Yinan Wan

Abstract The hypothalamic-pituitary-gonadal axis (HPG) controls pubertal development, sexual maturation, and fertility. We identified a role of hypothalamic microglia in controlling the HPG axis through receptor activator of nuclear factor κβ (Rank) signaling. Whole-body and microglia Rank depletion led to hypogonadotropic hypogonadism (HH) resulting from an alteration in gonadotropin-releasing hormone (GnRH) neuron function.

Editor’s summary Many species make their living by scavenging from kills made by other species. Observational knowledge posits that they do this by following predators around. Lorretto et al. tested this assumption by tagging ravens, wolves, and cougars in Yellowstone National Park. They found that the ravens weren’t following the predators; instead, they regularly returned to sites where they had encountered wolf kills before, like bats returning to known fruiting trees at the right time.

Editor’s summary Anthropogenic climate change is altering environments. Species do respond to such changes, but how quickly this can happen remains unknown. Fish have been shown to evolve rapidly in response to changing conditions, but outcomes are difficult to predict. Kozłowski et al. modeled the selective adaptation to warming waters and predicted that fish in these waters will grow faster but will also mature to smaller sizes (see the Perspective by Travis and Reznick).