Page URL: https://www.bionews.org.uk/page_93182

First mammalian stem cells grown with only one set of chromosomes

12 September 2011
Appeared in BioNews 624

UK researchers have for the first time created mouse embryonic stem cells using just one set of chromosomes. Most mammalian cells, except sperm and eggs, are diploid, meaning they contain two sets of chromosomes. The ability to produce haploid cells, that contain only one set of chromosomes, may prove helpful in revealing the different functions of our genes.

'These embryonic stem cells are much simpler than normal embryonic mammalian stem cells. Any genetic change we introduce to the single set of chromosomes will have an easy-to-determine effect. This will be useful for exploring in a systematic way the signalling mechanisms within cells and how networks of genes regulate development', said Dr Anton Wutz, who led the study at the Wellcome Trust Centre for Stem Cell Research at the University of Cambridge.

Genetic studies often involve randomly mutating a gene in order to uncover its importance in a cell or organism. In simple model organisms, like bacteria and yeast, this is more easily achieved as they have haploid genomes, with only one copy of the gene to mutate. Mice and other mammals however have diploid genomes and so contain two copies of the gene 

In diploid genomes, the effects of a mutation in one copy of the gene can be masked by the second, normal copy of the gene. Introducing the same mutation in both copies of the gene involves the more complicated procedure of introducing targeted, point mutations. The creation of haploid cells therefore overcomes the need for this complex procedure.

'If you take our haploid embryonic stem cells and you introduce a mutation in a gene, you can immediately assess what the loss of gene function does to the cell', said Dr Wutz 

Researchers created the haploid stem cells by stimulating unfertilised eggs to divide. A small proportion of these cells continued to divide into multicellular, haploid embryos from which the researchers derived haploid blastocysts. The inner stem cells of the blastocysts were then extracted and continued to divide, thereby creating a population of haploid embryonic stem cells.

Dr Michael Dunn, head of molecular and physiological sciences at the Wellcome Trust, who was not involved in the study said: 'This technique will help scientists overcome some of the significant barriers that have so far made studying the functions of genes so difficult. This is often the first step towards understanding why mutations lead to disease and, ultimately, to developing new drug treatments'.

SOURCES & REFERENCES
Derivation of haploid embryonic stem cells from mouse embryos
Nature |  7 September 2011
Haploid Stem Cells
The Scientist |  7 September 2011
Wutz, A., and Leeb, M. “Derivation of haploid embryonic stem cells from mouse embryos,” Nature, doi:10.1038/nature10448, 2011.
Wellcome Trust - press release |  8 September 2011
RELATED ARTICLES FROM THE BIONEWS ARCHIVE
21 March 2016 - by Dr Julia Hill 
Scientists have created human stem cells with 23 chromosomes instead of 46, the normal number in a complete genome contained in almost all cells...
18 July 2011 - by Dr Lux Fatimathas 
US researchers have successfully converted human skin cells directly into brain nerve cells, skipping an intermediate stem cell stage. The new technique has the potential to aid research into neurodegenerative disorders of the brain, such as Parkinson's and Alzheimer's....
20 June 2011 - by Dr Susan Kelly 
The world of genetically predicted futures has recently been joined by a test for what is advertised as ‘biological age’. The test promises to provide information about the rate at which one is ageing – and knowing when you will die would make planning for the future so much easier!...
13 December 2010 - by Dr Lux Fatimathas 
American researchers have for the first time created mice with genetically two male parents. In a three-step process, utilising stem cell technology to create induced pluripotent stem cells (iPS)...
21 January 2002 - by BioNews 
Scientists at the Reproductive Genetics Institute in Chicago, US, say that they have developed a technique that could be used to allow two women to have a child together, without the need for sperm. The technique involves manipulating cells taken from a woman and turning them into 'artificial sperm' which...
HAVE YOUR SAY
Log in to add a Comment.

By posting a comment you agree to abide by the BioNews terms and conditions


Syndicate this story - click here to enquire about using this story.