INTERLOCKING OF BIVALENT CHROMOSOMES IN TRADESCANTIA

Segmental Interchange in Chromosomes of Tradescantia.

Chromosome ring formation has been found in a number of difierent genera. In certain species of Oenothera and of Hypericum and in the monotypic genus Rhoeo, all the chromosomes may be united in a single ring or chain a t meiosis. Ring formation is maintained in these plants by a system of balanced lethals. In Datura, Zea, Pisum and Campanula rings of four or more chromosomes have been described...

An experimental analysis of bivalent interlocking in spermatocytes of the new Triturus vulgaris.

Interlocked bivalents at 1st meiotic metaphase are relatively uncommon in spermatocytes of the newt Triturus vulgaris, but their frequency of occurrence can be significantly increased by subjecting newts to a 24-h heat shock. Newt spermatocytes are sensitive to a heart shock at any stage between the end of premeiotic S and mid to late pachytene. The heat shock does not cause evidence desynapsis...

The Effects of Ultraviolet and X-Ray Treatment on the Pollen Tube Chromosomes of Tradescantia.

HE cytogenetic interest in ultraviolet radiation resides in the hope T that the qualitatively discriminating nature of this type of radiant energy will yield still further evidence as to the structure and behavior of the hereditary mechanism. It is now known that ultraviolet, like X-rays, can produce gene mutations and chromosomal changes; it is likewise known that, unlike X-rays, ultraviolet i...

Studies on the mechanism of the oxygen effect on the radiosensitivity of Tradescantia chromosomes.

Reduction of radiation damage to Tradescantia chromosomes by adenosine triphosphate, proline, and histidine.

N 1963, we reported that Tradescantia microspores treated with histidine or I proline prior to irradiation in helium showed fewer chromosome aberrations than the controls. In 1960 and 1962, similar results were obtained when material was pretreated in ATP, agreeing in general with the results that WOLFF and LUIPPOLD (1956) found in their work with Vicia faba. In 1960, we demonstrated by postirr...