1
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Mikucki EE, O’Leary TS, Lockwood BL. Heat tolerance, oxidative stress response tuning and robust gene activation in early-stage Drosophila melanogaster embryos. Proc Biol Sci 2024; 291:20240973. [PMID: 39163981 PMCID: PMC11335408 DOI: 10.1098/rspb.2024.0973] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2024] [Revised: 06/11/2024] [Accepted: 07/26/2024] [Indexed: 08/22/2024] Open
Abstract
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 of Drosophila melanogaster are 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.
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Affiliation(s)
- Emily E. Mikucki
- Department of Biology, University of Vermont, Burlington, VT, USA
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2
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Boisseau RP, Woods HA. Resource allocation strategies and mechanical constraints drive the diversification of stick and leaf insect eggs. Curr Biol 2024; 34:2880-2892.e7. [PMID: 38897201 DOI: 10.1016/j.cub.2024.05.042] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2023] [Revised: 03/14/2024] [Accepted: 05/22/2024] [Indexed: 06/21/2024]
Abstract
The diversity of insect eggs is astounding but still largely unexplained. Here, we apply phylogenetic analyses to 208 species of stick and leaf insects, coupled with physiological measurements of metabolic rate and water loss on five species, to evaluate classes of factors that may drive egg morphological diversification: life history constraints, material costs, mechanical constraints, and ecological circumstances. We show support for all three classes, but egg size is primarily influenced by female body size and strongly trades off with egg number. Females that lay relatively fewer but larger eggs, which develop more slowly because of disproportionately low metabolic rates, also tend to bury or glue them in specific locations instead of simply dropping them from the foliage (ancestral state). This form of parental care then directly favors relatively elongated eggs, which may facilitate their placement and allow easier passage through the oviducts in slender species. In addition, flightless females display a higher reproductive output and consequently lay relatively more and larger eggs compared with flight-capable females. Surprisingly, local climatic conditions had only weak effects on egg traits. Overall, our results suggest that morphological diversification of stick insect eggs is driven by a complex web of causal relationships among traits, with dominant effects of resource allocation and oviposition strategies, and of mechanical constraints.
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Affiliation(s)
- Romain P Boisseau
- Division of Biological Sciences, University of Montana, 32 Campus Drive, Missoula, MT 59812, USA; Department of Ecology and Evolution, University of Lausanne, 1015 Lausanne, Switzerland.
| | - H Arthur Woods
- Division of Biological Sciences, University of Montana, 32 Campus Drive, Missoula, MT 59812, USA
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3
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Sonmez UM, Frey N, LeDuc PR, Minden JS. Fly Me to the Micron: Microtechnologies for Drosophila Research. Annu Rev Biomed Eng 2024; 26:441-473. [PMID: 38959386 DOI: 10.1146/annurev-bioeng-050423-054647] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/05/2024]
Abstract
Multicellular model organisms, such as Drosophila melanogaster (fruit fly), are frequently used in a myriad of biological research studies due to their biological significance and global standardization. However, traditional tools used in these studies generally require manual handling, subjective phenotyping, and bulk treatment of the organisms, resulting in laborious experimental protocols with limited accuracy. Advancements in microtechnology over the course of the last two decades have allowed researchers to develop automated, high-throughput, and multifunctional experimental tools that enable novel experimental paradigms that would not be possible otherwise. We discuss recent advances in microtechnological systems developed for small model organisms using D. melanogaster as an example. We critically analyze the state of the field by comparing the systems produced for different applications. Additionally, we suggest design guidelines, operational tips, and new research directions based on the technical and knowledge gaps in the literature. This review aims to foster interdisciplinary work by helping engineers to familiarize themselves with model organisms while presenting the most recent advances in microengineering strategies to biologists.
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Affiliation(s)
- Utku M Sonmez
- Department of Mechanical Engineering, Carnegie Mellon University, Pittsburgh, Pennsylvania, USA;
- Current affiliation: Department of Neuroscience, Scripps Research, San Diego, California, USA
- Current affiliation: Department of NanoEngineering, University of California San Diego, La Jolla, California, USA
| | - Nolan Frey
- Department of Biological Sciences, Carnegie Mellon University, Pittsburgh, Pennsylvania, USA;
| | - Philip R LeDuc
- Department of Mechanical Engineering, Carnegie Mellon University, Pittsburgh, Pennsylvania, USA;
- Department of Electrical and Computer Engineering, Carnegie Mellon University, Pittsburgh, Pennsylvania, USA
- Department of Computational Biology, Carnegie Mellon University, Pittsburgh, Pennsylvania, USA
- Department of Biomedical Engineering, Carnegie Mellon University, Pittsburgh, Pennsylvania, USA
| | - Jonathan S Minden
- Department of Biological Sciences, Carnegie Mellon University, Pittsburgh, Pennsylvania, USA;
- Department of Biomedical Engineering, Carnegie Mellon University, Pittsburgh, Pennsylvania, USA
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4
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Joyce M, Falconio FA, Blackhurst L, Prieto-Godino L, French AS, Gilestro GF. Divergent evolution of sleep in Drosophila species. Nat Commun 2024; 15:5091. [PMID: 38876988 PMCID: PMC11178934 DOI: 10.1038/s41467-024-49501-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2023] [Accepted: 06/05/2024] [Indexed: 06/16/2024] Open
Abstract
Living organisms synchronize their biological activities with the earth's rotation through the circadian clock, a molecular mechanism that regulates biology and behavior daily. This synchronization factually maximizes positive activities (e.g., social interactions, feeding) during safe periods, and minimizes exposure to dangers (e.g., predation, darkness) typically at night. Beyond basic circadian regulation, some behaviors like sleep have an additional layer of homeostatic control, ensuring those essential activities are fulfilled. While sleep is predominantly governed by the circadian clock, a secondary homeostatic regulator, though not well-understood, ensures adherence to necessary sleep amounts and hints at a fundamental biological function of sleep beyond simple energy conservation and safety. Here we explore sleep regulation across seven Drosophila species with diverse ecological niches, revealing that while circadian-driven sleep aspects are consistent, homeostatic regulation varies significantly. The findings suggest that in Drosophilids, sleep evolved primarily for circadian purposes. The more complex, homeostatically regulated functions of sleep appear to have evolved independently in a species-specific manner, and are not universally conserved. This laboratory model may reproduce and recapitulate primordial sleep evolution.
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Affiliation(s)
- Michaela Joyce
- Department of Life Sciences, Imperial College London, London, UK
- The Francis Crick Research Institute, London, UK
| | | | | | | | - Alice S French
- Department of Life Sciences, Imperial College London, London, UK.
- The Francis Crick Research Institute, London, UK.
- School of Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol, UK.
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5
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Patil G, van Zon JS. Timers, variability, and body-wide coordination: C. elegans as a model system for whole-animal developmental timing. Curr Opin Genet Dev 2024; 85:102172. [PMID: 38432125 DOI: 10.1016/j.gde.2024.102172] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2023] [Revised: 02/06/2024] [Accepted: 02/06/2024] [Indexed: 03/05/2024]
Abstract
Successful development requires both precise timing of cellular processes, such as division and differentiation, and tight coordination of timing between tissues and organs. Yet, how time information is encoded with high precision and synchronized between tissues, despite inherent molecular noise, is unsolved. Here, we propose the nematode C. elegans as a unique model system for studying body-wide control of developmental timing. Recent studies combining genetics, quantitative analysis, and simulations have 1) mapped core timers controlling larval development, indicating temporal gradients as an underlying mechanism, and 2) elucidated general principles that make timing insensitive to inherent fluctuations and variation in environmental conditions. As the molecular regulators of C. elegans developmental timing are broadly conserved, these mechanisms likely apply also to higher organisms.
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6
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Bourn JJ, Dorrity MW. Degrees of freedom: temperature's influence on developmental rate. Curr Opin Genet Dev 2024; 85:102155. [PMID: 38335718 DOI: 10.1016/j.gde.2024.102155] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2023] [Revised: 01/14/2024] [Accepted: 01/15/2024] [Indexed: 02/12/2024]
Abstract
Temperature exerts a fundamental influence across scales of biology, from the biophysical nature of molecules, to the sensitivity of cells, and the coordinated progression of development in embryos. Species-specific developmental rates and temperature-induced acceleration of development indicate that these sensing mechanisms are harnessed to influence developmental dynamics. Tracing how temperature sensitivity propagates through biological scales to influence the pace of development can therefore reveal how embryogenesis remains robust to environmental influences. Cellular protein homeostasis (proteostasis), and cellular metabolic rate are linked to both temperature-induced and species-specific developmental tempos in specific cell types, hinting toward generalized mechanisms of timing control. New methods to extract timing information from single-cell profiling experiments are driving further progress in understanding how mechanisms of temperature sensitivity can direct cell-autonomous responses, coordination across cell types, and evolutionary modifications of developmental timing.
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Affiliation(s)
- Jess J Bourn
- Structural and Computational Biology, European Molecular Biology Laboratory, Heidelberg, Germany. https://twitter.com/@bournsupremacy
| | - Michael W Dorrity
- Structural and Computational Biology, European Molecular Biology Laboratory, Heidelberg, Germany.
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7
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Lye CM, Blanchard GB, Evans J, Nestor-Bergmann A, Sanson B. Polarised cell intercalation during Drosophila axis extension is robust to an orthogonal pull by the invaginating mesoderm. PLoS Biol 2024; 22:e3002611. [PMID: 38683880 PMCID: PMC11081494 DOI: 10.1371/journal.pbio.3002611] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2023] [Revised: 05/09/2024] [Accepted: 04/03/2024] [Indexed: 05/02/2024] Open
Abstract
As tissues grow and change shape during animal development, they physically pull and push on each other, and these mechanical interactions can be important for morphogenesis. During Drosophila gastrulation, mesoderm invagination temporally overlaps with the convergence and extension of the ectodermal germband; the latter is caused primarily by Myosin II-driven polarised cell intercalation. Here, we investigate the impact of mesoderm invagination on ectoderm extension, examining possible mechanical and mechanotransductive effects on Myosin II recruitment and polarised cell intercalation. We find that the germband ectoderm is deformed by the mesoderm pulling in the orthogonal direction to germband extension (GBE), showing mechanical coupling between these tissues. However, we do not find a significant change in Myosin II planar polarisation in response to mesoderm invagination, nor in the rate of junction shrinkage leading to neighbour exchange events. We conclude that the main cellular mechanism of axis extension, polarised cell intercalation, is robust to the mesoderm invagination pull. We find, however, that mesoderm invagination slows down the rate of anterior-posterior cell elongation that contributes to axis extension, counteracting the tension from the endoderm invagination, which pulls along the direction of GBE.
