Nup15401501/Nup154RV5 males have a "meiotic arrest" phenotype in the testis; early spermatogenic stages appear normal and spermatocytes accumulate, but cells in meiotic divisions and spermatid differentiation are lacking. Larvae transheterozygous for Nup15401501 and either Nup1542 or Nup154k08204 die throughout the early larval stages, with survivors found until only just after the third instar larval moult. Until the end of the second instar stage, the larvae appear morphologically similar to their heterozygous siblings in body and tissue size. After the third instar moult, the larvae fail to grow and show a "classic mitotic mutant" phenotype, including reduced overall body size and a reduction in the size of larval organs that normally contain proliferating cells. Homozygous, hemizygous or transheterozygous third instar larvae have smaller brains than their age-matched control siblings. Although the neuropil is relatively normal in size, the optic lobes are greatly reduced and imaginal discs are tiny and difficult if not impossible to locate. The lymph glands are also reduced in size in third instar larvae.
Nup154tlp2/Nup15401501 ovarioles have a "string of pearls" morphology in which egg chambers have degenerated before entering vitellogenic stages.