Conditional adult-specific over-expression (using TubGAL80ts) of lark^{Scer\UAS.T:Ivir\HA1} driven by Scer\GAL4^P2.4.Pdf (one copy of the UAS and the GAL4) results in a significant lengthening of circadian period.

Many adults expressing lark^{Scer\UAS.T:Ivir\HA1} under the control of either Scer\GAL4^386Y or Scer\GAL4^Eh.2.4 have completely unexpanded wings and unhardened cuticle.

Most adults expressing lark^{Scer\UAS.T:Ivir\HA1} under the control of Scer\GAL4^Ccap.PP have completely unexpanded wings and unhardened cuticle.

Nearly all adults expressing lark^{Scer\UAS.T:Ivir\HA1} under the control of Scer\GAL4^dimm-929 show normal wing expansion and normal tanning of the cuticle.

Animals expressing lark^{Scer\UAS.T:Ivir\HA1} under the control of Scer\GAL4^Ccap.PP show rhythmic eclosion, but two aspects of the rhythm are different compared to control populations. First, significantly more adults eclose in the 2 to 4 hour interval before lights-on in a given light/dark cycle compared with control populations. This trend persists under constant darkness conditions. Second, the mutant flies show a less pronounced response to the lights-on signal at the beginning of the photoperiod than control populations.

The locomotor activity rhythms of animals expressing lark^{Scer\UAS.T:Ivir\HA1} under the control of Scer\GAL4^Ccap.PP are relatively normal; more than 80% of the mutant flies (similar to controls), but the robustness of rhythmicity of the mutant flies is slightly reduced compared with controls.

Animals expressing lark^{Scer\UAS.T:Ivir\HA1} under the control of Scer\GAL4^Eh.2.4 have a late eclosion phenotype showing daily peaks of eclosion under light/dark conditions that are delayed 6 to 8 hours relative to controls. This phenotype also occurs under constant darkness conditions, with the peak of eclosion occurring at least 4 hours after that of controls. The eclosion defect appears to be independent of the wing expansion and cuticle defects that are sometimes seen in these flies. Locomotor activity rhythms are normal in these animals.

Flies expressing lark^{Scer\UAS.T:Ivir\HA1} under the control of Scer\GAL4^P2.4.Pdf are mostly arrhythmic or weakly rhythmic for locomotor activity.

Flies expressing lark^{Scer\UAS.T:Ivir\HA1} under the control of Scer\GAL4^tim.PE are completely arrhythmic for locomotor activity. These flies show a modest rhythm of eclosion under 12 hours light: 12 hour dark conditions, but eclosion rapidly becomes completely aperiodic in constant darkness.

Animals expressing lark^{Scer\UAS.T:Ivir\HA1} under the control of Scer\GAL4^ple.PF develop normally, emerge in the expected numbers and are morphologically normal.

Animals expressing lark^{Scer\UAS.T:Ivir\HA1} under the control of Scer\GAL4^ninaE.PHS have normal eye morphology and respond to light in a manner similar to controls in a fast phototaxis assay.

The number and morphology of the EH neurons is normal in pharate adults expressing lark^{Scer\UAS.T:Ivir\HA1} under the control of Scer\GAL4^Eh.2.4. The number and morphology of the CCAP neurons is normal in pharate adults expressing lark^{Scer\UAS.T:Ivir\HA1} under the control of Scer\GAL4^Ccap.PP. The number and projection patterns of LN[[V]] neurons does not appear dramatically different from normal in animals expressing lark^{Scer\UAS.T:Ivir\HA1} under the control of Scer\GAL4^P2.4.Pdf.

Expression of lark^{Scer\UAS.T:Ivir\HA1} under the control of Scer\GAL4^Act5C.PHb results in lethality prior to pupation. Expression of lark^{Scer\UAS.T:Ivir\HA1} under the control of Scer\GAL4^elav-C155 results in lethality, the degree of which depends on the particular P{UAS-lark-3HA} insertion used. The flies that do eclose show a significant delay in cuticle hardening and pigmentation and do not show normal wing expansion.

Scer\GAL4^P2.4.Pdf, dco^L, lark^UAS.Tag:HA has abnormal locomotor rhythm phenotype

Scer\GAL4^P2.4.Pdf, dco^S, lark^UAS.Tag:HA has abnormal locomotor rhythm phenotype

Scer\GAL4^P2.4.Pdf, dco^ar, lark^UAS.Tag:HA has abnormal locomotor rhythm phenotype

Scer\GAL4^P2.4.Pdf, dco^j3B9, lark^UAS.Tag:HA has abnormal locomotor rhythm phenotype