SEARCH · bioRxiv Science

Results for “Developmental Biology”

Search indexed bioRxiv preprints in genomics, neuroscience, cell biology and bioinformatics. Read source abstracts and check manuscript versions; preprints are not peer reviewed.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 973 records · Page 54Linked to original sources

bioRxiv2018

Determinants of Minimum Acceptable Diet among 6-23 Months Age Children in Ethiopia: A Multilevel Analysis of The Ethiopian Demographic Health Survey

BackgroundThough infant and young children should be fed according to a minimum acceptable diet to ensure appropriate growth and development, only 7% of Ethiopian 6-23 months age children meet the minimum acceptable dietary standards, which is lower than the national target of 11% set for 2016. Therefore, this study aims to assess the individual and community level determinants of minimum acceptable diet among 6-23 months age children in Ethiopia.\n\nMethodsThis study analyzed retrospectively a cross-sectional data on a weighted sample of 2919 children aged 6-23 months nested within 617 clusters after extracting from Ethiopian Demographic and Health Survey 2016 via the link www.measuredhs.com. By employing bi-variate multilevel logistic regression model, variables which were significant at the p-value < 25 were included in multivariable multilevel logistic regression analysis. Finally, variables with p-value < 0.05 were considered as significant predictors of minimum acceptable diet.\n\nResultsOnly 6.1% of 6-23 months age children feed minimum acceptable diet in Ethiopia. Children 18-23 months age (AOR=3.7, 95%CI 1.9, 7.2), fathers with secondary or higher education (AOR=2.1, 95%CI 1.2, 3.6), Employed mothers (AOR=1.7, 95%CI 1.2, 2.5), mothers have access to drinking water (AOR=1.9, 95%CI 1.2, 2.9), mothers with media exposure (AOR=2.1 95%CI 1.1, 2.7) were positive individual level predictors. Urban mothers (AOR=4.8, 95%CI 1.7, 13.2)) and agrarian dominant region (AOR=5.6, 95%CI 2.2, 14.5) were community level factors that significantly associated with minimum acceptable diet of 6-23 months age children.\n\nConclusionBoth individual and community level factors were significantly associated with minimum acceptable diet of 6-23 months age children in Ethiopia, suggesting that nutritional interventions designed to improve child health should not only be implemented at the individual level but tailored to community context as well.

developmental biology↗

bioRxiv2018

Morphogenesis of neurons and glia within an epithelium

To sense the outside world, some neurons protrude across epithelia, the cellular barriers that line every surface of our bodies. To study the morphogenesis of such neurons, we examined the C. elegans amphid, in which dendrites protrude through a glial channel at the nose. During development, amphid dendrites extend by attaching to the nose via DYF-7, a type of protein typically found in epithelial apical ECM. Here, we show that amphid neurons and glia exhibit epithelial properties, including tight junctions and apical-basal polarity, and develop in a manner resembling other epithelia. We find that DYF-7 is a fibril-forming apical ECM component that prevents rupture of the tube-shaped glial channel, reminiscent of roles for apical ECM in other narrow epithelial tubes. We also identify a role for FRM-2, a homolog of EPBL15/moe/Yurt which promote epithelial integrity in other systems. Finally, we show that other environmentally-exposed neurons share a requirement for DYF-7. Together, our results suggest that these neurons and glia can be viewed as part of an epithelium continuous with the skin, and are shaped by mechanisms shared with other epithelia.

