Why in News?

• A team from The Indian Institute of Science, Bengaluru, have found that Water bears found in Bangalore have a protective fluorescent shield which helps it survive harmful ultraviolet (UV) radiation.

Speciality of Water Bears (tardigrades)

• No more than a millimetre in size, these tiny eight-legged animals have survived all five mass extinctions, can endure temperatures beyond 150°C and lower than -200°C, and have been in earth for a half a billion years
• The tardigrade species, Paramacrobiotus BLR (BLR for Bengaluru) has a protective fluorescent shield which helps it survive harmful ultraviolet (UV) radiation.
• The study found this specific Paramacrobiotus BLR strain survived beyond 30 days after 15 minutes exposure to germicidal UV radiation.
• Paramacrobiotus BLR could have probably evolved this fluorescence mechanism to counter the high UV radiation of tropical southern India.

Potential uses of Tardigrades

• In a cryptobiotic state, tardigrades can endure radiation, extreme pressure and extreme heat and cold, including temperatures near absolute zero. Cryptobiosis or anabiosis is a metabolic state of life entered by an organism in response to adverse environmental conditions such as desiccation, freezing, and oxygen deficiency. In the cryptobiotic state, all measurable metabolic processes stop, preventing reproduction, development, and repair.
• Synthetic proteins from Tardigrades could be used, for example, to preserve organs needed for transplants, potentially keeping organs viable for longer than is possible by storing them on ice.
• They can help technicians working in nuclear power plants to guard against radiation.
• They can help astronauts to survive on long space flights and save them from radiation

Additional Details

• Ultraviolet is a form of electromagnetic radiation with wavelength from 10 to 400 nm, shorter than that of visible light, but longer than X-rays. UV radiation is present in sunlight, and constitutes about 10% of the total electromagnetic radiation output from the Sun.
• Fluorescence is the emission of light by a substance that has absorbed light or other electromagnetic radiation.( It is a form of luminescence.)

Reference:

1. https://www.thehindu.com/sci-tech/science/how-water-bears-survive-lethal-uv-radiation/article32991933.ece