Critique of in vivo cytogenetic test systems

Abstract

Experiments in laboratory animals in general are influenced by a number of factors that have to be taken into account in considering the results of cytogenetic studies. The points that are supposed to be pertinent are discussed in the following. Selection of speciesThe animals used in cytogenetic tests should be easy to breed, and their chromosomes should be easily identifiable. Beagle dogs, a species widely used in toxicological work, have 72 chromosomes that are difficult to analyze. The 40 chromosomes of the mouse are achrocentric and very similar in size. However, this species has the advantage that a large amount of genetic information is available.Rats, that are also widely used in toxicology seem to be more suitable animals for cytogenetic work than mice. Although the chromosome number of 42 is rather high the individual chromosomes are easily identifiable because of their different size and shape.The Chinese hamster is considered to be the most suitable animal for cytogenetic studies. This species has 22 chromosomes, all of which are morphologically easily identifiable. Species differencesAccording to cytogenetic investigations by R6HRBORN et al. [27] mice proved to be more sensitive to cyclophosphamide than rats, and these were more responsive than Chinese hamsters.

Impact of citrate- and chitosan-capped gold nanoparticles on the liver of Swiss albino mice: Histological and cyto-genotoxic study

“…Thus, the term clastogen is used for agents giving rise to structural chromosomal aberrations (52). The reason for choosing mice in the present work, and not rats, is that mice are generally more sensitive than rats in performing genotoxic tests (35,53).…”