developmental biology↗

bioRxiv2018

De novo genesis of retinal ganglion cells by targeted expression of KLF4 in vivo

Retinal ganglion cell (RGC) degeneration is a hallmark of glaucoma, the most prevalent cause of irreversible blindness. Thus, innovative therapeutic strategies are needed to protect and replace these projection neurons. It has been shown that endogenous glial cells of the retina, Muller cells, can be directly reprogrammed into late-born retinal interneurons. However, since RGCs are the first neurons born during development, the replacement of damaged RGCs requires the reprograming to an early neurogenic state. Here, we demonstrate that the pluripotency regulator Klf4 is sufficient to reprogram the potency of lineage-restricted retinal progenitor cells (RPCs) to generate RGCs in vivo. Transcriptome analysis disclosed that the overexpression of Klf4 induces crucial regulators of RGC competence and specification, including Atoh7 and Eya2. In contrast, loss-of-function studies in mice and zebrafish demonstrated that Klf4 is not essential for generation or differentiation of RGCs during retinogenesis. Nevertheless, induced RGCs (iRGCs) generated upon Klf4 overexpression migrate to the proper layer and project axons aligned with endogenous fascicles that reach the optic nerve head. Notably, iRGCs survive for up to 30 days after in vivo reprogramming. Finally, we demonstrate that Klf4 converts Muller cells into neurons that express markers of RGCs. Altogether, we identified Klf4 as a promising tool to reprogram retinal cells and regenerate RGCs in the mature retina.\n\nSignificance StatementCell fate determination is a key process for development, regeneration and for the design of therapeutic strategies that involve cellular reprogramming. This work shows that the manipulation of a single pluripotency regulator (Klf4) is sufficient to reprogram restricted progenitor cells in vivo. These reprogrammed progenitors reacquire the potency to generate retinal ganglion cells. Ganglion cell degeneration is the leading cause of irreversible blindness; therefore, manipulation of ganglion cell competence is of relevance for human health. Our findings point to Klf4 as a promising tool to develop therapeutic strategies for the replacement of damaged ganglion cells.

developmental biology↗

bioRxiv2018

Bacterial community dynamics during embryonic and larval development of three confamilial echinoids

Development of some animals is influenced by and, in some cases, dependent on the associated microbiota. The timing of when associated bacterial communities are established during the development of marine invertebrates and their subsequent dynamics across stages are known for only a few species. Here, we compare the bacterial communities of three confamilial echinoids from egg to juvenile using sequence-based approaches. Bacterial communities are established on unfertilized eggs and change gradually during embryonic and larval development. Despite the differences amongst these pre-metamorphic stages, approximately thirty-percent of OTUs identified in association with unfertilized egg were present in the juveniles. During embryonic development, host-associated communities diverged from the environmental microbiota but later converged following the onset of larval feeding. Taken together, the data presented here support the hypothesis that bacterial communities are established prior to fertilization and community composition shifts gradually thereafter, all while remaining distinct from the environment. Future work will need to determine the relative influence of the host and bacteria-bacteria interactions in shaping the associated bacterial community to determine the potential functional importance of bacteria during the development of larval sea urchins and benthic marine invertebrates more broadly.

developmental biology↗

bioRxiv2018

SOL1 and SOL2 Regulate Fate Transition and Cell Divisions in the Arabidopsis Stomatal Lineage

In the stomatal lineage, cells make fate transitions from asymmetrically dividing and self-renewing meristemoids, to commitment to the guard mother cell identity, and finally though a single division to create mature, post-mitotic stomatal guard cells. Flexibility in the stomatal lineage allows plants to alter leaf size and stomatal density in response to environmental conditions; however, transitions must be clean and unidirectional in order to produce functional and correctly patterned stomata. Among direct transcriptional targets of the stomatal initiating factor, SPEECHLESS, we found a pair of genes, SOL1 and SOL2, required for effective transitions in the lineage. Here we show that these two genes, which are homologues of the LIN54 DNA-binding components of the mammalian DREAM complex, are expressed in a cell cycle dependent manner and regulate cell fate and division properties in the self-renewing early lineage. In the terminal division of the stomatal lineage, however, these two proteins appear to act in opposition to their closest paralogue, TSO1, revealing complexity in the gene family may enable customization of cell divisions in coordination with development.

developmental biology↗

bioRxiv2018

Developmental Effects of the Pesticide Imidacloprid on Zebrafish Body Length and Mortality

The pesticide imidacloprid, a Neonicotinoid, is widely used and commercially available. Neonicotinoids are antagonists at nicotinic acetylcholine receptors, which can cause neurobehavioral effects in developing organisms. While the effects of other insecticides such as Malathion and Fipronil on zebrafish Danio rerio development have been studied, few studies describe the morphological effects of imidacloprid during zebrafish development. To test the hypothesis that imidacloprid concentration positively correlates to increased mortality and decreased body length, we exposed zebrafish to imidacloprid for five days post fertilization. Body length and embryo mortality were recorded at 1, 2, 3, 4, and 5 days post fertilization in 0 ug/L, 100 ug/L, 1,000 ug/L, and 10,000 ug/L imidacloprid concentrations. These concentrations were chosen to mimic levels that could be reached in the environment especially soon after application. Our results demonstrate statistically increased embryo mortality, with a f crit value of 3.193 and a f value of 3.098 from an ANOVA test, and impaired body length with a dose dependent correlation to the concentration of imidacloprid and a P value of less than 0.01 from a T test. Given the pesticides high prevalence, future studies should be considered to determine if this effect may impact livestock and human development.

