Syllabus:
GS3: Awareness in the fields of IT, Space, Computers, Robotics, Nano-technology, Bio-technology and issues relating to Intellectual Property Rights.
Context:
Researchers from the Indian Institute of Science Education and Research (IISER), Thiruvananthapuram, have found that blue light can greatly increase the number of genetic mutations in yeast.
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- The study suggest prolonged blue light exposure may pose similar risks to other species apart from yeast.
- The team found that blue light induced unique kinds of DNA mutations. For example, it oxidised DNA bases, causing errors in DNA copying.
- In the study, researchers employed yeast cells, commonly used in baking, with a mixed genetic background to monitor Loss of Heterozygosity (LOH) events.
- These cells were cultured over approximately 1,000 generations under various conditions, including a control setup, blue light exposure, low sugar, high temperature, high salinity, ethanol, and oxidative stress.
- In addition to understanding the possible role of blue light in tumorgenesis (formation of cancer cells), the study highlights chronic blue light exposure as a novel antifungal agent through its genotoxicity.
DNA Mutation
- DNA mutations are heritable changes in genomic DNA sequence, which may be transmitted to daughter cells or to offspring (when they occur in germ cells).
- Mutations can vary from point mutations, involving single or very few base pairs, to large deletions, insertions, duplications, inversions, and translocations.
- In organisms with multiple chromosomes, DNA from one chromosome can be joined to another and the actual chromosome number can be affected.
Loss of Heterozygosity (LoH)
- The DNA of every living organism changes slightly over time thanks to mutations.
- One kind of mutation is called loss of heterozygosity (LOH): when a cell loses genetic diversity at certain parts of its DNA.
- LOH can help evolution along but can also result in diseases like cancer.
- This above study attempted to understand how common environmental factors like light, temperature, and the availability of nutrients influence LOH.
- Yeast cells exposed to blue light had by far the most LOH mutations.
- The light caused large sections of DNA to lose genetic variation, making significant parts of the genome uniform.
- This occurred because blue light produced reactive oxygen molecules, like hydrogen peroxide, that damaged DNA.