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Affiliation(s)
- Claire M. Lye
- Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge, United Kingdom
| | - Guy B. Blanchard
- Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge, United Kingdom
| | - Jenny Evans
- Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge, United Kingdom
| | - Alexander Nestor-Bergmann
- Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge, United Kingdom
| | - Bénédicte Sanson
- Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge, United Kingdom
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8
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Sperling AL, Glover DM. Protocol for screening facultative parthenogenesis in Drosophila. STAR Protoc 2023; 4:102585. [PMID: 37740913 PMCID: PMC10520562 DOI: 10.1016/j.xpro.2023.102585] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2023] [Revised: 08/01/2023] [Accepted: 08/30/2023] [Indexed: 09/25/2023] Open
Abstract
Most species of sexually reproducing Drosophila are capable of some degree of facultative parthenogenesis, which involves the initiation of development in an unfertilized egg. Here, we present an optimized protocol to screen facultative parthenogenesis in Drosophila. We describe steps for the collection and maintenance of virgin flies. We then detail offspring screening for the analysis of parthenogenesis. This protocol can be applied to different Drosophila strains and can be adapted for the analysis of parthenogenesis in other animals. For complete details on the use and execution of this protocol, please refer to Sperling et al.1.
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Affiliation(s)
- Alexis L Sperling
- Department of Genetics, University of Cambridge, Cambridge, CB2 3EH Cambridgeshire, UK.
| | - David M Glover
- Department of Genetics, University of Cambridge, Cambridge, CB2 3EH Cambridgeshire, UK; Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA 91125, USA.
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9
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Toulany N, Morales-Navarrete H, Čapek D, Grathwohl J, Ünalan M, Müller P. Uncovering developmental time and tempo using deep learning. Nat Methods 2023; 20:2000-2010. [PMID: 37996754 PMCID: PMC10703695 DOI: 10.1038/s41592-023-02083-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2023] [Accepted: 10/15/2023] [Indexed: 11/25/2023]
Abstract
During animal development, embryos undergo complex morphological changes over time. Differences in developmental tempo between species are emerging as principal drivers of evolutionary novelty, but accurate description of these processes is very challenging. To address this challenge, we present here an automated and unbiased deep learning approach to analyze the similarity between embryos of different timepoints. Calculation of similarities across stages resulted in complex phenotypic fingerprints, which carry characteristic information about developmental time and tempo. Using this approach, we were able to accurately stage embryos, quantitatively determine temperature-dependent developmental tempo, detect naturally occurring and induced changes in the developmental progression of individual embryos, and derive staging atlases for several species de novo in an unsupervised manner. Our approach allows us to quantify developmental time and tempo objectively and provides a standardized way to analyze early embryogenesis.
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Affiliation(s)
- Nikan Toulany
- Systems Biology of Development, University of Konstanz, Konstanz, Germany
- Friedrich Miescher Laboratory of the Max Planck Society, Tübingen, Germany
- University Hospital and Faculty of Medicine, University of Tübingen, Tübingen, Germany
| | - Hernán Morales-Navarrete
- Systems Biology of Development, University of Konstanz, Konstanz, Germany
- Centre for the Advanced Study of Collective Behaviour, Konstanz, Germany
| | - Daniel Čapek
- Systems Biology of Development, University of Konstanz, Konstanz, Germany
| | - Jannis Grathwohl
- Systems Biology of Development, University of Konstanz, Konstanz, Germany
| | - Murat Ünalan
- Systems Biology of Development, University of Konstanz, Konstanz, Germany.
- Friedrich Miescher Laboratory of the Max Planck Society, Tübingen, Germany.
| | - Patrick Müller
- Systems Biology of Development, University of Konstanz, Konstanz, Germany.
- Friedrich Miescher Laboratory of the Max Planck Society, Tübingen, Germany.
- University Hospital and Faculty of Medicine, University of Tübingen, Tübingen, Germany.
- Centre for the Advanced Study of Collective Behaviour, Konstanz, Germany.
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10
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Abstract
Organismal development requires the reproducible unfolding of an ordered sequence of discrete steps (cell fate determination, migration, tissue folding, etc.) in both time and space. Here, we review the mechanisms that grant temporal specificity to developmental steps, including molecular clocks and timers. Individual timing mechanisms must be coordinated with each other to maintain the overall developmental sequence. However, phenotypic novelties can also arise through the modification of temporal patterns over the course of evolution. Two main types of variation in temporal patterning characterize interspecies differences in developmental time: allochrony, where the overall developmental sequence is either accelerated or slowed down while maintaining the relative duration of individual steps, and heterochrony, where the duration of specific developmental steps is altered relative to the rest. New advances in in vitro modeling of mammalian development using stem cells have recently enabled the revival of mechanistic studies of allochrony and heterochrony. In both cases, differences in the rate of basic cellular functions such as splicing, translation, protein degradation, and metabolism seem to underlie differences in developmental time. In the coming years, these studies should identify the genetic differences that drive divergence in developmental time between species.
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Affiliation(s)
- Margarete Diaz-Cuadros
- Department of Molecular Biology, Massachusetts General Hospital, Boston, Massachusetts, USA;
- Department of Genetics, Harvard Medical School, Boston, Massachusetts, USA;
| | - Olivier Pourquié
- Department of Genetics, Harvard Medical School, Boston, Massachusetts, USA;
- Department of Pathology, Brigham and Women's Hospital, Boston, Massachusetts, USA
- Harvard Stem Cell Institute, Harvard University, Cambridge, Massachusetts, USA
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11
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Dorrity MW, Saunders LM, Duran M, Srivatsan SR, Barkan E, Jackson DL, Sattler SM, Ewing B, Queitsch C, Shendure J, Raible DW, Kimelman D, Trapnell C. Proteostasis governs differential temperature sensitivity across embryonic cell types. Cell 2023; 186:5015-5027.e12. [PMID: 37949057 PMCID: PMC11178971 DOI: 10.1016/j.cell.2023.10.013] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2022] [Revised: 05/29/2023] [Accepted: 10/11/2023] [Indexed: 11/12/2023]
Abstract
Embryonic development is remarkably robust, but temperature stress can degrade its ability to generate animals with invariant anatomy. Phenotypes associated with environmental stress suggest that some cell types are more sensitive to stress than others, but the basis of this sensitivity is unknown. Here, we characterize hundreds of individual zebrafish embryos under temperature stress using whole-animal single-cell RNA sequencing (RNA-seq) to identify cell types and molecular programs driving phenotypic variability. We find that temperature perturbs the normal proportions and gene expression programs of numerous cell types and also introduces asynchrony in developmental timing. The notochord is particularly sensitive to temperature, which we map to a specialized cell type: sheath cells. These cells accumulate misfolded protein at elevated temperature, leading to a cascading structural failure of the notochord and anatomic defects. Our study demonstrates that whole-animal single-cell RNA-seq can identify mechanisms for developmental robustness and pinpoint cell types that constitute key failure points.
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Affiliation(s)
- Michael W Dorrity
- Department of Genome Sciences, University of Washington, Seattle, WA 98195, USA; Structural and Computational Biology, European Molecular Biology Laboratory, 69117 Heidelberg, Germany.
| | - Lauren M Saunders
- Department of Genome Sciences, University of Washington, Seattle, WA 98195, USA
| | - Madeleine Duran
- Department of Genome Sciences, University of Washington, Seattle, WA 98195, USA
| | - Sanjay R Srivatsan
- Department of Genome Sciences, University of Washington, Seattle, WA 98195, USA
| | - Eliza Barkan
- Department of Genome Sciences, University of Washington, Seattle, WA 98195, USA
| | - Dana L Jackson
- Department of Genome Sciences, University of Washington, Seattle, WA 98195, USA
| | - Sydney M Sattler
- Department of Genome Sciences, University of Washington, Seattle, WA 98195, USA
| | - Brent Ewing
- Department of Genome Sciences, University of Washington, Seattle, WA 98195, USA
| | - Christine Queitsch
- Department of Genome Sciences, University of Washington, Seattle, WA 98195, USA
| | - Jay Shendure
- Department of Genome Sciences, University of Washington, Seattle, WA 98195, USA; Brotman Baty Institute for Precision Medicine, Seattle, WA 98195, USA; Howard Hughes Medical Institute, Seattle, WA 98195, USA
| | - David W Raible
- Department of Biological Structure, University of Washington, Seattle, WA 98195, USA
| | - David Kimelman
- Department of Biochemistry, University of Washington, Seattle, WA 98195, USA
| | - Cole Trapnell
- Department of Genome Sciences, University of Washington, Seattle, WA 98195, USA.
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12
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Daňková K, Nicholas S, Nordström K. Temperature during pupal development affects hoverfly developmental time, adult life span, and wing length. Ecol Evol 2023; 13:e10516. [PMID: 37881229 PMCID: PMC10597744 DOI: 10.1002/ece3.10516] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2023] [Revised: 06/25/2023] [Accepted: 08/29/2023] [Indexed: 10/27/2023] Open
Abstract
Hoverflies (Diptera, Syrphidae) are cosmopolitan, generalist flower visitors and among the most important pollinators after bees and bumblebees. The dronefly Eristalis tenax can be found in temperate and continental climates across the globe, often synanthropically. Eristalis tenax pupae of different generations and different climate zones are thus exposed to vastly different temperatures. In many insects, the ambient temperature during the pupal stage affects development, adult size, and survival; however, the effect of developmental temperature on these traits in hoverflies is comparatively poorly understood. We here reared E. tenax pupae at different temperatures, from 10°C to 25°C, and quantified the effect on adult hoverflies. We found that pupal rearing at 17°C appeared to be optimal, with high eclosion rates, longer wings, and increased adult longevity. Rearing temperatures above or below this optimum led to decreased eclosion rates, wing size, and adult survival. Similar thermal dependence has been observed in other insects. We found that rearing temperature had no significant effect on locomotor activity, coloration or weight, despite evidence of strong sexual dimorphism for each of these traits. Our findings are important as hoverflies are key pollinators, and understanding the effects of developmental temperature could potentially be useful for horticulture.
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Affiliation(s)
- Klára Daňková
- Flinders Health and Medical Research InstituteFlinders UniversityAdelaideSouth AustraliaAustralia
- Department of Zoology, Faculty of ScienceCharles UniversityPraha 2Czech Republic
| | - Sarah Nicholas
- Flinders Health and Medical Research InstituteFlinders UniversityAdelaideSouth AustraliaAustralia
| | - Karin Nordström
- Flinders Health and Medical Research InstituteFlinders UniversityAdelaideSouth AustraliaAustralia
- Department of Medical Cell BiologyUppsala UniversityUppsalaSweden
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13
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Kilwein MD, Dao TK, Welte MA. Drosophila embryos allocate lipid droplets to specific lineages to ensure punctual development and redox homeostasis. PLoS Genet 2023; 19:e1010875. [PMID: 37578970 PMCID: PMC10449164 DOI: 10.1371/journal.pgen.1010875] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2022] [Revised: 08/24/2023] [Accepted: 07/17/2023] [Indexed: 08/16/2023] Open
Abstract
Lipid droplets (LDs) are ubiquitous organelles that facilitate neutral lipid storage in cells, including energy-dense triglycerides. They are found in all investigated metazoan embryos where they are thought to provide energy for development. Intriguingly, early embryos of diverse metazoan species asymmetrically allocate LDs amongst cellular lineages, a process which can involve massive intracellular redistribution of LDs. However, the biological reason for asymmetric lineage allocation is unknown. To address this issue, we utilize the Drosophila embryo where the cytoskeletal mechanisms that drive allocation are well characterized. We disrupt allocation by two different means: Loss of the LD protein Jabba results in LDs adhering inappropriately to glycogen granules; loss of Klar alters the activities of the microtubule motors that move LDs. Both mutants cause the same dramatic change in LD tissue inheritance, shifting allocation of the majority of LDs to the yolk cell instead of the incipient epithelium. Embryos with such mislocalized LDs do not fully consume their LDs and are delayed in hatching. Through use of a dPLIN2 mutant, which appropriately localizes a smaller pool of LDs, we find that failed LD transport and a smaller LD pool affect embryogenesis in a similar manner. Embryos of all three mutants display overlapping changes in their transcriptome and proteome, suggesting that lipid deprivation results in a shared embryonic response and a widespread change in metabolism. Excitingly, we find abundant changes related to redox homeostasis, with many proteins related to glutathione metabolism upregulated. LD deprived embryos have an increase in peroxidized lipids and rely on increased utilization of glutathione-related proteins for survival. Thus, embryos are apparently able to mount a beneficial response upon lipid stress, rewiring their metabolism to survive. In summary, we demonstrate that early embryos allocate LDs into specific lineages for subsequent optimal utilization, thus protecting against oxidative stress and ensuring punctual development.
