bioRxiv Science⌕ Search

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 Read source abstracts and check manuscript versions; preprints are not peer reviewed.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 793 records · Page 44Linked to original sources

Kinemomics: spatiotemporal morphodynamic mapping of ventricular kinematic subpopulations in organotypic fetal heart slices

Recent advancements in omics technologies have deepened our understanding of complex biological systems and the interplay among gene expression, mechanical cues, and cellular metabolism. However, capturing the spatiotemporal dynamics of live cellular behavior within intact tissue contexts remains a major challenge. Here, we introduce Kinemomics, a framework for spatiotemporal mapping of morphogenetic kinematic states in living tissue. Using a novel fetal cardiac organotypic slice culture system that preserves both beating and morphogenesis, Kinemomics integrates live fluorescent labeling, timelapse imaging, and endpoint immunofluorescence to generate morphodynamic profiles across full-thickness developing myocardium. We validate Kinemomics under controlled Yap-1 signaling perturbations and demonstrate its ability not only to intrinsically decode region- and treatment-specific phenotypes, but also to resolve their spatiotemporal evolution during development and malformation. Kinemomics further reveals localized emergent developmental and malforming fronts that drive system-level behavior, establishing a generalizable platform for investigating computational morphodynamics and cross-scale interactions in complex spatiotemporal systems.

developmental biology↗

Rabbit Development as a Model for Single Cell Comparative Genomics

Biomedical research relies heavily on the use of model organisms to gain insight into human health and development. Traditionally, the mouse has been the favored vertebrate model, due to its experimental and genetic tractability. Non-rodent embryological studies however highlight that many aspects of early mouse development, including the egg-cylinder topology of the embryo and its method of implantation, diverge from other mammals, thus complicating inferences about human development. In this study, we constructed a morphological and molecular atlas of rabbit development, which like the human embryo, develops as a flat-bilaminar disc. We report transcriptional and chromatin accessibility profiles of almost 180,000 single cells and high-resolution histology sections from embryos spanning gastrulation, implantation, amniogenesis, and early organogenesis. Using a novel computational pipeline, we compare the transcriptional landscape of rabbit and mouse at the scale of the entire organism, revealing that extra-embryonic tissues, as well as gut and PGC cell types, are highly divergent between species. Focusing on these extra-embryonic tissues, which are highly accessible in the rabbit, we characterize the gene regulatory programs underlying trophoblast differentiation and identify novel signaling interactions involving the yolk sac mesothelium during hematopoiesis. Finally, we demonstrate how the combination of both rabbit and mouse atlases can be leveraged to extract new biological insights from sparse macaque and human data. The datasets and analysis pipelines reported here set a framework for a broader cross-species approach to decipher early mammalian development, and are readily adaptable to deploy single cell comparative genomics more broadly across biomedical research.

developmental biology↗

Knock-in tagging in zebrafish facilitated by insertion into non-coding regions

Zebrafish provide an excellent model for in vivo cell biology studies due to their amenability to live imaging. Protein visualization in zebrafish has traditionally relied on overexpression of fluorescently tagged proteins from heterologous promoters, making it difficult to recapitulate endogenous expression patterns and protein function. One way to circumvent this problem is to tag the proteins by modifying their endogenous genomic loci. Such an approach is not widely available to zebrafish researchers due to inefficient homologous recombination and the error-prone nature of targeted integration in zebrafish. Here, we report a simple approach for tagging proteins in zebrafish on their N- or C termini with fluorescent markers by inserting PCR-generated donor amplicons into non-coding regions of the corresponding genes. Using this approach, we generated endogenously tagged alleles for several genes critical for epithelial biology and organ development including the tight junction components ZO-1 and Cldn15la, the trafficking effector Rab11a, and the ECM receptor {beta}1 integrin. Our approach facilitates the generation of knock-in lines in zebrafish, opening the way for accurate quantitative imaging studies. Summary statementGeneration of endogenously tagged stable zebrafish knock-in lines is simplified by the integration of fluorescent protein cassettes with mRNA splicing elements into non-coding regions of genes.

