As metagenomics advances, virus hunters are finding novel infections in colonies of laboratory mice across the world. What that means for scientific research and the animals themselves can depend on the mouse.

Zebrafish have a 50-year history as a model organism for studying vertebrate developmental biology and more recently have emerged as a powerful model system for studying vertebrate microbiome assembly, dynamics and function. In this Review, we discuss the strengths of the zebrafish model for both observational and manipulative microbiome studies, and we highlight some of the important insights gleaned

Recombinase-expressing mice are selected based on where and when they will activate conditional alleles, but some produce phenotypes in isolation that can complicate analysis of those alleles.

Differential gene expression based on the parental origin can have a big impact on phenotype

Caged neurotransmitters are widely used to study neurobiological processes such as synaptic transmission and plasticity. However, uncaging has been primarily restricted to in vitro and ex vivo experimental systems. Using caged neurotransmitters in vivo has posed a huge hurdle because photoactivatable cages bind to GABA-A receptors, acting as competitive antagonists towards GABA. This reduced inhibition

Vasculature has an essential role both in central nervous system health and diseases. A new optimized imaging and analysis pipeline helps to characterize blood vessel network topology and plasticity across large regions in detail.

As COVID-19 continues to spread, the urgency of the hunt for effective therapeutics and vaccines has likewise grown. As with past outbreaks, animal models will be an important component of efforts to understand how the SARS-CoV-2 virus causes disease, and how best to defeat it.

Thea Brabb and Sally Thompson-Iritani explain to Lab Animal how their mouse and nonhuman primate colonies continue to be cared for at the University of Washington and Washington National Primate Research Center.

To bridge brains and make the most of their nonhuman primate models, neuroscientists are setting standards, building tools, and starting to share their neuroimaging data.