Adverse biological effects of ingested polystyrene microplastics using Drosophila melanogaster as a model in vivo organism
Özet
The abundant presence and extensive use of polystyrene microplastics (PSMPs) has recently
become a serious environmental concern, as impact of exposure to these substances on human
health remains unknown. While in vitro studies yield data on adverse effect of PSMPs, in vivo
approaches are more relevant for risk assessment. Drosophila melanogaster is one of the most
genetically and experimentally accessible model organisms used in biology as an in vivo model.
D. melanogaster was selected as a representative in vivo model organism to examine the genotoxic
potential of PSMPs at 5 concentrations of three different sizes namely 4, 10, or 20 µm. In particular,
the wing somatic mutation and recombination test (SMART), a scalable, time-efficient in vivo assay
developed to study genotoxicity of various compounds in a rapid manner at low costs was used.
The third–instar Drosophila larvae were exposed to PSMPs through food at 5 concentrations
ranging from 0.01-10 mM. Viability (lethality), larval length, morphological deformations, locomotor
activity (climbing behavior), and genotoxic effects were the end-points measured. Exposure to
PSMPs at 4, 10, or 20 µm produced significant morphological defects, impaired climbing behavior,
and genotoxicity as evidenced by the SMART test demonstrating induction of somatic recombination. Significant increases were observed in the frequency of total spots, suggesting that PSMPs
might induce genotoxic activity predominantly via initiation of somatic DNA recombination in
a concentration-dependent manner.