Synaptonemal complexes as indicators of induced structural change in chromosomes after irradiation of spermatogonia.

The incidence of multivalent formation has been compared in primary spermatocytes at pachytene, using synaptonemal complex preparations and at diakinesis/metaphase, using air-dried preparations, from testes of Syrian hamsters several weeks after exposure to an acute dose of X-rays. The pachytene preparations revealed nearly twice the number of multivalents found at diakinesis/metaphase I, and showed the ability to reveal types of structural alteration undetectable in conventional air-dried techniques.