Strashnyuk V. Structural and functional characters of polytene chromosomes and displays of quantitative traits in Drosophila melanogaster Meig.

Object of investigation: structural and functional peculiarities of polytene chromosomes of Drosophila melanogaster Meig. in relation to differences of genotype, influence of the external and internal factors, and displays of quantitative traits. Purpose of research: the investigation of structural and functional characters of polytene chromosomes in relation to differences of genotype, influence of environmental factors, biologically active substances, and displays of quantitative traits in Drosophila melanogaster Meig., and as for the possibility to use the polytene chromosomes as a test-system for estimation of action of the external and internal factors. Methods: genetical, cytogenetical, statistical. Theoretical and practical results, the novelty: The genetic variegation of polytene level of chromosomes in Drosophila melanogaster so as the influence of temperature conditions, larvae overcrowding, ecdysterone and juvenile hormone analogue – metopren, and vitamin B12 on this feature were first investigated. It was studied the influence of temperature, culture density and hormonal preparations on the puffing activity of polytene chromosomes. The relationship between the functional activity of chromosomes and differential fitness of lines and hybrids was shown. New data about the influence of genotype on the structural characteristics of chromosomes, concerning of heteropuffing on the regions of asynapsis, distinguishes of inbred lines and interlinear hybrids of Drosophila as for homologous and non-homologous conjugation of chromosomes were obtained. It was shown the influence of genotype and external factors on the displays of genetic instability caused by the phenomenon of unequal crossing over. New cytogenetical methods were elaborated: the methods of definition of ecdysone, juvenile hormone, and their analogues in cultural environment, the method of definition of activity of biologically active substance. Sphere of use: New methods are proposed to use in bee-keeping, silk worm-keeping, in a system of plant protection, and in veterinary medicine.