par-1W3 mutant clones are significantly smaller than the corresponding wild type controls.
Germline stem cells (GSCs) in newly eclosed par-1k06323/par-1W3 males show a high frequency of centrosome misorientation and frequently undergo mitosis with misoriented spindles (mitosis with misoriented spindles is not seen in wild-type male GSCs).
Border follicle cell migration is disrupted in mosaic egg chambers containing homozygous follicle cell clones.
Border follicle cell migration is disrupted in par-1k06323/par-1W3 females.
par-1W3 homozygous mutant eye disc clones display normal cell polarity. However, the eye disc epithelium appears to locally deform basally in regions containing a par-1W3 clone.
Mutant follicle cells show an increase in the density of microtubules compared to their wild-type neighbours in mosaic egg chambers (when the egg chambers are fixed using an optimised procedure for preserving microtubules).
Egg chambers containing homozygous germline clones do develop, but they remain small and never reach the stage where the oocyte is larger than the nurse cells. The mutant cysts develop 16 nurse cells and no oocyte; none of the cells in the mutant egg chambers forms a karyosome (this is normally formed in the oocyte) and instead all 16 germ cells become polyploid. In contrast to wild type, mutant cysts contain up to 16 cells with synaptonemal complex (SC) in early region 2a, indicating that all of the cells have entered meiosis. The SC becomes progressively restricted to two cells and then to one cell in region 3. This restriction is delayed compared to wild-type cysts, where the SC is always restricted to the oocyte by region 2b. In addition, the SC disappears prematurely from mutant oocytes, being undetectable in stage 2 egg chambers (wild-type oocytes retain a compacted SC until stage 3-4). The centrosomes accumulate at the anterior of the oocyte in late region 2b or early region 3, indicating that the first phase of centrosome migration occurs normally. They remain at the anterior of the oocyte however, and never translocate to the posterior (as occurs in wild type). There is a slight delay in the focusing of the microtubules to one cell in region 2b, however, the overall organisation of microtubules in region 2 appears essentially normal. The formation and asymmetric segregation of the fusome appears normal.
Germline clones of par-1W3 cause oogenesis to arrest at stage 5. The progeny of par-1W3/par-1k06323 females show typical posterior group phenotypes; the embryos lack abdominal segments (only 5% of embryos and hatched larvae have the wild-type abdominal pattern and the average number of denticle belts is 0.7) and pole cells fail to form, giving rise to a grandchildless phenotype in which adult escapers have agametic gonads. Migration of the nucleus to the anterior occurs normally in par-1W3/par-1k06323 oocytes.