Day: January 30, 2018

Scientists have assembled the most complete human genome to be mapped with a single technology using a new pocket-size portable DNA sequencer, which they say could one day make genome mapping quick and simple enough to do at home.

Using a device about the size of a mobile phone and called a MinION, made by Oxford Nanopore Technologies, researchers from Britain, the United States and Canada said they were able to sequence much longer strands of DNA than previously, making the process cheaper and swifter.

“If you imagine the process of assembling a genome … is like piecing together a jigsaw puzzle, the ability to produce extremely long sequencing reads is like finding very large pieces of the puzzle, which makes the process far less complex,” said Nick Loman, a professor at the University of Birmingham’s Institute of Microbiology and Infection who co-led the work.

Understanding and interpreting the human genome is a cornerstone of modern medicine, offering a wealth of information about a person’s inherited genetics risks, the antibodies they have, or how their diseases — such as cancer — have developed.

The first mapping of the human genome — essentially a person’s genetic recipe — was completed in 2003. It cost government-funded scientists $3 billion and 13 years of work.

‘Landmark for genomics’

Loman said the mini-sequencer may soon allow genome mapping to become a routine part of medical care.

“At the moment, sequencing is quite laborious and occurs in expensively equipped laboratories,” he said. “But in future, we can imagine sequencing using pocket-size devices in [doctors’] surgeries, in clinics and even in people’s own homes.”

The MinION works by detecting the change in current flow as single molecules of DNA pass through a nanopore — or tiny hole — in a membrane. Mapping a human genome with this device costs around $1,000.

“This is a landmark for genomics,” said Matt Loose of the University of Nottingham, who worked with Loman. “The long reads that are possible with nanopore sequencing will provide us with a much clearer picture of the overall structure and organization of the genome than ever before.”

The research was published Monday in the journal Nature Biotechnology.
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Scientists have unearthed in a Sahara Desert oasis in Egypt fossils of a long-necked, four-legged, school bus-sized dinosaur that lived roughly 80 million years ago, a discovery that sheds light on a mysterious time period in the history of dinosaurs in Africa.

Researchers said on Monday the plant-eating Cretaceous Period dinosaur, named Mansourasaurus shahinae, was nearly 33 feet (10 meters) long and weighed 5.5 tons (5,000 kg) and was a member of a group called titanosaurs that included Earth’s largest-ever land animals. Like many titanosaurs, Mansourasaurus boasted bony plates called osteoderms embedded in its skin.

Mansourasaurus, which lived near the shore of the ancient ocean that preceded the Mediterranean Sea, is one of the very few dinosaurs known from the last 15 million years of the Mesozoic Era, or age of dinosaurs, on mainland Africa. Madagascar had a separate geologic history.

Its remains, found at the Dakhla Oasis in central Egypt, are the most complete of any mainland African land vertebrate during an even larger time span, the roughly 30 million years before the dinosaur mass extinction 66 million years ago, said paleontologist Hesham Sallam of Egypt’s Mansoura University, who led the study published in the journal Nature Ecology and Evolution.

The scientists recovered parts of its skull, lower jaw, neck and back vertebrae, ribs, shoulder and forelimb, back foot and osteoderms.

A lot of Africa is covered in grasslands, savannas and rain forests that obscure underlying rock where fossils may be found, said postdoctoral researcher Eric Gorscak of the Field Museum in Chicago, who was formerly at Ohio University.

While as massive as a bull African elephant, Mansourasaurus was modestly sized next to titanosaur cousins such as South America’s Argentinosaurus, Dreadnoughtus and Patagotitan and Africa’s Paralititan, some exceeding 100 feet (30 meters) long.

“Mansourasaurus, though a big animal by today’s standards, was a pipsqueak compared to some other titanosaurs,” said paleontologist Matt Lamanna of the Carnegie Museum of Natural History in Pittsburgh.

The researchers determined Mansourasaurus was more closely related to European and Asian titanosaurs than to those from elsewhere in Africa and other Southern Hemisphere land masses including South America formerly joined in a super-continent called Gondwana.

“This, in turn, demonstrates for the first time that at least some dinosaurs could move between North Africa and southern Europe at the end of the Mesozoic, and runs counter to long-standing hypotheses that have argued that Africa’s dinosaur faunas were isolated from others during this time,” Lamanna said.
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A group of young Colombians, one as young as seven, filed a lawsuit against the Colombian government on Monday demanding it protect their right to a healthy environment in what campaigners said was the first such action in Latin America.

The lawsuit, filed at a Bogota court, alleges the government’s failure to stem rising deforestation in Colombia puts their future in jeopardy and violates their constitutional rights to a healthy environment, life, food and water.

“Deforestation is threatening the fundamental rights of those of us who are young today and will face the impacts of climate change the rest of our lives,” the 25 plaintiffs, whose ages range from seven to 26, said in a joint statement.

“We are at a critical moment given the speed at which deforestation is happening in the Colombian Amazon. The government’s lack of capacity and planning as well as its failure to protect the environment makes the adoption of urgent measures necessary.”

It is the first climate change litigation in Latin America, according to the Bogota-based rights group, Dejusticia, which is supporting the plaintiffs’ case.

The lawsuit follows a recent surge in litigation around the world demanding action or claiming damages over the impact of climate change – from rising sea levels to pollution.

“Just as cities, like New York and San Francisco, have sued oil companies for their role in fueling climate change, and a court ordered the Netherlands’ government to reduce its carbon emissions, we are asking that Colombia fulfills its prior commitments to tackle climate change,” said Cesar Rodriguez, head of Dejusticia.

Experts say U.S. President Donald Trump’s move to pull out of the global Paris climate change accord and roll back environmental regulations means campaigners are increasingly resorting to litigation in the United States.

The Colombia lawsuit calls on the government to halt deforestation in Colombia’s Amazon and keep to its promises.

Colombia, home to a swathe of rainforest roughly the size of Germany and England combined, has declared a goal of zero net deforestation by 2020 and halting the loss of all natural forest by 2030.

Despite the government’s pledges, deforestation in Colombia’s Amazon region rose 23 percent and across the country increased by 44 percent from 2015 to 2016.

When forests are degraded or destroyed, the carbon stored in the trees is released into the atmosphere. Deforestation accounts for 10 to 15 percent of carbon emissions worldwide.

Stemming forest loss is even more urgent following Colombia’s 2016 peace deal that ended a decades-long civil war.

Experts say Colombia’s rainforests are under increasing threat with once no-go conflict areas opening up for development and criminal gangs cutting down trees for illegal gold mining.
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