Synaptonemal complexes as evidence for meiosis in the life cycle of the monomorphic diplokaryotic microsporidium Paranosema grylli

Characteristic configurations of the nuclei and synaptonemal complexes, indicative of the onset of meiosis, were observed in the meronts of the monomorphic diplokaryotic microsporidium, Paranosema grylli. This finding indicates that a process similar to the meiosis previously reported in polymorphic and some monomorphic monokaryotic microsporidia probably occurs in the development of P. grylli. It is the first evidence for the possible presence of a sexual phase in the life cycle of this microsporidium, which for a long time has been considered asexual.