Ahead of the herd in breakthrough
Allergy- free milk for children is a step closer after New Zealand scientists made a worldfirst breakthrough using a geneticallymodified cow.
The country’s largest crown research institute AgResearch said it had bred the first cow in the world to produce high-protein milk with greatly reduced amounts of a protein believed to be the leading cause of milk allergies in children.
‘‘ It’s a very significant result,’’ the institute’s research director Dr Warren McNabb said.
He was unable to say how much the breakthrough could mean financially for New Zealand or how much the project had cost to date.
It has been under way since 2006, funded by the Business, Innovation and Employment Ministry and AgResearch.
Whether the milk was hypoallergenic (low allergy) and could eventually be produced and marketed as such was the subject of further experiments, Dr McNabb said.
The cow, Daisy, is about 11 months old.
She is missing a tail that AgResearch said it is investigating.
It expects to have an answer in a couple of weeks but does not believe at this stage the lack of a tail is linked to genetic modification.
Before the milk could be tasted by humans, tested in clinical trials on humans or produced commercially, New Zealand’s genetic modification policies would need to change, Dr McNabb said.
New Zealand has restrictive policies with strict rules on genetic modification including containment provisions for research.
‘‘ It’s going to come down to what this country decides.
‘‘It’s more of a social issue than a scientific one,’’ he said.
Working in containment at Ruakura in Hamilton, the scientists, led by Dr Goetz Laible, used scientific processes to greatly reduce the amount of a milk protein known as beta- lactoglobulin ( BLG) in Daisy’s milk.
BLG is a milk whey component believed to be the main cause of allergic reactions to cows’ milk, particularly in infants and children, Dr McNabb said.
BLG is not in breast milk.
He said AgResearch achieved the results by working successfully with mice first. It then produced Daisy, a female calf genetically engineered to express two micro RNAs ( short ribonucleic acid molecules).
Using a technique called ‘‘ RNA inter- ference’’, the micro RNAs ‘‘ knocked- down’’ the expression of the BLG protein.
AgResearch’s Dr Stefan Wagner said Daisy was produced using similar technology to that used to create the worldfamous cloned sheep Dolly.
He confirmed that Daisy was ‘‘ all cow’’ without any other animal components.
Dr McNabb said the milk research was still in its early days.
The initial results came from inducing Daisy to milk as she was too young to produce milk naturally.
She had produced about a cup of milk over five consecutive days, which was ‘‘ more than enough’’ to do the analysis and allergenicity tests.
Next steps in the project include breeding from Daisy, possibly next year, to produce a calf and for Daisy to start milking naturally so further tests could be done.
‘‘ If we can see similar results in another lactation, we suddenly have cows’ milk without what everyone believes is the main allergen in cow’s milk,’’ Dr McNabb said.
There were also plans to produce a few more cows like Daisy by the beginning of next year.
Dr McNabb said possible commercial production of hypoallergenic milk was a long way off.
‘‘ If this milk is to be hypoallergenic, as we suspect it will be, then we’ve got to get over the hurdle of social acceptance of this type of technology before you can then apply it in the national herd.
The successful research team comprised co- authors Anower Jabed, Stefan Wagner, Judi McCracken, David Wells and Goetz Laible.
ALLERGY FREE: Milk is one step closer.