Title : Chromosome pairing during meiosis: Integrating molecular mechanisms, cytogenetic dynamics and evolutionary significance
Abstract:
Chromosome pairing is a fundamental cytogenetic process that ensures the accurate segregation of homologous chromosomes during meiosis, thereby maintaining genomic stability, fertility and evolutionary potential. This process is initiated during prophase I, when homologous chromosomes undergo recognition, alignment and synapsis, mediated by the formation of the synaptonemal complex. Precise chromosome pairing facilitates homologous recombination, enabling the exchange of genetic material while preserving chromosomal integrity. The efficiency and fidelity of this process are regulated by multiple factors, including chromosomal organization, DNA sequence homology, epigenetic modifications and the coordinated activity of meiotic proteins such as cohesions, synaptonemal complex components, and recombination regulators. Disruptions in chromosome pairing or synapsis can lead to meiotic abnormalities, including nondisjunction and aneuploidy, resulting in reduced fertility or gamete in viability. Advances in cytogenetic and molecular techniques, including fluorescence in situ hybridization (FISH), immunolocalization of meiotic proteins, super-resolution microscopy and genome-wide sequencing approaches have significantly enhanced understanding of the spatial and temporal dynamics of homologous chromosome interactions. In both plants and animals, insights into chromosome pairing mechanisms have important implications for crop improvement, hybrid breeding, genome evolution and speciation. Beyond its role in generating genetic diversity, chromosome pairing acts as a critical safeguard against genomic instability, reinforcing its dual importance in heredity and adaptation. This review integrates current knowledge on the molecular, cytological, and evolutionary aspects of chromosome pairing, highlighting its central role in meiotic regulation, maintenance of genetic integrity and the promotion of biological diversity.
Keywords: Chromosome Pairing, Meiosis, Synapsis, Synaptonemal Complex, Homologous Recombination, Genomic Stability, Cytogenetics, Aneuploidy, Meiotic Proteins, Genome Evolution, Fertility and Biodiversity.
