Principles of Genetics and Breeding

8.1.1 Chromosome manipulation

Growing demand for fish leads to the development of advanced farming practices for all the cultivable species. Also rapid developments in fish farming has highlighted the need to produce fast growing strains of fish suitable for high intensity commercial cultivation. Chromosome manipulation also called as genome/ploidy manipulation or chromosome engineering has been an important tool in the production of viable and more profitable offsprings for several commercial fish species. Upon changing the sex ratio, faster growing sex can be cultured and thereby unwanted reproduction is controlled thoroughly in the population. Chromosome engineering has immediate application in fish farming through improving the strain for better growth. The changes in the number of chromosome sets may be brought out by simple destruction of one set, as in egg or sperm cells or by the disruption of the metaphase spindle during karyokinesis in either somatic or germinal cells.