abnormal manchette morphology abnormal manchette perinuclear ring morphology 2022-03-14T12:21:08Z any structural morphology of the ring-like portion of the manchette that surrounds the base of the elongating spermatid nucleus below the acroplaxome marginal ring and plays a key role in shaping the nucleus and the sperm head; microtubules extend from the perinuclear ring into the cytoplasm and/or basal body of the spermatid MP:0031373 Although the perinuclear ring is regarded as the microtubule-organizing center for the manchette, findings about the nucleation site and the direction of microtubules are inconsistent. During spermatid differentiation, the manchette moves toward the tail neck region, with constriction of the perinuclear ring, which contributes to sculpting of the sperm head in mice. MPheno.ontology