developmental biology↗

Ultra-low photodamage three-photon microscopy assisted by neural network for monitoring regenerative myogenesis

Three-photon microscopy (3PM) enables high-resolution three-dimensional (3D) imaging in deeply situated and highly scattering biological specimens, facilitating precise characterization of biological morphology and cellular-level physiology in vivo. However, the use of fluorescent probes with relatively low three-photon absorption cross-sections necessitates high-peak-power lasers for excitation, which poses inherent risks of light-induced damage. Additionally, the low repetition frequency of these lasers prolongs scanning time per pixel, hampering imaging speed and exacerbating the potential for photodamage. Such limitations hinder the application of 3PM in studying vulnerable tissues, including muscle regeneration. To address this critical issue, we developed the Multi-Scale Attention Denoising Network (MSAD-Net), a precise and versatile denoising network suitable for diverse structures and varying noise levels. Our network enables the use of lower excitation power (1/4-1/2 of the common power) and shorter scanning time (1/6-1/4 of the common time) in 3PM while preserving image quality and tissue integrity. It achieves an impressive structural similarity index (SSIM) of up to 0.9932 and an incredibly fast inference time of just 80 milliseconds per frame which ensured both high fidelity and practicality for downstream applications. By utilizing MSAD-Net-assisted imaging, we comprehensively characterize the biological morphology and functionality of muscle regeneration processes through deep in vivo five-channel imaging under extremely low excitation power and short scanning time, while maintaining a high signal-to-background ratio (SBR) and excellent axial spatial resolution. Furthermore, we conducted high axial-resolution dynamic imaging of vascular microcirculation, macrophages, and ghost fibers. Our findings provide a deeper understanding of the mechanisms underlying muscle regeneration at the cellular and tissue levels.

developmental biology↗

Transcriptome Landscape Reveals Underlying Mechanisms of Ovarian Cell Fate Differentiation and Primordial Follicle Assembly

Primordial follicle assembly in mammals occurs at perinatal ages and largely determines the ovarian reserve available to support the reproductive lifespan. The primordial follicle structure is generated by a complex network of interactions between oocytes and ovarian somatic cells that remain poorly understood. In the present research, using single-cell RNA sequencing performed over a time-series on mouse ovaries coupled with several bioinformatics analyses, the complete dynamic genetic programs of germ and granulosa cells from E16.5 to PD3 are reported for the first time. The time frame of analysis comprises the breakdown of germ cell cysts and the assembly of primordial follicles. Confirming the previously reported expression of genes by germ cells and granulosa cells, our analyses identified ten distinct gene clusters associated to germ cells and eight to granulosa cells. Consequently, several new genes expressed at significant levels at each investigated stage were assigned. Building single-cell pseudo temporal trajectories five states and two branch points of fate transition for the germ cells, and three states and one branch point for the granulosa cells were revealed. Moreover, GO and ClueGO term enrichment enabled identifying biological processes, molecular functions and cellular components more represented in germ cells and granulosa cells or common to both cell types at each specific stage. Finally, by SCENIC algorithm, we were able to establish a network of regulons that can be postulated as likely candidates for sustaining germ cell specific transcription programs throughout the investigated period.

developmental biology↗

EMBRYONIC DEVELOPMENT OF THE FIRE-EYE-TETRA Moenkhausia oligolepis (CHARACIFORMES: CHARACIDAE)

This study describes the embryonic development of Moenkhausia oligolepis in captive conditions. After fertilization, the embryos were collected every 10 min up to 2 h, every 20 min up to 4 h, and every 30 min until hatching. The fertilized eggs of M. oligolepis measured approximately 0.85 {+/-} 0.5 mm and have an adhesive surface. The embryonic development lasted 14 hours at 25{degrees}C, with the Zygote, Cleavage, Blastula, Gastrula, Neurula and Segmentation phases. The hatching occurred in embryos around the 30-somites stage. Our results bring only the second description of embryonic development to a species of Moenkhausia genus, the first for the refereed species. Such data are of paramount importance considering the current conflicting state of this genus phylogenetic classification and may help taxonomic studies. Understand the biology of a species that is easily handling in captive conditions and has an ornamental appeal may assist studies in its reproduction in order to both, supply the aquarium market and help the species conservation in nature. Moreover, our data enable the M. oligolepis to be used as a model species in biotechnological applications, such germ cell transplantation approach.

