FlyBase Allele Report: Dmel\ptc[559.1]

ptc^559.1/Df(2R)Np3 transheterozygotes show lowly penetrant headcase defects, the affected individuals however show no loss of brain tissue, though the brain is located more to the interior.

ptc^559.1/Df(2R)Np3 adults show progressively more severe locomotor defects with age and even lethality (in 15 and 30-day-old flies). The brains of individuals with severe locomotor defects contain lipid droplets slightly more frequently than wild-type and although the brain tissue does not show any lesions it is more fragile overall than controls.

Brains from ptc^559.1/Df(2R)Np3 2-3 weeks old adults with severe locomotor defects show presence of lamellar inclusions and/or membranous material in neurons that are not present in either wild-type, young mutants or older mutant flies that do not display locomotor defects.

Cholesterol-rich diet ameliorates the locomotor defects observed in ptc^559.1/Df(2R)Np3 in 5,9 and 14 days old adults.

ptc^559.1/Df(2R)Np3 transheterozygotes show reduction in the density of synaptic terminals in the brain calyx of newly eclosed, 8 as well as 16-day-old flies compared to their wild-type counterparts.

Three weeks old ptc^559.1/Df(2R)Np3 transheterozygotes displaying severe locomotor defects show overall decrease in the number of synaptic connections in the adult brain compared to wild-type controls, but this number is (similarly to wild-type) higher in individuals fed a cholesterol-rich diet.

ptc^559.1/ptc^S2 (as well as ptc^hdl/ptc^S2) transheterozygous adults do not display any locomotor defects.

(Gazi et al., 2009)

Most ptc alleles in trans to ptc^559.1 do not cause head defects (ptc¹⁴ and ptc^G12) or have relatively mild head defects. The most severe (ptc³⁷ and ptc¹⁷) have mildly reduced eyes, slightly enlarged head vertex (ocellar triangle, fronto-orbital plate and frons) and low incidences of head cuticle outgrowths and ectopic or misplaced head bristles. The next most severely affected (ptc⁴⁷, ptc¹⁶) are as above, apart from having a normal sized head vertex. Finally the most mildly affected have wild-type heads, apart from occasional missing or misplaced head bristles (ptc^H84, ptc^tuf-1, ptc³⁴, ptc¹⁵ and ptc^S2). ptc¹³ falls into this category, but also has enlarged ocelli (not seen with other alleles). ptc⁹ also falls into this category, but along with ptc⁴⁷ and ptc¹⁷ occasionally lacks one or both antennae.

(Thomas and Ingham, 2003)

No homozygotes show head capsule defects. 3% of ptc^hdl/ptc^559.1 transheterozygotes show head capsule defects. 4% of ptc^H84/ptc^559.1 transheterozygotes show head capsule defects. 67% of Df(2R)Np3/ptc^559.1 transheterozygotes show head capsule defects.

(Shyamala and Bhat, 2002)

External Data

Linkouts

Interactions

Show genetic interaction network for Enhancers & Suppressors

Phenotypic Class

Suppressed by

Statement

Reference

Df(2R)Np3/ptc^559.1 has partially lethal - majority live | progressive phenotype, suppressible | partially by smo¹/smo[+]

(Gazi et al., 2009)

Df(2R)Np3/ptc^559.1 has abnormal locomotor behavior | adult stage | progressive phenotype, suppressible | partially by smo¹/smo[+]

(Gazi et al., 2009)

Phenotype Manifest In

Enhanced by

Statement

Reference

ptc^559.1/ptc^H84 has adult head capsule phenotype, enhanceable by smo¹

(Shyamala and Bhat, 2002)

Suppressed by

Statement

Reference

Df(2R)Np3/ptc^559.1 has synapse | adult stage phenotype, suppressible | partially by smo¹/smo[+]

(Gazi et al., 2009)

Df(2R)Np3/ptc^559.1 has adult head capsule phenotype, suppressible by Scer\GAL4^ptc-559.1/babo^Q302D.UAS

(Shyamala and Bhat, 2002)

Additional Comments

Genetic Interactions

Statement

Reference

The locomotor defects and increased lethality as well as the decrease in density of synaptic terminals in adult brain calyx characteristic for aged ptc^559.1/Df(2R)Np3 mutants can be partially suppressed by combination with smo¹ in heterozygous state.

(Gazi et al., 2009)

The addition of smo¹ to ptc^H84/ptc^559.1 animals produces an enhancement of the head capsule defect phenotype. 35% of animals exhibit the phenotype, compared to 4%. The addition of babo^{Q302D.Scer\UAS} (driven by Scer\GAL4^ptc-559.1) suppresses the head phenotype seen in ptc^559.1, Df(2R)Np3. None of these animals exhibit head capsule defects.