VL3 muscles in klar1 homozygous larvae exhibit nuclear positioning defects: present significantly shorter internuclear distances and longer nucleus-muscle edge distance, and significantly shorter distance between nuclear lines, as compared to controls; heterozygotes also show a significantly shorter internuclear distance, as compared to controls. Homozygous embryonic LT muscles exhibit nucleus clustering near the ventral end of the muscle or unequally distributed along the muscle, but no changes in nucleus:muscle area ratio, as compared to controls.
At 25[o]C the fraction and net velocity vector of motile osk ribonucleoproteins (RNPs) in klarYG3/klar1 oocytes is not significantly different from wild type. However the mean speed is slightly, but significantly reduced and RNP travel distance is significantly increased. At 18[o]C, the fraction of motile osk RNPs in the mutant oocytes is double that seen in control oocytes in a given imaging period. The RNP travel distance is significantly increased compared to wild type at this temperature.
klar1 embryos show aberrant lipid droplet transport.
Embryos laid by homozygous females are unusually transparent from gastrulation onward. The lipid droplets of these embryos are concentrated in the yolk sac, rather than distributed throughout the cellular layer as in wild-type. This is because basally accumulated droplets only spread apically to a minor degree during gastrulation. These embryos show no defects in cellularisation or gastrulation, and the distribution of nuclei, yolk vesicles and mitochondria is normal. Photoreceptor nuclei are mispositioned along the apical-basal axis in third larval instar eye discs, with most nuclei being found near the basal surface of the disc. Some nuclei migrate into axons in the optic stalk. The rhabdomeres of many photoreceptor cells are misshapen or missing in homozygous adult eyes.
maternal-effect No effect on viability or fertility of homozygotes. Homozygous females produce eggs with clear distinction between yolk and germ layers. Facilitates in vivo observation of developmental processes.