under constant light conditions at a constant temperature of 25[o]C, but become rhythmic after being exposed to a temperature cycle of 12 hours at 25[o]C and 12 hours at 30[o]C. The flies show two clear peaks at temperature transitions and an anticipatory activity before the temperature step-down. However, the anticipatory activity is not so sharp but rather dispersed in comparison with that of the wild-type flies. Some transient cycles are observed until establishment of a stable phase-angle relationship with the temperature cycle.

    Pdf01 flies kept in constant darkness show weak short-period rhythmicity.

    Loss of locomotor behavior is observed in 70% of Pdf01 flies and manifests gradually with residual rhythms being present for 2-3 days after release into constant dark conditions. In the brains of these flies, the phasing of ventral LN neurons disperses over time and the dorsal LN neurons phase advance when kept in constant darkness compared to control flies.

    Homozygous or hemizygous mutant animals exhibit a normal response to cocaine exposure.

    Pdf01 homozygous adults gradually lose circadian locomotor activity rhythms when kept in constant darkness. However, a significant fraction of are still weakly rhythmic after 4 days in constant darkness, but most of these accumulate an approximately 4-hour phase advance by this time relative to wild-type flies kept under the same conditions.

    Varying the dosage of Pdf significantly affects geotaxic behaviour. Order of geotaxis scores (genetic background for all Pdf alleles = Canton-S): Hi5 strain > Pdf01/Pdf01 (males > females) > Pdf01/Pdf01; Pdf+t3.530 (males > females) > Pdf01/Pdf01; Pdf+t3.530/Pdf+t3.530 (males > females) > Pdf01/+ = Canton-S > Pdf+t3.530 => Pdf+t3.530/Pdf+t3.530 >> Lo strain.

    Pdf01 flies display only two peaks of locomotor activity under cycling conditions. The morning peak lacks anticipation and is very narrow; the evening peak shows anticipation is sustained and is phase-advanced relative that of wild-type. Pdf01 flies remain rhythmic under constant conditions (DD) for days 1-2, but only 16% remain rhythmic over DD days 3-9.

    The number and morphology of LNv neurons, and tritocerebral and abdominal neurons that normally express Pdf is normal in hemizygous Pdf01/Df(3R)Tl-X flies. The locomotor activity of hemizygous Pdf01 flies is not entirely normal. The flies are well entrained during 12 hour light:12 hour dark (LD) cycles, but the evening activity peak is advanced by approximately 1 hour compared to wild-type flies and there is a lack of lights-on anticipation. Free-running locomotor activity in constant darkness is severely abnormal. Homozygous and hemizygous flies are much less rhythmic than wild-type controls. 50-98% of mutant flies show no detectable rhythmicity for the duration of 9 days in constant darkness. Most flies are rhythmic for 2 or 3 days in constant darkness but later lose rhythmicity. Homozygous and hemizygous flies that do maintain rhythmicity have free-running periods approximately 1 hour shorter than wild-type or heterozygous flies.

    External Data
    Show genetic interaction network for Enhancers & Suppressors
    Phenotypic Class
    Enhanced by
    NOT Enhanced by

    Pdf01 has locomotor rhythm defective phenotype, non-enhanceable by cryb

    Suppressed by
    NOT suppressed by

    Pdf01 has locomotor rhythm defective phenotype, non-suppressible by gl60j

    NOT Enhancer of
    Suppressor of

    Pdf01 is a suppressor of sleep defective phenotype of wakeD2

    NOT Suppressor of
    Phenotype Manifest In
    Additional Comments
    Genetic Interactions

    Dh3151, Pdf01 double mutants show a relatively high and constant temperature preference (~26[o]C) during daytime in 12h:12h light:dark cycles, and show a relatively low and constant temperature (~24[o]C) under constant darkness conditions, as compared o controls.

    Dh3151; Pdf01 double mutants exhibit light-dependent temperature preference similar to that of wild-type.

    The increase in sleep latency seen in wakeD2 flies is blocked if they are also mutant for Pdf01.

    roboBG01092 Pdf01 double mutants exhibit a lengthening of the free-running period in a dose-dependent manner. Introducing a copy of roboBG01092 into Pdf01 mutants gives rise to >80% rhythmic individuals. The average activity plot of roboBG01092 Pdf01 flies shows a modest increase in the activity ~1hr before the lights-on transition, indicating that the morning anticipation is rescued even in the absence of Pdf neuropeptide.

    roboBG01092 Pdf01 double mutants show a significantly lengthened period of locomotor activity.

    Transheterozygous roboBG01092 Pdf01 flies display wild-type period and rhythmicity.

    Under constant light, cryb Pdf01 double mutants display locomotor rhythms that are similar to cryb mutants. Conversely, cryb Pdf01 double mutants display locomotor rhythms that are similar to Pdf01 single mutants under constant darkness.

    pdfrP2-36 in trans with Pdf01 displays severe negative geotaxis.

    gl60j, Pdf01 and WGMR.PG; Pdf01 flies show similar weak short-period rhythmicity phenotypes when kept in constant darkness to Pdf01 single mutant flies.

    Xenogenetic Interactions

    Expression of Zzzz\ΒPDH-IScer\UAS.cBa in the PDF circuit, under the control of Scer\GAL4P2.4.Pdf, suppresses the homozygous Pdf01 mutant circadian behavior phenotype. In contrast, expression of Zzzz\ΒPDH-IIScer\UAS.cBa in the PDF circuit under the control of Scer\GAL4P2.4.Pdf, in a homozygous Pdf01 mutant background, only modestly improves the rhythmicity, with the flies displaying a unconsolidated activity profile. In addition, these flies show a short circadian period, reminiscent of Pdf01 mutant flies.

    Expression of Zzzz\ΒPDH-IIScer\UAS.cBa in the PDF circuit under the control of Scer\GAL4P2.4.Pdf fails to suppress the modest morning peak and an evening peak of activity that's found in Pdf01 mutants.

    The defects in locomotor activity rhythms seen in D. melanogaster Pdf01 flies under constant darkness conditions are completely rescued if the flies are also carrying Dvir\Pdf+t3.5.

    Complementation and Rescue Data
    Partially rescued by

    Pdf+t3.530 partially rescues the sex pheromone expression profile of Pdf01 males: (z)-5-Tricosene and (z)-7-Pentacosene are rescued to near wild-type levels, but (z)-7-Tricosene expression and the subjective day/night differences are not rescued (measured on the sixth day of constant darkness).

    Expression of PdfScer\UAS.cRa under the control of Scer\GAL4P2.4.Pdf rescues the Pdf01 circadian behavior phenotype.

    Pdf01 flies that also express PdfScer\UAS.ML.T:SS-trypsin.T:Hsap\MYC.T:GPI-lynx1 under the control of Scer\GAL4tim.Scer\UAS exhibit little arrhythmicity in constant darkness (unlike Pdf01 only flies), with only ~10% of flies arrhythmic and most exhibiting instead a complex free-running rhythm (which is still abnormal compared to wild type).

    Pdf+t3.530 or PdfScer\UAS.cRa expressed under the control of Scer\GAL4P2.4.Pdf partially rescues the locomotor activity defects of Pdf01 flies.

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    External Crossreferences and Linkouts ( 0 )
    Synonyms and Secondary IDs (4)
    References (59)