Journal covers celebrate the aesthetic achievements of researchers and showcase the beauty of science to the wider world. Here are all 24 of Development’s covers for the crazy year that was 2020 – click the images to open the gallery, and you’ll find the cover description. Be sure to check out Development’s review of 2020 over on Twitter.
Which one’s your favourite? Leave a comment and we’ll let the authors know!
Micrographs of C. elegans anchor cells (cdh-3>mCherry::moeABD, magenta) atop the uterine-vulval basement membrane (laminin::GFP, green), expressing endogenously-tagged transcription factors (nuclear, green), grouped by column (left to right: egl-43::GFP, fos-1::GFP, hlh-2::GFP and nhr-67::GFP). Each row represents a different RNAi perturbation [top to bottom: empty vector, egl-43(RNAi), fos-1(RNAi), hlh-2(RNAi) and nhr-67(RNAi)]. See Research article by Medwig-Kinney et al. (dev185850)
Coronal section of a postnatal day 0 mouse brain stained to reveal EGFP from Dlx5/6-CIE cells in green, calbindin in red, and Hoechst in blue. Intact JNK signalling is required for Dlx5/6-CIE-positive interneurons to travel in tangentially oriented migratory streams to their correct positions in the developing cortical wall. See Research article by Myers et al. (dev180646).
Mouse primary cortical neurons cultured for 8 days in microfluidic chambers, which allow the compartmentalisation and fluidic isolation of axons from the cell bodies. Tau-1 immunolabelling (magenta) shows axons crossing via microgrooves into the axon compartment. Immunolabelling of the dendritic marker Map2 (green) shows dendrites and cell bodies restricted to the somatodendritic compartment. See Research article by Lucci et al. (dev180232).
An adult of the basal echinoid (cidaroid) Prionocidaris baculosa. The endomesoderm gene regulatory network (GRN) in cidaroids appears to preserve the ancestral state of echinoids and provides a valuable model for understanding the diversification of the early developmental GRN. See Research article by Yamazaki et al. (dev182139). Picture credit: Makoto Urata (Kanazawa University).
Dorsal view of the abdominal epidermis of a Drosophila pupa stained for E-cadherin to visualize cell junctions (white). The small histoblasts (cyan and black) proliferate and replace the large larval epidermal cells. Larval epidermal cells of one segment are coloured according to their position at the time of their extrusion: at the border of the histoblast nest (yellow), at the dorsal midline (green) or in between (magenta). See Research article by Michel and Dahmann (dev179606).
Artistic rearrangement of leaf confocal micrographs displaying battery of fluorescently tagged cell fate determinants in response to injuries. Images created by Anju P. S., Dhanya Radhakrishnan and Abdul Kareem V. K. Artwork by Mabel Maria Mathew (Indian Institute of Science Education and Research, Thiruvananthapuram, India). See Research article by Radhakrishnan et al. (dev185710).
Metatarsal from an E16.5 Lifeact-EGFP embryo (Lifeact is false coloured in pink, centre), which has been dissected and put into culture. Blood vessels (visualised with CD31, purple) sprout from the metatarsal to form a complex vascular network, allowing for ex vivo analysis of vascular density and sprout dynamics. See Research article by Schimmel et al. (dev185405).
Dorsal view of a Drosophila larval posterior segment, showing the topology of internal organs. The alary muscles (red) connect to the heart (phalloidin, blue; cardioblast nuclei, green) and to pericardiac cells (green) via an extracellular matrix network (pericardin, cyan) and maintain the heart and trachea (cyan) in proper positions. See Research article by Bataillé et al. (dev185645).
Polarising region grafts made to the anterior margin of a wing bud of a host chick embryo produce mirror-image duplications of the feather bud pattern, as shown by the black pigmentation. See Research article by Busby et al. (dev188821).
Proliferating Muller glia-derived progenitor cells in the chick retina. A vertical section of the retina was labeled for Sox2 (red), neurofilament (green) and phospho-histone H3 (blue). Inhibition of NF-κB-signaling stimulates the formation of proliferating Muller glia-derived progenitors. See Research article by Palazzo et al. (dev183418).
Volume rendering of an E16.5 mouse foetus based on X-ray microCT imaging. A novel protocol for staining cartilage matrix with Ruthenium Red is introduced that allows isotropic 3D imaging of the entire developing skeleton at micron resolution. See Research article by Gabner et al. (dev187633).
