PubMed HealthSearch

SEARCH · PubMed Health

Results for “Gene Expression Regulation, Developmental”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

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

At least 37 records · Page 2Linked to original sources

Molting in Pancrustacea Is Characterized by Both Deeply Conserved and Recently Evolved Gene Modules.

Arthropods such as insects and crustaceans, which together form the monophyletic group Pancrustacea, possess a rigid chitinous exoskeleton that must be periodically shed through molting to allow growth and morphological change. Although molting is a deeply conserved developmental process across Arthropoda, our understanding of its molecular mechanisms is still largely derived from insect model species. Lineage-specific innovations and losses of molting-related genes raise fundamental questions about the extent of its conservation outside noninsect arthropods. Here, we investigate the evolutionary conservation of molting gene expression across five representative pancrustacean species using publicly available transcriptomic datasets. Changes in gene expression during molting are characterized by both deeply conserved and lineage-specific gene modules. Temporal gene expression analyses reveal that these lineage-specific signatures are not uniformly distributed across the molting process: the middle transitional phase is more lineage-specific, thereby exhibiting an inverse hourglass pattern. This is likely due to life-history-specific processes, development of the cuticle, and specialized structures of the exoskeleton. Overall, this study provides evidence for both the evolutionary conservation and divergence of this key postembryonic developmental process and highlights the modular architecture of the molting program.

Animals

Dynamic allelic expression in mouse mammary glands across the adult developmental cycle.

The mammary gland, which primarily develops postnatally, undergoes significant changes during pregnancy and lactation to facilitate milk production. Through the generation and analysis of 480 transcriptomes, we provide the most detailed allelic expression map of the mammary gland, cataloguing cell-type-specific expression from ex-vivo purified cell populations over 10 developmental stages, enabling comparative analysis. The work identifies genes involved in the mammary gland cycle, parental-origin-specific and genetic background-specific expression at cellular and temporal resolution, genes associated with human lactation disorders and breast cancer. Genomic imprinting, a mechanism regulating gene expression based on parental origin, is crucial for controlling gene dosage and stem cell potential throughout development. The analysis identified 25 imprinted genes monoallelically expressed in the mammary gland, with several showing allele-specific expression in distinct cell types. No novel imprinted genes were identified and the absence of biallelically expressed imprinted genes suggests that, unlike in brain, selective absence of imprinting does not regulate gene dosage in the mammary gland. This research highlights transcriptional dynamics within mammary gland cells and identifies novel candidate genes potentially significant in the tissue during pregnancy and lactation. Overall, this comprehensive atlas represents a valuable resource for future studies on expression and transcriptional dynamics in mammary cells.

Animals

Comprehensive identification and evolutionary analysis of the Wnt gene family in bivalves: Insights into the larval development of the noble scallop Chlamys nobilis.

The Wnt gene family regulates fundamental developmental processes in metazoans, but its evolutionary composition and developmental deployment in bivalves remain largely unresolved. Here, we performed a comparative genomic analysis of Wnt genes in 19 bivalve species and examined developmental expression profiles in the noble scallop Chlamys nobilis, with Crassostrea gigas and Chlamys farreri used for cross-species comparison. A total of 235 Wnt genes were identified and assigned to 12 subfamilies. No reliable Wnt3 ortholog was detected in any analyzed bivalve, supporting the view that Wnt3 loss occurred early during lophotrochozoan evolution rather than representing a lineage-specific absence. Most Wnt proteins retained the conserved WNT domain, indicating strong structural conservation, whereas lineage-specific copy-number variation and gene loss were observed among species. C. farreri and C. gigas each retained 12 Wnt genes and lacked Wnt3, whereas C. nobilis lacked Wnt3, Wnt7, and Wnt16. Developmental transcriptome analysis and RT-qPCR revealed clear stage-specific expression patterns. In C. gigas, Wnt2/10/A were highly expressed during earlydevelopment and peaked around the D-shaped larval stage, while Wnt8 and Wnt11 showed distinct stage-specific peaks. By contrast, Wnt1/5/6/9 were more active during later larval development or juvenile formation. These results provide a comparative framework for bivalve Wnt evolution and identify candidate Wnt genes potentially involved in larval development and aquaculture-relevant developmental transitions.

