The testis is significantly reduced in size compared to wild-type. The testes-tubes are coiled as in wild-type males. The cytology of the Y chromosomal lampbrush loops is normal, and the primary spermatocyte nucleus undergoes the normal shaping. Meiotic divisions do not occur in homozygous males, while female meiosis and the gonial divisions are normal. Sperm development arrests before individualisation.
Stated to be lost.