developmental biology↗

Reconstructing signaling histories of single cells via perturbation screens and transfer learning

Manipulating the signaling environment is an effective approach to alter cellular states for broad-ranging applications, from engineering tissues to treating diseases. Such manipulation requires knowing the signaling states and histories of the cells in situ, for which high-throughput discovery methods are lacking. Here, we present an integrated experimental-computational framework that learns signaling response signatures from a high-throughput in vitro perturbation atlas and infers combinatorial signaling activities in in vivo cell types with high accuracy and temporal resolution. Specifically, we generated signaling perturbation atlas across diverse cell types/states through multiplexed sequential combinatorial screens on human pluripotent stem cells. Using the atlas to train IRIS, a neural network-based model, and predicting on mouse embryo scRNAseq atlas, we discovered global features of combinatorial signaling code usage over time, identified biologically meaningful heterogeneity of signaling states within each cell type, and reconstructed signaling histories along diverse cell lineages. We further demonstrated that IRIS greatly accelerates the optimization of stem cell differentiation protocols by drastically reducing the combinatorial space that needs to be tested. This framework leads to the revelation that different cell types share robust signal response signatures, and provides a scalable solution for mapping complex signaling interactions in vivo to guide targeted interventions.

developmental biology↗

Local mechanical stimuli shape tissue growth in vertebrate joint morphogenesis

The correct formation of synovial joints is essential for proper motion throughout life. Movement-induced forces are critical to creating correctly shaped joints, but it is unclear how cells sense and respond to these mechanical cues. To determine how mechanical stimuli drive joint morphogenesis, we combined experiments on regenerating axolotl (Ambystoma mexicanum) forelimbs with a poroelastic model of bone rudiment growth. Animals either regrew forelimbs normally (control) or were injected with a TRPV4 agonist to impair chondrocyte mechanosensitivity during joint morphogenesis. We quantified growth and shape in regrown humeri from whole mount light sheet fluorescence images of the regenerated limbs. Results revealed statistically significant differences in morphology and cell proliferation between groups, indicating that mechanical stimuli play a role in the shaping of joints. We simulated local tissue growth in a finite element model with a biological contribution to growth proportional to chondrocyte density, and a mechanical contribution to growth proportional to fluid pressure. Computational predictions agreed with experimental outcomes, suggesting that interstitial pressure driven from cyclic mechanical stimuli promotes local tissue growth. Predictive computational models informed by experimental findings allow us to explore potential physical mechanisms involved in tissue growth to advance our understanding of the mechanobiology of joint morphogenesis.

developmental biology↗

The White Sea littoral oligochaete Lumbricillus sp. as a model for annelid development studies

Oligochaetes play a significant role in aquatic ecosystems, and studying their development can contribute to a deeper understanding of the evolutionary features of embryonic development in the phylum Annelida. In this paper, we initially explored a littoral oligochaete species from the White Sea, which is abundant in the vicinity of the White Sea Biological Station MSU and reproduces in the early summer. A molecular phylogenetic analysis utilizing COI and 18S markers confirmed that the species under investigation belongs to the genus Lumbricillus, family Enchytridae. The early stages of embryonic development were described in detail, and the timing of the onset of key stages was established. The specifics of the cellular patterns observed in the early embryo were elucidated using the fluorescence staining and confocal microscopy. The embryonic development of Lumbricillus sp. exhibits characteristics that are consistent with the typical development of oligochaetes. Additionally, it displays specific characteristics that are typical of representatives of the Enchytriidae family, including equal size of the 2nd and 2D blastomeres and a small size of the 4D blastomere in comparison to the large 4D blastomere. The combination of synchrony and low developmental variability, coupled with the accessibility of the object, ease of maintenance and manipulation, makes Lumbricillus sp. a highly promising object for the study of embryonic development in Annelides.