Animals

Studying the Role of HOX Genes in Thrombocyte Development.

In our laboratory, we study thrombopoiesis and hemostasis using zebrafish as a model organism to unravel the mechanisms of differentiation and development of thrombocytes. We have shown in our earlier work that thrombocytes are functional equivalents of platelets and have transcriptional machinery similar to megakaryocytes. We recently found evidence that hox genes play a role in their development. We used piggyback gene knockdown and thrombocyte quantification assays to understand the influence of these ancient developmental regulators on thrombopoiesis. In this chapter, we describe methods used to discover these hox genes.

Animals

Functional impact of cancer-associated cohesin variants on gene expression and cellular identity.

Cohesin is a ring-shaped protein complex that controls dynamic chromosome structure. Cohesin activity is important for a variety of biological processes, including formation of DNA loops that regulate gene expression. The precise mechanisms by which cohesin shapes local chromosome structure and gene expression are not fully understood. Recurrent mutations in cohesin complex members have been reported in various cancers, though it is not clear whether many cohesin sequence variants have phenotypes and contribute to disease. Here, we utilized CRISPR/Cas9 genome editing to introduce a variety of cohesin sequence variants into murine embryonic stem cells and investigate their molecular and cellular consequences. Some of the cohesin variants tested caused changes to transcription, including altered expression of gene encoding lineage-specifying developmental regulators. Altered gene expression was also observed at insulated neighborhoods, where cohesin-mediated DNA loops constrain potential interactions between genes and enhancers. Furthermore, some cohesin variants altered the proliferation rate and differentiation potential of murine embryonic stem cells. This study provides a functional comparison of cohesin variants found in cancer within an isogenic system, revealing the relative roles of various cohesin perturbations on gene expression and maintenance of cellular identity.

Animals

Morphological changes and transcriptomic insights into skeletal development of embryos and larvae of the sea urchin Strongylocentrotus intermedius.

To explore morphological features and molecular dynamics underlying skeletogenesis in the sea urchin Strongylocentrotus intermedius, we conducted combined morphological observation and comparative transcriptome analyses across representative embryonic and larval developmental stages. Morphological results showed that triradiate spicules first emerged at the gastrula stage. The 8-arm pluteus stage was identified as a key phase for skeletal remodeling, during which new three-radiate crystals transformed into complex stereoscopic ossicles including tube feet, spines and test plates. Transcriptomic data indicated that most differentially expressed genes (DEGs) were downregulated from the blastula to gastrula. The altered expression of basal metabolic genes and extracellular matrix genes including Colp2α and calm may be correlated with the linear mineralization of early spicules, which potentially reflects an energy adjustment pattern in developing larvae. During the transition from 6-arm to 8-arm pluteus, expression changes of calmodulin-like, Colp2α and SISin18G001660 suggest potential associations with regional calcium deposition and modifications of skeletal matrix properties. This work systematically characterizes morphological traits and transcriptional dynamics of skeletogenesis in S. intermedius. Its early spiculogenesis follows the conserved developmental pattern of echinoderms, while massive formation of stereoscopic ossicles occurs at the 8-arm pluteus stage. Stage-specific transcriptional changes across key larval skeletogenic stages are uncovered, offering transcriptomic resources for functional verification of skeletal regulatory genes.

Animals

Transcriptome sequencing provides novel insights into larval development and sexual dimorphism in the firefly Aquatica leii (Coleoptera: Lampyridae).

