E1 levels and temporal pattern of expression are significantly altered in <i>E1+/+E2−/−</i> spermatocytes.

<p>(A) (a–e) Localization of cyclin E2 (green) and SYCP3 (red) during prophase I in <i>E1−/−E2+/+</i> spermatocytes. Insets magnify the sex chromosomes (XY) present in c–e. (B) (a,b) Immunohistochemistry of <i>E1+/+E2−/−</i> adult testes reveals the presence of E1 in Sertoli cells but also in pachytene and diplotene spermatocytes. Arabic numerals indicate step of spermatid differentiation; Roman numerals indicate stage of the tubules. (c–g) Localization of E1 (green) and SYCP3 (red) during prophase I in <i>E1+/+E2−/−</i> spermatocytes. E1 is now detected from leptotene to diplotene. E1 expression in the sex chromosomes (XY) remains as foci on the AEs (e–g, insets).