Recombination and Chromosomal Rearrangements

Maintenance of chromosome stability is essential for the survival of all organisms and the transmission of their genetic information. Chromosomes undergo various structural changes spontaneously or through environmental factors. Mutation and recombination in the genome are driving forces for variations in evolution. In this chapter, we will discuss one of the most important discoveries since Mendel’s work: Alfred SturtevantSturtevant’s findings of recombination and linear arrangement of genes. Chromosomal crossovercrossovers allowed recombination mapping of genes, which laid a foundation for constructing the genome structure. We will examine various abnormal chromosomal rearrangementschromosomal rearrangements, their effects, and their uses in genetic studies. I will introduce Hermann MullerHermann Muller’s X-ray mutagenesismutagenesisHermann Muller, which led to identifying the first induced mutations and various chromosomal rearrangements such as deletiondeletion, duplicationduplication, inversioninversion, and translocationtranslocation. These chromosomal rearrangements have been crucial resources for genetic research. BalancerBalancer chromosomes with inversions are essential genetic tools for preventing recombination. Compound chromosomes derived from the fusion of homologous chromosomeshomologous chromosome will be described. Abnormal segregation of chromosomes, uniparental disomyuniparental disomy, and associated human diseases will be discussed.