Test for Chromosomal Rearrangement

The classical mutation tests in Drosophila use special strains that detect recessive lethal mutations on the X chromosome. They have the advantage that mutations at all lethal-producing loci on the chromosome, and not just those at a few selected loci, are detected. Various germ cell stages can be tested in both sexes. There are also tests for chromosomal breakage and rearrangement. These Drosophila tests require a few weeks. 

J. Muller initiated both the mutagenesis work and the development of genetic strains for the rapid and easy detection of mutations, chromosomal rearrangements, and aneuploidy. The reader is referred to several detailed reviews of the many testing procedures available.5 295 508... 

There are usually a few females that demand further progeny testing to ascertain the nature of the induced genetic alteration (Fig. 2, part 8). Among these are females with mosaic gonads, complementary lethals, complex chromosome rearrangements, and position-effect lethals. Females heterozygous for temperature-sensitive lethals and visible mutations are usually saved too. 

The characteristic meiotic configurations of spermatocyte I chromosomes at the diakinesis first metaphase stage thus provide a reliable technique for the detection of rearrangements or other chromosome aberrations induced in spermatogonia of the treated males spermatocyte test on treated males). Cytological analysis of dividing spermatocytes can also be used to confirm in Fi males the presence of translocations indicated by semisterility, the Fi females being indirectly tested by examination of sons F translocation test) (Table 1). 

---