A mouse model with human ACE2 receptors that can be used to study COVID-19 is now available and other improved ones may soon follow, the Economist writes.
It notes that the Jackson Laboratory got a head start on developing the model system following the 2003 SARS outbreak. That virus — now dubbed SARS-CoV-1 — also used the ACE2 receptor to enter human cells, much as SARS-CoV-2 does, and researchers at the University of Iowa developed a mouse with ACE2 receptors, and provided sperm from the mice to the Jackson Laboratory. At the beginning of the current pandemic, the lab defrosted those samples to ramp up production of the mice, according to the Economist.
It adds that though these mice have the human ACE2 receptor, they still retain the mouse version and the human version is incorporated in the wrong spot. However, the Economist reports that researchers from the National Institutes for Food and Drug Control in Beijing have been using CRISPR tools to remove the mouse ACE2 receptor and replace it with the human ACE2 receptor. These mice, it says, appear to generate ACE2 receptors in the same parts of the body where SARS-CoV-2 seems to attack.