Skoltech professor Petr Sergiev have co-authored a paper “Novel transgenic mice with Cre-dependent co-expression of GFP and human ACE2: a safe tool for study of COVID-19 pathogenesis” in Transgenic Research. Mice cannot be a fully valid model for COVID-19 because the infected mice do not have many important symptoms of COVID-19 typical of humans such as pneumonia. That is why hamsters have been largely used for COVID-19 modelling still being not the best model for COvid-19. The authors of the current research report novel humanized mice with Cre-dependent expression of hACE2, the main entry receptor of SARS-CoV-2. These mice carry hACE2 and GFP transgenes floxed by the STOP cassette, allowing them to be used as breeders to create animals with tissue-specific coexpression of hACE2 and GFP. Moreover, the inducible expression of hACE2 makes this line biosafe, whereas the coexpression with GFP simplifies detecting the transgene-expressing cells. The scientists believe that their model can be a useful tool for studying COVID-19 pathogenesis because the selective expression of hACE2 can shed light on the roles of different tissues in SARS-CoV-2-associated complications. Obviously, it can also be used for preclinical trials of antiviral drugs and new vaccines. Full text of the paper is available here.