Mean diplotene chiasma frequency is shown to be significantly and positively correlated with mean synaptonemal complex (SC) length in 21 males of Locusta migratoria belonging to three different families. This may reflect a direct causal connection between SC length and chiasma frequency or an indirect relationship arising from the action of other factors with effects on both parameters. Various interpretations of the correlation are discussed in the light of old and new information on synaptic and recombinational processes during meiotic prophase I.

Mean diplotene chiasma frequency is shown to be significantly and positively correlated with mean synaptonemal complex (SC) length in 21 males of Locusta migratoria belonging to three different families. This may reflect a direct causal connection between SC length and chiasma frequency or an indirect relationship arising from the action of other factors with effects on both parameters. Various interpretations of the correlation are discussed in the light of old and new information on synaptic and recombinational processes during meiotic prophase I.