Scientists Create Genetically-Engineered Mice with Human Chromosomes

Scientists have created genetically-engineered mice with artificial human chromosomes in every cell of their bodies, as part of a series of studies showing that it may be possible to treat genetic diseases with a radically new form of gene therapy.
In one of the unpublished studies, researchers made a human artificial chromosome in the laboratory from chemical building blocks rather than chipping away at an existing human chromosome, indicating the increasingly powerful technology behind the new field of synthetic biology.

The development comes as the Government announces today that it will invest tens of millions of pounds in synthetic biology research in Britain, including an international project to construct all the 16 individual chromosomes of the yeast fungus in order to produce the first synthetic organism with a complex genome.

A synthetic yeast with man-made chromosomes could eventually be used as a platform for making new kinds of biological materials, such as antibiotics or vaccines, while human artificial chromosomes could be used to introduce healthy copies of genes into the diseased organs or tissues of people with genetic illnesses, scientists said.

Researchers involved in the synthetic yeast project emphasised at a briefing in London earlier this week that there are no plans to build human chromosomes and create synthetic human cells in the same way as the artificial yeast project. A project to build human artificial chromosomes is unlikely to win ethical approval in the UK, they said.

However, researchers in the US and Japan are already well advanced in making "mini" human chromosomes called HACs (human artificial chromosomes), by either paring down an existing human chromosome or making them "de novo" in the lab from smaller chemical building blocks.

Natalay Kouprina of the US National Cancer Institute in Bethesda, Maryland, is part of the team that has successfully produced genetically engineered mice with an extra human artificial chromosome in their cells. It is the first time such an advanced form of a synthetic human chromosome made "from scratch" has been shown to work in an animal model, Dr Kouprina said.

"The purpose of developing the human artificial chromosome project is to create a shuttle vector for gene delivery into human cells to study gene function in human cells," she told The Independent. "Potentially it has applications for gene therapy, for correction of gene deficiency in humans. It is known that there are lots of hereditary diseases due to the mutation of certain genes."

Synthetic biology is loosely defined as designing new kinds of life-forms or making new genetic arrangements that do not exist in nature, which could provide practical benefits to society, notably in medicine, manufacturing or environmental monitoring.

At a speech to the Royal Society last November, the Chancellor George Osborne identified synthetic biology as one of eight areas of scientific development that the Government wants British scientists to focus on in the coming years.

David Willetts, the minister responsible for universities, will tell an international meeting on synthetic biology at Imperial College London today that the Government will spend more than £60m on synthetic biology, including £10m on a new innovation centre to translate academic research into industrial processes and products, and £1m on the international synthetic yeast project.

"Synthetic biology has huge potential. Indeed it has been said that it will heal us, feed us and fuel us. The UK can be world-leading in this emerging technology," Mr Willetts said.

"Synthetic biology has huge potential for our economy and society in so many areas, from life sciences to agriculture. But to realise this potential we need to ensure researchers and businesses work together."  UCN