Fireflies are regarded as one of the most charismatic beetles due to their bioluminescence and ecological importance as bioindicators of freshwater quality. However, molecular mechanisms of larval development and sexual dimorphism in aquatic species remain poorly understood. Here, we performed multi-stage transcriptomic analysis of the aquatic firefly Aquatica leii across larval instars from L2 to L6, together with adult females and males, with three biological replicates per stage. Using time-series expression clustering, differential expression analysis, and weighted gene co-expression network analysis (WGCNA), we characterized the transcriptional dynamics of continuous larval development and the onset of sex-biased gene expression. We identified a critical transcriptional transition occurred at L5-L6, marked by downregulation of early morphogenetic genes and upregulation of juvenile hormone metabolism, oxidoreductase activity, and muscle contraction genes, indicating a shift from growth to metamorphic preparation. WGCNA identified a module strongly correlated with L6 (R = 0.97) enriched for the same functions, confirming a coordinated late-larval program. Notably, genes exhibiting sex-biased expression in adults were already expressed during late larval stages (L5 and L6), and 123 genes progressively upregulated from L2 to L6 showed enrichment in chitin biosynthesis, heart contraction, and ion transport; among these, six genes maintained high expression in adults with clear male-biased (Alei052192, Alei006658, and Alei087054) or female-biased (Alei003725, Alei096818, and Alei074026) patterns. These findings establish that transcriptional foundations for sexual dimorphism and adult tissue formation are laid during late larval stages, providing the first multi-stage transcriptomic resource for aquatic firefly conservation and breeding.

Animals

A time-resolved single-cell roadmap of the logic driving anterior neural crest diversification from neural border to migration stages.

Neural crest cells exemplify cellular diversification from a multipotent progenitor population. However, the full sequence of early molecular choices orchestrating the emergence of neural crest heterogeneity from the embryonic ectoderm remains elusive. Gene-regulatory-networks (GRN) govern early development and cell specification toward definitive neural crest. Here, we combine ultradense single-cell transcriptomes with machine-learning and large-scale transcriptomic and epigenomic experimental validation of selected trajectories, to provide the general principles and highlight specific features of the GRN underlying neural crest fate diversification from induction to early migration stages using Xenopus frog embryos as a model. During gastrulation, a transient neural border zone state precedes the choice between neural crest and placodes which includes multiple converging gene programs. During neurulation, transcription factor connectome, and bifurcation analyses demonstrate the early emergence of neural crest fates at the neural plate stage, alongside an unbiased multipotent-like lineage persisting until epithelial-mesenchymal transition stage. We also decipher circuits driving cranial and vagal neural crest formation and provide a broadly applicable high-throughput validation strategy for investigating single-cell transcriptomes in vertebrate GRNs in development, evolution, and disease.

Animals

Single-cell profiling decodes patagium development in gliding mammal.

The gliding patagium represents a key adaptation for mammalian flight, but its cellular development remains unexplored. Using single-nucleus RNA sequencing of embryonic flying squirrel patagium and dorsal skin, we construct a single-cell atlas of patagium development and identify two distinct fibroblast subpopulations (Fp2 and Fr) highly enriched in the patagium. These fibroblasts are characterized by the patagium upregulation of Wnt5a, Fgf7, and Fgf10, and are associated with patagium morphogenesis through dermal-epidermal putative communication interactions between dermal fibroblasts (Fp2 and Fr) and epithelial basal keratinocytes. Specifically, Fp2 fibroblasts are potentially involved in distal dermal condensation and epithelial thickening together with elevated Wnt5a expression, while both Fp2 and Fr fibroblasts could play a role in epithelial polarization and thickening through Fgf7 and Fgf10, as suggested by ex vivo assays. Our data suggest that gliding patagium development results from the co-option of conserved WNT and FGF signaling pathways within a specialized fibroblast-epithelial context, illustrating how modifications of conserved developmental programs give rise to derived morphological traits.

Animals

A Balanced Inversion Polymorphism Exhibits a Dominance Reversal at the Gene Expression Level that Depends on Developmental Context.

