Study implicates disruption in prenatal neurogenesis in the development of ASDs A new study of autism risk genes by UC San Francisco and UC Berkeley scientists implicates disruption in prenatal neurogenesis - a process in which specialized "progenitor" cells give rise to new brain cells - in the development of autism spectrum disorders (ASDs). The study also shows that estrogen, perhaps in a form produced within brain cells, can protect against this disruption and steer the brain on a normal course of development. The most striking findings in the study, published on January 25, 2021 in Neuron, were derived from experiments using embryos of the western clawed frog (Xenopus tropicalis), a species prized by biologists for the unique insights it offers into development. Human genes involved in development have counterparts with similar functions in Xenopus, and extensive studies correlating human embryonic stages with those of the frog mean that genetic studies in Xenopus can have direct relevance to human development in both health and disease.