Genetic control of chromosome behaviour: Implications in evolution, crop improvement, and human biology

Abstract

Chromosomes and chromosome pairing are pivotal to all biological sciences. The study of chromosomes helps unravel several aspects of an organism. Although the foundation of genetics occurred with the formulation of the laws of heredity in 1865, long before the discovery of chromosomes, their subsequent discovery put genetics on a sound footing. With the elucidation of parallelism between chromosome behaviour during meiosis and genes during the course of breeding, the laws of genetics, viz., the law of segregation and the law of independent assortment, could be explained. The interdependence of the disciplines of cytology and genetics led to their alliance resulting in the birth of the hybrid discipline of cytogenetics, during the first decade of the twentieth century. The fast, heterotic growth exhibited by cytogenetics has no parallel in the history of science. Research on chromosome pairing helped elucidate evolutionary phenomena that led to the production of allopolyploid crop plants. Chromosome research enriched the disciplines of genetics, plant breeding, biology, and medicine, which, in turn, have contributed to human welfare. The advances in genetics and cytogenetics accelerated the process of crop improvement as well, and resulted in the development of improved cereal cultivars that launched the famous Green Revolution. Cytogenetic manipulation of chromosome pairing facilitated alien gene transfers and genomic reconstruction of crop species. Alien chromosome additions also contributed to genomic repatterning and crop improvement. The discovery of chromosome number in humans helped unravel the effects of chromosomal imbalance on physical and mental abnormalities, miscarriage in pregnant women, and incidence of several forms of cancer in humans. The study of various aspects of chromosomes has positively impacted human welfare. How chromosome research has influenced basic genetics, plant breeding, and human biology and medicine is briefly described in this paper.