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Science & Technology - March 2022

Researchers have succeeded in isolating the entire genome of the dodo, a bird that went extinct in the 17th century

“Can we bring animals back from extinction?” In a panel discussion on this topic organised recently by the Royal Society, evolutionary biologist Beth Shapiro mentioned that if there were an animal she would like to bring back from extinction, it was the dodo. This follows on the fact that researchers at her lab at the University of California, Santa Cruz have succeeded in isolating the entire genome of the dodo.

What is the dodo, and why is it so interesting?

The dodo is a bird that lived in the Mauritius region and was last spotted 350 years back, in 1662. Since then it has become extinct. It would not be exaggerating to say that it is the very symbol of extinction. The phrase “dead as a dodo” is common in English to refer to something totally dead. The form of the bird has been revived from old drawings and the closest resemblance is in an Indian Mughal painting rediscovered in the Hermitage Museum in St Petersburg. In the painting it is slimmer and browner than in other descriptions. It is believed to be a more accurate depiction because it is pictured along with other birds which can be easily identified. The painting is by Mughal painter Ustad Mansur, probably commissioned by Emperor Jahangir who was famous for getting flora and fauna documented in paintings.

So, bringing the dodo alive would be the ultimate story of de-extinction.

How does the dodo look?

A species endemic to the island of Mauritius, the dodo is believed to be about 1 metre tall, flightless and weighed between 10 and 18 kilograms. Its real appearance is known only from paintings and drawings which vary a lot.

What animal is its closest living relative and how do we know that?

Beth Shapiro’s lab has sequenced the complete genome of the dodo, in work that is as yet unpublished, and she says that the closest living relative of the dodo is the Nicobar pigeon.

How does one recreate the full genome of an ancient, dead animal?

You need a specimen of the animal that has not been fossilized over the ages. Icy places like permafrost may contain remains of living beings in such a preserved form.

A small piece about the size of a finger-nail is taken from these specimens, and broken into small pieces. In an absolutely uncontaminated state, this is added to a PCR kit which multiplies the genome and makes many, many copies. From these fragments, the entire genome is pieced together, comparing it to genomes of other, living close relatives.

First the researchers in Shapiro’s team tried to do this from a piece taken from a specimen at Oxford. But it was not nearly large enough. Later they found a specimen in Denmark from which they were able to sequence the entire Genome.

Can the genome be used to resurrect an animal, In particular the dodo?

Beth Shapiro explained in the discussion that the known way of doing this would be to first stick in parts of the extinct animal’s genome into a framework provided by its close relative. For example, by inserting the mammoth genome into the elephant’s and construct a cell that contained sufficient amount of mammoth genome in it and then to clone it like Dolly the sheep. But while this process has been somewhat understood in the case of mammals, a new process has to be worked out for birds. “There are different groups that are working on this, and I have no doubt that we’ll get there, but this is a hurdle we face with birds,” she said.

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The M2 protein is considered to be a holy grail of designing a universal flu vaccine. The seasonal influenza strains mutate rapidly and new strains of the virus proliferate. This makes it very difficult to make a vaccine that can consistently generate a sufficient degree of immunity.

The M2e peptide is a section of the influenza virus that is conserved, meaning it doesn’t undergo too many mutations. Researchers have observed through the years that the M2e peptide region is pretty much unchanged across the several kinds of influenza A strains. Therefore, it is possible to design a vaccine that targets this peptide and prime the immune system to generate antibodies.

For this reason, M2e has for years been seen as a leading universal flu candidate. However, it has a limited ability to trigger a strong and long-lasting immune response and this has represented a major roadblock in its clinical development.

Recently researchers have reported a novel vaccine platform to deliver M2e to immune cells. By deploying this platform, a single shot vaccine containing M2e was able to trigger long-lasting immune responses that could protect effectively against multiple strains of the flu.

The team was also able to demonstrate that this vaccination approach significantly enhanced protective immune responses in the context of pre-existing flu immunity-- a situation particularly relevant in adult and elderly populations, where individuals have been exposed to flu viruses multiple times in the past and have low levels of M2e-specific antibodies in their blood circulation.

This vaccine approach has the potential to minimise the amount of M2e vaccine antigen (substance that triggers the body’s immune response against that itself) and the need for strong adjuvants (a substance which enhances the body’s immune response to an antigen), reducing potential side-effects, particularly in more vulnerable populations.

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Question Corner

What is the effecting of thawing permafrost on seafloor? Read the answer here

Of Flora and Fauna

How are mosquitoes able to avoid insect repellents?

Do looks correlate with caregiving in frogs and toads?

How do damaged plants warn neighbours about herbivore attacks?

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What kind of microplastics were found in human blood in a recent study? Can these particles travel through the body?

The story so far: Microplastics are, as the name suggests, tiny particles of plastics found in various places — the oceans, the environment, and now in human blood. A study by researchers from The Netherlands (Heather A. Leslie et al, Environment International, Published online 24 March) has examined blood samples of 22 persons, all anonymous donors and healthy adults, and found plastic particles in 17 of them. A report on this work, published in The Guardian conveys that about half of these were PET (polyethylene tertraphthalate) plastics, which is used to make food grade bottles. The size of the particles that the group looked for was as small as about 700 nanometres (equal to 0.0007 millimetres). This is really small and it remains to be seen if there is a danger of such particles crossing the blood cell walls and affecting the organs. Also, a larger study needs to be conducted to firm up the present findings.

