Egg-free surrogate chickens produced in bid to save rare breeds

The surrogate chickens are the first gene-edited birds to be produced in Europe
The surrogate chickens are the first gene-edited birds to be produced in Europe

Hens that do not produce their own chicks have been developed for use as surrogates to lay eggs from rare breeds.

The advance – using gene-editing techniques – could help to boost breeding of endangered birds, as well as improving production of commercial hens, researchers say.

A team led by University of Edinburgh’s Roslin Institute used a genetic tool called TALEN to delete a section of chicken DNA.

They targeted part of a gene called DDX4, which is crucial for bird fertility.

Hens with the genetic modification were unable to produce eggs but were otherwise healthy, the team found.

DDX4 plays an essential role in the generation of specialised cells – called primordial germ cells – which give rise to eggs.

Researchers say that primordial germ cells from other bird breeds could be implanted into eggs carrying the gene edited birds. The hens would then grow up to produce eggs containing all of the genetic information from the other breeds.

'First step'

The surrogate chickens are the first gene-edited birds to be produced in Europe.

Experts say they could potentially be used to help breed birds of other species, as long a supply of primordial germ cells is available from a donor bird, the team says. Further research will be needed to investigate this.

Scientists from the US biotechnology company Recombinetics also worked on the project.

The study is published in the journal Development and was funded by strategic investment from the Biotechnology and Biological Sciences Research Council.

Lead researcher Dr Mike McGrew, of The University of Edinburgh’s The Roslin Institute, said: "These chickens are a first step in saving and protecting rare poultry breeds from loss in order to preserve future biodiversity of our poultry from both economic and climate stresses."

Dr Jef Grainger, Associate Director, Science at BBSRC added: "This research partnership involving the BBSRC strategically funded The Roslin Institute highlights the UK’s place as a global partner of choice, specifically in bioscience research. UK researchers excel in this kind of frontier bioscience which is a key challenge area in the Industrial Strategy to promote growth."