developmental biology↗

Sprouting and anastomosis in the Drosophila trachea and the vertebrate vasculature: similarities and differences in cell behaviour

Branching morphogenesis is a fascinating process whereby a simple network of biological tubes increases its complexity by adding new branches to existing ones, generating an enlarged structure of interconnected tubes. Branching morphogenesis has been studied extensively in animals and much has been learned about the regulation of branching at the cellular and molecular level. Here, we discuss studies of the Drosophila trachea and of the vertebrate vasculature, which have revealed how new branches are formed and connect (anastomose), leading to the establishment of complex tubular networks. We briefly describe the cell behaviour underlying tracheal and vascular branching. Although similar at many levels, the branching and anastomosis processes characterized thus far show a number of differences in cell behaviour, resulting in somewhat different tube architectures in these two organs. We describe the similarities and the differences and discuss them in the context of their possible developmental significance. We finish by highlighting some old and new data, which suggest that live imaging of the development of capillary beds in adult animals might reveal yet unexplored endothelial behaviour of endothelial cells.\n\nO_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=161 SRC=\"FIGDIR/small/458281_ufig1.gif\" ALT=\"Figure 1\">\nView larger version (25K):\norg.highwire.dtl.DTLVardef@1f61f04org.highwire.dtl.DTLVardef@16e76fborg.highwire.dtl.DTLVardef@1458fd7org.highwire.dtl.DTLVardef@1e67d51_HPS_FORMAT_FIGEXP M_FIG C_FIG

developmental biology↗

Meiosis-specific ZFP541 repressor complex promotes meiotic prophase exit during spermatogenesis

During spermatogenesis, meiosis is accompanied by robust alteration in gene expression and chromatin status. However, it remained elusive how meiotic transcriptional program is established to ensure completion of meiotic prophase. Here, we identified a novel protein complex consisting of germ-cell-specific zinc-finger protein ZFP541 and its interactor KCTD19 as the key transcriptional regulator for meiotic prophase exit. Our genetic study showed that ZFP541 and KCTD19 are co-expressed from pachytene onward and play an essential role in the completion of meiotic prophase program in the testis. Furthermore, our ChIP-seq and transcriptome analyses revealed that ZFP541 binds to and suppresses a broad range of genes whose function is associated with biological processes of transcriptional regulation and covalent chromatin modification. The present study demonstrated that germ-cell specific ZFP541-KCTD19 containing complex promotes meiotic prophase exit in males, and triggers reconstruction of the transcription network and chromatin organization leading to post-meiotic development.

developmental biology↗

Protein-intrinsic properties and epigenetic effects regulate pioneer-factor binding and function

Chromatin is a barrier to the binding of many transcription factors. By contrast, pioneer factors access nucleosomal targets and promote chromatin opening. Despite binding to target motifs in closed chromatin, many pioneer factors display cell-type specific binding and activity. The mechanisms governing pioneer-factor occupancy and the relationship between chromatin occupancy and opening remain unclear. We studied three Drosophila transcription factors with distinct DNA-binding domains and biological functions: Zelda, Grainy head, and Twist. We demonstrated that the level of chromatin occupancy is a key determinant of pioneering activity. Multiple factors regulate occupancy, including motif content, local chromatin, and protein concentration. Regions outside the DNA-binding domain are required for binding and chromatin opening. Our results show that pioneering activity is not a binary feature intrinsic to a protein but occurs on a spectrum and is regulated by a variety of protein-intrinsic and cell-type-specific features.

developmental biology↗

Persistent Cyfip1 expression is required to maintain the adult subventricular zone neurogenic niche

