Scientists find evidence of virus-eating microorganisms
New York: Scientists have found the first compelling evidence that two groups of ecologically important marine microorganisms could be eating viruses -- catching their "prey" and engulfing them, an advance that may lead to a better understanding of the flow of organic matter in the oceans.
The findings, published in the journal Frontiers in Microbiology, go against the currently predominant views of the role of both viruses and these groups of single-celled organisms called protists in the marine food webs.
"Our data show that many protist cells contain DNA of a wide variety of non-infectious viruses but not bacteria, strong evidence that they are feeding on viruses rather than on bacteria," said study corresponding author Ramunas Stepanauskas, Director of the Single Cell Genomics Center at Bigelow Laboratory for Ocean Sciences in the US.
The scientists explained that the predominant model of the role of viruses in the marine ecosystem is that of the "viral shunt," where microbes infected with viruses lose a substantial fraction of their chemicals back to the pool of dissolved organic matter.
However, the current study noted that the viral shunt could be complemented by a link in the marine microbial food web which may constitute a "sink of viral particles in the ocean."
According to the researchers, this finding "has implications for the flow of carbon through the microbial food web."
In the study, Stepanauskas and his colleagues sampled surface seawater from the Northwestern Atlantic in the Gulf of Maine in the US in July 2009, and the Mediterranean off Catalonia, Spain in January and July 2016.
They used modern single-cell genomics tools to sequence the total DNA from 1,698 individual protists in the water, and found evidence of protists with or without associated DNA.
The researchers explained that the associated DNA could be from symbiotic organisms, ingested prey, or viruses or bacteria sticking to the protists' exterior.
While the technique is very sensitive, the scientists said it doesn't directly show the type of relationship between a protist and its associates.
The scientists found a range of protists including groups called alveolates, stramenopiles, chlorophytes, cercozoans, picozoans, and choanozoans.
They said 19 per cent of the genome from the single cell organisms taken from the Gulf of Maine and 48 per cent of those from the Mediterranean were associated with bacterial DNA, suggesting that these protists had eaten bacteria.
But they added that viral sequences were more common, making up 51 per cent of the protists' genome from the Gulf of Maine and 35 per cent of those from the Mediterranean, with a frequency of one to 52 virus types per protist.
According to the researchers, most of these were from viruses known to infect bacteria -- presumably representing parasites of the protists' bacterial prey.
But they said choanozoans and picozoans, which only occurred in the Gulf of Maine sample, were different since these groups, neither of which have chloroplasts, are poorly known.
The scientists noted that the choanozoans are of great evolutionary interest as the closest living relatives of animals and fungi.
The tiny single-celled organisms were first discovered twenty years ago, and until now, their food sources were a puzzle, as their feeding apparatus is too small for bacteria, but ample for viruses, the researchers said.
In the current research, they found that every single one of the choanozoan and picozoan genomes were associated with viral sequences from bacteria-eating viruses called phages, but mostly without any bacterial DNA.
The same genome sequences were found across a great diversity of species, the study noted.
"It is very unlikely that these viruses are capable of infecting all the protists in which they were found," said Julia Brown, a co-author of the study at the Bigelow Laboratory for Ocean Sciences.
Based on these findings, the scientists concluded that choanozoans and picozoans "probably routinely eat viruses."
"Viruses are rich in phosphorus and nitrogen, and could potentially be a good supplement to a carbon-rich diet that might include cellular prey or carbon-rich marine colloids," Brown said.
The scientists believe the removal of viruses from the water may reduce the number of viruses available to infect other organisms, while also shuttling the organic carbon within virus particles higher up the food chain.
"Future research might consider whether protists that consume viruses accumulate DNA sequences from their viral prey within their own genomes, or consider how they might protect themselves from infection," Brown said.
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'Well-planned conspiracy by UP CM Adityanath, BJP-RSS': Cong on Sambhal violence
New Delhi, Nov 24: In the wake of violence in Uttar Pradesh's Sambhal, the Congress on Sunday alleged that the Yogi Adityanath administration is squarely responsible for killing innocents and only the BJP-RSS is guilty of "setting fire" to the peace and harmony there.
The opposition party said the videos of direct firing on the protesters in Sambhal depict the horrifying result of a "well-planned conspiracy" by Adityanath and the BJP-RSS.