developmental biology↗

bioRxiv2018

MicroRNA regulation of BMP signaling; cross-talk between endothelium and vascular smooth muscle cells

Vascular smooth muscle cells (vSMC) are essential to the integrity of blood vessels, and therefore an attractive target of therapeutics aimed at improving vascular function. Smooth muscle cells are one of the few cell types that maintain plasticity and can switch phenotypes from differentiated (contractile) to de-differentiated (synthetic) and vice versa. As small regulatory transcripts, miRNAs act as genetic fine tuners of posttranscriptional events and can act as genetic switches promoting phenotypic switching. The microRNA miR26a targets the BMP signalling effector, smad1. We show that loss of miR26 leads to hemorrhage (a loss of vascular stability) in vivo, suggesting altered vascular differentiation. Reduction in miR26a levels increases smad1 mRNA and phospho-Smad1 (pSmad1) levels. We show that increasing BMP signalling by overexpression of smad1 also leads to hemorrhage and that normalization of Smad1 levels through double knockdown of miR26 and smad1 rescues hemorrhage suggesting a direct relationship between miR26 and smad1 and vascular stability. Using a BMP genetic reporter and pSmad1 staining we show that the effect of miR26 on vascular instability is non-autonomous; BMP signalling is active in embryonic endothelial cells, but not in smooth muscle cells. Nonetheless, increased BMP signalling due to loss of miR26 results in an increase in acta2-expressing smooth muscle cell numbers and promotes a differentiated smooth muscle morphology. Taken together our data suggests that miR26 modulates BMP signalling in endothelial cells and indirectly promotes a differentiated smooth muscle phenotype. Our data also suggests that crosstalk from BMP-responsive endothelium to smooth muscle is important for its differentiation.

developmental biology↗

bioRxiv2018

Single cell RNA-seq study of wild type and Hox9,10,11 mutant developing uterus

The uterus is a remarkable organ that must guard against infections while maintaining the ability to support growth of a fetus without rejection. The Hoxa10 and Hoxa11 genes have previously been shown to play essential roles in uterus development and function. In this report we show that the Hoxc9,10,11 genes play a redundant role in the formation of uterine glands. In addition, we use single cell RNA-seq to create a high resolution gene expression atlas of the developing wild type mouse uterus. Cell types and subtypes are defined, for example dividing endothelial cells into arterial, venous, capillary, and lymphatic, while epithelial cells separate into luminal and glandular subtypes. Further, a surprising heterogeneity of stromal and myocyte cell types are identified. Transcription factor codes and ligand/receptor interactions are characterized. We also used single cell RNA-seq to globally define the altered gene expression patterns in all developing uterus cell types for two Hox mutants, with 8 or 9 mutant Hox genes. The mutants show a striking disruption of Wnt signaling as well as the Cxcl12/Cxcr4 ligand/receptor axis.\n\nSummary statementA single cell RNA-seq study of the developing mouse uterus defines cellular heterogeneities, lineage specific gene expression programs and perturbed pathways in Hox9,10,11 mutants.

developmental biology↗

bioRxiv2018

Zebrafish Otolith Biomineralization Requires Polyketide Synthase

Deflecting biomineralized crystals attached to vestibular hair cells are necessary for maintaining balance. Zebrafish (Danio rerio) are useful organisms to study these biomineralized crystals called otoliths, as many required genes are homologous to human otoconial development. We sought to identify and characterize the causative gene in a trio of mutants, no content (nco) and corkscrew (csr), and vanished (vns), which fail to develop otoliths during early ear development. We show that nco, csr, and vns have potentially deleterious mutations in polyketide synthase (pks1), a multi-modular protein that has been previously implicated in biomineralization events in chordates and echinoderms. We found that Otoconin-90 (Oc90) expression within the otocyst is normal in nco and csr; therefore, it is not sufficient for otolith biomineralization in zebrafish. Similarly, normal localization of Otogelin, a protein required for otolith tethering in the otolithic membrane, is not sufficient for Oc90 attachment. Furthermore, eNOS signaling and Endothelin-1 signaling were the most up- and down-regulated pathways during otolith agenesis in nco, respectively. Our results demonstrate distinct processes for otolith nucleation and biomineralization in vertebrates and will be a starting point for models that are independent of Oc90-mediated seeding. This study will serve as a basis for investigating the role of eNOS signaling and Endothelin-1 signaling during otolith formation.

