pathdg50/pathdg50 mutants do not show significant defects in larval growth. pathdg50/Df(3L)BSC773 larvae show defects in C4da dendrite growth, with pathdg50/Df(3L)BSC773 mutants showing significant reductions in dendrite length compared to wild type. C4da dendrite growth is more severely affected in PNS neurons located in more posterior abdominal segments (A2 vs A5 vs A8), with significantly shorter dendrites and fewer branches in pathdg50/Df(3L)BSC773 larvae compared to wild type. Axonal arbors show progressive growth defects that are more severe in posterior segments (similar to controls prior to 48hr AEL, and by 120hr AEL C4da neurons in posterior segments show severe axon growth defects), compared to wild type. pathGFP/pathdg50 or pathGFP/pathΔ larvae show normal dendrite growth in C4da neurons.
pathdg50 larvae show severe dendrite growth defects in the large C4da and medium C3da dendritic arbors but no obvious effect on the smaller C1da arbor (or chordotonal or bipolar dendrite neurons) or whole animal growth. Early growth and patterning of C4da neurons proceed normally, but, beginning in late first larval instar larvae, two growth defects are manifest. First, C4da dendrite length plateaus at ~3.5 mm, which the mutants reach by ~36-40 h after egg laying, whereas control C4da dendrites continue growing throughout larval development, reaching ~20 mm. Second, C4da dendrite arbors are remodeled after reaching their maximum length in the mutants: terminal dendrites are progressively lost, whereas primary dendrites continue to grow, maintaining a constant value of total dendrite length.
pathKG06640/pathdg50 or pathdg50/Df(3L)BSC773 larvae show severe dendrite growth defects in the large C4da dendritic arbors.
C4da dendrites in larvae generated from pathdg50 germline clones arrested at the same value of dendrite growth as zygotic pathdg50 mutants.
pathdg50 C4da MARCM clones exhibit dendrite growth defects.
Cell size in the epidermis, oenocytes, fat body or salivary glands of pathdg50/Df(3L)BSC773 larvae is not reduced - only the size of neurons with extreme growth requirements (C4da/C3da neurons) appear to be affected.