FIG. 6.

Histological analysis of testis and spermatozoa isolated from Neuralized null animals. (A) Wild-type testis. There is normal morphology and active spermatogenesis in the seminiferous tubules. (B) Testis isolated from Neuralized null animals. No difference from wild-type tissues could be detected at this level of resolution. (C) Spermatozoa isolated from wild-type control animals. Spermatozoa were isolated from the epididydimus and showed high mobility. (D) Spermatozoa isolated from Neuralized null animals. Most spermatozoa lacked tail motility. In addition, defective spermatozoa were detected frequently in Neuralized null samples (arrows). (E) A Neuralized transcript of approximately 3,000 bp is detected in wild-type mouse testis by poly(A) RNA Northern blot hybridization (lane 3). The transcript is significantly smaller than the transcript found in skeletal muscle (lane 1). As shown in Fig. 1, the Neuralized transcript is absent in the thymus (lane 2).