COVER A reconstruction of multiple optical slices from the developing eye of a fruit fly (Drosophila melanogaster) larva. Each observed photoreceptor neuron expresses one of three protein tags (either alone or in combination), corresponding to different colors. The neurons maintain their spatial proximity while sending projections to the brain. The Gordon Research Conference on Neural Development will be held from 7 to 12 August 2022 in Newport, Rhode Island. See page 900 for the Gordon Research Conference schedule and preliminary programs.

Image: Amanda A. G. Ferreira

ONLINE COVER Primary cilia, as depicted here, are cellular antennae with a crucial role in animal development. Defects in their formation can cause developmental disorders and other diseases in humans. Using an unbiased screening approach. Kumar et al. identified DENND2B protein as a key regulator in the development of primary cilia. The authors found that the presence of DENND2B at the base of the primary cilia affects the length of the cilia and their ability to function properly. Understanding the relationship between DENND2B and primary cilia formation has implications in disease paradigms from developmental disorders to neurodegeneration and cancer.

ONLINE COVER Blocked Exit Route. This month's cover features a colorized scanning electron micrograph showing protruding clusters of mucin granules (green) on the apical surface of the distal colon in mice lacking gasdermin D (GSDMD) in intestinal epithelial cells. The abnormal extracellular accumulation of mucin granules observed by Zhang et al. was associated with failure to form a normal protective mucus layer, increased bacterial adherence, and impaired clearance of infection by the enteric pathogen Citrobacter rodentium. This phenotype reveals an unexpected requirement for GSDMD in enabling successful release of mucins from the secretory granules of intestinal goblet cells.

ONLINE COVER Special Issue on Soft Systems and Sensors. Soft robots require a sustainable source of raw materials to facilitate recyclability and degradation following the end of their life cycle. Unlike the synthetic polymers widely used to date, Heiden et al. 3D-printed soft robots from gelatin and sugar, with the capacity to dissolve fully in water and degrade enzymatically. These soft robots can also be recycled and reprinted at least four more times using the same material without losing their mechanical stability. Furthermore, the integration of waveguides enables actuators to sense objects within their vicinity through changes in light intensity. This month's cover shows a melt extrusion-based printer nozzle depositing a gelatin-based hydrogel to fabricate a 3D structure of a soft robot (see also the Focus by Tan).

ONLINE COVER This week, Aiolfi et al. report that interferon produced during arenaviral infection increases bleeding risk in infected mice not by directly affecting platelets but rather by decreasing the expression of genes involved in platelet formation and function in megakaryocytes, the precursors to platelets. The image shows a megakaryocyte in the process of generating two small platelets.

ONLINE COVER Alternative Antimalarial Application. This image depicts two alveolar macrophages infected with a clinical isolate of a nontuberculous mycobacteria, Mycobacterium abscessus (red). Nuclei are shown in blue. Limited treatment options exist for this lung pathogen. Belardinelli et al. showed that disruption of the gene that encodes the M. abscessus two-component regulator, dosRS, reduced tolerance to antibiotics. They identified repurposed antimalarial drugs that target DosRS and have bactericidal activity, one of which enhanced the efficacy of standard-of-care antibiotics.