Explore Research Products in the PAR
It may take a few hours for recently added research products to appear in PAR search results.


Title: Reducing Cofilin dosage makes embryos resilient to heat stress
Abstract In addition to regulating the actin cytoskeleton, Cofilin also senses and responds to environmental stress. Cofilin can promote cell survival or death depending on context. Yet, many aspects of Cofilin’s role in survival need clarification. Here, we show that exposing earlyDrosophilaembryos to mild heat stress (32°C) induces a Cofilin-mediated Actin Stress Response and upregulation of heat- and ER-stress response genes. However, these responses do not alleviate the negative impacts of heat exposure. Instead, heat stressed embryos show downregulation of hundreds of developmental genes, including determinants of the embryonic body plan, and are less likely to hatch as larvae and adults. Remarkably, reducing Cofilin dosage blunts induction of all stress response pathways, mitigates downregulation of developmental genes, and completely rescues survival. Thus, Cofilin intersects with multiple stress response pathways, and modulates the transcriptomic response to heat stress. Strikingly, Cofilin knockdown emerges as a potent pro-survival manipulation for embryos.  more » « less
Award ID(s):
2243257
PAR ID:
10595351
Author(s) / Creator(s):
; ; ; ; ; ; ; ;
Publisher / Repository:
bioRxiv
Date Published:
Format(s):
Medium: X
Institution:
bioRxiv
Sponsoring Org:
National Science Foundation
More Like this
  1. ; ; (, Proceedings of the Royal Society B: Biological Sciences)
    In organisms with complex life cycles, life stages that are most susceptible to environmental stress may determine species persistence in the face of climate change. Early embryos ofDrosophila melanogasterare particularly sensitive to acute heat stress, yet tropical embryos have higher heat tolerance than temperate embryos, suggesting adaptive variation in embryonic heat tolerance. We compared transcriptomic responses to heat stress among tropical and temperate embryos to elucidate the gene regulatory basis of divergence in embryonic heat tolerance. The transcriptomes of tropical and temperate embryos differed in both constitutive and heat-stress-induced responses of the expression of relatively few genes, including genes involved in oxidative stress. Most of the transcriptomic response to heat stress was shared among all embryos. Embryos shifted the expression of thousands of genes, including increases in the expression of heat shock genes, suggesting robust zygotic gene activation and demonstrating that, contrary to previous reports, early embryos are not transcriptionally silent. The involvement of oxidative stress genes corroborates recent reports on the critical role of redox homeostasis in coordinating developmental transitions. By characterizing adaptive variation in the transcriptomic basis of embryonic heat tolerance, this study is a novel contribution to the literature on developmental physiology and developmental genetics. 
    more » « less
  2. ; ; ; (, Biomolecules)
    Diapause is a state of developmental and metabolic dormancy that precedes exposure to environmental stresses. Yet, diapausing embryos are typically stress-tolerant. Evidence suggests that diapausing embryos “prepare” for stress as part of a gene expression program as they enter dormancy. Here, we investigate if diapause II embryos of the annual killifish Austrofundulus limnaeus, which can survive for hundreds of days of anoxia, can mount a transcriptomic response to anoxic insult. Bulk RNAseq was used to characterize the transcriptomes of diapause II embryos exposed to normoxia, 4 h and 24 h anoxia, and 2 h and 24 h normoxic recovery from anoxia. Differential expression and gene ontology analyses were used to probe for pathways that may mitigate survival. Transcriptional factor analysis was used to predict potential mediators of this response. Diapausing embryos exhibited a robust transcriptomic response to anoxia and recovery that returns to near baseline conditions after 24 h. Anoxia induced an upregulation of genes involved in the integrated stress response, lipid metabolism, p38mapk kinase signaling, and apoptosis. Developmental and mitochondrial genes decreased. We conclude that diapause II embryos mount a robust transcriptomic stress response when faced with anoxic insult. This response is consistent with mediating expected challenges to cellular homeostasis in anoxia. 
    more » « less
  3. ; ; ; ; ; ; (, Frontiers in Immunology)
    BackgroundEnhancing an organism’s survival hinges on the development of balanced and adaptable stress response systems. While the initial stress-response set-points in the hypothalamus may be genetically determined, they are further influenced by epigenetic factors during embryonic development. A debate persists regarding the heritability of such behavioral traits. The chickin ovoheat conditioning model offers a unique insight into this fundamental question, where manipulation during embryonic development can induce heat resilience and even cross-tolerance to promote immunological resilience. In this study, we conducted an analysis of thermal manipulation during embryogenesis to demonstrate paternal heredity and investigate its transmission through sperm DNA methylation in coordination with miR-200a action. ResultFirst-generation embryos underwentin ovoheat conditioning (EHC), creating a cohort of embryonic EHC and control chicks. These chicks were then subjected to an intracranial lipopolysaccharide (LPS) challenge. Conditioning rendered the chicks immune resilient, as evidenced by their fibril effect. Male offspring were raised to maturity, and their sperm was analyzed for methylome patterns, revealing significant differences between treatments, particularly in immune and development related genes. Additionally, sperm from EHC males was used for artificial insemination of naïve Cobb hens, resulting in untreated offspring that displayed immune resilience upon LPS challenge, indicating transgenerational effects. Overlap analysis of sperm methylome and differentially methylated sites (DMS) of offspring hypothalamus revealed inheritance of altered methylation associated with specific genes. Several of these genes are potential effectors of miR-200a, whose expression profile in the hypothalamus during LPS challenge was conserved across both generations. To evaluate the role of miR-200a in cross-tolerance acquisition, miR-200a was intracranially injected, and RNA-seq analysis of the hypothalamus revealed genes involved in the regulation of developmental and metabolic processes, stress, and immune response. ConclusionThis study demonstrates paternal trait heredity by revealing that EHC induces cross-tolerance with the immunological system, rendering chicks resilient to LPS that transgenerationally transmit this to untreated offspring. Additionally, analysis of sperm methylation patterns in EHC mature chicks led to identification of genes associated with neuronal development and immune response, indicating potential neural network reorganization. Finally, miR-200a emerges as a regulator potentially involved in mediating the cross-tolerance effect. 
