X-ray induced visible alterations in the giant chromosomes of Phryne cincta (Nematocera, Diptera): relation of radiation sensitivity to pronuclear chromosome structure

Trenimon: biochemical, physiological and genetic effects on cells and organisms

The trifunctional alkylating mutagen Trenimon interferes with the genetic material of a variety of organisms and test systems with respect to the induction of point and chromosomal mutations, sister-chromatid exchanges, recombination phenomena and phage induction. Beneath these mutagenic effects several biochemical and cell physiological aspects have been investigated. In this review we discuss chemical and cell physiological effects of Trenimon, aspects of cancer therapy with Trenimon and genetic effects induced by Trenimon. The available data on mutagenic effects of Trenimon are presented according to organisms or test systems. A short discussion on a possible genetic load by therapy with Trenimon in man concludes this review. DNA damage, especially the induction of cross-linkings, seems to represent the common reason for most of the described effects of Trenimon on cells and organisms.

The relation of radiation sensitivity to pronuclear chromosome structure. I. Different radiation sensitivities between Drosophila melanogaster and Phryne cincta

After treatment of mature spermatozoa of Phryne cincta egg mortality rates were determined and chromosomal mutation rates by examination of the polytene chromosomes of the F1 progeny.--A comparison of the results with similar studies made on Drosophila melanogaster yielded a two- to threefold higher sensitivity in Phryne cincta. Evaluation of data concerning DNA amounts, heterochromatin contents, distribution of breaks, repair capacities in two-break sites and oxygen concentrations in mature spermatozoa revealed no contradiction to the hypothesis that the greater sensitivity of Phryne cincta is mainly due to a high degree of spiralization of the paternal pronucleus chromosomes.