Figure 3
Histological sections of gonads of hybrids stained with hematoxylin and eosin (A–E) and Gomori trichrome (detail E), immunofluorescence for caspase 3 (F,G) and electron microscopy (H–K). A: testis with spermatocytes in degeneration (SP1*), interstitial tissue (IT), blood vessel (arrow) and spermatogonia (G). Detail: Apoptotic bodies. (B) Ovary with a normal perinucleolar oocyte (PN), type B oogonia in degeneration (GB*) and normal oogonia (G). (C) Spermatocytes in degeneration showing chromatin attached to the nuclear envelope at the periphery of the cell (arrowhead), little evident nucleolus and signs of interrupted meiosis with formation of chromosomes and altered spindle fibers (arrows). (D) Presence of granulocytes (GR) in the interstitial tissue. (E) Degenerated tissue (star) with cells without evident nucleus and increased interstitial tissue (IT). Detail: same tissue stained with Gomori trichrome. (F) Immunolocalization of caspase 3 in testis, positive reaction for spermatocytes in degeneration (fine arrow) and spermatogonia (thick arrow); negative reaction (arrowhead) and interstitial tissue (asterisk). (G) Immunolocalization of caspase 3 in ovary, positive reaction for type B oogonia in degeneration (arrow), normal oogonia (arrowhead) and perninucleolar oocytes (PN); negative reaction for interstitial tissue (asterisk). (H) Ultrastructure of spermatogonia presenting elongated nucleus (N) and presence of nuages (arrow). (I) Normal spermatocytes (SP) and in degeneration (SP*). (J) Detail of the cytoplasm of an intensely vacuolated cell. (K) Large autophagic vacuole, containing organelles in degeneration (arrow) inside. Bar: (A) 20 µm, (detail) 6 µm; (B) 40 µm; (C,I) 5 µm; (D) 20 µm; (E) 15 µm, (detail) 10 µm; (F) 20 µm, detail (6 µm); (G) 30 µm; (H) 2 µm; (J) 0.5 µm, (K) 1 µm.
