AFP, published on Friday March 27, 2020 at 3:26 p.m.
Researchers around the world are working to find treatments or vaccines for the new coronavirus, but they’re also looking for … laboratory mice. But not just any, they need transgenic rodents, which are becoming rare.
“The usual laboratory mice cannot be used to study SARS-Cov-2”, the official name of the new coronavirus, explains to AFP Christophe D’Enfert, scientific director of the Institut Pasteur.
They lack a receptor sensitive to the coronavirus, the one that allows it to enter cells: suddenly “we are not able to infect these mice effectively” with the new virus, continues Mr. D’Enfert.
Hence the need for special mice, responding to the small name of ACE2, genetically modified, he says, and supplied by specialized companies, obviously very much in demand these days.
– Where are the mice? –
These precious small rodents were used to study SARS, which raged in Asia in 2002/2003 but “no one was interested in these mice” once the epidemic had weakened, suddenly, the research labs n ‘had more,’ explains Christophe D’Enfert.
“We have ordered some, we are going to have some, but it will take a little time,” he said again. “It takes three weeks of gestation and three months for a generation”, that is to say mice able to reproduce, explains the researcher.
Located in the United States, the Jackson Laboratory is a large supplier of K18-hACE2 – their full name – and is accelerating the pace to fulfill orders for these super mice.
“We have had requests for mice from many laboratories and organizations around the world” for several weeks, said AFP Cat Lutz, their manager “Mice” and in vivo pharmacology.
Genetically modified to be able to catch the coronavirus, “they also reproduce the respiratory complications created by the infection, which makes them a good model for the disease”, continues the specialist.
“These are the mice that will be used to test therapies and vaccines,” says Ms. Lutz, who says she will be able “very soon” to have suitable mice to supply to the labs.
To go faster and produce a lot of mice, the Jackson Laboratory uses in vitro fertilization rather than traditional reproduction: the sperm of a single male fertilizes hundreds of oocytes and then transfers the embryos to females for gestation.
The company thus hopes for first limited shipments “early May” before larger cohorts “a few weeks later”.
– Second wave –
Good news, these delays do not prevent scientists from working on the current coronavirus explains Christophe D’Enfert.
“It slows things down a bit for research but that doesn’t prevent progress”: we can for example test a vaccine on a lambda mouse and see if it produces effective antibodies, reassures the researcher.
Its teams are also themselves trying to quickly develop modified mice or are looking to see if, luckily, certain mice available at the Institute harbor genes sensitive to SARS-Cov-2.
As for the biotech company GenOway, in Lyon, it is already positioning itself to try to develop other models of transgenic mice, “more relevant” than ACE2.
“We are in a second wave, with a + relevant + model (which makes it possible to predict what can happen in humans, editor’s note) and ours are not yet available”, explains AFP its manager Alexandre Fraichard , evoking “autumn-winter” 2020 as the horizon.
Beyond that, “we are trying to prepare the widest possible tools for the next pandemics. But this is a medium-term issue, of several years. Models with mice, that does not happen like that, like a new smartphone. You have to design, manufacture and test it, “he said.
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