Line art traced using a real zebrafish retina image for reference and filled with single-cell transcriptome-defined clusters of cells depicted in different colours, representing a unified developmental program shared by embryonic and post-embryonic retinogenesis. See Techniques and Resources article by Xu et al. (dev185660).
Caenorhabditis elegans embryos imaged using single-molecule FISH to detect maternally-loaded mRNAs (clu-1, chs-1, imb-2, erm-1, F40G12.11, lem-3, nos-2 and cpg-2) in combination with cellular markers (PH::GFP, GLH-1::GFP, and DAPI). mRNAs accumulate at cell membranes, nuclear peripheries and within P granules. See Research article by Parker et al. (dev186817).
Root growth trajectories of Arabidopsis mutants in genes encoding RNA-binding proteins with specific N6-methyladenosine (m6A)-binding capacity, showing that a set of m6A-binding proteins controls directionality of root growth, and is required for rapid cellular proliferation during organogenesis, including root formation. See Research article by Arribas-Hernández et al. (dev189134).
Drosophila melanogaster embryos expressing an endogenously tagged EGFR-sfGFP construct showing localization of the EGFR in the developing tissue. Stage 7 (top), 9 (middle) and 11 (bottom) embryos are shown in a lateral view and are co-stained with EGFR-sfGFP (anti-GFP; green) and diphosphorylated ERK (dpERK; blue) antibodies. Images are depicted with anterior to the left and posterior to the right. See Techniques and Resources article by Revaitis et al. (dev183210).
Blood-brain barrier disruption in mice lacking FGFBP1 in endothelial cells. Brain blood vessels lacking FGFBP1 (podocalyxin; magenta) fail to deposit collagen IV (green) in the basement membrane and become permeable to circulating compounds (cadaverin; red). See Research article by Cottarelli et al. (dev185140).
The stereocilia bundles are apical extensions of the sensory cells of the inner ear (hair cells), here labelled with phalloidin in a newborn mouse utricle. The development and survival of the hair cells requires the transcription factor GFI1, which functions to repress a neuronal-associated gene expression profile. See Research report by Matern et al. (dev186015).
Interactive 3D model of an E18.5 typically developing mouse skull based on microCT data. Different colours indicate distinct bones. See Research article by Samuels et al. (dev191213).
An eight-cell embryo cultured within the confines of a cylindrical channel in a biocompatible hydrogel, in order to alter the shape and position of its blastomeres, and test the influence of these parameters on cell specification (magenta, pERM; yellow, F-actin; grey, DAPI). See Research article by Royer et al. (dev189449).
A cross-section of the small intestine in an embryonic day 14.5 Ryk knockout mouse (magenta, F-actin; cyan, nuclei). See Research article by Wang et al. (dev195388).
Dorsal view of the nervous system of a Xenopus tropicalis tadpole following β-tubulin antibody staining and confocal microscopy. X. tropicalis is a valuable model for understanding the function of human neurodevelopmental risk disorder genes due to its conserved diploid genome, the ability to make unilateral mutants, and the wealth of experimental tools and knowledge. See Research report by Willsey et al. (dev189290).
ChIP-seq binding data for HOXC6 (left), HOXC9 (center) and HOXC10 (right) in spinal cord patterning. The image was made by Dylan Iannitelli from experimental ChIP-seq data for Hox binding generated by Milica Bulajić. See Research article by Bulajić et al. (dev194761)
Scanning electron micrograph of the junction of the internal and external jugular vein with the superior vena cava in an E16.5 mouse embryo. Venous valves that guard the jugular veins are highlighted in green. Lymphovenous valves that prevent back flow of venous blood into lymphatic sacs are highlighted in magenta. Development of both types of valve is blocked in embryos that lack the RASA1 Ras-GTPase-activating protein, VEGF-C signalling and the transcription co-factors YAP and TAZ. See Research articles by Chen et al. (dev192351) and Cha et al (dev195453).
An image of the moment the optic fissure fuses to create the eye globe in human embryonic development. A section through the eye globe and lens was labelled for the transcription factor PAX6 (blue) and the actin cytoskeleton (white). Cells at the margins rearrange to form two complete epithelial layers. See Research article by Patel et al. (dev193649)