How genetic variance for fitness is maintained is incompletely understood. Mutation-selection balance and single-locus overdominance cannot account for the large variance observed. Recent work suggests that antagonistic balancing selection, favoring different alleles in different contexts and involving beneficial dominance reversals, might contribute to maintaining fitness variance. However, while this mechanism is plausible, evidence for dominance reversals remains scarce. Here, we study how In(3R)Payne, a balanced inversion polymorphism in Drosophila melanogaster, affects gene expression and chromatin accessibility by using RNA-seq and ATAC-seq (assay for transposase-accessible chromatin with sequencing). We find that, in embryos, the inverted (INV) arrangement tends to have dominant effects, while the standard (STD) arrangement behaves like a recessive Mendelian allele. Yet, in wing discs, this pattern is reversed: STD has mostly dominant effects, whereas INV behaves recessively. Since this shift in the dominance of the INV "allele" between developmental contexts affects the expression of suites of genes in a concerted manner, it might be mediated by a dominance modifier, for example, a transcription factor. In favor of this idea, 25% of the differentially expressed genes between INV and STD encode transcription factors. Interestingly, while only four differentially expressed genes are shared between embryos and wing discs, one of them is HP1c, a chromatin-binding protein and major transcriptional regulator, and thus a promising candidate for mediating the context-dependent change in dominance. Although the relationship between these patterns and fitness is presently unknown, our observations are consistent with a potential role of reversals (or, more generally, shifts) of dominance in maintaining inversion polymorphism.

Animals

Two Paralogues as They Like It: Conserved and Divergent Evolution of Vertebrate Gcm Genes.

Gcm1 and Gcm2 are paralogous transcription factors in vertebrates that play key roles in the development of pharyngeal-derived epithelia, yet their deployment across vertebrate lineages remains incompletely understood. While Gcm2 shows deeply conserved pharyngeal expression across gnathostomes, Gcm1 has been mainly characterized in mammals, where it exhibits broader expression patterns. How Gcm1 is deployed in non-mammalian vertebrates has remained unexplored. Here, we performed a comparative analysis of Gcm1 expression in cartilaginous fishes, non-teleost actinopterygians, and amphibians. RNA in situ hybridization revealed conserved Gcm1 expression in gill epithelia across these taxa. Parallel analyses showed that Gcm2 is also expressed in gill epithelia, with overlapping but distinct spatial patterns. In addition, Gcm1 showed lineage-specific expression in bichir embryos, including strong expression in external gills and scattered epithelial cells in the yolk-sac membrane. In the external gills, Gcm1-positive cells possess vacuole-like cytoplasmic structures, suggesting a previously unrecognized epithelial cell population. Together, our findings indicate that Gcm1 and Gcm2 share ancestral expression in pharyngeal epithelia but have followed distinct evolutionary trajectories, with Gcm1 exhibiting greater lineage-specific diversification.

Animals

Developmental analysis of the cone photoreceptor-less little skate retina reveals distinct Onecut1 isoforms.

The retinal development of elasmobranchs, the subclass comprising sharks, skates, and rays, remains poorly understood. This group is diverse in retinal phenotype, with many sharks and rays possessing rods together with one or more cone types. In contrast, the little skate (Leucoraja erinacea) has only a single rod photoreceptor type, which has been reported to exhibit some physiological and anatomical properties associated with cones. To investigate how this unusual photoreceptor system develops, we first identified an embryonic stage of early photoreceptor formation based on otx2 expression. We then developed a retinal electroporation approach to test whether a onecut1-dependent cone-associated reporter could be activated in the embryonic skate retina. Activation of this reporter was not detected, indicating that the corresponding enhancer is not robustly active under the conditions tested. To assess developmental changes in gene expression, we generated bulk RNA-seq datasets from embryonic, hatchling, and adult retinas. These analyses showed strong embryonic expression of onecut1, increasing expression of rod-associated genes through development, and pseudogenization or loss of multiple cone-enriched genes. We further identified a developmentally regulated onecut1 splice isoform containing an additional 48 amino acid sequence between the CUT and homeodomain DNA-binding domains. This spacer-containing isoform, termed LSOC1X2, was most abundant in the embryonic retina. To test whether LSOC1X2 retained regulatory activity, we assayed it in a mouse retinal reporter system. Both skate Onecut1 isoforms activated the ThrbCRM1 reporter in this heterologous context. Together, these findings identify a novel, developmentally regulated retinal onecut1 isoform in the little skate and establish it as a candidate regulator for future studies of photoreceptor development in this species and its elasmobranch relatives.

