MAMMALIAN MALE PACHYTENE CHROMOSOME INTERCONNECTIONS AND KARYOTYPES

Abstract

Pachytene chromosomes from mammalian primary spermatocytes can be prepared by two new and related techniques. The first involves pretreatment of the dispersed spermatocytes with a mixture of serum and salts followed by a sodium chloride treatment. The second technique uses the same pretreatment, but is followed by a naphthylamine-sodium chloride treatment. Primary spermatocytes release their pachytene chromosomes in a spread that is three to five times the diameter of the intact spermatocytes. Interconnections between the paired chromosomes hold the configuration together in the absence of the nuclear membranes.