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Affiliation(s)
- Marcus D. Kilwein
- Department of Biology, University of Rochester, Rochester, New York, United States of America
| | - T. Kim Dao
- Department of Biology, University of Rochester, Rochester, New York, United States of America
| | - Michael A. Welte
- Department of Biology, University of Rochester, Rochester, New York, United States of America
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14
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Rothenberg KE, Chen Y, McDonald JA, Fernandez-Gonzalez R. Rap1 coordinates cell-cell adhesion and cytoskeletal reorganization to drive collective cell migration in vivo. Curr Biol 2023:S0960-9822(23)00603-6. [PMID: 37244252 DOI: 10.1016/j.cub.2023.05.009] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2022] [Revised: 03/16/2023] [Accepted: 05/04/2023] [Indexed: 05/29/2023]
Abstract
Collective cell movements contribute to tissue development and repair and spread metastatic disease. In epithelia, cohesive cell movements require reorganization of adherens junctions and the actomyosin cytoskeleton. However, the mechanisms that coordinate cell-cell adhesion and cytoskeletal remodeling during collective cell migration in vivo are unclear. We investigated the mechanisms of collective cell migration during epidermal wound healing in Drosophila embryos. Upon wounding, the cells adjacent to the wound internalize cell-cell adhesion molecules and polarize actin and the motor protein non-muscle myosin II to form a supracellular cable around the wound that coordinates cell movements. The cable anchors at former tricellular junctions (TCJs) along the wound edge, and TCJs are reinforced during wound closure. We found that the small GTPase Rap1 was necessary and sufficient for rapid wound repair. Rap1 promoted myosin polarization to the wound edge and E-cadherin accumulation at TCJs. Using embryos expressing a mutant form of the Rap1 effector Canoe/Afadin that cannot bind Rap1, we found that Rap1 signals through Canoe for adherens junction remodeling, but not for actomyosin cable assembly. Instead, Rap1 was necessary and sufficient for RhoA/Rho1 activation at the wound edge. The RhoGEF Ephexin localized to the wound edge in a Rap1-dependent manner, and Ephexin was necessary for myosin polarization and rapid wound repair, but not for E-cadherin redistribution. Together, our data show that Rap1 coordinates the molecular rearrangements that drive embryonic wound healing, promoting actomyosin cable assembly through Ephexin-Rho1, and E-cadherin redistribution through Canoe, thus enabling rapid collective cell migration in vivo.
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Affiliation(s)
- Katheryn E Rothenberg
- Institute of Biomedical Engineering, University of Toronto, Toronto, ON M5S 3G9, Canada; Translational Biology and Engineering Program, Ted Rogers Centre for Heart Research, University of Toronto, Toronto, ON M5G 1M1, Canada
| | - Yujun Chen
- Division of Biology, Kansas State University, Manhattan, KS 66506, USA
| | | | - Rodrigo Fernandez-Gonzalez
- Institute of Biomedical Engineering, University of Toronto, Toronto, ON M5S 3G9, Canada; Translational Biology and Engineering Program, Ted Rogers Centre for Heart Research, University of Toronto, Toronto, ON M5G 1M1, Canada; Department of Cell and Systems Biology, University of Toronto, Toronto, ON M5S 3G5, Canada; Developmental and Stem Cell Biology Program, The Hospital for Sick Children, Toronto, ON M5G 1X8, Canada.
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15
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Alamos S, Reimer A, Westrum C, Turner MA, Talledo P, Zhao J, Luu E, Garcia HG. Minimal synthetic enhancers reveal control of the probability of transcriptional engagement and its timing by a morphogen gradient. Cell Syst 2023; 14:220-236.e3. [PMID: 36696901 PMCID: PMC10125799 DOI: 10.1016/j.cels.2022.12.008] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2021] [Revised: 09/03/2022] [Accepted: 12/21/2022] [Indexed: 01/26/2023]
Abstract
How enhancers interpret morphogen gradients to generate gene expression patterns is a central question in developmental biology. Recent studies have proposed that enhancers can dictate whether, when, and at what rate promoters engage in transcription, but the complexity of endogenous enhancers calls for theoretical models with too many free parameters to quantitatively dissect these regulatory strategies. To overcome this limitation, we established a minimal promoter-proximal synthetic enhancer in embryos of Drosophila melanogaster. Here, a gradient of the Dorsal activator is read by a single Dorsal DNA binding site. Using live imaging to quantify transcriptional activity, we found that a single binding site can regulate whether promoters engage in transcription in a concentration-dependent manner. By modulating the binding-site affinity, we determined that a gene's decision to transcribe and its transcriptional onset time can be explained by a simple model where the promoter traverses multiple kinetic barriers before transcription can ensue.
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Affiliation(s)
- Simon Alamos
- Department of Plant and Microbial Biology, University of California at Berkeley, Berkeley, CA, USA
| | - Armando Reimer
- Biophysics Graduate Group, University of California at Berkeley, Berkeley, CA, USA
| | - Clay Westrum
- Department of Physics, University of California at Berkeley, Berkeley, CA, USA
| | - Meghan A Turner
- Department of Plant and Microbial Biology, University of California at Berkeley, Berkeley, CA, USA
| | - Paul Talledo
- Department of Molecular and Cell Biology, University of California at Berkeley, Berkeley, CA, USA
| | - Jiaxi Zhao
- Department of Physics, University of California at Berkeley, Berkeley, CA, USA
| | - Emma Luu
- Department of Physics, University of California at Berkeley, Berkeley, CA, USA
| | - Hernan G Garcia
- Biophysics Graduate Group, University of California at Berkeley, Berkeley, CA, USA; Department of Physics, University of California at Berkeley, Berkeley, CA, USA; Department of Molecular and Cell Biology, University of California at Berkeley, Berkeley, CA, USA; Institute for Quantitative Biosciences-QB3, University of California at Berkeley, Berkeley, CA, USA; Chan Zuckerberg Biohub, San Francisco, CA, USA.
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16
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Chahda JS, Ambrosi P, Mizutani CM. The nested embryonic dorsal domains of BMP-target genes are not scaled to size during the evolution of Drosophila species. JOURNAL OF EXPERIMENTAL ZOOLOGY. PART B, MOLECULAR AND DEVELOPMENTAL EVOLUTION 2023; 340:131-142. [PMID: 35451554 PMCID: PMC9587137 DOI: 10.1002/jez.b.23137] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/07/2021] [Revised: 03/21/2022] [Accepted: 04/03/2022] [Indexed: 11/08/2022]
Abstract
Egg size is a fast-evolving trait among Drosophilids expected to change the spatial distribution of morphogens that pattern the embryonic axes. Here we asked whether the patterning of the dorsal region of the embryo by the Decapentaplegic/Bone Morphogenetic Protein-4 (DPP/BMP-4) gradient is scaled among Drosophila species with different egg sizes. This region specifies the extra-embryonic tissue amnioserosa and the ectoderm. We find that the entire dorsal region scales with embryo size, but the gene expression patterns regulated by DPP are not proportional, suggesting that the DPP gradient is differentially scaled during evolution. To further test whether the DPP gradient can scale or not in Drosophila melanogaster, we created embryos with expanded dorsal regions that mimic changes in scale seen in other species and measured the resulting domains of DPP-target genes. We find that the proportions of these domains are not maintained, suggesting that the DPP gradient is unable to scale in the embryo. These and previous findings suggest that the embryonic dorso-ventral patterning lack scaling in the ventral and dorsal sides but is robust in the lateral region where the neuroectoderm is specified and two opposing gradients, Dorsal/NFkappa-B and DPP, intersect. We propose that the lack of scaling of the DPP gradient may contribute to changes in the size of the amnioserosa and the numbers of ectodermal cells with specific cortical tensions, which are expected to generate distinct mechanical forces for gastrulating embryos of different sizes.
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Affiliation(s)
- Juan Sebastian Chahda
- Department of Biology, College of Arts and Sciences, Case Western Reserve University, Cleveland, Ohio, USA
| | - Priscilla Ambrosi
- Department of Biology, College of Arts and Sciences, Case Western Reserve University, Cleveland, Ohio, USA
| | - Claudia Mieko Mizutani
- Department of Biology, College of Arts and Sciences, Case Western Reserve University, Cleveland, Ohio, USA.,Department of Genetics and Genome Sciences, School of Medicine, Case Western Reserve University, Cleveland, Ohio, USA.,Corresponding author:
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17
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Quicray M, Wilhelm L, Enriquez T, He S, Scheifler M, Visser B. The Drosophila-parasitizing wasp Leptopilina heterotoma: A comprehensive model system in ecology and evolution. Ecol Evol 2023; 13:e9625. [PMID: 36703713 PMCID: PMC9871341 DOI: 10.1002/ece3.9625] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2022] [Revised: 11/22/2022] [Accepted: 11/24/2022] [Indexed: 01/25/2023] Open
Abstract
The parasitoid Leptopilina heterotoma has been used as a model system for more than 70 years, contributing greatly to diverse research areas in ecology and evolution. Here, we synthesized the large body of work on L. heterotoma with the aim to identify new research avenues that could be of interest also for researchers studying other parasitoids and insects. We start our review with a description of typical L. heterotoma characteristics, as well as that of the higher taxonomic groups to which this species belongs. We then continue discussing host suitability and immunity, foraging behaviors, as well as fat accumulation and life histories. We subsequently shift our focus towards parasitoid-parasitoid interactions, including L. heterotoma coexistence within the larger guild of Drosophila parasitoids, chemical communication, as well as mating and population structuring. We conclude our review by highlighting the assets of L. heterotoma as a model system, including its intermediate life history syndromes, the ease of observing and collecting natural hosts and wasps, as well as recent genomic advances.
