SYNAPSIS IN A PARACENTRIC INVERSION HETEROZYGOTE OF CHORTHIPPUS-JACOBSI (GRASSHOPPER)

Analysis of surface-spread synaptonemal complexes of zygotene and pachytene spermatocytes was carried out on a grasshopper heterozygous for a paracentric inversion in chromosome L3. Inverted segments usually heterosynapse at pachytene without previous homosynapsis, although the possibility of synaptic adjustment in some nuclei is not excluded. A relationship between this synaptic behaviour and the absence of chromosome bridges and acentric fragments in the nine anaphase I cells analysed is established. The lack of reports concerning the existence of paracentric inversions in grasshopper natural populations is also discussed.