Biology subjects

Sutton, G.

Publications and source records attributed to Sutton, G..

8 recordsLinked to original sources

bioRxiv2026

Lost and found: beer belly is a novel, ancient regulator of animal development

Single-cell RNA sequencing (scRNA-seq) can provide new insights into the regulation of developmental processes by revealing unknown or overlooked genes. We identified a novel gene called beer belly (bebe) as a marker of a segment addition zone (SAZ) associated cell cluster in a single-cell atlas of the spider Parasteatoda tepidariorum. Here we show that bebe is an ancient toolkit gene encoding a previously uncharacterised protein predicted to be secreted, which likely plays an important role in the development of most animal phyla. However, we could not identify a bebe ortholog in any mammal or holometabolous insect, suggesting it has been lost in these lineages and explaining why it has been overlooked to date. Knock-down of bebe expression in P. tepidariorum demonstrates that it regulates SAZ size and consequently segment size by interacting with Wnt8. Our findings also suggest that bebe may regulate segmentation in other invertebrates and play additional developmental roles in bilaterian and non-bilaterian animals, likely ancestrally, through modulation of Wnt signalling. This study emphasises the promise of applying single-cell sequencing across a diverse range of species to better understand the regulation of development beyond candidate genes from traditional models, allowing us to better characterise the animal developmental toolkit and its evolution.

developmental biology↗

bioRxiv2026

Rab8a-positive vesicles transport Wnt8a along cytonemes in zebrafish embryogenesis.

Wnt signalling is a conserved pathway that orchestrates key developmental processes by regulating cell fate, proliferation, and tissue organisation. While the production and secretion of Wnt ligands are well characterised, less is known about how lipid-modified Wnts are delivered for long-range communication. Recently, cytonemes - actin-based signalling filopodia - have been identified as transporters of Wnts over distances to target specific cells in embryogenesis. Here, we characterise Rab8a-dependent vesicular trafficking as a crucial step in this process. Using human cell lines and zebrafish embryos, we show that Wnt ligands, such as Wnt8a, are transported with their carrier protein Wntless (Wls) in Rab8a-positive vesicles along cytonemes, where they fuse at the tips to enable hand-over and signal activation in neighbouring cells. Disruption of Rab8a function results in the intracellular retention of Wnt8a, reduces Wnt spreading and paracrine signalling, and alters embryonic patterning, consistent with reduced Wnt/{beta}-catenin function. Conversely, Rab8a activation enhances Wnt8a dissemination, leading to increased long-range signalling and, consequently, patterning defects in embryogenesis. Our findings uncover a dedicated intracellular trafficking route for Wnt delivery to and along cytonemes, offering new insights into how the spatial precision of Wnt spreading in vertebrate tissues is achieved.

developmental biology↗

bioRxiv2024

Structure and stabilization of the antigenic glycoprotein building blocks of the New World mammarenavirus spike complex

The spillover of New World (NW) arenaviruses from rodent reservoirs into human populations poses a continued risk to human health. NW arenaviruses present a glycoprotein (GP) complex on the envelope surface of the virion, which orchestrates host-cell entry and is a key target of the immune response arising from infection and immunization. Each protomer of the trimeric GP is composed of a stable signal peptide (SSP), a GP1 attachment glycoprotein, and a GP2 fusion glycoprotein. To glean insights into the architecture of this key therapeutic target, we determined the crystal structures of NW GP1-GP2 heterodimeric complexes from Junin virus (JUNV) and Machupo virus (MACV). Due to the metastability of the interaction between GP1 and GP2, structural elucidation required the introduction of a disulfide bond at the GP1-GP2 complex interface, but no other stabilizing modifications were required. While the overall assembly of NW GP1-GP2 is conserved with that presented by Old World (OW) arenaviruses, including Lassa virus (LASV) and lymphocytic choriomeningitis virus (LCMV), NW GP1-GP2 complexes are structurally distinct. Indeed, we note that when compared to the OW GP1-GP2 complex, the globular portion of NW GP1 undergoes limited structural alterations upon detachment from its cognate GP2. We further demonstrate that our engineered GP1-GP2 heterodimers are antigenically relevant and recognized by neutralizing antibodies. These data provide insights into the distinct assemblies presented by NW and OW arenaviruses, as well as provide molecular-level blueprints that may guide vaccine development. ImportanceAlthough the emergence of New World (NW) hemorrhagic fever mammarenaviruses poses an unceasing threat to human health, there is a paucity of reagents capable of protecting against the transmission of these pathogens from their natural rodent reservoirs. This is, in part, attributed to our limited understanding of structure and function of the NW glycoprotein spike complex presented on the NW arenavirus surface. Here, we provide a detailed molecular-level description of how the two major components of this key therapeutic target assemble to form a key building block of the NW arenaviral spike complex. The insights gleaned from this work provide a framework for guiding the structure-based development of NW arenaviral vaccines.