Animals

Heterokairic Genes and the Eco-Evo-Devo of Timing.

Concepts of developmental timing have traditionally been framed under heterochrony as evolved (genetically based) differences in timing, while environmentally induced shifts in timing within genotypes have been treated more loosely. In this article, heterokairy is presented as plasticity in the timing of developmental events, and the term "heterokairic genes" is proposed for environmentally modulated heterochronic genes that underlie this plasticity. Evidence from nematodes, insects, plants, and vertebrates is assembled, with emphasis placed on systems where environmental cues are relayed through endocrine or metabolic pathways to known timing modules/genes. On this basis, a distinction is drawn between validated heterokairic genes, supported by direct mechanistic data, and a broader set of candidates inferred from gene-environment interactions in developmental timing. The eco-evolutionary consequences of such genes are considered, and experimental and genomic strategies for their identification are outlined. It is argued that heterokairic genes provide a useful bridge between environmental variation, developmental mechanisms, and evolutionary change in timing.

Animals

Genome-wide characterization of the FOX gene family reveals sex-biased expression and FoxO-associated regulation during gonadal development in Bellamya aeruginosa.

Forkhead box (FOX) transcription factors are important regulators of development and reproduction, but their roles in molluscan gonadal development remain unclear. In this study, the FOX gene family was systematically identified in the freshwater gastropod Bellamya aeruginosa, and comparative gonadal transcriptomic analyses were performed across sexes and developmental stages.A total of 35 FOX genes were identified and classified into 19 subfamilies. Phylogenetic and synteny analyses indicated that the FOX gene family is generally conserved among mollusks, whereas FoxG and FoxL2 showed lineage-specific expansion. Structural analyses demonstrated that most BaeFOX proteins retained the conserved Forkhead domain architecture. Transcriptomic analyses revealed that gene expression divergence between testes and ovaries was markedly greater than that between developmental stages within the same gonad, indicating that sexual dimorphism is the major source of gonadal transcriptional variation. Functional enrichment consistently identified the FoxO signaling pathway in sex-biased comparisons. Several FOX genes also displayed clear gonad-biased expression patterns, and network analyses suggested that BaeFoxO, BaeFoxL2, and BaeFoxG may play central regulatory roles in gonadal development. These findings provide the first comprehensive characterization of the FOX gene family in B. aeruginosa and suggest that FOX-related regulatory networks potentially participate in gonadal development in gastropod mollusks.

Animals

Stem Cell Differentiation Disperses Transcriptional Clusters via a Conserved Surface-Condensate Trajectory.

Stem cells exhibit exceptionally prominent transcriptional clusters, which dissolve with progressing differentiation. Although these clusters are assigned central roles in embryonic gene regulation, their formation and loss during differentiation remain poorly understood. This study reveals that these prominent clusters disperse along a conserved trajectory in mouse embryonic stem cells, fruit fly testes, and zebrafish embryos. Imaging and lattice simulations show that these clusters form via surface condensation on H3K27ac-marked super-enhancer regions, which act as genomic scaffolds. Upon differentiation, partial loss of these active epigenetic marks and transcription-driven unfolding lead to dispersal of the prominent clusters. The block copolymer-based lattice simulations explain this process as a conserved trajectory through a three-dimensional state space, governed by surface condensation principles that extend beyond canonical liquid-liquid phase separation. This work marks surface condensation as a biophysical mechanism for the dynamic organization of stem cell-specific transcriptional hubs and demonstrates evolutionary conservation in several organisms. By uncovering a conserved biophysical mechanism for transcriptional organization in development, our work illustrates how polymer properties can contribute to the control of cell identity and fate.