Neural stem cells (NSCs) persist throughout life in the subventricular zone (SVZ) niche of the lateral ventricles as B1 cells. Maintaining this population of NSCs depends on the balance between quiescence and self-renewing or self-depleting proliferation. Interactions between B1 cells and the surrounding niche are important in regulating this balance, but the mechanisms governing these processes have not been fully elucidated in adult mammals. The cytoplasmic FMRP-interacting protein (CYFIP1) regulates apical-basal polarity in the embryonic brain. Loss of Cyfip1 during embryonic development in mice disrupts the embryonic niche and affects cortical neurogenesis. However, a direct role for Cyfip1 in the regulation of adult NSCs has not been established. Here, we demonstrate that Cyfip1 expression is preferentially localized to B1 cells in the adult SVZ. Loss of Cyfip1 in the embryonic mouse brain results in altered adult SVZ architecture and expansion of the adult B1 cell population at the ventricular surface. Furthermore, acute deletion of Cyfip1 in adult NSCs results in a rapid change in adherens junction proteins as well as increased proliferation and the number of B1 cells at the ventricular surface. Together, these data indicate that CYFIP1 plays a critical role in the formation and maintenance of the adult SVZ niche and, furthermore, deletion of Cyfip1 unleashes the capacity of adult B1 cells for symmetric renewal to increase the adult NSC pool.\n\nSIGNIFICANCENeural stem cells (NSCs) persist in the subventricular zone (SVZ) of the lateral ventricles in adult mammals and their population is determined by the balance between quiescence and self-depleting or renewing cell division. The mechanisms regulating their biology are not fully understood. This study establishes that the cytoplasmic FMRP interacting protein 1 (Cyfip1) regulates NSC fate decisions in the adult SVZ and NSCs that are quiescent or typically undergo self-depleting divisions retain the ability to self-renew in the adult. This contributes to our understanding of how adult NSCs are regulated throughout life and has potential implications for human brain disorders.

developmental biology↗

Distribution and restoration of serotonin-immunoreactive paraneuronal cells during caudal fin regeneration in zebrafish

Aquatic vertebrates possess diverse types of sensory cells in their skin to detect stimuli in the water. In the adult zebrafish, a common model organism, the presence of such cells in fins has only rarely been studied. Here, we identified scattered serotonin (5-HT)-positive cells in the epidermis of the caudal fin. These cells were distinct from keratinocytes as revealed by their low immunoreactivity for cytokeratin and desmosome markers. Instead, they were detected by Calretinin (Calbindin-2) and Synaptic vesicle glycoprotein 2 (SV2) antibodies, indicating a calcium-regulated neurosecretory activity. Consistently, electron microscopy revealed abundant secretory organelles in desmosome-negative cells in the fin epidermis. Based on the markers, 5-HT, Calretinin and SV2, we referred to these cells as HCS-cells. We found that HCS-cells were spread throughout the entire caudal fin at an average density of 140 cells per mm2 on each fin surface. These cells were strongly enriched at ray bifurcations in wild type fins, as well as in elongated fins of another longfin mutant fish. To determine whether hydrodynamics play a role in the distribution of HCS-cells, we used an interdisciplinary approach and performed kinematic analysis. Measurements of particle velocity with a fin model revealed differences in fluid velocities between bifurcated rods and adjacent non-bifurcated regions. Therefore the accumulation of HCS-cells near bone bifurcations may be a biological adaptation for sensing of water parameters. The significance of this HCS-cell pattern is reinforced by the fact, that it is reestablished in the regenerated fin after amputation. Regeneration of HCS-cells was not impaired by the chemical inhibition of serotonin synthesis, suggesting that this neurotransmitter is not essential for the restorative process. In conclusion, our study identified a specific population of solitary paraneurons in the zebrafish fin, whose distribution correlates with fluid dynamics.

developmental biology↗

An accelerated miRNA-based screen implicates Atf-3 in odorant receptor expression

Large scale genetic screening is tedious and time-consuming. To address this problem, we propose a novel two-tiered screening system comprising an initial \"pooling\" screen that identifies miRNAs whose tissue-specific over-expression causes a phenotype of interest followed by a more focused secondary screen that uses gene-specific RNAi. As miRNAs inhibit translation or direct the destruction of their target mRNAs, any phenotype observed with miRNA over-expression can be attributed to the loss-of-function of one or more target mRNAs. Since miRNA-target pairing is sequence-specific, a list of predicted targets for miRNAs identified in the initial screen serves as a list of candidates for the secondary RNAi-based screen. These predicted miRNA targets can be prioritized by expression pattern, and if multiple miRNAs produce the same phenotype, overlapping target predictions can be given higher priority in the follow-up screen.\n\nSince miRNAs are short, miRNA misexpression will likely uncover artifactual miRNA-target relation-ships. Thus, we are using miRNAs as a tool to accelerate genetic screening rather than focus on the biology of miRNAs themselves. This two-tiered system allows us to rapidly identify individual target genes involved in a phenomenon of interest, often in less than 200 crosses. Here we demonstrate the effectiveness of this method by identifying miRNAs that alter Drosophila odorant receptor expression. With subsequent miRNA target prediction and follow-up RNAi screening we identify and validate a novel role for the transcription factor Atf3 in the expression of the socially relevant receptor Or47b.

