مرکز منطقه ای اطلاع رساني علوم و فناوري - Effect of sodium arsenite and chromium (III) chloride on the polytene chromosomes of Drosophila melanogaster

Abstract :

In this study the effect of sodium arsenite (NaAsO2) and chromium (III) chloride (CrCl3) on Drosophila melanogaster’s polytene chromosomes has been investigated. Substance application has been performed through feeding to the organism. Polytene chromosomes of third instar larvae which developed in medium contained metal have been examined. Due to the effects of the applied substances, a number of anomalies such as segment loss from tips, ectopic extensions, hairpin-like structures on some band regions, separation of homologous chromosomes from each other at some band regions (asynapsis), regional contractions called weak point, full or half fractions on chromosome arms have been observed. Both substances have been applied separately and together, and lead to a large number of chromosomal anomalies on polytene chromosomes. The anomaly rate of 14% observed in the control group was 62% in the experimental group treated with chromium(III) choride, 65% in the experimental group treated with sodium arsenite, and 53% in the experimental group treated with both. The probable causes of the disruption of development were discussed by associating the location of findings of this research with the elucidated expression of gene regions on polythene chromosomes.