developmental biology↗

bioRxiv2018

DEVELOPMENTAL DYNAMICS OF GREEN FLUORESCENT CHROMATOPHORES IN THE DAGGERBLADE GRASS SHRIMP, PALAEMONETES PUGIO HOLTHUIS, 1949 (DECAPODA, CARIDEA, PALAEMONIDAE)

The daggerblade grass shrimp, Palaemonetes pugio Holthuis 1949 relies heavily on transparency as the primary form of camouflage yet possess several types of pigmented chromatophores located throughout the body. A distinct sub-population of yellow/white chromatophores have been discovered to exhibit brilliant green fluorescence. These cells develop in the embryo and are the primary chromatophore present in larval organisms. Post-larval grass shrimp undergo a major restructuring of the pattern and morphology of fluorescent chromatophores after metamorphosis with chromatophores found uniformly distributed throughout the body and at high concentration on the hepatopancreas and the eye stalks. In adult P. pugio the number of fluorescent chromatophores is significantly reduced and fluorescence is limited to only a subset of these chromatophores. The novel fluorescent properties of these cells, there relatively high abundance during early life stages, and pattern of development, suggest important cellular functions for these fluorescent chromatophores in grass shrimp.

developmental biology↗

bioRxiv2018

Single cell dynamics of embryonic muscle progenitor cells in zebrafish

Muscle stem cells hold a great therapeutic potential in regenerating damaged muscles. However, the in vivo behavior of muscle stem cells during muscle growth and regeneration is still poorly understood. Using zebrafish as a model, we describe the in vivo dynamics and function of dermomyotome cells, a population of embryonic muscle progenitor cells. Dermomyotome cells are located in a superficial layer external to muscle fibers and express many extracellular matrix (ECM) genes including col1a2. Utilizing a new col1a2 transgenic line, we show that dermomyotome cells display a ramified morphology with dynamic cellular processes. Cell lineage tracing demonstrates that col1a2+ dermomyotome cells contribute to normal muscle growth as well as muscle injury repair. Combination of live imaging and single cell clonal analysis reveals a highly-choreographed process of muscle regeneration. Activated dermomyotome cells change from the quiescent ramified morphology to a polarized and elongated morphology and generate daughter cells that fuse with existing muscle fibers. Ablation of the dermomyotome severely compromises muscle injury repair. Our work provides a dynamic view of embryonic muscle progenitor cells during zebrafish muscle regeneration.\n\nSummary statementLive imaging and single cell clonal analysis reveal dynamic behaviors of zebrafish embryonic muscle progenitor cells in quiescence and activation.

developmental biology↗

bioRxiv2018

A large-scale systemic RNAi screen in the red flour beetle Tribolium castaneum identifies novel genes involved in arthropod muscle development

Although muscle development has been widely studied in Drosophila melanogaster there are still many gaps in our knowledge, and it is not known to which extent this knowledge can be transferred to other insects. To help in closing these gaps we participated in a large-scale RNAi screen that used the red flour beetle, Tribolium castaneum, as a screening platform. The effects of systemic RNAi were screened upon double-stranded RNA injections into appropriate muscle-EGFP tester strains. Injections into pupae were followed by the analysis of the late embryonic/early larval muscle patterns, and injections into larvae by the analysis of the adult thoracic muscle patterns. Herein we describe the results of the first-pass screens with pupal and larval injections, which covered ~8,500 and ~5,000 genes, respectively, of a total of ~16,500 genes of the Tribolium genome. Apart from many genes known from Drosophila as regulators of muscle development, a collection of genes previously unconnected to muscle development yielded phenotypes in larval body wall and leg muscles as well as in indirect flight muscles. We then present the main candidates from the pupal injection screen that remained after being processed through a series of verification and selection steps. Further, we discuss why distinct though overlapping sets of genes are revealed by the Drosophila and Tribolium screening approaches.

developmental biology↗

bioRxiv2018

RNAi screen in Tribolium reveals involvement of F-BAR proteins in myoblast fusion and visceral muscle morphogenesis in arthropods

