Special Issue: Imaging Development, Stem Cells and Regeneration
Advances in live imaging early mouse development: exploring the researcher's interdisciplinary toolkit
Summary: Live imaging is an intrinsically interdisciplinary endeavour, dependent on advances in several disciplines including embryo culture, microscopy hardware and computational analysis, any one of which can become limiting.
Summary: This Primer offers a practical review of the field of tissue clearing, a process which enables 3D imaging of intact embryos and animals, but can be daunting to implement.
Summary: This Primer explains and provides advice on two- and three-dimensional stress inference, an increasingly popular technique to identify the role of mechanics during embryo development.
Summary: This Review describes how advances in light microscopy and computational methods enable the examination of embryonic development like never before, with new tools and methods that make it possible to track cells and map their fates.
Summary: This Review summarizes recent advances in bioimage analysis enabled by deep learning algorithms.
Single-molecule tracking technologies for quantifying the dynamics of gene regulation in cells, tissue and embryos
Summary: Single-molecule tracking in live cells and embryos is a powerful approach for studying the molecular dynamics underlying gene regulation. This Review covers core technologies, concepts, recent advances and applications of in vivo single-molecule tracking.
Summary: This review presents in vivo imaging methods currently used to investigate adult neural stem cell activation and physiology.
Summary: This Review outlines genetically encoded biosensors that monitor ERK activity in living cells and discusses spatiotemporal ERK dynamics and their roles in developmental contexts.
Summary: This Review describes recent advances in the field of axonal development prompted by breakthroughs in imaging technology, with a special focus on contributions of light-sheet and super-resolution microscopy.
STEM CELLS AND REGENERATION
Live imaging of the Drosophila ovarian niche shows spectrosome and centrosome dynamics during asymmetric germline stem cell division
Summary: Imaging of live Drosophila germline stem cells in the ovarian niche reveals their asymmetric division and centrosome behaviour, whereas tumorous stem cells divide symmetrically.
Summary: This study reveals how clonal heterogeneity may arise in distinct body regions, highlighting clonal dominance as an integral adaptive mechanism through which stem cells shape vertebrate skin.
Summary: A new target-specific nerve regeneration model reveals that zebrafish vagus neurons rely on a cell-intrinsic memory of their positional identities to rebuild the topographic innervation pattern of the nerve robustly after injury.
Cyclic growth of dermal papilla and regeneration of follicular mesenchymal components during feather cycling
Summary: Dermal components of feather follicles undergo large scale remodeling involving stem cells, transient amplifying cells and differentiated cells. The control of this homeostasis in physiological and plucked-induced cycling is analyzed.
Summary: A method that allows live imaging of proliferating cardiomyocytes during zebrafish heart regeneration in their native tissue context.
Anterior expansion and posterior addition to the notochord mechanically coordinate zebrafish embryo axis elongation
Summary: Targeted multi-photon tissue ablation reveals that coordinated cell expansion and addition to the notochord in zebrafish embryos contributes to the elongation of segmented tissue required for embryo anterior-posterior axis extension.
The Arabidopsis stomatal polarity protein BASL mediates distinct processes before and after cell division to coordinate cell size and fate asymmetries
Summary: Discrete roles for cell polarity and the polarity protein BASL before and after asymmetric divisions are revealed through quantitative imaging and lineage tracking of plants expressing BASL at restricted points in the cell cycle.
Summary: This paper presents three endogenously-tagged mouse models for investigating the localization and dynamics of transmembrane planar cell polarity proteins Celsr1, Frizzled6 and Vangl2.
Summary: A multicolor transgene, NeuroPAL, is used to differentially label all male-specific neurons of C. elegans, thereby providing landmarks for gene expression, neuronal activity and cell fate analysis.
Summary: Improved live imaging on a subcellular scale in the context of the entire Drosophila embryo by a combination of light-sheet engineering and multiview techniques.
The initial expansion of the C. elegans syncytial germ line is coupled to incomplete primordial germ cell cytokinesis
Summary:C. elegans germ cells divide within a syncytium in which intercellular bridges are maintained by stable actomyosin rings. We herein demonstrate that stable rings arise de novo as a result of incomplete germ cell cytokinesis.
Summary: Metaphloem sieve element differentiation in Arabidopsis roots follows a robust developmental trajectory that is not directly influenced by adjacent or preceding protophloem sieve element development under normal circumstances.
Stable establishment of organ polarity occurs several plastochrons before primordium outgrowth in Arabidopsis
Summary: We revisited classical surgical experiments in Solanaceae, using precise laser ablations to show that dorsoventral patterning in vegetative and floral meristems in Arabidopsis is robustly programmed in primordia some time before polarity is completely established.
Collective nuclear behavior shapes bilateral nuclear symmetry for subsequent left-right asymmetric morphogenesis in Drosophila
Summary: The distinctive positioning and a novel collective nuclear behavior by which nuclei align left-right (LR) symmetrically in the Drosophila anterior midgut are responsible for the LR-asymmetric development of this organ.
Dynamics of hunchback translation in real-time and at single-mRNA resolution in the Drosophila embryo
Summary: Use of the SunTag method to allow single-molecule imaging in fixed and live Drosophila embryos reveals translational repression of zygotic hunchback mRNAs.
Summary: Oriented cell movement at the leading edge mesendoderm surface allows this tissue to move by being pulled forward by cells at its front end.
TECHNIQUES AND RESOURCES
Summary: A new approach for automating 3D reconstructions of multicellular structures that highlights its utility by analyzing patterns of growth present during Drosophila oogenesis.
QuantifyPolarity, a new tool-kit for measuring planar polarized protein distributions and cell properties in developing tissues
Summary: We present a novel planar polarity quantification method based on Principal Component Analysis that performs robustly in quantifying planar polarity independently of variation in cell geometry and other image properties.
Summary: MOrgAna, an open access software with a user-friendly interface, implements deep learning networks to segment, quantify and visualize morphological and fluorescence information of hundreds of organoid images within minutes.
Summary: A nanobody-based method, NaNuTrap, allows early in vivo cell nuclei labelling independently of the maturation time of the fluorescent protein and for transforming of cytoplasmic GFP-expressing lines into nuclear-labelled lines.
Summary: Parallel microfluidic long-term imaging allows reliable long-term study of Caenorhabditis elegans development across multiple larval stages at high-resolution and with minimal effect on physiological development.
Summary: Introducing an easy-to-use automated anatomical phenotyping pipeline for mouse embryos along with a highly-detailed anatomical E14.5 atlas.
A landmark-free morphometrics pipeline for high-resolution phenotyping: application to a mouse model of Down syndrome
Summary: This paper presents a new computational pipeline for comparing and mapping global and local anatomical shape differences that is higher-resolution and requires less expertise and labour than traditional landmarking methods.
Concerted morphogenesis of genital ridges and nephric ducts in the mouse captured through whole-embryo imaging
Summary: Whole-embryo tissue clearing and light sheet microscopy are used to characterize mouse early urogenital morphogenesis. Regional patterns found in the gonad show parallels in the adjacent mesonephric ducts.