eIF4G2^Z3-3283/eIF4G2^BR21-37 males have testes that contain plentiful spermatocytes but completely lack elongated spermatids or mature sperm. The spermatocytes do not appear to properly undergo meiotic divisions in these males; the meiotic chromosomes initiate condensation, but never condense completely or move to the centre of the nucleus (as occurs in wild type) and no metaphase or anaphase figures are detected.

eIF4G2^Z3-3283/eIF4G2^BR21-37 males germ cells appear to proceed to early stages of spermatid differentiation, despite the failure in meiotic division; they produce large aberrant cells resembling abnormal early spermatids with a large nucleus and a partially aggregated mitochondrial cloud. A fraction of late stage mutant germ cells show partial spermatid elongation.

Homozygous testes lack elongating spermatids and are instead filled with cells resembling primary spermatocytes, having large nuclei and prominent nucleoli. The mutant spermatocytes appear smaller than wild type. The fraction of cysts per testis that are undergoing pre-meiotic S phase is similar in homozygous and control animals.

The cross-sectional area of young spermatocyte cells in homozygous clones in the testis are significantly smaller than age-matched cells in wild-type clones in the testis.

Young eIF4G2^Z3-3283/Df(3R)mbc-R1 spermatocytes are smaller than control cells in heterozygous siblings.