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Affiliation(s)
- Maude Quicray
- Evolution and Ecophysiology Group, Department of Functional and Evolutionary EntomologyUniversity of Liège ‐ Gembloux Agro‐Bio TechGemblouxBelgium
| | - Léonore Wilhelm
- Evolution and Ecophysiology Group, Department of Functional and Evolutionary EntomologyUniversity of Liège ‐ Gembloux Agro‐Bio TechGemblouxBelgium
| | - Thomas Enriquez
- Evolution and Ecophysiology Group, Department of Functional and Evolutionary EntomologyUniversity of Liège ‐ Gembloux Agro‐Bio TechGemblouxBelgium
| | - Shulin He
- Evolution and Ecophysiology Group, Department of Functional and Evolutionary EntomologyUniversity of Liège ‐ Gembloux Agro‐Bio TechGemblouxBelgium
| | - Mathilde Scheifler
- Evolution and Ecophysiology Group, Department of Functional and Evolutionary EntomologyUniversity of Liège ‐ Gembloux Agro‐Bio TechGemblouxBelgium
| | - Bertanne Visser
- Evolution and Ecophysiology Group, Department of Functional and Evolutionary EntomologyUniversity of Liège ‐ Gembloux Agro‐Bio TechGemblouxBelgium
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18
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Karkali K, Jorba I, Navajas D, Martin-Blanco E. Measuring ventral nerve cord stiffness in live flat-dissected Drosophila embryos by atomic force microscopy. STAR Protoc 2022; 3:101901. [PMID: 36595903 PMCID: PMC9732408 DOI: 10.1016/j.xpro.2022.101901] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2022] [Revised: 10/06/2022] [Accepted: 11/10/2022] [Indexed: 12/12/2022] Open
Abstract
Drosophila is an amenable system for addressing the mechanics of morphogenesis. We describe a workflow for characterizing the mechanical properties of its ventral nerve cord (VNC), at different developmental stages, in live, flat-dissected embryos employing atomic force microscopy (AFM). AFM is performed with spherical probes, and stiffness (Young's modulus) is calculated by fitting force curves with Hertz's contact model. For complete details on the use and execution of this protocol, please refer to Karkali et al. (2022).
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Affiliation(s)
- Katerina Karkali
- Instituto de Biología Molecular de Barcelona, Consejo Superior de Investigaciones Científicas, 08028 Barcelona, Spain,Corresponding author
| | - Ignasi Jorba
- Institute for Bioengineering of Catalonia, 08028 Barcelona, Spain,CIBER de Enfermedades Respiratorias (CIBERES), 28029 Madrid, Spain,Facultat de Medicina i Ciencies de la Salut, Universitat de Barcelona, 08036 Barcelona, Spain,Corresponding author
| | - Daniel Navajas
- Institute for Bioengineering of Catalonia, 08028 Barcelona, Spain,CIBER de Enfermedades Respiratorias (CIBERES), 28029 Madrid, Spain,Facultat de Medicina i Ciencies de la Salut, Universitat de Barcelona, 08036 Barcelona, Spain
| | - Enrique Martin-Blanco
- Instituto de Biología Molecular de Barcelona, Consejo Superior de Investigaciones Científicas, 08028 Barcelona, Spain
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19
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Hayden L, Hur W, Vergassola M, Di Talia S. Manipulating the nature of embryonic mitotic waves. Curr Biol 2022; 32:4989-4996.e3. [PMID: 36332617 PMCID: PMC9691596 DOI: 10.1016/j.cub.2022.10.014] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2022] [Revised: 09/05/2022] [Accepted: 10/06/2022] [Indexed: 11/06/2022]
Abstract
Early embryogenesis is characterized by rapid and synchronous cleavage divisions, which are often controlled by wave-like patterns of Cdk1 activity. Two mechanisms have been proposed for mitotic waves: sweep and trigger waves.1,2 The two mechanisms give rise to different wave speeds, dependencies on physical and molecular parameters, and spatial profiles of Cdk1 activity: upward sweeping gradients versus traveling wavefronts. Both mechanisms hinge on the transient bistability governing the cell cycle and are differentiated by the speed of the cell-cycle progression: sweep and trigger waves arise for rapid and slow drives, respectively. Here, using quantitative imaging of Cdk1 activity and theory, we illustrate that sweep waves are the dominant mechanism in Drosophila embryos and test two fundamental predictions on the transition from sweep to trigger waves. We demonstrate that sweep waves can be turned into trigger waves if the cell cycle is slowed down genetically or if significant delays in the cell-cycle progression are introduced across the embryo by altering nuclear density. Our genetic experiments demonstrate that Polo kinase is a major rate-limiting regulator of the blastoderm divisions, and genetic perturbations reducing its activity can induce the transition from sweep to trigger waves. Furthermore, we show that changes in temperature cause an essentially uniform slowdown of interphase and mitosis. That results in sweep waves being observed across a wide temperature range despite the cell-cycle durations being significantly different. Collectively, our combination of theory and experiments elucidates the nature of mitotic waves in Drosophila embryogenesis, their control mechanisms, and their mutual transitions.
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Affiliation(s)
- Luke Hayden
- Department of Cell Biology, Research Drive, Duke University School of Medicine, Durham, NC 27710, USA
| | - Woonyung Hur
- Department of Cell Biology, Research Drive, Duke University School of Medicine, Durham, NC 27710, USA
| | - Massimo Vergassola
- Laboratoire de Physique de l'École Normale Supérieure, CNRS, PSL Research University, Sorbonne Université, 24 Rue Lhomond, 75005 Paris, France; Department of Physics, University of California, San Diego, 9500 Gillman Drive, La Jolla, CA 92093, USA.
| | - Stefano Di Talia
- Department of Cell Biology, Research Drive, Duke University School of Medicine, Durham, NC 27710, USA.
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20
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van Dis NE, Risse JE, Pijl AS, Hut RA, Visser ME, Wertheim B. Transcriptional regulation underlying the temperature response of embryonic development rate in the winter moth. Mol Ecol 2022; 31:5795-5812. [PMID: 36161402 PMCID: PMC9828122 DOI: 10.1111/mec.16705] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2022] [Revised: 09/08/2022] [Accepted: 09/15/2022] [Indexed: 01/13/2023]
Abstract
Climate change will strongly affect the developmental timing of insects, as their development rate depends largely on ambient temperature. However, we know little about the genetic mechanisms underlying the temperature sensitivity of embryonic development in insects. We investigated embryonic development rate in the winter moth (Operophtera brumata), a species with egg dormancy which has been under selection due to climate change. We used RNA sequencing to investigate which genes are involved in the regulation of winter moth embryonic development rate in response to temperature. Over the course of development, we sampled eggs before and after an experimental change in ambient temperature, including two early development weeks when the temperature sensitivity of eggs is low and two late development weeks when temperature sensitivity is high. We found temperature-responsive genes that responded in a similar way across development, as well as genes with a temperature response specific to a particular development week. Moreover, we identified genes whose temperature effect size changed around the switch in temperature sensitivity of development rate. Interesting candidate genes for regulating the temperature sensitivity of egg development rate included genes involved in histone modification, hormonal signalling, nervous system development and circadian clock genes. The diverse sets of temperature-responsive genes we found here indicate that there are many potential targets of selection to change the temperature sensitivity of embryonic development rate. Identifying for which of these genes there is genetic variation in wild insect populations will give insight into their adaptive potential in the face of climate change.
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Affiliation(s)
- Natalie E. van Dis
- Department of Animal EcologyNetherlands Institute of Ecology (NIOO‐KNAW)WageningenThe Netherlands,Groningen Institute for Evolutionary Life SciencesUniversity of GroningenGroningenThe Netherlands
| | - Judith E. Risse
- Department of Animal EcologyNetherlands Institute of Ecology (NIOO‐KNAW)WageningenThe Netherlands
| | - Agata S. Pijl
- Department of Animal EcologyNetherlands Institute of Ecology (NIOO‐KNAW)WageningenThe Netherlands
| | - Roelof A. Hut
- Groningen Institute for Evolutionary Life SciencesUniversity of GroningenGroningenThe Netherlands
| | - Marcel E. Visser
- Department of Animal EcologyNetherlands Institute of Ecology (NIOO‐KNAW)WageningenThe Netherlands,Groningen Institute for Evolutionary Life SciencesUniversity of GroningenGroningenThe Netherlands
| | - Bregje Wertheim
- Groningen Institute for Evolutionary Life SciencesUniversity of GroningenGroningenThe Netherlands
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21
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Comparative analysis of temperature preference behavior and effects of temperature on daily behavior in 11 Drosophila species. Sci Rep 2022; 12:12692. [PMID: 35879333 PMCID: PMC9314439 DOI: 10.1038/s41598-022-16897-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2022] [Accepted: 07/18/2022] [Indexed: 11/08/2022] Open
Abstract
Temperature is one of the most critical environmental factors that influence various biological processes. Species distributed in different temperature regions are considered to have different optimal temperatures for daily life activities. However, how organisms have acquired various features to cope with particular temperature environments remains to be elucidated. In this study, we have systematically analyzed the temperature preference behavior and effects of temperatures on daily locomotor activity and sleep using 11 Drosophila species. We also investigated the function of antennae in the temperature preference behavior of these species. We found that, (1) an optimal temperature for daily locomotor activity and sleep of each species approximately matches with temperatures it frequently encounters in its habitat, (2) effects of temperature on locomotor activity and sleep are diverse among species, but each species maintains its daily activity and sleep pattern even at different temperatures, and (3) each species has a unique temperature preference behavior, and the contribution of antennae to this behavior is diverse among species. These results suggest that Drosophila species inhabiting different climatic environments have acquired species-specific temperature response systems according to their life strategies. This study provides fundamental information for understanding the mechanisms underlying their temperature adaptation and lifestyle diversification.
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22
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Real age prediction from the transcriptome with RAPToR. Nat Methods 2022; 19:969-975. [PMID: 35817937 DOI: 10.1038/s41592-022-01540-0] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2021] [Accepted: 05/25/2022] [Indexed: 11/08/2022]
Abstract
Transcriptomic data is often affected by uncontrolled variation among samples that can obscure and confound the effects of interest. This variation is frequently due to unintended differences in developmental stages between samples. The transcriptome itself can be used to estimate developmental progression, but existing methods require many samples and do not estimate a specimen's real age. Here we present real-age prediction from transcriptome staging on reference (RAPToR), a computational method that precisely estimates the real age of a sample from its transcriptome, exploiting existing time-series data as reference. RAPToR works with whole animal, dissected tissue and single-cell data for the most common animal models, humans and even for non-model organisms lacking reference data. We show that RAPToR can be used to remove age as a confounding factor and allow recovery of a signal of interest in differential expression analysis. RAPToR will be especially useful in large-scale single-organism profiling because it eliminates the need for accurate staging or synchronisation before profiling.
