Transgenic, hypoallergenic milk
Transgenic cow started producing hypoallergenic milk
Copper news
Scientists from New Zealand have created a transgenic cow that produces allergy-free milk, reports the BBC (GM cows make 'low allergy' milk). The results of the joint work of researchers from AgResearch and the University of Waikato, conducted under the leadership of Goetz Laible (AgResearch), are published in the journal Proceedings of the National Academy of Sciences (Jabed et al., Targeted microRNA expression in dairy cattle directs production of β-lactoglobulin-free, high-casein milk; a popular presentation with the portrait of the heroine of the story given here and a link to detailed Q&A can be read in the press release of A scientific world first at AgResearch - VM).
The hypoallergenic milk obtained from a cow named Daisy is due to the absence of beta-lactoglobulin (BLG), a whey protein recognized as the strongest allergen of cow's milk. Breast milk does not contain BLG.
To reduce the amount of BLG, scientists used the technique of RNA interference, which involves suppressing gene expression using micro-RNA. First, ten micro-RNAs were selected for the experiment. In vitro studies have revealed two micro-RNAs, the combined action of which leads to a decrease in beta-lactoglobulin production by 98 percent.
The researchers then conducted an experiment on model mice whose milk contained sheep BLG. The rodents were injected with micro-RNA, after which the beta-lactoglobulin content in their milk decreased by 96 percent.
The next stage of the work was the creation of a transgenic calf. Daisy's genetic code has been modified so that the animal's body produces two micro-RNAs necessary to suppress the expression of the BLG-coding gene. As a result of a number of genetic abnormalities, unrelated, according to scientists, to their experiments, Daisy was born without a tail.
Hormones were injected into the animal to stimulate the early onset of lactation. Beta-lactoglobulin was not detected in milk samples obtained from a transgenic cow, and the casein level was twice as high as normal.
Now the researchers plan to get offspring from Daisy and wait for the beginning of the lactation period. The authors also want to find out the reasons why the animal was born tailless, since this deviation is usually attributed to rare hereditary diseases of cows.
Other representatives of the scientific world call the work of Labley and his colleagues a breakthrough. "RNA interference has long been successfully used for the genetic modification of various organisms - from plants to worms. Their work is the first and impressive report on the use of this technique for the genetic modification of livestock," said Professor Bruce Whitelaw, biotechnologist from the University of Edinburgh.
His admiration is shared by Professor Keith Campbell, who participated in the cloning of Dolly the sheep. According to Campbell, despite the success, the authors of the work now need to prove that the genetic modification they introduced persists in animals throughout life. In addition, it should be demonstrated that several generations of offspring will inherit these genetic changes.
Portal "Eternal youth" http://vechnayamolodost.ru02.10.2012