Immunocytochemical Techniques Applied to Meiotic Chromosomes

During the prophase of the first meiotic division, homologous chromosomes align, pair, recombine, and segregate. These processes are accompanied by the appearance of meiosis-specific structures. Chromosome alignment is accompanied by the formation of axial elements along each chromosome (1 ); in meiocytes of some species, fibers appear to pull the axial elements of homologous chromosomes together (2 ). Alignment is followed by a process called synapsis: The axes of homologous chromosomes are closely apposed, and a tripartite structure, called the synaptonemal complex (SC), is formed. It consists of the axial elements of the homologs, connected by transversal filaments, and a central element that is formed on the transversal filaments between the axes (1 ).