The leptotene-zygotene transition of meiosis

The leptotene/zygotene transition of meiosis, as defined by classical cytol ogical studies, is the period when homologous chromosomes, already being di scernible individualized entities, begin to be close together or touching o ver portions of their lengths. This period also includes the bouquet stage: Chromosome ends, which have already become integral components of the inne r nuclear membrane, move into a polarized configuration, along with other n uclear envelope components. Chromosome movements, active or passive, also o ccur. The detailed nature of interhomologue interactions during this period , with special emphasis on the involvement of chromosome ends, and the over all role for meiosis and recombination of chromosome movement and, especial ly, the bouquet stage are discussed.