The synaptinemal complex and four-strand crossing over.
The synaptinemal complex provides a structural basis for four-strand crossing over: prior to chromosome pairing, both sister chromatids of each homologous chromosome participate in the genesis of one lateral component. During precise pairing, the two lateral components are combined into one synaptinemal complex per bivalent.
D001203:Ascomycota; D002842:Chromatids; D003434:Crossing Over, Genetic; D004261:DNA Replication; D006651:Histocytochemistry; D008540:Meiosis