Chromosomal Rearrangements and Genetic Fusion–Fission Dynamics in Eukaryotes: Mechanisms, Evolution, and Functional Implications

Structural changes in chromosomes arise through various processes and are often associated with specific genomic features that promote genetic instability. Chromosomal rearrangements have long been recognised as having significant effects on fertility and increasing the risk of human miscarriage. The study aims to evaluate the mechanisms, evolution, and functional implications of chromosomal rearrangements and gene fusion–fission dynamics in eukaryotes. The present review was conducted using secondary sources derived from existing academic literature, including peer-reviewed journal articles, books, and conference proceedings. Chromosomal fusion and fission are key drivers of genome evolution, impacting recombination rates, gene linkage, and reproductive isolation. Importantly, chromosomal rearrangements have profound biological and clinical implications. They contribute to adaptation, speciation, and genome plasticity, while also being implicated in various diseases, particularly cancer, where gene fusions act as oncogenic drivers and therapeutic targets. Advances in cytogenetic and genomic technologies have enhanced the detection and characterisation of these rearrangements, providing deeper insights into their mechanisms and consequences. Overall, chromosomal rearrangements, including fusion and fission events, represent fundamental processes that shape genome architecture, regulate gene function, and drive both evolutionary innovation and pathological outcomes. The study concludes that chromosomal rearrangements such as gene fusion and fission serve as powerful tools for investigating a wide range of biological processes.