In a large-scale RNAi screen in Tribolium castaneum for genes with knock-down phenotypes in the larval somatic musculature, one recurring phenotype was the appearance of larval muscle fibers that were significantly thinner than those in control animals. Several of the genes producing this knock-down phenotype corresponded to orthologs of Drosophila genes that are known to participate in myoblast fusion, particularly via their effects on actin polymerization. A new gene previously not implicated in myoblast fusion but displaying a similar thin-muscle knock-down phenotype was the Tribolium ortholog of Nostrin, which encodes an F-BAR and SH3 domain protein. Our genetic studies of Nostrin and Cip4, a gene encoding a structurally related protein, in Drosophila show that the encoded F-BAR proteins jointly contribute to efficient myoblast fusion during larval muscle development. Together with the F-Bar protein Syndapin they are also required for normal embryonic midgut morphogenesis. In addition, Cip4 is required together with Nostrin during the profound remodeling of the midgut visceral musculature during metamorphosis. We propose that these F-Bar proteins help govern proper morphogenesis particularly of the longitudinal midgut muscles during metamorphosis.

developmental biology↗

bioRxiv2018

Bovine blastocyst development depends on threonine catabolism

Increasing evidence suggests that pluripotency is a metabolically specialised state. In mouse, inner cell mass (ICM) cells and ICM-derived pluripotent stem cells (PSCs) critically depend on catabolising the amino acid threonine, while human PSCs require leucine, lysine, methionine or tryptophan. However, little is known about the specific amino acid requirements of putative pluripotent cells in bovine. We selectively depleted candidate essential amino acids (EAAs) from individually cultured bovine embryos to study their role in blastocyst development. Depleting one (-T, -M), two (-MT, -CM, -CT, -IL, -IK, -KL) or three (-CMT, -IKL) EAAs from chemically defined protein-free culture medium did not affect the morula-to-blastocyst transition from day five (D5) to D8 in vitro. By contrast, removing six (-CIKLMT, -FHRYVW), nine (+CMT, +IKL), eleven EAAs (+T, +M) or all twelve EAAs increasingly impaired blastocyst development. As no clear candidate emerged from this targeted screen, we focussed on threonine dehydrogenase (TDH), which catalyses threonine catabolism. TDH mRNA and protein was present at similar levels in trophectoderm (TE) and ICM but absent from several adult somatic tissues. We then treated morulae with an inhibitor (Qc1) that blocks TDH from catabolising threonine. Continuous exposure to Qc1 reduced total and high-quality blastocyst development from 37% to 26% and 18% to 8%, respectively (P<0.005). This was accompanied by [~]2-fold decrease in ICM, TE and total cell numbers (P<0.005), which was due to increased autophagy (P<0.05). At the same time, ICM-(NANOG) and TE-restricted (KRT8) genes were up-and down-regulated, respectively (P<0.05). In summary, bovine blastocyst viability depended on TDH-mediated threonine catabolism. However, ICM and TE cells did not metabolically differ in this regard, highlighting species-specific connections between metabolism and pluripotency regulation in mouse vs cattle.

developmental biology↗

bioRxiv2018

Actomyosin-driven tension at compartmental boundaries orients cell division independently of cell geometry in vivo

During animal development, planar polarization of the actomyosin cytoskeleton underlies key morphogenetic events such as axis extension and boundary formation. Actomyosin is enriched along compartment boundaries during segmentation of the Drosophila embryo, forming supracellular contractile cables that keep cells segregated at boundaries. Here, we show that these contractile actomyosin cables bias the orientation of division in cells in contact with compartment boundaries. By decreasing actomyosin cable tension locally using laser ablation or, conversely ectopically increasing tension using laser wounding, we demonstrate that localised subcellular force is necessary and sufficient to orient mitoses in vivo. Moreover this bias is independent of cell geometry and involves capture of the spindle pole by the actomyosin cortex.

developmental biology↗

bioRxiv2018

Drosophila R8 photoreceptor cell subtype specification requires Notch and hibris.