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23
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Chenevert M, Miller B, Karkoutli A, Rusnak A, Lott SE, Atallah J. The early embryonic transcriptome of a Hawaiian Drosophila picture-wing fly shows evidence of altered gene expression and novel gene evolution. JOURNAL OF EXPERIMENTAL ZOOLOGY. PART B, MOLECULAR AND DEVELOPMENTAL EVOLUTION 2022; 338:277-291. [PMID: 35322942 DOI: 10.1002/jez.b.23129] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/15/2021] [Revised: 01/14/2022] [Accepted: 02/13/2022] [Indexed: 06/14/2023]
Abstract
A massive adaptive radiation on the Hawaiian archipelago has produced approximately one-quarter of the fly species in the family Drosophilidae. The Hawaiian Drosophila clade has long been recognized as a model system for the study of both the ecology of island endemics and the evolution of developmental mechanisms, but relatively few genomic and transcriptomic datasets are available for this group. We present here a differential expression analysis of the transcriptional profiles of two highly conserved embryonic stages in the Hawaiian picture-wing fly Drosophila grimshawi. When we compared our results to previously published datasets across the family Drosophilidae, we identified cases of both gains and losses of gene representation in D. grimshawi, including an apparent delay in Hox gene activation. We also found a high expression of unannotated genes. Most transcripts of unannotated genes with open reading frames do not have identified homologs in non-Hawaiian Drosophila species, although the vast majority have sequence matches in genomes of other Hawaiian picture-wing flies. Some of these unannotated genes may have arisen from noncoding sequence in the ancestor of Hawaiian flies or during the evolution of the clade. Our results suggest that both the modified use of ancestral genes and the evolution of new ones may occur in rapid radiations.
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Affiliation(s)
- Madeline Chenevert
- Department of Biological Sciences, University of New Orleans, New Orleans, Louisiana, USA
- Hayward Genetics Center, Tulane University School of Medicine, New Orleans, Louisiana, USA
| | - Bronwyn Miller
- Department of Biological Sciences, University of New Orleans, New Orleans, Louisiana, USA
| | - Ahmad Karkoutli
- Department of Biological Sciences, University of New Orleans, New Orleans, Louisiana, USA
- LSUHSC School of Medicine, New Orleans, Louisiana, USA
| | - Anna Rusnak
- Department of Biological Sciences, University of New Orleans, New Orleans, Louisiana, USA
- Center for Biomedical Engineering, Brown University, Box A-2, Arnold Lab, Providence, Rhode Island, USA
| | - Susan E Lott
- Department of Evolution & Ecology, University of California-Davis, Davis, California, USA
| | - Joel Atallah
- Department of Biological Sciences, University of New Orleans, New Orleans, Louisiana, USA
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24
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Reply to Zhang et al.: The critical temperature dependence of developmental rates is in search of a mechanism. Proc Natl Acad Sci U S A 2022; 119:e2206338119. [PMID: 35733254 PMCID: PMC9245673 DOI: 10.1073/pnas.2206338119] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
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25
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Khachaturyan G, Holle AW, Ende K, Frey C, Schwederski HA, Eiseler T, Paschke S, Micoulet A, Spatz JP, Kemkemer R. Temperature-sensitive migration dynamics in neutrophil-differentiated HL-60 cells. Sci Rep 2022; 12:7053. [PMID: 35488042 PMCID: PMC9054779 DOI: 10.1038/s41598-022-10858-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2019] [Accepted: 04/13/2022] [Indexed: 11/09/2022] Open
Abstract
Cell migration plays an essential role in wound healing and inflammatory processes inside the human body. Peripheral blood neutrophils, a type of polymorphonuclear leukocyte (PMN), are the first cells to be activated during inflammation and subsequently migrate toward an injured tissue or infection site. This response is dependent on both biochemical signaling and the extracellular environment, one aspect of which includes increased temperature in the tissues surrounding the inflammation site. In our study, we analyzed temperature-dependent neutrophil migration using differentiated HL-60 cells. The migration speed of differentiated HL-60 cells was found to correlate positively with temperature from 30 to 42 °C, with higher temperatures inducing a concomitant increase in cell detachment. The migration persistence time of differentiated HL-60 cells was higher at lower temperatures (30-33 °C), while the migration persistence length stayed constant throughout the temperature range. Coupled with the increased speed observed at high temperatures, this suggests that neutrophils are primed to migrate more effectively at the elevated temperatures characteristic of inflammation. Temperature gradients exist on both cell and tissue scales. Taking this into consideration, we also investigated the ability of differentiated HL-60 cells to sense and react to the presence of temperature gradients, a process known as thermotaxis. Using a two-dimensional temperature gradient chamber with a range of 27-43 °C, we observed a migration bias parallel to the gradient, resulting in both positive and negative thermotaxis. To better mimic the extracellular matrix (ECM) environment in vivo, a three-dimensional collagen temperature gradient chamber was constructed, allowing observation of biased neutrophil-like differentiated HL-60 migration toward the heat source.
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Affiliation(s)
- Galina Khachaturyan
- Department of Cellular Biophysics, Max Planck Institute for Medical Research, 69120, Heidelberg, Germany
- Department of Biophysical Chemistry, University of Heidelberg, 69120, Heidelberg, Germany
| | - Andrew W Holle
- Department of Cellular Biophysics, Max Planck Institute for Medical Research, 69120, Heidelberg, Germany
- Mechanobiology Institute, National University of Singapore, 117411, Singapore, Republic of Singapore
- Department of Biomedical Engineering, National University of Singapore, 117411, Singapore, Republic of Singapore
| | - Karen Ende
- School of Applied Chemistry, Reutlingen University, Alteburgstrasse 150, 72762, Reutlingen, Germany
| | - Christoph Frey
- Department of Cellular Biophysics, Max Planck Institute for Medical Research, 69120, Heidelberg, Germany
- Department of Biophysical Chemistry, University of Heidelberg, 69120, Heidelberg, Germany
| | - Heiko A Schwederski
- School of Applied Chemistry, Reutlingen University, Alteburgstrasse 150, 72762, Reutlingen, Germany
| | - Tim Eiseler
- Internal Medicine I, University Clinic Ulm, 89081, Ulm, Germany
| | - Stephan Paschke
- General and Visceral Surgery, University Clinic Ulm, 89081, Ulm, Germany
| | - Alexandre Micoulet
- Department of Cellular Biophysics, Max Planck Institute for Medical Research, 69120, Heidelberg, Germany
- Department of Biophysical Chemistry, University of Heidelberg, 69120, Heidelberg, Germany
| | - Joachim P Spatz
- Department of Cellular Biophysics, Max Planck Institute for Medical Research, 69120, Heidelberg, Germany
- Department of Biophysical Chemistry, University of Heidelberg, 69120, Heidelberg, Germany
| | - Ralf Kemkemer
- Department of Cellular Biophysics, Max Planck Institute for Medical Research, 69120, Heidelberg, Germany.
- School of Applied Chemistry, Reutlingen University, Alteburgstrasse 150, 72762, Reutlingen, Germany.
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26
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Developmental timing of Drosophila pachea pupae is robust to temperature changes. J Therm Biol 2022; 106:103232. [DOI: 10.1016/j.jtherbio.2022.103232] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2021] [Revised: 03/10/2022] [Accepted: 03/26/2022] [Indexed: 11/21/2022]
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27
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Abstract
An enduring mystery of development is how its timing is controlled, particularly for development after birth, where timing is highly flexible and depends on environmental conditions, such as food availability and diet. We followed timing of cell- and organism-level events in individual Caenorhabditis elegans larvae developing from hatching to adulthood, uncovering widespread variations in event timing, both between isogenic individuals in the same environment and when changing conditions and genotypes. However, in almost all cases, we found that events occurred at the same time, when time was rescaled by the duration of development measured in each individual. This observation of “temporal scaling” poses strong constraints on models to explain timing of larval development. It is essential that correct temporal order of cellular events is maintained during animal development. During postembryonic development, the rate of development depends on external conditions, such as food availability, diet, and temperature. How timing of cellular events is impacted when the rate of development is changed at the organism level is not known. We used a unique time-lapse microscopy approach to simultaneously measure timing of oscillatory gene expression, hypodermal stem cell divisions, and cuticle shedding in individual Caenorhabditis elegans larvae, as they developed from hatching to adulthood. This revealed strong variability in timing between isogenic individuals under the same conditions. However, this variability obeyed “temporal scaling,” meaning that events occurred at the same time when measured relative to the total duration of development in each individual. We also observed pervasive changes in timing when temperature, diet, or genotype were varied, but with larval development divided in “epochs” that differed in how event timing was impacted. Yet, these variations in timing were still explained by temporal scaling when time was rescaled by the duration of the respective epochs in each individual. Surprisingly, timing obeyed temporal scaling even in mutants lacking lin-42/Period, presumed a core regulator of timing of larval development, that exhibited strongly delayed, heterogeneous timing. However, shifting conditions middevelopment perturbed temporal scaling and changed event order in a highly condition-specific manner, indicating that a complex machinery is responsible for temporal scaling under constant conditions.
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28
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DeBardlabon KM, Rajamohan A, Rinehart JP. Vitrification of manually stage-selected embryos of Drosophila have significantly higher survival and emergence - Consequences for insect germplasm storage. Cryobiology 2022; 105:83-87. [PMID: 35032470 DOI: 10.1016/j.cryobiol.2022.01.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Revised: 01/02/2022] [Accepted: 01/06/2022] [Indexed: 11/03/2022]
Abstract
Embryonic selection for vitrification and cryostorage in Drosophila and other dipterans is generally carried out by gross observation of the embryonic development at a constant temperature. In this study, the effect of embryo developmental temperature (19, 20 and 21 °C) on the stage specific convergence of the embryonic development to the developmental stages 15-17, that is useful for cryopreservation, was studied in a flightless mutant strain of Drosophila melanogaster and compared with the Ore-R strain. The temperature that allowed for the best convergence to stage 16 was chosen for further selection and treatment of the embryos. The converged embryos (SS) were directly treated or further manually sorted (MS) for the requisite developmental stage to reduce the number of non-convergent embryos. These selected embryos were then permeabilized and cryopreserved. While at all the three incubation temperatures the embryos exhibited convergence peaks, it was only at 20 °C and at hour 22 that a maximum number of stage 16 embryos converged and remained at a much higher proportion than the other developmental stages in both the strains. When permeabilized, MS embryos showed higher mean viability and hatching proportion compared to SS embryos (wingless: ∼0.70 vs. ∼0.58; Ore-R: ∼0.77 versus 0.54). Upon vitrification, the manually selected embryos hatched and survived at significantly higher mean rates than the converged embryos at stage 16 (wingless: 0.32 vs. ∼0.08; Ore-R: 0.47 vs. 0.15) after adjusting for permeabilization mortality. The maximum proportion hatch after vitrified storage that could be obtained by this method was 0.74 for both the wingless and Ore-R strains. More than 55% of the larvae pupated and >72% of the pupae eclosed in MS and vitrified wingless stage 16. In Ore-R, well over 85% of the larvae pupariated and eclosed as flight capable flies.
