The rate of Y chromosome loss in the developing wing imaginal disc in lds^hor-rvP2/Df(3R)ED5218 males is significantly higher than that seen in wild type.

The vast majority of eggs deposited by heterozygous females hatch.

XX//X0 mosaics are not seen in the progeny of heterozygous males.

The fertility of lds^hor-rvP2/Df(3R)dsx15 males is very strongly reduced. XX//X0 mosaics are not seen in the progeny of these males.

lds^hor-rvP2/lds³ males males are almost completely sterile. XX//X0 mosaics are not seen in the progeny of these males.

lds^hor-rvP2/Df(3R)dsx15 females are completely sterile.

Abnormal chromosome segregation is seen in approximately 30% of eggs derived from hemizygous females during the first meiotic division and approximately 38% of the second meiotic divisions appear abnormal in both chromosome segregation and the formation of unusual spindles. All the eggs are fertilised, and cleavage divisions commence inside approximately 60% of the eggs, but larvae never hatch. Once they have started, the cleavage divisions proceed more or less normally and cells may form over relatively large areas in the egg cortex and differentiate as indicated by the cuticle fragments that form inside 20.6% of the eggs. Daughter centrosomes separate appropriately, but several of them lose their ability to nucleate microtubules. This leads to the formation of abnormal spindles, which results in a distorted arrangement of the chromosomes. The nuclei close to the abnormal centrosomes drop from the egg cortex into the cytoplasm, but the abnormal centrosomes remain in place. Most of these free chromosomes nucleate microtubules, resulting in further abnormalities by disturbing the nearby cleavage spindles.

Hemizygous males show defects during spermatogenesis. Larger and smaller than normal onion stage spermatid nuclei appear side by side due to non-disjunction. Several of the sperm nuclei are displaced from their sperm tip position and a number of sperm tails bear no nucleus. The sperm bundles are abnormal; individualisation is incomplete, some sperm heads are dislocated and the sperm head is missing from several sperm tails.

Analysis of germ-line chimeras indicates that the lds^hor-rvP2 defects are due to an effect in germ-line cells rather than in somatic cells.