A bouquet-like attachment plate for telomeres in leptotene of rye revealed by heterochromatin staining

Abstract

Using a “C“ banding technique the behaviour of the heterochromatic telomeres of rye (Secale cereale L.) was followed throughout the meiotic cycle. Marked aggregation of these telomeres occurred during leptotene concurrently with nucleolar fusion. A conspicuous chromocentre was formed at the nuclear membrane, often in association with the single nucleolus. Telomere groupings at later stages, which derived from this chromocentre, included non-heterochromatic telomeres which indicated that the association did not depend on the presence of heterochromatin. This aggregation of the telomeres at the nuclear membrane makes leptotene in rye comparable to published reports of the leptotene bouquet, even though characteristic polarisation of the chromosome segments close to the bouquet attachment plate was not seen in rye. Because telomere aggregation is often associated with nucleolar fusion, it is concluded that similar attachments are formed when nucleoli fuse at meiosis of hexaploid wheat, although, because of the absence of heterochromatic telomeres in wheat, no chromocentres are observed.