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Affiliation(s)
- Korie M DeBardlabon
- USDA-ARS Red River Valley Agricultural Research Center, Biosciences Research Laboratory, 1605 Albrecht Boulevard North, Fargo, ND, 58102-2765, USA
| | - Arun Rajamohan
- USDA-ARS Red River Valley Agricultural Research Center, Biosciences Research Laboratory, 1605 Albrecht Boulevard North, Fargo, ND, 58102-2765, USA.
| | - Joseph P Rinehart
- USDA-ARS Red River Valley Agricultural Research Center, Biosciences Research Laboratory, 1605 Albrecht Boulevard North, Fargo, ND, 58102-2765, USA
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Temperature sensitivity of Notch signaling underlies species-specific developmental plasticity and robustness in amniote brains. Nat Commun 2022; 13:96. [PMID: 35013223 PMCID: PMC8748702 DOI: 10.1038/s41467-021-27707-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2020] [Accepted: 12/06/2021] [Indexed: 11/08/2022] Open
Abstract
Ambient temperature significantly affects developmental timing in animals. The temperature sensitivity of embryogenesis is generally believed to be a consequence of the thermal dependency of cellular metabolism. However, the adaptive molecular mechanisms that respond to variations in temperature remain unclear. Here, we report species-specific thermal sensitivity of Notch signaling in the developing amniote brain. Transient hypothermic conditions increase canonical Notch activity and reduce neurogenesis in chick neural progenitors. Increased biosynthesis of phosphatidylethanolamine, a major glycerophospholipid components of the plasma membrane, mediates hypothermia-induced Notch activation. Furthermore, the species-specific thermal dependency of Notch signaling is associated with developmental robustness to altered Notch signaling. Our results reveal unique regulatory mechanisms for temperature-dependent neurogenic potentials that underlie developmental and evolutionary adaptations to a range of ambient temperatures in amniotes. Ambient temperature significantly affects embryogenesis, but adaptive molecular mechanisms that respond to temperature remain unclear. Here, the authors identified species-specific thermal sensitivity of Notch signaling in developing amniote brains.
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Kiral FR, Dutta SB, Linneweber GA, Hilgert S, Poppa C, Duch C, von Kleist M, Hassan BA, Hiesinger PR. Brain connectivity inversely scales with developmental temperature in Drosophila. Cell Rep 2021; 37:110145. [PMID: 34936868 DOI: 10.1016/j.celrep.2021.110145] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2021] [Revised: 10/04/2021] [Accepted: 11/29/2021] [Indexed: 11/17/2022] Open
Abstract
Variability of synapse numbers and partners despite identical genes reveals the limits of genetic determinism. Here, we use developmental temperature as a non-genetic perturbation to study variability of brain wiring and behavior in Drosophila. Unexpectedly, slower development at lower temperatures increases axo-dendritic branching, synapse numbers, and non-canonical synaptic partnerships of various neurons, while maintaining robust ratios of canonical synapses. Using R7 photoreceptors as a model, we show that changing the relative availability of synaptic partners using a DIPγ mutant that ablates R7's preferred partner leads to temperature-dependent recruitment of non-canonical partners to reach normal synapse numbers. Hence, R7 synaptic specificity is not absolute but based on the relative availability of postsynaptic partners and presynaptic control of synapse numbers. Behaviorally, movement precision is temperature robust, while movement activity is optimized for the developmentally encountered temperature. These findings suggest genetically encoded relative and scalable synapse formation to develop functional, but not identical, brains and behaviors.
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Affiliation(s)
- Ferdi Ridvan Kiral
- Division of Neurobiology, Institute for Biology, Freie Universität Berlin, 14195 Berlin, Germany
| | - Suchetana B Dutta
- Division of Neurobiology, Institute for Biology, Freie Universität Berlin, 14195 Berlin, Germany
| | - Gerit Arne Linneweber
- Division of Neurobiology, Institute for Biology, Freie Universität Berlin, 14195 Berlin, Germany
| | - Selina Hilgert
- Institute of Developmental Biology and Neurobiology (iDN), Hanns-Dieter-Hüsch-Weg 15, 55128 Mainz, Germany
| | - Caroline Poppa
- Division of Neurobiology, Institute for Biology, Freie Universität Berlin, 14195 Berlin, Germany
| | - Carsten Duch
- Institute of Developmental Biology and Neurobiology (iDN), Hanns-Dieter-Hüsch-Weg 15, 55128 Mainz, Germany
| | - Max von Kleist
- MF1 Bioinformatics, Robert Koch-Institute, 13353 Berlin, Germany
| | - Bassem A Hassan
- Division of Neurobiology, Institute for Biology, Freie Universität Berlin, 14195 Berlin, Germany; Institut du Cerveau - Paris Brain Institute - ICM, Sorbonne Université, Inserm, CNRS, Hôpital Pitié-Salpêtrière, Paris, France
| | - P Robin Hiesinger
- Division of Neurobiology, Institute for Biology, Freie Universität Berlin, 14195 Berlin, Germany.
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31
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Scepanovic G, Hunter MV, Kafri R, Fernandez-Gonzalez R. p38-mediated cell growth and survival drive rapid embryonic wound repair. Cell Rep 2021; 37:109874. [PMID: 34686334 DOI: 10.1016/j.celrep.2021.109874] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2020] [Revised: 08/02/2021] [Accepted: 09/30/2021] [Indexed: 12/18/2022] Open
Abstract
Embryos repair wounds rapidly, with no inflammation or scarring, in a process that involves polarization of the actomyosin cytoskeleton. Actomyosin polarization results in the assembly of a contractile cable around the wound that drives wound closure. Here, we demonstrate that a contractile actomyosin cable is not sufficient for rapid wound repair in Drosophila embryos. We show that wounding causes activation of the serine/threonine kinase p38 mitogen-activated protein kinase (MAPK) in the cells adjacent to the wound. p38 activation reduces the levels of wound-induced reactive oxygen species in the cells around the wound, limiting wound size. In addition, p38 promotes an increase in volume in the cells around the wound, thus facilitating the collective cell movements that drive rapid wound healing. Our data indicate that p38 regulates cell volumes through the sodium-potassium-chloride cotransporter NKCC1. Our work reveals cell growth and cell survival as cell behaviors critical for embryonic wound repair.
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Affiliation(s)
- Gordana Scepanovic
- Department of Cell and Systems Biology, University of Toronto, Toronto, ON M5S 3G5, Canada; Ted Rogers Centre for Heart Research, University of Toronto, Toronto, ON M5G 1M1, Canada
| | - Miranda Victoria Hunter
- Department of Cell and Systems Biology, University of Toronto, Toronto, ON M5S 3G5, Canada; Ted Rogers Centre for Heart Research, University of Toronto, Toronto, ON M5G 1M1, Canada
| | - Ran Kafri
- Cell Biology Program, The Hospital for Sick Children, Toronto, ON M5G 1X8, Canada; Department of Molecular Genetics, University of Toronto, Toronto, ON M5S 1A8, Canada
| | - Rodrigo Fernandez-Gonzalez
- Department of Cell and Systems Biology, University of Toronto, Toronto, ON M5S 3G5, Canada; Ted Rogers Centre for Heart Research, University of Toronto, Toronto, ON M5G 1M1, Canada; Institute of Biomedical Engineering, University of Toronto, Toronto, ON M5S 3G9, Canada; Developmental and Stem Cell Biology Program, The Hospital for Sick Children, Toronto, ON M5G 1X8, Canada.
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32
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Crapse J, Pappireddi N, Gupta M, Shvartsman SY, Wieschaus E, Wühr M. Evaluating the Arrhenius equation for developmental processes. Mol Syst Biol 2021; 17:e9895. [PMID: 34414660 PMCID: PMC8377445 DOI: 10.15252/msb.20209895] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2020] [Revised: 07/20/2021] [Accepted: 07/21/2021] [Indexed: 11/15/2022] Open
Abstract
The famous Arrhenius equation is well suited to describing the temperature dependence of chemical reactions but has also been used for complicated biological processes. Here, we evaluate how well the simple Arrhenius equation predicts complex multi-step biological processes, using frog and fruit fly embryogenesis as two canonical models. We find that the Arrhenius equation provides a good approximation for the temperature dependence of embryogenesis, even though individual developmental intervals scale differently with temperature. At low and high temperatures, however, we observed significant departures from idealized Arrhenius Law behavior. When we model multi-step reactions of idealized chemical networks, we are unable to generate comparable deviations from linearity. In contrast, we find the two enzymes GAPDH and β-galactosidase show non-linearity in the Arrhenius plot similar to our observations of embryonic development. Thus, we find that complex embryonic development can be well approximated by the simple Arrhenius equation regardless of non-uniform developmental scaling and propose that the observed departure from this law likely results more from non-idealized individual steps rather than from the complexity of the system.
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Affiliation(s)
- Joseph Crapse
- Undergraduate Integrated Science CurriculumPrinceton UniversityPrincetonNJUSA
- Department of Molecular BiologyPrinceton UniversityPrincetonNJUSA
- Lewis‐Sigler Institute for Integrative GenomicsPrinceton UniversityPrincetonNJUSA
| | - Nishant Pappireddi
- Department of Molecular BiologyPrinceton UniversityPrincetonNJUSA
- Lewis‐Sigler Institute for Integrative GenomicsPrinceton UniversityPrincetonNJUSA
| | - Meera Gupta
- Department of Molecular BiologyPrinceton UniversityPrincetonNJUSA
- Lewis‐Sigler Institute for Integrative GenomicsPrinceton UniversityPrincetonNJUSA
- Department of Chemical and Biological EngineeringPrinceton UniversityPrincetonNJUSA
| | - Stanislav Y Shvartsman
- Undergraduate Integrated Science CurriculumPrinceton UniversityPrincetonNJUSA
- Department of Molecular BiologyPrinceton UniversityPrincetonNJUSA
- Lewis‐Sigler Institute for Integrative GenomicsPrinceton UniversityPrincetonNJUSA
- Center for Computational BiologyFlatiron InstituteSimons FoundationNew YorkNYUSA
| | - Eric Wieschaus
- Undergraduate Integrated Science CurriculumPrinceton UniversityPrincetonNJUSA
- Department of Molecular BiologyPrinceton UniversityPrincetonNJUSA
- Lewis‐Sigler Institute for Integrative GenomicsPrinceton UniversityPrincetonNJUSA
| | - Martin Wühr
- Undergraduate Integrated Science CurriculumPrinceton UniversityPrincetonNJUSA
- Department of Molecular BiologyPrinceton UniversityPrincetonNJUSA
- Lewis‐Sigler Institute for Integrative GenomicsPrinceton UniversityPrincetonNJUSA
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33
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Large-scale characterization of sex pheromone communication systems in Drosophila. Nat Commun 2021; 12:4165. [PMID: 34230464 PMCID: PMC8260797 DOI: 10.1038/s41467-021-24395-z] [Citation(s) in RCA: 36] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2020] [Accepted: 06/11/2021] [Indexed: 11/08/2022] Open
Abstract
Insects use sex pheromones as a reproductive isolating mechanism to attract conspecifics and repel heterospecifics. Despite the profound knowledge of sex pheromones, little is known about the coevolutionary mechanisms and constraints on their production and detection. Using whole-genome sequences to infer the kinship among 99 drosophilids, we investigate how phylogenetic and chemical traits have interacted at a wide evolutionary timescale. Through a series of chemical syntheses and electrophysiological recordings, we identify 52 sex-specific compounds, many of which are detected via olfaction. Behavioral analyses reveal that many of the 43 male-specific compounds are transferred to the female during copulation and mediate female receptivity and/or male courtship inhibition. Measurement of phylogenetic signals demonstrates that sex pheromones and their cognate olfactory channels evolve rapidly and independently over evolutionary time to guarantee efficient intra- and inter-specific communication systems. Our results show how sexual isolation barriers between species can be reinforced by species-specific olfactory signals. Despite the profound knowledge of sex pheromones, little is known about the coevolutionary mechanisms and constraints on their production and detection. Whole-genome sequences from 99 drosophilids, with chemical and behavioural data, show that sex pheromones and their cognate olfactory channels evolve rapidly and independently.