    more » « less
  4. ; ; ; ; ; ; ; (, bioRxiv)
    Abstract BackgroundMorphologic sex differences between males and females typically emerge after the primordial germ cell migration and gonad formation, although sex is determined at fertilization based on chromosome composition. A key debated sexual difference is the embryonic developmental rate, within vitroproduced male embryos often developing faster. However, the molecular mechanisms driving early embryonic sex differences remain unclear. ResultsTo investigate the transcriptional sex difference during early development,in vitroproduced bovine blastocysts were collected and sexed by PCR. A significant male-biased development was observed in expanded blastocysts. Ultra-low input RNA-seq analysis identified 837 DEGs, with 231 upregulated and 606 downregulated in males. Functional enrichment analysis revealed male-biased DEGs were associated with metabolic regulation, whereas female-biased DEGs were related to female gonad development, sex differentiation, inflammatory pathways, and TGF-beta signaling. Comparing X chromosome and autosome expression ratio, we found that female-biased DEGs contributed to the higher X-linked gene dosage, a phenomenon not observed in male embryos. Moreover, we identified the sex-biased transcription factors and RNA-bind proteins, including pluripotent factors such asSOX21andPRDM14, and splicing factorsFMR1andHNRNPH2. Additionally, we revealed 1,555 significantly sex-biased differential alternative splicing (AS), predominantly skipped exons, mapped to 906 genes, with 59 overlapping with DEGs enriched in metabolic and autophagy pathways. By incorporating novel isoforms from long reads sequencing, we identified 1,151 sex-biased differentially expressed isoforms (DEIs) associated with 1,017 genes. Functional analysis showed that female-biased DEIs were involved in the negative regulation of transcriptional activity, while male-biased DEIs were related to energy metabolism. Furthermore, we identified sex-biased differential exon usage inDENND1B, DIS3L2, DOCK11, IL1RAPL2,andZRSR2Y,indicating their sex-specific regulation in early embryo development. ConclusionThis study provided a comprehensive analysis of transcriptome differences between male and female bovine blastocysts, integrating sex-biased gene expression, alternative splicing, and isoform dynamics. Our findings indicate that enriched metabolism processes in male embryos may contribute to the faster developmental pace, providing insights into sex-specific regulatory mechanisms during early embryogenesis. Plain English summaryMale and female early embryos develop at different speeds, with male embryos often developing faster than female embryos. However, the reasons behind these early differences remain unclear. In this study, we examined gene activity in bovine embryos to uncover the biological factors regulating these early sex differences. We collected in vitro-produced bovine blastocysts, examined their sex, and confirmed that male embryos develop faster. By analyzing global gene activity, including alternative splicing, which allows one gene to code for multiple RNA isoforms and proteins, we found distinct gene expression profiles between male and female embryos. Male embryos showed higher activity in genes related to metabolism and cellular functions, while female embryos had increased activity in genes associated with female-specific gonad development and gene expression regulation. We also examined differences in how genes on the X chromosome were expressed. Female embryos had higher X-linked gene expression, which may contribute to sex-specific developmental regulation. Additionally, we identified sex-specific transcription factors and RNA-binding proteins that regulate early embryo development, some of which are known to control pluripotency and gene splicing. Overall, our study provides new insights into how gene activity shapes early sex differences, suggesting that enhanced metabolism in male embryos may be a key driver of their faster developmental rate. HighlightsMale embryos develop faster due to increased gene expression in metabolism pathwaysFemale embryos exhibit higher X-linked gene expression, suggesting X-dosage compensation plays a role in early developmentSex-biased alternative splicing events contribute to embryonic metabolism, autophagy, and transcriptional regulation in embryosSex-biased isoform diversity contributes to distinct developmental regulation in male and female embryosKey pluripotency factors (SOX21, PRDM14) and splicing regulators (FMR1, HNRNPH2) drive sex-specific gene expression 
    more » « less
  5. ; ; ; ; ; ; ; ; ; ; et al (, Nature Communications)
    Abstract Maintenance of water homeostasis is a fundamental cellular process required by all living organisms. Here, we use the single-celled green algaChlamydomonas reinhardtiito establish a foundational understanding of osmotic-stress signaling pathways through transcriptomics, phosphoproteomics, and functional genomics approaches. Comparison of pathways identified through these analyses with yeast and Arabidopsis allows us to infer their evolutionary conservation and divergence across these lineages. 76 genes, acting across diverse cellular compartments, were found to be important for osmotic-stress tolerance in Chlamydomonas through their functions in cytoskeletal organization, potassium transport, vesicle trafficking, mitogen-activated protein kinase and chloroplast signaling. We show that homologs for five of these genes have conserved functions in stress tolerance in Arabidopsis and reveal a novel PROFILIN-dependent stage of acclimation affecting the actin cytoskeleton that ensures tissue integrity upon osmotic stress. This study highlights the conservation of the stress response in algae and land plants, and establishes Chlamydomonas as a unicellular plant model system to dissect the osmotic stress signaling pathway. 
    more » « less
  • Citation Formats
  • MLA
  • APA
  • Chicago
  • BibTeX
  • Text Encoded Conversion
  • XML
  • Save / Share this Record
  • Send to Email