The Brazilian Zika virus strain causes birth defects in experimental models

Zika virus infection has been linked to an increase in the number of infants born with microcephaly in Brazil, but direct experimental proof that Zika virus causes birth defects was lacking. Here Alysson Muotri and colleagues show that the Brazilian Zika virus strain can cross the placenta and cause intrauterine growth restriction, including signs of microcephaly, in the SJL strain of mice. They also show that the virus can infect human brain organoids, inducing cell death by apoptosis and disrupting cortical layers.