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34
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Wei KHC, Chan C, Bachtrog D. Establishment of H3K9me3-dependent heterochromatin during embryogenesis in Drosophila miranda. eLife 2021; 10:55612. [PMID: 34128466 PMCID: PMC8285105 DOI: 10.7554/elife.55612] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2020] [Accepted: 06/14/2021] [Indexed: 12/27/2022] Open
Abstract
Heterochromatin is a key architectural feature of eukaryotic genomes crucial for silencing of repetitive elements. During Drosophila embryonic cellularization, heterochromatin rapidly appears over repetitive sequences, but the molecular details of how heterochromatin is established are poorly understood. Here, we map the genome-wide distribution of H3K9me3-dependent heterochromatin in individual embryos of Drosophila miranda at precisely staged developmental time points. We find that canonical H3K9me3 enrichment is established prior to cellularization and matures into stable and broad heterochromatin domains through development. Intriguingly, initial nucleation sites of H3K9me3 enrichment appear as early as embryonic stage 3 over transposable elements (TEs) and progressively broaden, consistent with spreading to neighboring nucleosomes. The earliest nucleation sites are limited to specific regions of a small number of recently active retrotransposon families and often appear over promoter and 5' regions of LTR retrotransposons, while late nucleation sites develop broadly across the entirety of most TEs. Interestingly, early nucleating TEs are strongly associated with abundant maternal piRNAs and show early zygotic transcription. These results support a model of piRNA-associated co-transcriptional silencing while also suggesting additional mechanisms for site-restricted H3K9me3 nucleation at TEs in pre-cellular Drosophila embryos.
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Affiliation(s)
- Kevin H-C Wei
- Department of Integrative Biology, University of California, Berkeley, Berkeley, United States
| | - Carolus Chan
- Department of Integrative Biology, University of California, Berkeley, Berkeley, United States
| | - Doris Bachtrog
- Department of Integrative Biology, University of California, Berkeley, Berkeley, United States
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35
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Abstract
Half a century after Lewis Wolpert's seminal conceptual advance on how cellular fates distribute in space, we provide a brief historical perspective on how the concept of positional information emerged and influenced the field of developmental biology and beyond. We focus on a modern interpretation of this concept in terms of information theory, largely centered on its application to cell specification in the early Drosophila embryo. We argue that a true physical variable (position) is encoded in local concentrations of patterning molecules, that this mapping is stochastic, and that the processes by which positions and corresponding cell fates are determined based on these concentrations need to take such stochasticity into account. With this approach, we shift the focus from biological mechanisms, molecules, genes and pathways to quantitative systems-level questions: where does positional information reside, how it is transformed and accessed during development, and what fundamental limits it is subject to?
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Affiliation(s)
- Gašper Tkačik
- Institute of Science and Technology Austria, Am Campus 1, AT-3400 Klosterneuburg, Austria
| | - Thomas Gregor
- Joseph Henry Laboratories of Physics and the Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ 08544, USA
- Department of Developmental and Stem Cell Biology, UMR3738, Institut Pasteur, FR-75015 Paris, France
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36
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Mirth CK, Saunders TE, Amourda C. Growing Up in a Changing World: Environmental Regulation of Development in Insects. ANNUAL REVIEW OF ENTOMOLOGY 2021; 66:81-99. [PMID: 32822557 DOI: 10.1146/annurev-ento-041620-083838] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
All organisms are exposed to changes in their environment throughout their life cycle. When confronted with these changes, they adjust their development and physiology to ensure that they can produce the functional structures necessary for survival and reproduction. While some traits are remarkably invariant, or robust, across environmental conditions, others show high degrees of variation, known as plasticity. Generally, developmental processes that establish cell identity are thought to be robust to environmental perturbation, while those relating to body and organ growth show greater degrees of plasticity. However, examples of plastic patterning and robust organ growth demonstrate that this is not a hard-and-fast rule.In this review, we explore how the developmental context and the gene regulatory mechanisms underlying trait formation determine the impacts of the environment on development in insects. Furthermore, we outline future issues that need to be resolved to understand how the structure of signaling networks defines whether a trait displays plasticity or robustness.
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Affiliation(s)
- Christen K Mirth
- School of Biological Sciences, Monash University, Melbourne 3800, Victoria, Australia;
| | - Timothy E Saunders
- Mechanobiology Institute, National University of Singapore, Singapore 117411, Republic of Singapore
- Department of Biological Sciences, National University of Singapore, Singapore 117588, Republic of Singapore
- Institute of Molecular and Cell Biology, A*Star, Proteos, Singapore 138673, Republic of Singapore
| | - Christopher Amourda
- MRC London Institute of Medical Sciences, Imperial College London, London W12 0NN, United Kingdom
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37
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Scepanovic G, Florea A, Fernandez-Gonzalez R. Multiscale In Vivo Imaging of Collective Cell Migration in Drosophila Embryos. Methods Mol Biol 2021; 2179:199-224. [PMID: 32939723 DOI: 10.1007/978-1-0716-0779-4_17] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Coordinated cell movements drive embryonic development and tissue repair, and can also spread disease. Time-lapse microscopy is an integral part in the study of the cell biology of collective cell movements. Advances in imaging techniques enable monitoring dynamic cellular and molecular events in real time within living animals. Here, we demonstrate the use of spinning disk confocal microscopy to investigate coordinated cell movements and epithelial-to-mesenchymal-like transitions during embryonic wound closure in Drosophila. We describe image-based metrics to quantify the efficiency of collective cell migration. Finally, we show the application of super-resolution radial fluctuation microscopy to obtain multidimensional, super-resolution images of protrusive activity in collectively moving cells in vivo. Together, the methods presented here constitute a toolkit for the modern analysis of collective cell migration in living animals.
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Affiliation(s)
- Gordana Scepanovic
- Department of Cell and Systems Biology, University of Toronto, Toronto, ON, Canada.,Ted Rogers Centre for Heart Research, University of Toronto, Toronto, ON, Canada
| | - Alexandru Florea
- Ted Rogers Centre for Heart Research, University of Toronto, Toronto, ON, Canada.,Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, ON, Canada
| | - Rodrigo Fernandez-Gonzalez
- Department of Cell and Systems Biology, University of Toronto, Toronto, ON, Canada. .,Ted Rogers Centre for Heart Research, University of Toronto, Toronto, ON, Canada. .,Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, ON, Canada. .,Developmental and Stem Cell Biology Program, The Hospital for Sick Children, Toronto, ON, Canada.
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38
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Falahati H, Hur W, Di Talia S, Wieschaus E. Temperature-Induced uncoupling of cell cycle regulators. Dev Biol 2020; 470:147-153. [PMID: 33278404 DOI: 10.1016/j.ydbio.2020.11.010] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2020] [Revised: 11/23/2020] [Accepted: 11/24/2020] [Indexed: 12/24/2022]
Abstract
The early stages of development involve complex sequences of morphological changes that are both reproducible from embryo to embryo and often robust to environmental variability. To investigate the relationship between reproducibility and robustness we examined cell cycle progression in early Drosophila embryos at different temperatures. Our experiments show that while the subdivision of cell cycle steps is conserved across a wide range of temperatures (5-35 °C), the relative duration of individual steps varies with temperature. We find that the transition into prometaphase is delayed at lower temperatures relative to other cell cycle events, arguing that it has a different mechanism of regulation. Using an in vivo biosensor, we quantified the ratio of activities of the major mitotic kinase, Cdk1 and one of the major mitotic phosphatases PP1. Comparing activation profile with cell cycle transition times at different temperatures indicates that in early fly embryos activation of Cdk1 drives entry into prometaphase but is not required for earlier cell cycle events. In fact, chromosome condensation can still occur when Cdk1 activity is inhibited pharmacologically. These results demonstrate that different kinases are rate-limiting for different steps of mitosis, arguing that robust inter-regulation may be needed for rapid and ordered mitosis.
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Affiliation(s)
- Hanieh Falahati
- Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ, 08544, USA
| | - Woonyung Hur
- Department of Cell Biology, Duke University Medical Center, Durham, NC, 27710, USA
| | - Stefano Di Talia
- Department of Cell Biology, Duke University Medical Center, Durham, NC, 27710, USA
| | - Eric Wieschaus
- Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ, 08544, USA; Howard Hughes Medical Institute, Department of Molecular Biology, Princeton University, Princeton, NJ, 08544, USA.
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39
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Zhao J, Warman G, Cheeseman J. The Development and Decay of the Circadian Clock in Drosophila melanogaster. Clocks Sleep 2020; 1:489-500. [PMID: 33089181 PMCID: PMC7445846 DOI: 10.3390/clockssleep1040037] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2019] [Accepted: 11/15/2019] [Indexed: 12/28/2022] Open
Abstract
The way in which the circadian clock mechanism develops and decays throughout life is interesting for a number of reasons and may give us insight into the process of aging itself. The Drosophila model has been proven invaluable for the study of the circadian clock and development and aging. Here we review the evidence for how the Drosophila clock develops and changes throughout life, and present a new conceptual model based on the results of our recent work. Firefly luciferase lines faithfully report the output of known clock genes at the central clock level in the brain and peripherally throughout the whole body. Our results show that the clock is functioning in embryogenesis far earlier than previously thought. This central clock in the fly remains robust throughout the life of the animal and only degrades immediately prior to death. However, at the peripheral (non-central oscillator level) the clock shows weakened output as the animal ages, suggesting the possibility of the breakdown in the cohesion of the circadian network.
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Affiliation(s)
- Jia Zhao
- Department of Anaesthesiology, School of Medicine, Faculty of Medical and Health Sciences, The University of Auckland, Auckland 1142, New Zealand; (J.Z.); (G.W.)
| | - Guy Warman
- Department of Anaesthesiology, School of Medicine, Faculty of Medical and Health Sciences, The University of Auckland, Auckland 1142, New Zealand; (J.Z.); (G.W.)
| | - James Cheeseman
- Department of Anaesthesiology, School of Medicine, Faculty of Medical and Health Sciences, The University of Auckland, Auckland 1142, New Zealand; (J.Z.); (G.W.)
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40
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Zhu H, Cui Y, Luo C, Liu F. Quantifying Temperature Compensation of Bicoid Gradients with a Fast T-Tunable Microfluidic Device. Biophys J 2020; 119:1193-1203. [PMID: 32853562 PMCID: PMC7499060 DOI: 10.1016/j.bpj.2020.08.003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2020] [Revised: 08/02/2020] [Accepted: 08/04/2020] [Indexed: 10/23/2022] Open
Abstract
As a reaction-diffusion system strongly affected by temperature, early fly embryos surprisingly show highly reproducible and accurate developmental patterns during embryogenesis under temperature perturbations. To reveal the underlying temperature compensation mechanism, it is important to overcome the challenge in quantitative imaging on fly embryos under temperature perturbations. Inspired by microfluidics generating temperature steps on fly embryos, here we design a microfluidic device capable of ensuring the normal development of multiple fly embryos as well as achieving real-time temperature control and fast temperature switches for quantitative live imaging with a home-built two-photon microscope. We apply this system to quantify the temperature compensation of the morphogen Bicoid (Bcd) gradient in fly embryos. The length constant of the exponential Bcd gradient reaches the maximum at 25°C within the measured temperatures of 18-29°C and gradually adapts to the corresponding value at new temperatures upon a fast temperature switch. The relaxation time of such an adaptation becomes longer if the temperature is switched in a later developmental stage. This age-dependent temperature compensation could be explained if the traditional synthesis-diffusion-degradation model is extended to incorporate the dynamic change of the parameters controlling the formation of Bcd gradients.
