show defects in the orientation of the mitotic spindle in dividing pI sensory precursor cells.
pupae, the mitotic spindles of dividing sensory organ precursor cells in the developing notum are not aligned with the anterior-posterior axis, but instead are randomly oriented.
mutant pupae, unlike wild-type, the pI cells exhibit almost no centrosome rotation before spindle formation. Complete rotation values for the spindle are similar to wild-type, however in 7% of mutant pI cells, the spindle rotates in one direction before rotating in the opposite direction, bidirectional movements are not seen in wild-type. The spindle does not line up properly with the pon
crescent, leading to defective partitioning of pon
. 5% of fz37
flies have at least one bristle with two shafts and two sockets on the notum.
Only 47.1 +/- 8.9 % of ommatidia in fz37
flies have the correct chiral shape.
The orientation of projections of R1-R6 axons onto the lamina is normal for those ommatidia that are correctly orientated, and rotated for those ommatidia that are rotated.
Dendritic development in homozygous mutants is indistinguishable from wild-type.
Mosaic ommatidia at the boundaries of homozygous clones can show incorrect chirality. In incorrect chiral ommatidia where the mosaic boundary separates the R3/R4 pair, the R4 cell is invariably mutant and the R3 cell is wild type. In these cases the presumptive R3 cell has developed as an R4 cell. The R3/R4 pair can also either both be mutant or both be wild-type in mosaic ommatidia with incorrect chirality. Chirally incorrect ommatidia that have wild-type R3 and R4 cells can occur at any position along the border of the clone, but are predominantly found at the polar side of the clone. Mosaic ommatidia at the boundaries of homozygous clones can show correct chirality. In those ommatidia with mosaicism between R3/R4, the R3 cell is almost always wild type and the R4 cell is almost always mutant. Mosaic ommatidia at the boundaries of homozygous clones are occasionally symmetrical, and in these cases both members of the R3/R4 pair are generally mutant. Expression of fzhs.sev
in a fz37
background in either the presumptive R3 or R4 cell in mosaic ommatidia causes the cell expressing fzhs.sev
to become an R3 cell and the other to become an R4 cell.
transheterozygotes the socket, shaft and pIIb cells are always localised in the region of the cell in contact with pIIb. The socket cells always occupies an eccentric position.
Rough eye phenotype, facets have lost their normal hexagonal shape and exhibit disarranged bristles. The ommatidial polarity is disrupted due to randomised direction of ommatidial rotation, insufficient degree of rotation and incorrect asymmetry established between R3 and R4 cells.