Congress' media and publicity department head Pawan Khera said Adityanath's administration has once again shown a blatant disregard for communal harmony.
"In this entire matter, the BJP neither wanted the survey to proceed nor to stop it; its sole objective was to destroy harmony," he alleged.
Three people were killed and scores of others, including around 20 security personnel, were injured as the protesters opposing a court-ordered survey of a Mughal-era mosque Sambhal clashed with police on Sunday.
"No citizen in Uttar Pradesh is 'safe' under CM Adityanath, who gave the reprehensible slogan of 'Batenge toh Katenge'. This is evident by the highly deplorable incidents of Sambhal today," Khera said in a statement.
The videos of direct firing on the protesters in Sambhal depict the horrifying result of a "well-planned conspiracy" by Adityanath and the BJP-RSS, he alleged.
Western Uttar Pradesh, which has been a symbol of goodwill and harmony for years, has today witnessed three people killed and many injured under a "well-planned conspiracy", the Congress leader said.
"We say with full responsibility that the Adityanath administration is squarely responsible for killing innocents and only the BJP-RSS is guilty of setting fire to the peace and harmony of Sambhal. Modi-Yogi 'double assault' governments, which consider the minority community as second-class citizens, hurriedly got a petition filed in court," Khera said.
It is public knowledge that the court ordered an immediate survey without hearing the other side, he said.
"No action was taken against the rioters who accompanied the survey team. This makes it clear that after the by-elections in the state, the Yogi government has further intensified the politics of violence and hatred," he added.
The Congress leader said that questions are being raised about the role of the police and the administration because many innocent people have lost their lives in this violence and more than two dozen people have been injured.
"Inciting communal hatred and driving a wedge between two communities - is the DNA of BJP-RSS!" Khera said.
"On one hand, there is an empty slogan of 'Ek Hai Toh Safe Hain' - on the other hand, they divide communities! On one hand, there is lie of 'Sabka Saath- Sabka Vishwas' that has been going on for a decade, on the other hand, the minority community is constantly being targeted in Uttar Pradesh," he added.
The BJP government in Uttar Pradesh is destroying communal harmony and brotherhood for political gains, which is highly condemnable and objectionable, Khera said.
"We appeal to the BJP to prioritize the nation's interests over their political ambitions," he added.
"We want to ask Prime Minister Modi and Chief Minister Adityanath whether they will follow the statement of their own Mohan Bhagwat ji in June 2022 (even if it is pretentious!) in which he said that 'History is something that we cannot change. Neither today's Hindus nor today's Muslims made it, it happened at that time.... Why see Shivling in every mosque?.... Now we do not have to do any agitation..?'" Khera said.
"Neither Modi ji, nor Chief Minister Adityanath nor Mohan Bhagwat ji have the answer to this!" he added.
Khera said Rahul Gandhi has been continuously and stridently talked about 'Nafrat Ke Bazaar Mein Mohabbat Ki Dukaan' and in such a situation, an appeal is made to the people of Sambhal to recognise the politics of hatred, maintain mutual unity, amity and harmony, and take steps to protect their rights in a legal manner.
Moradabad Divisional Commissioner Aunjaneya Kumar Singh said the protesters torched vehicles and pelted stones at the police, who used tear gas and batons to disperse the mob.
"Shots were fired by the miscreants... the PRO of the superintendent of police suffered a gunshot to the leg, the police circle officer was hit by pellets and 15 to 20 security personnel were injured in the violence," he said.
Singh said that a constable also suffered a serious head injury, while the deputy collector fractured his leg.
Internet services have been suspended in Sambhal tehsil for 24 hours and the district administration declared a holiday on November 25 for all students up to Class 12.
Purported images shared on social media showed the protesters pelting stones at cops from atop buildings and in front of the Shahi Jama Masjid. Later, the police personnel were purportedly seen cornering and hitting people as they tried to disperse a large crowd in a narrow alleyway.
Our statement on the tragic and avoidable riots in Sambhal:
— Pawan Khera 🇮🇳 (@Pawankhera) November 24, 2024
संभल में हुए दुखद एवं परिहार्य दंगों पर कांग्रेस पार्टी का वक्तव्य: pic.twitter.com/uOpKjYbw8g
