Radical plan to maintain diversity of gene pool proposes use of genetically modified chickens as surrogate mothers
Hannah Devlin Science correspondent in Boston
Friday 17 February 2017 17.24 GMT Last modified on Wednesday 22 February 2017 17.37 GMT
The Rumpless Game is squawky and, as its name suggests, lacks a tail, while the Burmese Bantam, has fantastically flared leg feathers and a head like a feather duster. But the true value of rare chicken breeds, according to a team of scientists working to save them from obsolescence, is not their decorative crests and plumage, but the diversity they bring to the chicken gene pool.
In a radical plan to preserve rare varieties such as the Nankin, Scots Dumpy and Sicilian Buttercup, scientists at the the University of Edinburgh’s Roslin Institute have bred genetically modified chickens designed to act as surrogates that would be capable of laying eggs from any rare breed.
Speaking to journalists at the AAAS conference in Boston, Mike McGrew, who is leading the project, said: “These chickens are a first step in saving and protecting rare poultry breeds from loss.”
The surrogacy technique, which places a new, mind-bending twist on the classic chicken or egg question, involves first genetically engineering hens to be sterile. This is done by deleting a gene, called DDX4, that is required for the development of primordial follicles (the precursors to eggs) meaning that the surrogate hens will never lay eggs that are biologically their own.
A batch of sterile GM chicks hatched at the Roslin Institute in 2016, becoming the first genetically modified birds created in Europe. “We produced a hen that doesn’t have any eggs,” said McGrew, who is first author on a paper on the work published this week in the journal Development.
The next step will be to transplant follicles from rare birds into the surrogate (this is done before the surrogate chick is hatched from its own egg), meaning it would go on to lay eggs belonging to entirely different breeds of chicken.
Given that the hens would also need to be artificially inseminated with sperm from the same rare variety, the approach may appear unnecessarily convoluted. Why not just breed the rare birds the normal way?