Caenorhabditis elegans
Ontology highlight
ABSTRACT:
PROVIDER: PRJNA217930 | ENA |
REPOSITORIES: ENA
Similar Datasets
Project description:The germ layer concept has been one of the foremost organizing principles in developmental biology, classification, systematics and evolution for 150 years. Of the three germ layers, the mesoderm is found in bilaterian animals but is absent in species in the phyla Cnidaria and Ctenophora, which has been taken as evidence that the mesoderm was the final germ layer to evolve. The origin of the ectoderm and endoderm layers, however, remains unclear with models supporting the antecedence of each as well as a simultaneous origin. We hypothesized that global analysis of gene expression in each layer throughout development may resolve the early events of animal evolution. Here, we determine the temporal and spatial components of gene expression spanning embryonic development for all C. elegans genes and use it to determine the evolutionary age of the germ layers. The gene expression programs of the mesoderm is generally induced after the ectoderm and endoderm germ layers, thus making it the last germ layer to both evolve and develop. Strikingly, the C. elegans endoderm and ectoderm expression programs do not co-induce; rather the endoderm activates earlier. We also observed early expression of endoderm orthologs during the embryology of Xenopus tropicalis, Nematostella vectensis, and the sponge Amphimedon queenslandica. Querying for the phylogenetic ages of specifically expressed genes revealed that the endoderm is comprised of older genes, supporting its antecedence among the germ layers. Taken together, we propose that the endoderm program has retained the feeding functions of the last common ancestor with the choanoflagellates, thus allowing for the specialization of an ectoderm germ layer. Our work reveals that the evolutionary appearance of the germ layers continues to constrain regulatory networks in metazoans. Two temporal assays of C. elegans embryonic development, starting at the zygote: (a) Embryos collected at fixed (~10 minute) time intervals. (b) Embryo segregates, up to five lines of blastomeres, isolated in reference to mitotic events. There were 184 samples in total, representing 100 distnict data points.
2014-12-11 | E-GEOD-50548 | biostudies-arrayexpress
Project description:The concept of germ layers has been one of the foremost organizing principles in developmental biology, classification, systematics and evolution for 150 years. Of the three germ layers, the mesoderm is found in bilaterian animals but is absent in species in the phyla Cnidaria and Ctenophora, which has been taken as evidence that the mesoderm was the final germ layer to evolve. The origin of the ectoderm and endoderm germ layers, however, remains unclear, with models supporting the antecedence of each as well as a simultaneous origin. Here we determine the temporal and spatial components of gene expression spanning embryonic development for all Caenorhabditis elegans genes and use it to determine the evolutionary ages of the germ layers. The gene expression program of the mesoderm is induced after those of the ectoderm and endoderm, thus making it the last germ layer both to evolve and to develop. Strikingly, the C. elegans endoderm and ectoderm expression programs do not co-induce; rather the endoderm activates earlier, and this is also observed in the expression of endoderm orthologues during the embryology of the frog Xenopus tropicalis, the sea anemone Nematostella vectensis and the sponge Amphimedon queenslandica. Querying the phylogenetic ages of specifically expressed genes reveals that the endoderm comprises older genes. Taken together, we propose that the endoderm program dates back to the origin of multicellularity, whereas the ectoderm originated as a secondary germ layer freed from ancestral feeding functions.
2014-12-11 | GSE50548 | GEO
Project description:It is generally accepted that epiblast cells ingress into the primitive streak by epithelial-to-mesenchymal transition (EMT) to give rise to the mesoderm; however, it is less clear how the endoderm acquires an epithelial fate. Here, we used embryonic stem cell and mouse embryo knock‐in reporter systems to combine time-resolved lineage labelling with high-resolution single-cell transcriptomics. This allowed us to resolve the morphogenetic programs that segregate the mesoderm from the endoderm germ layer. Strikingly, while the mesoderm is formed by classical EMT, the endoderm is formed independent of the key EMT transcription factor Snail1 by mechanisms of epithelial cell plasticity. Importantly, forkhead box transcription factor A2 (Foxa2) acts as an epithelial gatekeeper and EMT suppressor to shield the endoderm from undergoing a mesenchymal transition. Altogether, these results not only establish the morphogenetic details of germ layer formation, but also have broader implications for stem cell differentiation and cancer metastasis.
2021-06-24 | GSE148226 | GEO
Project description:Host-microbe associations underlie many key processes of host development, immunity, and life history. Yet, none of the current research on the central model species Caenorhabditis elegans considers the worm’s natural microbiome. Instead, almost all laboratories exclusively use the canonical strain N2 and derived mutants, maintained through routine bleach sterilization in monoxenic cultures with an E. coli strain as food. Here, we characterize for the first time the native microbiome of C. elegans and assess its influence on nematode life history characteristics via transcriptomics.
