Which phase of meiosis involves the formation of the synaptonemal complex?
Prophase of meiosis I is extended into five substages to accomplish pairing, synapsis, and recombination unique to germ cells. Leptotene initiates with chromosome condensation into thin threads and formation of axial elements along each chromatid containing cohesin Rec8 and HORMA proteins. Zygotene marks onset of homologous pairing facilitated by telomere bouquet clustering at nuclear envelope driven by cytoskeletal forces and homology search mediated by DMC1 recombinase. Synaptonemal complex assembly begins in zygotene: lateral elements SYCP2 and SYCP3 polymerize along axes, transverse filame
Ref: Page & Hawley, Annu Rev Cell Dev Biol 2004, Meiotic Synapsis. Alberts 7th ed., Chapter 21, Meiosis I Prophase.