Category Archives: Transhuman News

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The 'Napoleon' oak has few single-letter mutations in its genome.

The towering 234-year-old 'Napoleon' oak on the campus of the University of Lausanne in Switzerland has weathered storms both meteorological and political. The tree was young when Napoleons troops passed through town in 1800, and has grown into a majestic city landmark. But through it all, its genome has remained largely and surprisingly unchanged.

Researchers at the university discovered this unexpected stability after sequencing the genome in different branches of the tree. Their work posted on 13 June as a bioRxiv preprint, which has not been peer reviewed meshes with a growing body of evidence that plants are able to shield their stem cells from mutations1. The practice may be valuable for sustaining their health over a lifespan that can reach hundreds of years.

If you just accumulate more and more mutations, you would eventually die of mutational meltdown, says Cris Kuhlemeier, a developmental biologist at the University of Bern in Switzerland.

Each time a cell divides, mutations can arise because of errors made while copying the genome. Animals shield their reproductive cells from these mutations by isolating them early in development. These cells, called the germline, then follow a different developmental path, and typically have a low rate of cell division.

But plants do not have a dedicated germline: the cluster of stem cells that gives rise to the reproductive parts of flowers also generates plant stems and leaves. Because of this, scientists thought that the stem cells would accumulate many mutations, and that newer branches at the top of a long-lived tree would be remarkably different from the lower branches.

Plant biologist Philippe Reymond and his team at the University of Lausanne decided to test this hypothesis using the universitys prized oak tree. They sequenced the genome from leaves on lower, older branches and upper, younger ones, and tallied the number of single-letter changes they found in the tree's DNA. (Reymond declined to be interviewed by Nature because the paper is currently under review at a scientific journal.)

The team found that the number of mutations was much lower than would be expected based on calculations of the number of cell divisions that occurred between the lower branch and the higher one.

Its a tantalizing study, says Daniel Schoen, a plant evolutionary biologist at McGill University in Montreal, Canada. It touches on something that was simmering always, in the back of the minds of plant biologists.

It is too soon to say how general this phenomenon will be in plants, cautions Karel ha, a plant geneticist at the Central European Institute of Technology in Brno, Czech Republic. The researchers also looked only at one kind of genetic change single-letter changes to the sequence and did not evaluate other kinds of mutations, such as deleted DNA.

Mao-Lun Weng, a plant evolutionary biologist at South Dakota State University in Brookings, notes that the team used a stringent filter to weed out background noise in the sequencing data, and may have inadvertently missed some mutations as a result.

This could mean that some mutations were left out of the analysis. But ha and Weng are quick to note that the results are in line with two studies published last year. In the first2, led by Kuhlemeier, researchers tracked individual stem-cell divisions in the growth region of plants called the meristem. They found that in tomato and thale cress (Arabidopsis), the meristem contains a set of three or four cells that are set aside and divide much less often than the other cells in the region. The other study3, led by ha, also found few mutations between old and new leaves in thale cress.

For Kuhlemeier, the results provide an answer to a question that has troubled him ever since a trip to Oregon 20 years ago. As he looked up at a soaring, 400-year-old Douglas fir, Kuhlemeier wondered how the branches towards the top of the tree would differ from those at the bottom. I had always thought of a tree not as an organism, but as a collection of organisms with different genomes more like a colony, he says. Many ecologists shared his view, but now he has begun to question his earlier idea.

A clearer picture of plant development could help breeders as they increasingly focus on long-lived, perennial plants, says Schoen. If, as plants age, there is this mutation accumulation that could impact vigour, we would want to know about it, he says. We need more information of this type.

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Ancient oak's youthful genome surprises biologists : Nature News ... - Nature.com

An Australia-first service that combines whole genome sequencing and a comprehensive health assessment couldofferindividuals anunprecedented glimpse into their future health.

People with a niggling curiosity and $6400 can now find out if their genetics and lifestyle has left themprone todevelopinga suite of life-threatening conditionsincluding 31 types of cancer and 13 heart conditionsacross 230 genes.

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Patients with rare genetic disease will have access to whole genome testing at Australia's first clinic in Sydney's Garvan Institute.

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Police arrest a 39-year-old man on the Central Coast in relation to the death of Carly McBride who disappeared in September 2014.

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Patients with rare genetic disease will have access to whole genome testing at Australia's first clinic in Sydney's Garvan Institute.

Launched on Tuesday by Sydney'sGarvan Institute's Genome.One lab and corporate clinic Life First, the service also offers individualsthe ability to predict how they would likely reactto more than 220 medications, allowing clinicians to better tailor treatment to their patients.

CEO of Genome.One Dr Marcel Dinger said the service marked the start of a new era in precision medicine that balanced an individual's genetic predisposition to disease with lifestyle factors.

"Today's launch is a major milestone towards transforming our health system into one based on truly individualised information and one that focuses on prevention rather than treating disease," Dr Dinger said.

"Genetic information provides an entirely new dimension to understand your health, but its value is best realised in the context of other health data.

"Personal and family medical history and lifestyle are key components for consideration in this service," he said.

With its hefty price tag and government subsidies, the service is geared towards those who can afford to pay for it and took a highly proactive approach to their health.

"Others are simply curious about what their genome holds, and if they have any predispositions they want to know about them," Dr Dinger said.

Blood samples provide the raw material needed to sequence a patient's genome. Individuals also undergo a physical examination as well as pathology testing and a review of lifestyle risks like smoking, diet and alcohol intake.

Genetic counsellors guidepatients through the process, explaining how the testing works, managing expectations and interpreting the results.

Roughly 5 per cent to 10per cent of people would discover they carried a genetic variation in their genes that put them at increased risk of one of the conditions the service tests for, Genone.One genetic counsellor Mary-Anne Young said.

"It's not about giving people good news or bad news. It's about explaining 'you have a variation in your genes that causes an increased risk or say, heart disease or cancer or another treatable condition'," Ms Young said.

"Some people are taken aback at first. But the counterbalance is that it doesn't necessarily mean they are going to develop the condition.

"It means they have a higher risk than the average person and they can take steps to reducing their risk," she said.

The service can refer patientsfor further testing, treatment and prevention programs via First Lifeprograms attached to St Vincent's outpatient clinicsin Sydney and Melbourne.

The service only offers testing for conditions with known treatments and effective evidence-based prevention strategies.

Medical ethicists have previously raised concerned about the potential of genetic testing for predispositions leading to over-testing and inappropriate treatment, and creating a cohort of "worried well".

"If people have those concerns we should be addressing them," Ms Young said.

"But I think this is less likely creating a society of worried well and more likely creating a preventative, personalised health system instead of waiting for people to develop the condition then doing something about it."

A total of 47,753 Australians will die of cancer, and 134,174 new cancers will be diagnosed in 2017, government estimatespredict

In 2015, heart disease was responsible for 45,392 deaths and 480,392 largely preventable hospitalisations,according to the Heart Foundation.

See original here:
Australian-first whole genome sequencing and health testing open to public - The Sydney Morning Herald