2019-02-25 | GSE111364 | GEO
Project description:The definitive endoderm germ layer is the provenance of multiple internal organs, including the lungs, liver, pancreas and intestines. Molecular events driving initial endoderm germ layer specification and subsequent anterior-posterior patterning of endoderm into distinct organ primordia remain largely cryptic. Through microarray analyses, we captured genome-wide transcriptional dynamics driving successive stages of endoderm development with the intent of identifying novel regulatory genes or diagnostic markers that respectively drive or mark endoderm committment. HES3 human embryonic stem cells (hESCs) were differentiated into highly homogeneous endodermal progenitor populations, and microarray analyses were conducted of six different populations at different tiers of the endodermal lineage hierarchy: undifferentiated hESCs, anterior primitive streak (day 1 of in vitro differentiation), definitive endoderm (day 3) and anterior foregut, posterior foregut or midgut/hindgut patterned endoderm populations (day 7). Additionally, we compared hESCs differentiated using two alternative endoderm induction protocols, serum-based or AFBLy-based differentiation (both day 3 of differentiation).
2013-11-07 | E-GEOD-52158 | biostudies-arrayexpress
Project description:We sequenced the transcriptome of a host (Caenorhabditis elegans) following its interaction with a non-native bacterium (Enterococcus faecalis) that has protective traits against the pathogen, Staphylococcus aureus. We also investigated the impact that the evolutionary history of the protective bacterium has on the transcriptional history of the host. We tested protective bacteria that had either coevolved against the pathogen within C. elegans, or had evolved on its own within C. elegans.
2021-04-20 | GSE151731 | GEO
Project description:The definitive endoderm germ layer is the provenance of multiple internal organs, including the lungs, liver, pancreas and intestines. Molecular events driving initial endoderm germ layer specification and subsequent anterior-posterior patterning of endoderm into distinct organ primordia remain largely cryptic. Through microarray analyses, we captured genome-wide transcriptional dynamics driving successive stages of endoderm development with the intent of identifying novel regulatory genes or diagnostic markers that respectively drive or mark endoderm committment.
2013-11-07 | GSE52158 | GEO
Project description:SEIPIN, an evolutionary conserved protein, plays pivotal roles during lipid droplet (LD) biogenesis and is associated with various human diseases with unclear mechanisms. Here, we analyzed C. elegans mutants deleted of the sole SEIPIN gene, seip-1. Homozygous seip-1 mutants displayed penetrant embryonic lethality, which is caused by the disruption of the lipid-rich permeability barrier, the innermost layer of the C. elegans embryonic eggshell. In C. elegans oocytes and embryos, SEIP-1 is associated with LDs and crucial for controlling LD size and lipid homeostasis. The seip-1 deletion mutants reduced the ratio of polyunsaturated fatty acids (PUFAs) in their embryonic fatty acid pool. Interestingly, dietary supplementation of selected n-6 PUFAs rescued the embryonic lethality and defective permeability barrier. Accordingly, we propose that SEIP-1 may maternally regulate LD biogenesis and lipid homeostasis to orchestrate the formation of the permeability barrier for eggshell synthesis during embryogenesis. A lipodystrophy allele of seip-1 resulted in embryonic lethality as well and could be rescued by PUFA supplementation. These experiments support a great potential for using C. elegans to model seipin-associated human diseases.
2020-09-14 | GSE157800 | GEO
Project description:Anterior mesoderm (AM) and definitive endoderm (DE) progenitors represent the earliest embryonic cell types that are specified during germ layer formation at the primitive streak (PS) of the mouse embryo. Genetic experiments indicate that both lineages segregate from Eomes expressing progenitors in response to different NODAL signaling levels. However, the precise spatiotemporal pattern of the emergence of these cell types and molecular details of lineage segregation remain unexplored. We combined genetic fate labeling and imaging approaches with single cell RNA sequencing (scRNA-seq) to follow the transcriptional identities and define lineage trajectories of Eomes dependent cell types. Accordingly, all cells moving through the PS during the first day of gastrulation express Eomes AM and DE specification occurs before cells leave the PS from Eomes positive progenitors in a distinct spatiotemporal pattern. ScRNA-seq analysis further suggest the immediate and complete separation of AM and DE lineages from Eomes expressing cells as last common bipotential progenitor.
2020-12-07 | GSE151824 | GEO
Project description:Here, we constructed monkey blastoids resembling blastocysts in morphology and transcriptomics using naïve ESCs and optimized protocol. The synthetic blastoids could develop to embryonic disk stage with the structure of yolk sac, chorionic cavity, amnion cavity, primitive streak, connecting stalk along the rostral–caudal axis by in-vitro prolonged culture (IVC). Primordial germ cells, gastrulating cells, visceral endoderm/yolk-sac endoderm, three germ layers and haemato-endothelial progenitors were identified in the monkey blastoid IVC embryo by single-cell transcriptomics or immunostaining. Besides, pregnancies with early gestation sacs were achieved by transferring monkey blastoids to surrogates. Our results revealed the in-vitro gastrulation and in-vivo early pregnancy of primate synthetic embryos, providing a powerful system to dissect primate embryonic development with less ethical concerns and restrict access.
2023-04-06 | GSE218375 | GEO