Synaptonemal complex complement of man in spreads of spermatocytes, with details of the sex chromosome pair.

Human pachytene chromosome pairs have been characterized electron microscopically in spread preparations on the basis of synaptonemal complex length, kinetochore position and attached nucleoli when present. The X and Y chromosomes can be followed by their filamentous axial cores from partial synapsis, through precocious disjuction and end-to-end attachment, to differentiation of a network in the sex chromosome pair.