biochemistry↗

bioRxiv2021

Development of an in-situ printing system with human platelet lysate based bioink to treat corneal perforation

PurposeCorneal perforation is a clinical emergency. Tissue glue to seal the perforation, and supplementary topical medication represents existing standard treatment. Previously, our group developed a transparent human platelet lysate (hPL)-based biomaterial that showed good cell compatibility and accelerated corneal epithelial cells healing in-vitro. This study aims to develop a novel treatment method for corneal perforation using this biomaterial. MethodsRheometry was used to measure the hPL-based biomaterial behaviour at room and corneal surface temperatures. Its adhesiveness to porcine skin and burst pressure limit were also measured. Based on rheological behaviour, a hand-held biopen was developed to extrude it onto the cornea. An animal trial (5 New Zealand white rabbits) to compare impact of the biomaterial and cyanoacrylate glue (control group) on a 2mm perforation was conducted to evaluate safety and efficacy. ResultsThe hPL-based biomaterial showed higher adhesiveness compared to commercial fibrin glue and withstood burst pressure approximately 6.4x higher than routine intraocular pressure. Treatment rabbits had lower pain scores and faster recovery, despite generating similar scar-forming structure compared to controls. No secondary corneal ulcer was generated in rabbits treated with the bio-adhesive. ConclusionsThis study reports a novel in-situ printing system capable of delivering a hPL-based, transparent bio-adhesive and successfully treating small corneal perforations. Bio-adhesive-treated rabbits recovered faster and required no additional analgesia. Both groups showed scarred corneal tissue after healing, however no infection and inflammation was observed by 3 weeks. The delivery system was easy to use and may represent an alternative treatment for corneal perforation. HighlightsO_LIThis study presents a novel in situ printing system to treat corneal perforation C_LIO_LIThe system is comprised of a human platelet lysate-based bio-adhesive and a pen-like hand held delivery system C_LIO_LIMechanical tests showed our transparent bio-adhesive has a higher adhesiveness compared to existing treatments and burst pressure threshold approximately 6.4 times higher than normal intraocular pressure. C_LIO_LIIn vivo rabbit trial showed that compared to cyanoacrylate glue, the bio-adhesive was safer, faster healing and led to less pain in rabbits. C_LI

bioengineering↗

bioRxiv2020

Further evidence against a force-velocity trade-off in muscle driven dynamic lever systems

Here we argue that quasi-static analyses are insufficient to predict the speed of an organism from its skeletal mechanics alone (i.e. lever arm mechanics). Using a musculoskeletal numerical model we specifically demonstrate that 1) a single lever morphology can produce a range of output velocities, and 2) a single output velocity can be produced by a drastically different set of lever morphologies. These two sets of simulations quantitatively demonstrate that it is incorrect to assume a one-to-one relationship between lever arm morphology and organism maximum velocity. We then use a statistical analysis to quantify what parameters are determining output velocity, and find that muscle physiology, geometry, and limb mass are all extremely important. Lastly we argue that the functional output of a simple lever is dependent on the dynamic interaction of two opposing factors: those decreasing velocity at low mechanical advantage (low torque and muscle work) and those decreasing velocity at high mechanical advantage (muscle force-velocity effects). These dynamic effects are not accounted for in static analyses and are inconsistent with a force-velocity tradeoff in lever systems. Therefore, we advocate for a dynamic, integrative approach that takes these factors into account when analyzing changes in skeletal levers.

