Two-dimensional spreads of synaptonemal complexes from solanaceous plants. IV. Synaptic irregularities

Abstract

Irregularities in the structure of synaptonemal complexes have been reported in a wide variety of organisms, but so far there has been no study concentrating on synaptic irregularities per se. We have used a hypotonic bursting technique to spread synaptonemal complexes from autotetraploid Solanum tuberosum (potato) and diploid, tetraploid, and trisomic Lycopersicon esculentum (tomato). In this study we observed most of the synaptic irregularities that have been reported in other organisms as well as an irregularity that has not been illustrated previously (lateral element buckles containing additional synaptonemal complex components). These observations have been used to provide partial answers to the following questions about the formation of the synaptonemal complex. (i) In what way does homology affect synapsis? (ii) What controls multiple synapsis? (iii) What is the relationship of synaptonemal complex components to chromatin and to each other? (iv) Do lateral elements have structural or functional polarity?Key words: synaptonemal complexes, synapsis, synaptic irregularities, solanaceous plants.