Listen and read 37: Laboratory mice - Thấm Tâm Vy

Nội dung text: Listen and read 37: Laboratory mice - Thấm Tâm Vy

1. LISTEN AND READ – 37 of the gene is in the wrong place in the cell nucleus. The ACE2 gene’s proper home is Laboratory mice the x chromosome, one of the sex chromosomes. In Perlman mice it is elsewhere. That could change its activity. Here’s one I prepared earlier Help may be on its way, though, from Wang Youchun at the National Institutes for Food and Drug Control in Beijing. As they describe in this week’s Cell Host & An animal model of covid-19 is now available. Another is on its way Microbe, Dr Wang and his colleagues have excised the murine version of the ACE2 gene completely from their own mice and substituted the human version in exactly the MICE as it were, the guinea pigs of science. And these days they are often genetically same place. They did this using crispr/Cas9 gene-editing technology, a technique engineered guinea pigs, to boot. The unavailable to Dr Perlman back in 2007. emergence of covid-19, for example, Spot-on has created demand for laboratory Dr Wang’s initial tests of the new mouse suggest it generates ACE2 receptor animals that have human versions of a molecules in all of the parts of the body where researchers think the virus makes its protein called the ACE2 receptor. This initial attacks in human beings. They show, too, that sars-cov-2 replicates well in the molecule is the hook that sars-cov-2, animals’ lungs and tracheas, and also in their digestive systems—another part of the the virus which causes covid-19, uses to human body that seems susceptible to sarscov-2 infection. In the case of the digestive attach itself to a cell before entering and systems, however, the dose of virus needed to establish a gut infection is ten times that turning that cell into a virus factory. needed to start a respiratory-tract infection. Dr Wang suspects that this might be The murine version of ACE2 is, important. If alimentary-canal infection requires an equivalently large initial dose of however, the wrong shape for the virus viruses in people, as well, then that might make it easier to stop it happening in human to link up with. That means unmodified intestines, by the practice of good food hygiene. mice cannot catch the infection. Hence One further result of Dr Wang’s investigation was the discovery that the virus also the need for genetic engineering. replicates in the brains of his mice. This suggests it may be making use of human The first version of such a mouse has nervous tissue for replication in a way that is not currently being detected, but is recently become available courtesy of suspected by some researchers because one symptom of some people who have the the Jackson Laboratory, a not-for-profit illness is loss of the sense of smell. biomedical research institution in Maine Curiously, despite their propensity to infection by sars-cov-2, Dr Wang’s mice, that specialises in breeding laboratory unlike Dr Perlman’s, do not show obvious symptoms when infected. Given the mice. By luck, the team that produced it apparently high rate of symptomless infection in human beings, that, too, may be a had a head start. The original SARS pertinent observation. . [The Economist US, 13.06.2020] virus (now known as sars-cov-1), which came close to causing a pandemic in 2003, also uses ACE2 as Notes: its point of entry. As a consequence, - receptor: đầu dây thần kinh thị giác và thính giác - murine: thuộc về loài gặm nhắm Stanley Perlman and Paul McCray of the University of Iowa, who were researching - to put on ice: tạm hoãn lại - genome: bộ mã di truyền - cell nucleus: nhân tế bào - tracheas: khí quản SARS, created a mouse with human ACE2 receptors in 2007. That project was - alimentary-canal infection: viêm thực quản - to replicate: tái tạo; tạo bản sao eventually put on ice. But not before Dr Perlman had given some semen from his - propensity : tính năng theo hướng tự nhiên - pertinent: thích đáng modified mice to the Jackson Lab. On hearing about the virus in early January researchers there, led by Cat Lutz, quickly thawed out this stored semen and started work. Five months later they have created enough of Dr Perlman’s mice to start making them widely available. The Perlman mice are, however, not quite perfect for the job. Though their genome has had human ACE2 added, the mouse variety has not been subtracted. This means they make both versions of the protein. Also, the human version Thẩm Tâm Vy, June 16, 2020 LISTEN AND READ 37