LEAD NITRATE INDUCED DEVELOPMENTAL DEFECTS IN DROSOPHILA MELANOGASTER ACCOMPANIED WITH LARVAL CHROMOSOMAL REARRANGEMENTS.

Abstract

Lead induced toxicity is common in human due to repeated occupational exposure of this heavy metal as well as its incorporation into the body through contaminated food and environmental pollutions. With a view to assess toxic potential of this heavy metal on development, dose dependent exposures of lead nitrate was given to a model organism, Drosophila melanogaster during its development. It was observed that at low doses lead nitrate did not affect the development of this fly. However, beyond at certain concentration, it exerted negative influences on its metamorphosis as well as in the number of pupa and emerging adults accompanied with various chromosomal abnormalities in third instar larval polytene chromosomes. From our experimental results it can be suggested that lead nitrate induced chromosomal abnormalities in larvae may cause dysfunction of developmental genes that give rise to developmental delay and reduce the the population of emerging individuals. As Drosophila melanogaster exhibit subtantial similarities with human genome, negative developmental outcome owing to a lead salt exposure in this fly may reflect analogous situation during human pregnancy.