抑制禽流感,基因改造 z-bo 2020-11-06 360

　　Scientists at the University of Edinburgh injected green fluorescent protein into chicks to make them easier to distinguish from other birds in the experiment. Each chicken has been genetically modified, through a "decoy" gene, scientists can observe their susceptibility to bird flu.

　　Compared with ordinary birds, genetically modified birds are less susceptible to avian influenza (microscopic images of pathogens in the picture). Most avian influenza viruses do not infect humans, but some variants such as H5N1 and H7N9 can cause serious human infections.

　　These fluorescent chickens look like the product of a nuclear accident, but they actually represent the forefront of bird flu research. Scientists injected a green fluorescent protein into the chicken body to make it easier to distinguish it from other birds in the experiment. And each chicken has been genetically modified. By tracking a "decoy" gene, scientists can observe their susceptibility to the avian influenza virus.

　　The research was co-chaired by Professor Helen Sang of the University of Edinburgh and Laurence Tiley of the University of Cambridge. It was funded by the British government and a number of poultry companies. The purpose of the research is to avoid future outbreaks of bird flu similar to this year. Since December last year, 48 million chickens and turkeys have died or been killed due to bird flu in the United States alone.

　　In order to genetically modify these chickens, the researchers injected the "decoy" gene into a cluster of cells in the newborn egg. The chicks hatched from these eggs carry the decoy gene and can pass the gene to the offspring. Also injected into the cell along with the decoy gene is a fluorescent protein, which enables the chicken to fluoresce under ultraviolet light.

　　When these modified chickens come into contact with the avian influenza virus, their genetic code will be designed by scientists to make the virus replicate the decoy gene, thereby inhibiting the proliferation of the virus. In one study, scientists put 16 infected chicks together with 16 normal chicks and 16 genetically modified chicks.

　　It was found that these modified chickens are less likely to be infected, and the infection process is slower than that of ordinary chickens. Researchers hope to block the spread of avian flu in two ways. One is to block the initial infection when the chicken is laying eggs; the other is to prevent the chicken from spreading the virus to other species after the chicken is infected. At present, these genetically modified chickens cannot be raised and grown unless they are approved for commercial farming.

　　In the early 20th century, bird flu was first noticed by veterinarians. Scientists believe that the droppings and feathers of wild ducks on the farm are one of the reasons for the outbreak of bird flu in the United States. Humans can also spread the bird flu virus through boots and trucks. Most avian influenza viruses do not infect humans, but some variants such as A H5N1 and A H7N9 can cause serious human infections. Symptoms include fever, sore throat and cough. H5N1 is the deadliest avian influenza virus, with 50% of the infected people dying.

　　Chickens may die without showing any symptoms after being infected with avian influenza, but usually, infected birds will suddenly swell their eyes and earlobes.