zoology↗

bioRxiv2020

Assembly intermediates of orthoreovirus captured in the cell

Traditionally molecular assembly pathways for viruses have been inferred from high resolution structures of stable intermediates purified in vitro, and from low resolution images of cell sections as well as from genetic approaches including conditionally lethal mutants. Here, we directly visualise a previously unsuspected single shelled icosahedral intermediate for a mammalian orthoreovirus, in addition to the expected virions, in cryo-preserved infected cells by cryo-electron tomography of cellular lamellae1,2. Particle classification and averaging yielded structures at resolutions as high as 5.6 [A], sufficient to identify secondary structural elements and place known molecular structures, allowing us to produce an atomic model of the intermediate, comprising 120 copies of protein {lambda}1 and 120 copies of {sigma}2. This {lambda}1 shell is in a collapsed form compared to the mature virions, with the molecules pushed inwards at the icosahedral 5-folds by ~100 [A]. This grossly indented shell, although produced by a mammalian reovirus, is reminiscent of the first assembly intermediate of prokaryotic dsRNA viruses belonging to a different virus family3, adding weight to the supposition that these diverse viruses share a common ancestor, and suggesting mechanisms for the assembly of viruses of the Reoviridae. Such methodology holds enormous promise for the dissection of the replication cycle of many viruses.

microbiology↗

bioRxiv2019

Cyp26b1 is required for proper airway epithelial differentiation during lung development

Proper organ development depends on coordinated communication between multiple cell types. Retinoic acid (RA) is an autocrine and paracrine signaling molecule critical for the development of most organs including the lung. Both RA excess and deficiency lead to drastic alterations in embryogenesis, often culminating in embryonic or neonatal lethality. Therefore, RA levels must be spatially and temporally titrated to ensure proper organogenesis. Despite extensive work detailing the effects of RA deficiency in early lung morphogenesis, little is known about how RA levels are modulated during late lung development. Here, we investigate the role of the RA catabolizing protein Cyp26b1 in lung development. Cyp26b1 is highly enriched in lung endothelial cells (ECs) throughout the course of development. We find that loss of Cyp26b1 impacts differentiation of the distal epithelium without appreciably affecting proximal airways, EC lineages, or stromal populations. Cyp26b1-/- lungs exhibit an increase in cellular density, with an expansion of distal progenitors at the expense of alveolar type 1 (AT1) cells, which culminates in neonatal death. Exogenous administration of RA in late gestation was able to partially reproduce this defect in epithelial differentiation; however, transcriptional analyses of Cyp26b1-/- lungs and RA-treated lungs reveal separate, but overlapping, transcriptional responses. These data suggest that the defects observed in Cyp26b1-/- lungs are caused by both RA-dependent and RA-independent mechanisms. This work highlights critical cellular crosstalk during lung development involving a crucial role for Cyp26b1-expressing endothelium, and identifies a novel RA rheostat in lung development.\n\nHIGHLIGHTSO_LICyp26b1 is highly expressed in lung ECs throughout development\nC_LIO_LICyp26b1-null lungs fail to undergo proper differentiation of distal epithelium leading to an increase in progenitors and AT2 cells at the expense of AT1 cells\nC_LIO_LIFunctional and transcriptional analyses suggest both RA-dependent and RA-independent mechanisms\nC_LI

developmental biology↗

bioRxiv2019

High accuracy DNA sequencing on a small, scalable platform via electrical detection of single base incorporations

High throughput DNA sequencing technologies have undergone tremendous development over the past decade. Although optical detection-based sequencing has constituted the majority of data output, it requires a large capital investment and aggregation of samples to achieve optimal cost per sample. We have developed a novel electronic detection-based platform capable of accurately detecting single base incorporations. The GenapSys technology with its electronic detection modality allows the system to be compact, accessible, and affordable. We demonstrate the performance of the system by sequencing several different microbial genomes with varying GC content. The platform is capable of generating up to 2 Gb of high-quality nucleic acid sequence in a single run. We routinely generate sequence data that exceeds 99% raw accuracy with read lengths of up to 175 bp. Average quality scores remain above Q30 (99.9% raw sequencing accuracy) beyond 150 bp, with more than 85% of total bases at or above Q30. The utility of the platform is highlighted by targeted sequencing of the human genome. We show high concordance of SNP detection on the human NA12878 HapMap cell line with data generated on the Illumina sequencing platform. In addition, we sequenced a targeted panel of cancer-associated genes in a well characterized reference standard. With multiple library preparation approaches on this sample, we were able to identify low frequency mutations at expected allele frequencies.

genomics↗