Cell differentiation and cell fate determination in sensory systems are essential for stimulus discrimination and coding of environmental stimuli. Color vision is based on the differential color sensitivity of retinal photoreceptors, however the developmental programs that control photoreceptor cell differentiation and specify color sensitivity are poorly understood. In Drosophila melanogaster, there is evidence that the color sensitivity of different photoreceptors in the compound eye is regulated by inductive signals between cells, but the exact nature of these signals and how they are propagated remains unknown. We conducted a genetic screen to identify additional regulators of this process and identified a novel mutation in the hibris gene. hibris encodes an irre cell recognition module protein (IRM). These immunoglobulin super family cell adhesion molecules include human neph and nephrin (NPHS1). hibris is expressed dynamically in the developing Drosophila melanogaster eye and loss-of-function mutations give rise to a diverse range of mutant phenotypes including disruption of the specification of R8 photoreceptors cell diversity. The specification of blue or green sensitivity in R8 cells is also dependent upon Notch signaling. We demonstrate that hibris is required within the retina, non-cell autonomously for these effects, suggesting an additional layer of complexity in the signaling process that produces paired expression of opsin genes in adjacent R7 and R8 photoreceptor cells.\n\nAuthor SummaryAs humans, our ability to distinguish different colors is dependent upon the presence of three different types of cone cell neurons in the retina of the eye. The cone cells express blue, green or red absorbing visual pigments that detect and discriminate between these colors. The principle of color discrimination by neurons \"tuned\" to different colors is an evolutionarily conserved specialization that occurs in many different animals. This specialization requires 1) visual pigments that detect different colors and 2) a developmental program that regulates the expression of these pigments in different types of cells. In this study we discovered that the fruit fly (Drosophila melanogaster) gene hibris is required for the developmental program that produces blue sensitive neurons in the fly retina. When we over-expressed hibris throughout the developing retina, extra blue sensitive cells were produced. These results demonstrate that if there is not enough hibris, too few blue sensitive cells form, but if there is too much hibris, too many blue sensitive cells form. Finally, we discovered that the hibris gene does not act in color sensitive neurons of the retina themselves. This surprising discovery suggests that hibris may influence development of the retina in a completely new and different way.

developmental biology↗

bioRxiv2018

The transmembrane protein Crb2a regulates cardiomyocyte apicobasal polarity and adhesion in zebrafish

Tissue morphogenesis requires changes in cell-cell adhesion as well as in cell shape and polarity. Cardiac trabeculation is a morphogenetic process essential to form a functional ventricular wall. Here we show that zebrafish hearts lacking Crb2a, a component of the Crumbs polarity complex, display compact wall integrity defects and fail to form trabeculae. Crb2a localization is very dynamic, at a time when other cardiomyocyte junctional proteins also relocalize. Before the initiation of cardiomyocyte delamination to form the trabecular layer, Crb2a is expressed in all ventricular cardiomyocytes colocalizing with the junctional protein ZO-1. Subsequently, Crb2a becomes localized all along the apical membrane of compact layer cardiomyocytes and is downregulated by those delaminating. We show that blood flow and Nrg/ErbB2 signaling regulate these Crb2a localization changes. crb2a mutants display a multilayered wall with polarized cardiomyocytes, a unique phenotype. Our data further indicate that Crb2a regulates cardiac trabeculation by controlling the localization of tight and adherens junctions in cardiomyocytes. Importantly, transplantation data show that Crb2a controls trabeculation in a CM-autonomous manner. Altogether, our study reveals a critical role for Crb2a during cardiac development.\n\nSummary statementInvestigation of the Crumbs polarity protein Crb2a in zebrafish reveals a novel role in cardiac development via regulation of cell-cell adhesion and apicobasal polarity.

developmental biology↗

bioRxiv2018

Regulation of tensile stress in response to external forces coordinates epithelial cell shape transitions with organ growth and elongation

The role of actomyosin contractility at epithelial adherens junctions has been extensively studied. However, little is known about how external forces are integrated to establish epithelial cell and organ shape in vivo. We use the Drosophila follicle epithelium to investigate how tension at adherens junctions is regulated to integrate external forces arising from changes in germline size and shape. We find that overall tension in the epithelium decreases despite pronounced growth of enclosed germline cells, suggesting that the epithelium relaxes to accommodate growth. However, we find local differences in adherens junction tension correlate with apposition to germline nurse cells or the oocyte. We demonstrate that medial Myosin II coupled to corrugating adherens junctions resists nurse cell-derived forces and thus maintains apical surface areas and cuboidal cell shapes. Furthermore, medial reinforcement of the apical surface ensures cuboidal-to-columnar cell shape transitions and imposes circumferential constraints on nurse cells guiding organ elongation. Our study provides insight into how tension within an adherens junction network integrates growth of a neighbouring tissue, mediates cell shape transitions and channels growth into organ elongation.

developmental biology↗