FIG. 8.
TRF2 expression in testes and influence of phP1 trf2P1 mutation on spermatogenesis. (A) Immunostaining of an adult testis with antibodies against TRF2; shorter arrow indicates cysts of mature primary spermatocytes, and longer arrows demarcate cysts undergoing meiotic divisions. (B) Testis of a third instar larva stained for TRF2 and DNA. (C) Diagram of a whole adult testis demonstrating the positions of the main differentiation stages; the elongating spermatid bundles and mature sperm that occupy the inner part of the testis are not shown. (D) The image from panel A, stained with antibodies against TBP. The strong TBP signal shown by the longer arrow corresponds to somatic cells of the seminal vesicle, and the shorter arrows show TBP expression in somatic cells of epithelium covering the testis. Arrowheads in A to D show the region of transition from the mitotic (spermatogonia) to meiotic (primary spermatocytes) differentiation program. (E) Primary spermatocytes and cyst cells stained for TRF2 and DNA. TRF2 is absent from nuclei of somatic cyst cells (indicated by asterisks). (F) Late meiotic prophase nucleus stained for TRF2 and DNA. (G) The metaphase nuclei of wild-type and mutant primary spermatocytes stained for DNA and tubulin. (H) The nuclei of mature primary spermatocytes from wild-type and mutated testes: staining for DNA and phase contrast. In all preparations DNA was stained either with DAPI (blue) or with propidium iodide (red); Ab1 was used for TRF2, and polyclonal rabbit antibodies were used for TBP. Bar, 10 μm.