Figure 4.

Abnormal acrosomal morphology of Setd2 cKO mouse spermatids. Shown are TEM analyses in ultrathin sections of spermatids from adult control (A and C) and Setd2 cKO (B and D) mice. A, in the Golgi phase of control spermatids, a single acrosomal granule is observed attached to the nuclear envelope. B, in the Golgi phase of Setd2 cKO mouse spermatids, as indicated by the arrows, multiple acrosomal vesicular structures are seen. C, in the cap phase, the acrosome flattens and forms a cap covering one pole of the nucleus. D, in the cap phase of Setd2 cKO mouse spermatids, as indicated by arrows, multiple acrosomal vesicular structures are observed (scale bars, 1 μm).