What are microplastics?

Microplastics are tiny bits of various types of plastic found in the environment. The name is used to differentiate them from “macroplastics” such as bottles and bags made of plastic. There is no universal agreement on the size that fits this bill — the U.S. NOAA (National Oceanic and Atmospheric Administration) and the European Chemical Agency define microplastic as less than 5mm in length. However, for the purposes of this study, since the authors were interested in measuring the quantities of plastic that can cross the membranes and diffuse into the body via the blood stream, the authors have an upper limit on the size of the particles as 0.0007 millimetre.

What were the plastics that the study looked for in the blood samples?

The study looked at the most commonly used plastic polymers. These were polyethylene tetraphthalate (PET), polyethylene (used in making plastic carry bags), polymers of styrene (used in food packaging), poly (methyl methylacrylate) and poly propylene. They found a presence of the first four types.

How was the study conducted?

In the study, blood from 22 adult healthy volunteers was collected anonymously, stored in vessels protected from contamination, and then analysed for its plastic content. The size of the bore in the needle served to filter out microplastics of a size greater than desired. This was compared against suitable blanks to rule out pre-existing plastic presence in the background.

What are the key results of this study?

The study found that 77% of tested people (17 of the 22 persons) carried various amounts of microplastics above the limit of quantification. In 50% of the samples, the researchers detected PET particles. In 36%, they found presence of polystyrene. 23% of polyethylene and 5% of poly(methyl methylacrylate) were also found. However, traces of poly propylene were not detected.

They found in each donor, on average, 1.6 microgram of plastic particles per milli litre of blood sample. They write in the paper that this can be interpreted as an estimate of what to expect in future studies. It is a helpful starting point for further development of analytical studies for human matrices research.

What is the significance of the study?

Making a human health risk assessment in relation to plastic particles is not easy, perhaps not even possible, due to the lack of data on exposure of people to plastics. In this sense, it is important to have studies like this one. The authors of the paper also remark that validated methods to detect the tiny (trace) amounts of extremely small-sized (less than 10 micrometre) plastic particles are lacking. Hence this study, which builds up a methods to check the same, is important. Owing to the small size of the participants, the study results cannot be taken as such to mould policy etc, but the power of this paper is in the method and in demonstrating that such a possibility of finding microplastics in the blood exists.

Does the presence of microplastics in blood have health impacts?

It is not yet clear if these microplastics can cross over from the blood stream to deposit in organs and cause diseases. The authors point out that the human placenta has shown to be permeable to tiny particles of polystyrene ( 50, 80 and 24 nanometre beads). Experiments on rats where its lungs were exposed to polystryrene spheres (20 nanometre) led to translocation of the nanoparticles to the placental and foetal tissue. Oral administration of microplastics in rats led to accumulation of these in the liver, kidney and gut.

Further studies have to be carried out to really assess the impact of plastics on humans.

Microplastics are tiny bits of plastic found in the environment in various places — the oceans, the environment, and now as per recent studies in human blood as well.
In the study, blood from 22 healthy volunteers was collected and analysed for its plastic content. It found that 77% of tested people (17 of the 22 persons) carried various amounts of microplastics above the limit of quantification.
It is not yet clear if these microplastics can cross over from the blood stream to deposit in organs and cause diseases.

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The 45-day exhibition will be showcased from April 1 to May 15

Science Gallery Bengaluru’s new online exhibition, PSYCHE, seeks to explore the complexities of the human mind in socio-political and cultural contexts. The 45-day exhibition, in collaboration with National Institute of Mental Health and Neuro Sciences (NIMHANS), The Wellbeing Project and Museum Dr. Guislain, Ghent, will be showcased from April 1 to May 15.

Curated by the Science Gallery Bengaluru team, PSYCHE brings together philosophers, neuroscientists, artists, psychologists, filmmakers, sociologists, writers and performers. The exhibition will feature 10 exhibits, six films and over 40 live programmes including workshops, masterclasses and public lectures.

The exhibits trace the complexities of the mind. They are not all about research, however; they speak about the society as well. For instance, the audio-visual installation, ‘Black Men’s Minds’, rests upon the voices of black men who are often missing in conversations on mental health, trauma and stigma.

The exhibits will also feature interactive experiences such as ‘Playing with Reality’, based on the winner of the Best VR Immersive Work in 2019 at the Venice International Film Festival, which unravels what the phenomenon of psychosis can teach about the limits of reality; ‘The Serpent of A Thousand Coils’ gives participants of the game an empathetic insight into the minds of people with Obsessive Compulsive Disorder (OCD); another participatory web experience ‘Change My Mind’ helps understand the implication of brain implants on the mind.

‘Hamlets Live’ is a six-part performance that explores Hamlet’s inner monologues in a world that is strongly dictated by the real and hyperreal aspects of social media.

“In PSYCHE, we explore the human mind in a most unusual journey where we try to understand the mind with the help of our mind,” says Jahnavi Phalkey, the founding director of Science Gallery Bengaluru. “We pay close attention to both, the maladies as well as the health of our sentient selves. As always, we unpack objects of research inquiry across research disciplines at Science Gallery