Pallab Ghosh
Science correspondent.
The image is from the Crick Institute.
The image caption is.
Male or female-only offspring can be produced from genetically altered mice.
Scientists have used technology to create male and female litters of mice.
Hundreds of thousands of unwanted mice could be prevented from being destroyed in research.
Millions of male chickens in the UK are culled because they don't lay eggs, and the team says it could be prevented.
The livestock industry in England could be allowed to use gene editing.
The technique is outlined in the journal Nature Communications.
The system can be programmed to kick in for either male or female embryos at a very early stage of development.
The researchers believe that the technique could work on farm animals and they are in discussions to set up scientific pilot studies with the Roslin Institute near Edinburgh, which is among the world leaders in gene editing of livestock.
If the results translate from the lab to commercial use, they could have a far reaching impact on animal welfare, according to Dr Peter Ellis of Kent University.
Four and six billion birds are killed each year in the poultry industry. He said that we could set up a system so that if a chick has a nervous system that is capable of suffering, the eggs are never hatched.
The image is from the science photo library.
The image caption is.
Millions of male chicks are killed in the UK each year according to Compassion in World Farming.
The new technique could reduce the number of lab mice that are killed because either males or females are required for certain medical experiments.
Dr James Turner from the Francis Crick Institute in London has identified 25,000 research papers that required male or female-only mice.
The total mouse usage would be in the hundreds of thousands, but the numbers of mice used in each case obviously varies. This work could have a big impact on scientific laboratories.
An independent report published this week stated that animal welfare had to be at the center of any relaxation of the rules that would allow gene editing on farm animals. Peter Stevenson is the chief policy adviser for Compassion in World Farming and he says that he is wary of the use of gene editing in factory farming of livestock.
Ensuring that hens only produce female chicks would prevent the killing of millions of unwanted male chicks in the UK each year, and we support its use to improve animal welfare.
Barney Reed said that the technology had to be regulated.
"This is especially pertinent when so many of the benefits are for dealing with animal welfare or environmental problems created by humans ourselves."
Dr Ellis agrees. Changes to legislation and extensive public discussion are required for any potential use in agriculture.
There is a lot of work to be done on the scientific side. First, there needs to be further research to make sure the particular gene editing toolkits are safe and effective.
Sex chromosomes determine whether a mammal is male or female. Females have two X chromosomes, one from the mother and one from the father. Males have one X and Y chromosomes from their parents.
The researchers were able to prevent either XX or XY mouse embryo from developing by deactivating a gene, which stopped the embryo from progressing beyond 16 to 32 cells.
They were able to select for sex by putting one half of the Crispr-Cas9 molecule into the mother's and the other into the father's X or Y chromosomes.
If both parts of Crispr-Cas9 are brought together, the gene can be turned off.
If the father's half of the editing molecule was on his Y chromosomes, the resulting XY male embryo would have both parts of the molecule that deactivated the gene, preventing further development. The female embryos that did not inherit the molecule from the father would develop normally.
Half of the Crispr-Cas9 is embedded into the father's X chromosomes for an all-male litter.
