C(1;Y)6/Dp(1;f)YP223 males that are homozygous for mei(2)yoh71341 show an increased frequency of non-disjunction of the sex chromosomes (6.2%) and fourth chromosomes (8.7%) compared to wild type. Homozygous XY males show an increased frequency of non-disjunction of the sex chromosomes (2.8%) and fourth chromosomes (6.9%) compared to wild type (0.1 and 0.3% respectively). Analysis of the progeny of homozygous males mated to compound-X females indicates that mei(2)yoh71341 exclusively affects meiosis I. Homozygous female lay a large number of eggs with normal eggshell morphology, but nuclear divisions become abnormal by the syncytial blastoderm stage.
Excision of the P-element can revert both the male meiotic and female sterile mutant phenotypes.