Developmental Biology↗

Hormonally responsive bovine oviductal organoids recapitulate native oviductal secretions and enhance sperm capacitation

The oviduct provides the dynamic microenvironment that supports fertilization and early embryo development yet replicating its hormonally regulated secretory activity in vitro remains a major challenge. Here, we established bovine oviductal epithelial organoids that reproduce the structural polarity and endocrine responsiveness of the native oviduct. Exposure to either estradiol or progesterone resulted in distinct transcriptomic and proteomic landscapes that were characteristic of the follicular and luteal phases, respectively. This included the upregulation of canonical phase-specific markers, such as OVGP1, NTS, HP and TGM2. Proteomic profiling of organoid-derived secretions (ODS) revealed extensive overlap with in vivo oviductal fluid. Integration of transcriptomic and proteomic datasets by multi-omics factor analysis identified coherent biological signatures defining each hormonal state. Functionally, ODS obtained from estradiol-treated organoids enhanced sperm capacitation and acrosome reaction, recapitulating the activity of follicular-phase oviductal fluid. These findings demonstrate that hormonally responsive oviductal organoids generate bioactive secretions that emulate the molecular and functional features of the native oviductal environment, providing a sustainable and physiologically relevant platform for studying gamete-maternal communication and improving assisted reproduction technologies.

developmental biology↗

Coupling optogenetics and light-sheet microscopy to study signal transduction in vivo

Optogenetics allows precise, fast and reversible intervention in biological processes. Light-sheet microscopy allows observation of the full course of embryonic development from egg to larva. Bringing the two approaches together allows unparalleled precision into the temporal regulation of signaling pathways and cellular processes in vivo. To develop this method, we investigated the regulation of canonical Wnt signaling during anterior-posterior patterning of the Drosophila embryonic epidermis. Cryptochrome 2 (CRY2) from Arabidopsis Thaliana was fused to mCherry fluorescent protein and Drosophila {beta}-catenin to form an easy to visualize optogenetic switch. Blue light illumination caused oligomerization of the fusion protein and inhibited downstream Wnt signaling in vitro and in vivo. Temporal inactivation of {beta}-catenin confirmed that Wnt signaling is required not only for Drosophila pattern formation, but also for maintenance later in development. We anticipate that this method will be easily extendable to other developmental signaling pathways and many other experimental systems.

developmental biology↗

STAT3 regulates basal cell identity and morphogenesis during early esophageal development

The transcription factor STAT3 plays broad roles in epithelial biology, yet its function in human esophageal development remains undefined. Using 2D and 3D human induced pluripotent stem cell (hiPSC)-derived platforms, we investigated how STAT3 regulates esophageal epithelial differentiation. We find that STAT3 is dispensable for definitive endoderm and anterior foregut endoderm specification but becomes essential during the transition to esophageal progenitor cells (EPCs). Inhibition of STAT3, via CRISPR-mediated knockout or siRNA, impairs the expression of key EPC and differentiation markers, including TP63, and disrupts 3D organoid formation. These defects are accompanied by reduced epithelial proliferation. Notably, STAT3 is highly expressed in human fetal esophageal tissues and hiPSC-derived organoids, while its deletion in the developing mouse esophagus does not affect epithelial architecture, highlighting species-specific differences. Together, these findings identify STAT3 as a critical determinant of basal cell identity and epithelial morphogenesis, revealing a developmental checkpoint in early human esophageal lineage commitment.

developmental biology↗