Homozygous RetC168 mutant larvae exhibit class IV dendritic arborizing (C4da) neuron dendrite patterning defects, resulting in out of plane crossing of isoneuronal branches.
More severe dendritic patterning defects are seen in RetC168/Df(2L)BSC312 mutant larvae. The C4da neurons do not show a significant reduction in dendrite length, but display excessive crossings of isoneuronal dendrites outside of their normal 2D growth plane and reduced dendritic field coverage. Large stretches of dendrites, in particular terminal arbors, are detached from the ECM and enclosed by the epidermis. These dendrite defects are seen from 48hr after egg laying. The C4da neurons also display disrupted dendritic dynamics compared to wild type, and aberrant F-actin localisation, with dendrites displaying increased proximal, but reduced distal, F-actin levels. Abnormal accumulation of F-Actin is seen in aberrant crossing RetC168/Df(2L)BSC312 mutant dendrites and many terminal dendrites exhibit lower levels of F-actin than controls.
RetC168/Df(2L)BSC312 has abnormal neuroanatomy phenotype, suppressible | partially by mewUAS.cMBa/mysUAS.cDa/Scer\GAL4ppk.PH
RetC168/Ret[+], mewM6 has abnormal neuroanatomy phenotype
RetC168/Ret[+], mys1 has abnormal neuroanatomy phenotype
RetC168/Df(2L)BSC312 has larval multidendritic class IV neuron phenotype, suppressible | partially by mewUAS.cMBa/mysUAS.cDa/Scer\GAL4ppk.PH
RetC168/Ret[+], mewM6 has larval multidendritic class IV neuron phenotype
RetC168/Ret[+], mys1 has larval multidendritic class IV neuron phenotype
RetC168 mewM6 transheterozygous third instar larvae exhibit defects in class IV dendritic arborizing neuron dendrite crossing and a substantial loss of dendrite-ECM interaction. No phenotypes are observed in either heterozygote alone.
RetC168 mys1 transheterozygous third instar larvae exhibit defects in class IV dendritic arborizing neuron dendrite crossing and a substantial loss of dendrite-ECM interaction. No phenotypes are observed in either heterozygote alone.
Co-expression of mysScer\UAS.cDa and mewScer\UAS.cMBa in class IV dendritic arborizing neurons under the control of Scer\GAL4ppk.PH partially suppresses the dendrite growth seen in RetC168/Df(2L)BSC312 mutant larvae and completely suppresses the loss of dendrite-ECM interaction. The reduction in dendritic field coverage is not suppressed.
RetC168 Rac1J11 transheterozygous third instar larvae exhibit defects in class IV dendritic arborizing neuron dendrite-ECM interaction. The phenotype is not observed in either heterozygote alone.
RetC168/Df(2L)BSC312 is rescued by RetUAS.mCherry/Scer\GAL4ppk.PH
Expression of RetScer\UAS.T:Disc\RFP-mCherry in class IV dendritic arborizing neurons under the control of Scer\GAL4ppk.PH rescues the dendrite growth and crossing phenotypes seen in RetC168/Df(2L)BSC312 mutant larvae.