Animals

Teleost Hox code defines regional identities competent for the formation of dorsal and anal fins.

The dorsal and anal fins can vary widely in position and length along the anterior-posterior axis in teleost fishes. However, the molecular mechanisms underlying the diversification of these fins remain unknown. Here, we used genetic approaches in zebrafish and medaka, in which the relative positions of the dorsal and anal fins are opposite, to demonstrate the crucial role of hox genes in the patterning of the teleost posterior body, including the dorsal and anal fins. By the CRISPR-Cas9-induced frameshift mutations and positional cloning of spontaneous dorsalfinless medaka, we show that various hox mutants exhibit the absence of dorsal or anal fins, or a stepwise posterior extension of these fins, with vertebral abnormalities. Our results indicate that multiple hox genes, primarily from hoxc-related clusters, encompass the regions responsible for the dorsal and anal fin formation along the anterior-posterior axis. These results further suggest that shifts in the anterior boundaries of hox expression which vary among fish species, lead to diversification in the position and size of the dorsal and anal fins, similar to how modulations in Hox expression can alter the number of anatomically distinct vertebrae in tetrapods. Furthermore, we show that hox genes responsible for dorsal fin formation are different between zebrafish and medaka. Our results suggest that a novel mechanism has occurred during teleost evolution, in which the gene network responsible for fin formation might have switched to the regulation downstream of other hox genes, leading to the remarkable diversity in the dorsal fin position.

Animals

A conserved Notch-Meis1-Pbx cascade specifies secretory progenitors into spatially diverse intestinal best4 + cells.

best4 + cells are a recently described vertebrate intestinal epithelial cell type. best4 + cells are altered in inflammatory bowel disease and colorectal cancer, suggesting that stimulation of their homeostatic replenishment may have therapeutic potential. However, the development and function of best4 + cells remain unclear. Since mice lack best4 + cells, we established zebrafish as a tractable in vivo model to observe, manipulate, and remove best4 + cells in an organismal context. We dissected best4 + cell developmental regulation in vivo from birth to differentiation and specialization, focusing on factors conserved in best4 + cells across vertebrates. Lineage tracing demonstrated that best4 + cells arise from secretory progenitors, where Notch/Dll4 signaling mediates a decision between best4 + and enterochromaffin cells by triggering meis1b expression. Following specification by meis1b, pbx3a spatially diversifies best4 + cells, which develop regional heterogeneity in gene expression, intracellular pH, and function. In vivo live imaging and removal of best4 + cells showed that best4+ cells sense luminal pH changes and extend dynamic luminal and stromal projections, but are not required to restore global luminal pH after challenge. Altogether, this study experimentally delineates best4 + cell developmental regulation and develops a genetic toolkit to examine their function in vivo, both of which will aid investigating how best4 + cells are altered or can be restored during disease.

Animals

The DLX/Notch axis is necessary for spatiotemporal regulation of neural cell fate.

Neuronal-glial cell fate switch during forebrain development is highly regulated. DLX transcription factors are necessary for promoting GABAergic interneuron differentiation and migration but the mechanisms for concomitant repression of glial fate in neural progenitors remain elusive. Here, the DLX2 regulatory network dynamic in the developing ventral telencephalon is characterised using a multi-omic approach at single-cell resolution, including single-cell whole genome spatial transcriptomics. We identify a secondary proliferative zone in the ventral subventricular zone and spatiotemporal-context dependent Notch pathway repression by DLX2 in maintaining progenitor populations and facilitating neural differentiation. We find that DLX2 controls cell fate determination by directly repressing Notch signalling genes as well as glial fate-promoting transcription factors, thereby inhibiting early adoption of oligodendroglial differentiation during neurogenesis. Here, we show that temporal cell fate switch is mediated by DLX2 via a multilayer gene regulatory network, redefining current understanding of neuronal-glial cell specification mechanisms in the developing telencephalon.

Animals