Improving the Efficiency of Mitotic Chromosome Analysis for Translocations

摘要

The Heritable Translocation Assay (HTA) tests the offspring of treated male parents for heritable cytogenetic damage. Translocation heterozygotes (TH) can be ascertained by reduced fertility or sterility. During spermatogenesis, the meiotic chromosomes cannot pair properly and this impairs spermatid development. Alternatively, the segregation of the chromosomes into the embryo may result in the duplication-deficiency of segments of the chromosomes, usually a lethal event. Either would reduce fertility as measured by litter size, thus suspect TH F1 males can be ascertained through breeding tests. It is important to confirm that the cause of the impaired fertility is the presence of a translocation. Presumed TH males can be subjected to meiotic chromosome analysis to confirm translocation. However, in sterile males and those with severly reduced gametogenesis, meiotic cells may not be available for analysis. To confirm a suspect animal, mitotic chromosome analysis would be necessary.