Stage 1 (“hyphal stage”) and 2 (“peridial stage”) FBs did not exhibit any significant positivity to the TUNEL reaction (not shown). In stage 3 (“veined stage”) FBs, on the other hand, some TUNEL-positive nuclei could be detected, particularly at the level of the interface between developing sterile and fertile veins, where specialized hyphae called paraphyses begin to appear (Fig. 3a–c). At stage 4 (“ascal stage”) more numerous TUNEL-positive nuclei were visible in the paraphyses (Fig. 3d–f), while (some) TUNEL positivity could be seen also in fertile veins and in some developing asci (Fig. 3g, h). In stage 5 (“sporal stage”) FBs TUNEL-positive nuclei were present both in sterile and fertile veins; in these latter, more specifically, they were particularly evident in some asci-surrounding hyphae (Fig. 3i–k) and, to some extent, at the level of the hypothecium (not shown). Finally, numerous TUNEL-positive nuclei were observed in stage 6 (“pigmented stage”) FBs, mostly at the interface between fertile veins and remnants of sterile veins (Fig. 3l–n).