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Biomedical subjects

F H Sobels

Publications and source records attributed to F H Sobels.

At least 55 records · Page 3Linked to original sources

The capacity of Drosophila for detecting relevant genetic damage.

For the detection and study of mutagenic agents, Drosophila offers many advantages. It is a higher organism with a short generation time that is cheap and easy to breed in large numbers. The simple genetic testing methods provide unequivocal answers about the whole spectrum of relevant genetic damage. A comparison of the detection capacity of assays sampling different kinds of genetic damage revealed that various substances are highly effective in inducing mutations, but do not produce chromosome breakage effects at all, or only at much higher concentrations than those required for mutation induction. Of the different assay systems available, the classical sex-linked recessive lethal test thus deserves priority, in view of its superior capacity to detect mutagens. Of practical importance is also its high sensitivity, because a large number of loci in one-fifth of the genome is tested for newly induced forward mutations, including small deletions. Drosophila is capable of carrying out the same metabolic activation reactions as the mammalian liver. An additional advantage, in this respect, is the capacity of Drosophila for detecting short-lived activation products, because intracellular activation occurs within the spermatids ans spermatocytes. These properties make the test for recessive sex-linked lethals a useful tool for verifying results obtained in the pre-screening of potential mutagens with fast microbial assay systems. In studies on non-disjunction, detailed genetic analysis of the induced changes is possible, and these may shed light on the mechanisms involved. A new adaptation of the bithorax transvection method by Mendelson permits the recovery of high yields of chromosome aberrations in a fast one-generation test.

Animals↗

Assaying potential carcinogens with Drosophila.

Drosophila offers many advantages for the detection of mutagenic activity of carcinogenic agents. It provides the quickest assay system for detecting mutations in animals today. Its generation time is short, and Drosophila is cheap and easy to breed in large numbers. The simple genetic testing methods give unequivocal answers about the whole spectrum of relevant genetic damage. A comparison of the detection capacity of assays sampling different kinds of genetic damage revealed that various substances are highly effective in inducing mutations but do not produce chromosome breakage effects at all, or only at much higher concentrations than those required for mutation induction. Of the different assay systems available, the classical sex-linked recessive lethal test deserves priority, in view of its superior capacity to detect mutagens. Of practical importance is also its high sensitivity, because a large number of loci in one fifth of the genome is tested for newly induced forward mutations, including small deletions. The recent findings that Drosophila is capable of carrying out the same metabolic activation reactions as the mammalian liver makes the organism eminently suitable for verifying results obtained in prescreening with fast microbial assay systems. An additional advantage in this respect is the capacity of Drosophila for detecting short-lived activation products, because intracellular metabolic activation appears to occur within the spermatids and spermatocytes.

Animals↗

Charlotte Auerbach and chemical mutagenesis.

A review is presented of the many conceptual contributions of Charlotte Auerbach to the development of the field of chemical mutagenesis during the past thirty years. The following aspects are discussed: (1) differences between the genetic effects of chemicals and X-rays; (2) mosaicism, delayed mutation and replicating instabilities; (3) mutation as a cellular process; (4) specificity; (5) dose-effect curves, and (6) correlation between different kinds of damage.

Dose-Response Relationship, Drug↗