Spermatogenesis in S-Lap1^Δ7 homozygotes shows normal cell divisions, normal nebenkern number and formation, normal length of elongated cysts, normal establishment of individualization complexes around the needle shaped nuclei, and normal number of total individualization complexes; however, individualization complexes migrate less frequently and more asynchronously than controls and the associated major mitochondrial derivatives show structural defects (investment cones are synchronized but DJ-GFP distribution is slightly dashed). As in controls, elongated spermatids shows normal axoneme structures, there is complete formation of the two mitochondrial derivatives, and paracrystalline material start accumulating in the major mitochondrial derivative, although the major mitochondrial derivative has abnormal size and the paracrystalline material is disorganized/dispersed.