Indian cobra genome decoded: how this knowledge can help fight snakebite
Paper: GS III
Topic: Science and technology, Conservation, Environmental Impact Assessment.
For Prelims: Genome editing, Snakebites in India.
For Mains: Need for research and development and government policy.
Why in News: Indian cobra genome decoded, how this knowledge can help fight snakebite.
Snakebites in India and world
- Accidental contact with snakes leads to over 100,000 deaths across the world every year.
- India alone accounts for about 50,000 deaths annually, and these are primarily attributed to the “big four” snakes category.
The new development in genome decoding
- An international team of researchers reported that they have sequenced the genome of the Indian cobra, in the process of identifying the genes that define its venom.
- In the Indian cobra genome, the authors identified 19 key toxin genes, the only ones that should matter in snakebite treatment.
- This, they hope, can provide a blueprint for developing more effective anti-venom.
Are existing anti-venoms not effective enough?
- Their efficacy varies, besides producing side effects.
- In India, the challenge has been producing anti-venom for the species known collectively as the “big four” —
- The Indian cobra (Naja naja)
- Common krait (Bungarus caeruleus),
- Russell’s viper (Daboia russelii), and
- Saw-scaled viper (Echis carinatus).
- Common anti-venom is marketed for the treatment of bites from the “big four”, but its effectiveness came under question in a study published (not connected to the one that sequenced the cobra genome).
- While the common anti-venom worked as marketed against the saw-scaled viper and the common cobra, it fell short against some neglected species and also against one of the “big four” the common krait.
So, there are two different studies?
Sequence information of the genes that code for venom proteins is very important for the production of recombinant anti-venoms.
- The first one to describe the cobra genome. It is a multinational study by 42 authors, including from India, and is published in Nature Genetics.
- It is led by Dr Sekar Seshagiri, president of the nonprofit SciGenom Research Foundation based in Bengaluru.
- The other study, while unrelated, also deals with antivenom. Published in PLOS Neglected Tropical Diseases last month, it is ed by Professor Kartik Sunagar of IISc Bengaluru.
Why has the production of effective anti-venom been challenging?
- Venom is a complex mixture of an estimated 140-odd protein or peptides.
- Only some of these constituents are toxins that cause the physiological symptoms seen after snakebite.
- But anti-venom available today does not target these toxins specifically.
- Anti-venom is currently produced by a century-old process a small amount of venom is injected into a horse (or a sheep), which produces antibodies that are then collected and developed into anti-venom.
- This is expensive, cumbersome and comes with complications.
- Some of the antibodies raised from the horse may be completely irrelevant: The horse also has a lot of antibodies floating in its blood that have nothing to do with the venom toxins.
- One more problem with horse antibodies: The human immune system recognises it as foreign and when anti-venom is given to the human body mounts an antibody response, this leads to what is called serum sickness.
- Severe allergic reaction: Also, if one is unlucky and has a snakebite incident (even if it is a different snake) and they are given horse-derived anti-venom, the body is going to have a severe allergic reaction.
How does decoding the genome help?
- In the Indian cobra genome, the identified 19 key toxin genes, the only ones that matter in snakebite treatment.
- They stress the need to leverage this knowledge for the creation of anti-venom using synthetic human antibodies.
- Targeting these 19 specific toxins using synthetic human antibodies should lead to a safe and effective anti-venom for treating Indian cobra bites.
- And the logical next step would be obtaining the genomes and the venom gland genes from the other three of the “big four” (as well as deadly African species), leading to possible common anti-venom against bites from all four.
Is genomics the only way forward?
- To develop new-generation anti-venom requires more research.
- Scientist is trying to produce highly specific antibodies to counter the toxic effects of snake venoms.
- The aim is to produce antibodies that are broadly effective, not only against snake venoms in India but also in sub-Saharan Africa.
- However, there is a very long way to go from genomes to effective anti-snake venoms.
Topic: Achievements of Indians in science & technology; indigenization of technology and developing new technology.
For Prelims: Goldilocks Zone and TOI 700 d.
For Mains: Features of TOI 700 d and NASA’s Transiting Exoplanet Survey Satellite mission.
Why in news?
- Recently, NASA reported the discovery of an Earth-size planet, named TOI 700 d, orbiting its star in the “habitable zone”.
- A habitable zone, also called the “Goldilocks zone”, is the area around a star where it is not too hot and not too cold for liquid water to exist on the surface of surrounding planets.
- Obviously, our Earth is in the Sun’s Goldilocks zone. If Earth were where the dwarf planet Pluto is, all its water would freeze; on the other hand, if Earth were where Mercury is, all its water would boil off.
- Life on Earth started in water, and water is a necessary ingredient for life as we know it. So, when scientists search for the possibility of alien life, any rocky exoplanet in the habitable zone of its star is an exciting find.
NASA’s Transiting Exoplanet Survey Satellite mission:
- The newest such planet was found by NASA’s Transiting Exoplanet Survey Satellite (TESS) mission, which it launched in 2018.
- Very few such Earth-size planets have been found so far, including some by NASA’s Kepler mission, and this one is the first such discovery by TESS.
- The find was confirmed by the Spitzer Space Telescope, which sharpened the measurements that TESS had made, such as orbital period and size.
Features of the TOI 700 d:
- TOI 700 d measures 20% larger than Earth. It orbits its star once every 37 days and receives an amount of energy that is equivalent to 86% of the energy that the Sun provides to Earth.
- The star, TOI 700, is an “M dwarf” located just over 100 light-years away in the southern constellation Dorado, is roughly 40% of our Sun’s mass and size, and has about half its surface temperature.
- Two other planets orbit the star TOI 700 b, which is almost exactly Earth-size, probably rocky, and which completes an orbit every 10 days, and TOI 700 c, the middle planet, which is 2.6 times larger than Earth, is probably gas-dominated, and orbits every 16 days.
- TOI 700 d is the outermost planet and the only one in the star’s habitable zone.
- NASA said future missions may be able to identify whether the planets have atmospheres and, if so, even determine their compositions.
- Another discovery announced was TESS’s first finding of an exoplanet orbiting two stars instead of one, also known as a circumbinary planet.
- The announcement prompted comparisons with Luke Skywalker’s home world of Tatooine in the “Star Wars” movie series, with its bewitching double sunsets.
- But the newly found planet’s size alone – it is 6.9 times larger than Earth, almost the size of Saturn – makes it unlikely to be livable.
- Named TOI 1338 b, it is the only planet in the TOI 1338 system, which lies 1,300 light-years away in the constellation Pictor, and orbits its stars every 95 days.
- The two stars orbit each other every 15 days. One is about 10 percent bigger than our Sun, while the other is cooler, dimmer and only one-third the Sun’s mass.
- The planet is covered in oceans with a “dense, carbon-dioxide-dominated atmosphere similar to what scientists suspect surrounded Mars when it was young.”
- The planet is tidally locked to TOI 700, meaning that one side always faces the star, in the same way that Earthlings never see the “dark side” of the Moon.
- This synchronous rotation meant that, in another model, one side of the planet was constantly covered in clouds.
- Multiple astronomers will observe the planet with other instruments, in order to obtain new data that may match one of NASA’s models.