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Updated: Oct 1, 2026
Electrophysiological Recording of The Central Nervous System Activity of Third-Instar Drosophila Melanogaster
Published on: November 21, 2018
Mutagenic effects of nitrogen dioxide combined with methylurea and ethylurea in Drosophila melanogaster
Abstract:
The standard sex-linked recessive lethal test was used to test whether NO2 induces lethal mutations in male germ cells of Drosophila in the presence or absence of alkylureas. Methylurea, ethylurea and NO2 alone did not enhance the mutation frequency significantly. However, highly significant enhancement in the mutation frequency was observed when adult flies were exposed to NO2 (150--280 ppm) for 3 h after ingestion of methylurea (0.1 M) or ethylurea (0.1 M) for 2 days. Oral administration of ethylnitrosourea and also of methylurea or ethylurea that had been exposed to NO2 in vitro were more effective in increasing the mutation frequency than methylurea or ethylurea combined in vivo with NO2. These results suggest that ingested alkylurea is converted in vivo by inhaled NO2 to highly mutagenic nitrosoalkylurea and/or other mutagens. No significant enhancement of the mutation frequency was observed when flies were fed on methylurea solution after they had been exposed to NO2.
Insights
Nitrogen dioxide (NO2) can convert ingested alkylureas into potent mutagens in Drosophila male germ cells. This interaction significantly increases mutation frequency, suggesting a novel mutagenic pathway.
Area of Science:
- Environmental Toxicology
- Genetics
- Mutagenesis
Background:
- Nitrogen dioxide (NO2) is an environmental pollutant.
- Alkylureas are chemical compounds with potential mutagenic properties.
- The interaction between environmental factors and chemical mutagens requires further investigation.
Purpose of the Study:
- To investigate the mutagenic potential of nitrogen dioxide (NO2) in Drosophila melanogaster.
- To determine if NO2 enhances the mutagenicity of alkylureas (methylurea, ethylurea) in male germ cells.
- To elucidate the mechanism of NO2-induced mutagenesis in the presence of alkylureas.
Main Methods:
- Utilized the standard sex-linked recessive lethal test in Drosophila melanogaster.
- Exposed adult flies to NO2 (150–280 ppm) for 3 hours.
- Administered methylurea or ethylurea (0.1 M) orally for 2 days prior to NO2 exposure.
- Compared mutation frequencies in flies exposed to NO2 alone, alkylureas alone, and combined treatments.
- Investigated in vitro exposure of alkylureas to NO2.
Main Results:
- NO2 alone, methylurea alone, and ethylurea alone did not significantly increase mutation frequency.
- Combined exposure of flies to NO2 after ingesting methylurea or ethylurea resulted in a highly significant enhancement of mutation frequency.
- In vitro exposure of alkylureas to NO2 yielded more potent mutagens than in vivo combined exposure.
- No significant mutation enhancement was observed when flies were fed methylurea after NO2 exposure.
Conclusions:
- Inhaled NO2 likely converts ingested alkylureas into highly mutagenic nitrosoalkylureas or other mutagens in vivo.
- This study reveals a novel pathway for NO2-induced mutagenicity through interaction with ingested alkylureas.
- The findings highlight the potential synergistic mutagenic effects of environmental pollutants and ingested chemicals.
