BOLL

This gene belongs to the DAZ gene family required for germ cell development. It encodes an RNA-binding protein which is more similar to Drosophila Boule than to human proteins encoded by genes DAZ (deleted in azoospermia) or DAZL (deleted in azoospermia-like). Loss of this gene function results in the absence of sperm in semen (azoospermia). Histological studies demonstrated that the primary defect is at the meiotic G₂ / M transition in fruitfly but in mice the primary defect is postmeiotic at round spermatid stage.^[8] Multiple alternatively spliced transcript variants encoding distinct isoforms have been found for this gene.^[7][9]

The boule-like protein appears to be ubiquitously expressed in males of all animal species, except in the most primitive trichoplax.^[10]