No abstract

Discoveries made in the nematode Caenorhabditis elegans revealed that aging is under genetic control. Since these transformative initial studies, C. elegans has become a premier model system for aging research. Critically, the genes, pathways, and processes that have fundamental roles in organismal aging are deeply conserved throughout evolution. This conservation has led to a wealth of knowledge regarding both the processes that influence aging and the identification of molecular and cellular hallmarks that play a causative role in the physiological decline of organisms. One key feature of age-associated decline is the failure of mechanisms that maintain proper function of the proteome (proteostasis). Here we highlight components of the proteostatic network that act to maintain the proteome and how this network integrates into major longevity signaling pathways. We focus in depth on the heat shock transcription factor 1 (HSF1), the central regulator of gene expression for proteins that maintain the cytosolic and nuclear proteomes, and a key effector of longevity signals.

Dividing cells often move apically within epithelial tissue layers, likely to escape the spatial confinement of their neighbors. Because of this movement, daughter cells may be born displaced from the tissue layer. Reintegration of these displaced cells helps support tissue growth and maintain tissue architecture. In the Drosophila follicular epithelium, reintegration relies on the immunoglobulin-superfamily cell-adhesion molecules (IgCAMs) Neuroglian and Fasciclin 2, which line cell-cell borders 1 . These molecules have been described in epithelia, but are wellstudied for their roles in neural development 2-8 . We show here that reintegration works in the same way as IgCAM-mediated axon growth and pathfinding; it relies not only on extracellular adhesion but also mechanical coupling between IgCAMs and the lateral Spectrin-Based Membrane Skeleton. Our work indicates that reintegration is mediated by a distinct epithelial cell-cell junction that is compositionally and functionally equivalent to junctions made between axons.

Reef-building corals are the primary component of coral reefs and are significant for marine ecosystems. However, currently coral reefs are declining globally due to El Niño, ocean acidification and overexploitation. To maintain coral populations and reduce the impact of ecological threats, it is crucial to understand the structures and formation processes of coral reefs. Large-scale microtomography can reveal the structures of entire coral reefs at the resolution of micrometres, providing an effective and innovative way to study the formation of coral reefs. Here, we use this technique to capture the entire structure of a reef-building coral in the Fungiidae from the South China Sea, Cycloseris vaughani, a reef-building coral of high ecological and economic value. In this study, we investigate its distinctive skeletal structure and growth rings. Reconstructed results exhibit microporous tunnels in the central mouth area and radiant rib-shaped skeletons surrounding the mouth. Our work promotes an in-depth understanding of coral structure while also providing a novel research approach for the protection of coral reefs. It also shows that large-scale microtomography is an effective method in tracking the growth process of reef-building corals, facilitating the understanding of coral biological characteristics, and filling the gaps in current coral research.