Mitochondria in muscle fibres 6/7 in abdominal segments of tam³/tam⁹ mutant third instar larvae exhibit decreased mtDNA content, increased mitochondrial density and mitochondria appear abnormally tightly packed instead of arranged in normal banded patterns, but there is no qualitative difference in mitochondrial morphology when examined via electron microscopy, as compared to controls. Third instar larvae display significantly higher mitochondrial density in the proximal region of the segmental nerve, but not in the medial or distal regions. Mitochondrial flux in tam³/tam⁹ third instar motor neurons is significantly increased in both directions, and there is no difference in retrograde velocity, but a significant decrease in anterograde velocity, as compared to controls.

There is no significant difference in synaptic vesicle precursor flux or velocity in tam³/+ third instar motor neurons, as compared to controls.

The reticular pattern of mitochondria surrounding the nuclei of larval brain cells is disrupted in tam⁹/Df(2L)b80c1 animals. The CNS of tam⁹/Df(2L)b80c1 larvae is smaller than that of wild-type controls. These larvae have a reduction in cell proliferation (measured by BrdU incorporation) in the CNS. Both the outer and inner proliferation centers in the optic lobes are equally affected.

Hemizygous lethality occurs during the late third larval instar stage. Homozygous larvae fail to wander out of the food at the appropriate time and have a prolonged foraging phase that can last up to 20 days, after which they die. tam³/tam⁹ larvae fail to wander at the appropriate time. Hemizygous larvae have reduced eye discs. The disc shows the usual pattern of clustering of the developing ommatidia although they are somewhat disorganised. The projection of the photoreceptor axons into the optic lobes is disrupted, probably due to the abnormal differentiation of the retinal cells. The larval optic nerve is present. tam⁹/tam³ larvae have smaller eye discs than normal and show delayed photoreceptor differentiation. The area of differentiated photoreceptors is abnormal and their projection pattern is abnormal. Homozygous larvae show no response to light in contrast to wild-type larvae, which is probably due to their reduced locomotion compared to wild type. Larvae transheterozygous for tam⁹ and either tam³ or tam² respond to light, suggesting partial complementation of this phenotype. tam³/tam⁹ larvae move significantly less than wild-type larvae.

PolG1⁹ is a suppressor of lethal - all die before end of pupal stage phenotype of PolG2¹

PolG1⁹ is a suppressor of lethal - all die before end of pupal stage phenotype of PolG2²