The leptotene-zygotene transition of meiosis is a complex and critical process that involves diverse cellular mechanisms. During this period, chromosome ends change into a polarized configuration along with other nuclear envelope components. Active and passive chromosome events take place as part of meiotic chromosome metabolism while genetic recombination undergoes several critical changes in and around the transition. Chromosomes also undergo a series of cyclic genome-wide transitions in overall chromatin/chromosome structure.