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.

More on the News

• 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.