MEIOTIC CONJUNCTIVE ELEMENTS NOT INVOLVING CHIASMATA

Abstract

The Urge features of chiasmaless conjunction at spermatogenests by X-and Y-chromosomes in normal sequence are specified. It is shown that conjunctive competence at spermatogenesis is not a property uniformly distributed throughout the heterochromatic region of X, nor throughout the limbs of Y. At least the proximal fourth of the heterochromatic region of X, the right limb of X, the distal third of Ys, the distal half of YL, the kinetochores, and very likely the nucleolus organizers, are conjunctively inert with respect to each other at spermatogenesis. The conjunctive properties are reviewed as expressions of mappable, linear differentiations within the heterochromatic region, not as aspects of "heterochromatin.".