Rearrangements of Chromosome Segments

Abstract

Inversions rearrange segments within or between arms of single chromosomes, whereas reciprocal translocations exchange segments between chromosomes. • Inversions and translocations can be detected by changes in mitotic chromosome structure and by distinctive meiotic configurations. • The frequency of aborted gametes or zygotes resulting from heterozygous inversions or translocations depends on the number and locations ofcrossovers, as well as the orientation of the translocation rings at metaphase I. • Inversions and translocations rearrange genes and create new genes, depending on the positions of the breakpoints, and can lead to cancers. • Chromosome rearrangements have significant roles in some natural populations.