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Affiliation(s)
- Hongcun Zhu
- State Key Laboratory of Nuclear Physics and Technology, School of Physics, Peking University, Beijing, China
| | - Yeping Cui
- State Key Laboratory of Nuclear Physics and Technology, School of Physics, Peking University, Beijing, China
| | - Chunxiong Luo
- Center for Quantitative Biology, Peking University, Beijing, China; The State Key Laboratory for Artificial Microstructures and Mesoscopic Physics, School of Physics, Peking University, Beijing, China
| | - Feng Liu
- State Key Laboratory of Nuclear Physics and Technology, School of Physics, Peking University, Beijing, China; Center for Quantitative Biology, Peking University, Beijing, China.
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41
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Kutcherov D. Stagewise resolution of temperature-dependent embryonic and postembryonic development in the cowpea seed beetle Callosobruchus maculatus (F.). BMC Ecol 2020; 20:50. [PMID: 32917176 PMCID: PMC7488527 DOI: 10.1186/s12898-020-00318-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2020] [Accepted: 08/31/2020] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The thermal plasticity of life-history traits receives wide attention in the recent biological literature. Of all the temperature-dependent traits studied, developmental rates of ectotherms are especially often addressed, and yet surprisingly little is known about embryonic responses to temperature, including changes in the thermal thresholds and thermal sensitivity during early development. Even postembryonic development of many cryptically living species is understood superficially at best. RESULTS This study is the first to estimate the exact durations of developmental stages in the cowpea seed beetle C. maculatus from oviposition to adult emergence at five permissive constant temperatures from 20 to 32 °C. Early embryonic development was tracked and documented by means of destructive sampling and subsequent confocal imaging of fluorescently stained specimens. Late embryonic and early larval development was studied with the use of destructive sampling and light microscopy. Well-resolved temporal series based on thousands of embryos allowed precise timing of the following developmental events: formation of the blastoderm; formation, elongation, and retraction of the germ band; dorsal closure; the onset and completion of sclerotization of the cuticle; hatching, and penetration of the first-instar larva into the cowpea seed. Pupation and adult eclosion were observed directly through an incision in the seed coat. The thermal phenotype of C. maculatus was found to vary in the course of ontogeny and different stages scaled disproportionately with temperature, but pitfalls and caveats associated with analyses of relative durations of individual stages are also briefly discussed. CONCLUSION Disproportionate changes in developmental durations with temperature may have important implications when study design requires a high degree of synchronization among experimental embryos or when the occurrence of particular stages in the field is of interest, as well as in any other cases when development times need to be estimated with precision. This work provides one of the first examples of integration of embryological techniques with ecophysiological concepts and will hopefully motivate similar projects in the future. While experiments with Drosophila continue to be the main source of information on animal development, knowledge on other model species is instrumental to building a broader picture of developmental phenomena.
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Affiliation(s)
- Dmitry Kutcherov
- Department of Entomology, St. Petersburg State University, St. Petersburg, 199034, Russia.
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42
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Casares F, McGregor AP. The evolution and development of eye size in flies. WILEY INTERDISCIPLINARY REVIEWS-DEVELOPMENTAL BIOLOGY 2020; 10:e380. [PMID: 32400100 DOI: 10.1002/wdev.380] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/01/2019] [Revised: 03/08/2020] [Accepted: 03/12/2020] [Indexed: 01/19/2023]
Abstract
The compound eyes of flies exhibit striking variation in size, which has contributed to the adaptation of these animals to different habitats and their evolution of specialist behaviors. These differences in size are caused by differences in the number and/or size of ommatidia, which are specified during the development of the retinal field in the eye imaginal disc. While the genes and developmental mechanisms that regulate the formation of compound eyes are understood in great detail in the fruit fly Drosophila melanogaster, we know very little about the genetic changes and mechanistic alterations that lead to natural variation in ommatidia number and/or size, and thus overall eye size, within and between fly species. Understanding the genetic and developmental bases for this natural variation in eye size not only has great potential to help us understand adaptations in fly vision but also determine how eye size and organ size more generally are regulated. Here we explore the genetic and developmental mechanisms that could underlie natural differences in compound eye size within and among fly species based on our knowledge of eye development in D. melanogaster and the few cases where the causative genes and mechanisms have already been identified. We suggest that the fly eye provides an evolutionary and developmental framework to better understand the regulation and diversification of this crucial sensory organ globally at a systems level as well as the gene regulatory networks and mechanisms acting at the tissue, cellular and molecular levels. This article is categorized under: Establishment of Spatial and Temporal Patterns > Regulation of Size, Proportion, and Timing Invertebrate Organogenesis > Flies Comparative Development and Evolution > Regulation of Organ Diversity.
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Affiliation(s)
| | - Alistair P McGregor
- Department of Biological and Medical Sciences, Oxford Brookes University, Oxford, UK
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43
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Testa ND, Kaul S, Le KN, Zhan M, Lu H, Paaby AB. A portable, low-cost device for precise control of specimen temperature under stereomicroscopes. PLoS One 2020; 15:e0230241. [PMID: 32160236 PMCID: PMC7065815 DOI: 10.1371/journal.pone.0230241] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2019] [Accepted: 02/25/2020] [Indexed: 11/27/2022] Open
Abstract
To facilitate precise and convenient control of biological sample temperature, we developed a low-cost device that can be used independently or with any stereomicroscope. The purpose of the device is to control the thermal environment during experimental intervals in which a specimen must be manipulated outside of an incubator, e.g. for dissection or slide-mounting in preparation for imaging. Sample temperatures can be both cooled to below and heated to above room temperatures, and stably maintained at a precision of +/- 0.1˚C. To demonstrate the utility of this device, we report improved characterization of the penetrance of a short-acting temperature-sensitive allele in C. elegans embryos, and identification of the upper temperature threshold for embryonic viability for six Caenorhabditis species. By controlling the temperature environment even as a specimen is manipulated, this device offers consistency and flexibility, reduces environmental noise, and enables precision timing in experiments requiring temperature shifts.
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Affiliation(s)
- Nicholas D. Testa
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA, United States of America
| | - Samiksha Kaul
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA, United States of America
| | - Kim N. Le
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, Georgia, United States of America
| | - Mei Zhan
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, Georgia, United States of America
| | - Hang Lu
- School of Chemical & Biomolecular Engineering, Georgia Institute of Technology, Atlanta, GA, United States of America
| | - Annalise B. Paaby
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA, United States of America
- * E-mail:
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44
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Abstract
Spatially distributed signaling molecules, known as morphogens, provide spatial information during development. A host of different morphogens have now been identified, from subcellular gradients through to morphogens that act across a whole embryo. These gradients form over a wide-range of timescales, from seconds to hours, and their time windows for interpretation are also highly variable; the processes of morphogen gradient formation and interpretation are highly dynamic. The morphogen Bicoid (Bcd), present in the early Drosophila embryo, is essential for setting up the future Drosophila body segments. Due to its accessibility for both genetic perturbations and imaging, this system has provided key insights into how precise patterning can occur within a highly dynamic system. Here, we review the temporal scales of Bcd gradient formation and interpretation. In particular, we discuss the quantitative evidence for different models of Bcd gradient formation, outline the time windows for Bcd interpretation, and describe how Bcd temporally adapts its own ability to be interpreted. The utilization of temporal information in morphogen readout may provide crucial inputs to ensure precise spatial patterning, particularly in rapidly developing systems.
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45
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Barry C, Schmitz MT, Argus C, Bolin JM, Probasco MD, Leng N, Duffin BM, Steill J, Swanson S, McIntosh BE, Stewart R, Kendziorski C, Thomson JA, Bacher R. Automated minute scale RNA-seq of pluripotent stem cell differentiation reveals early divergence of human and mouse gene expression kinetics. PLoS Comput Biol 2019; 15:e1007543. [PMID: 31815944 PMCID: PMC6922475 DOI: 10.1371/journal.pcbi.1007543] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2019] [Revised: 12/19/2019] [Accepted: 11/12/2019] [Indexed: 12/22/2022] Open
Abstract
Pluripotent stem cells retain the developmental timing of their species of origin in vitro, an observation that suggests the existence of a cell-intrinsic developmental clock, yet the nature and machinery of the clock remain a mystery. We hypothesize that one possible component may lie in species-specific differences in the kinetics of transcriptional responses to differentiation signals. Using a liquid-handling robot, mouse and human pluripotent stem cells were exposed to identical neural differentiation conditions and sampled for RNA-sequencing at high frequency, every 4 or 10 minutes, for the first 10 hours of differentiation to test for differences in transcriptomic response rates. The majority of initial transcriptional responses occurred within a rapid window in the first minutes of differentiation for both human and mouse stem cells. Despite similarly early onsets of gene expression changes, we observed shortened and condensed gene expression patterns in mouse pluripotent stem cells compared to protracted trends in human pluripotent stem cells. Moreover, the speed at which individual genes were upregulated, as measured by the slopes of gene expression changes over time, was significantly faster in mouse compared to human cells. These results suggest that downstream transcriptomic response kinetics to signaling cues are faster in mouse versus human cells, and may offer a partial account for the vast differences in developmental rates across species.
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Affiliation(s)
- Christopher Barry
- Morgridge Institute for Research, Madison, WI, United States of America
| | | | - Cara Argus
- Morgridge Institute for Research, Madison, WI, United States of America
| | - Jennifer M. Bolin
- Morgridge Institute for Research, Madison, WI, United States of America
| | | | - Ning Leng
- Morgridge Institute for Research, Madison, WI, United States of America
| | - Bret M. Duffin
- Morgridge Institute for Research, Madison, WI, United States of America
| | - John Steill
- Morgridge Institute for Research, Madison, WI, United States of America
| | - Scott Swanson
- Morgridge Institute for Research, Madison, WI, United States of America
| | - Brian E. McIntosh
- Morgridge Institute for Research, Madison, WI, United States of America
| | - Ron Stewart
- Morgridge Institute for Research, Madison, WI, United States of America
| | - Christina Kendziorski
- Department of Biostatistics and Medical Informatics, University of Wisconsin-Madison, Madison, WI, United States of America
| | - James A. Thomson
- Morgridge Institute for Research, Madison, WI, United States of America
- Department of Cell and Regenerative Biology, University of Wisconsin School of Medicine and Public Health, Madison, WI, United States of America
- Department of Molecular, Cellular, and Developmental Biology, University of California, Santa Barbara, CA, United States of America
| | - Rhonda Bacher
- Department of Biostatistics, University of Florida, Gainesville, FL, United States of America
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46
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Martin Anduaga A, Evantal N, Patop IL, Bartok O, Weiss R, Kadener S. Thermosensitive alternative splicing senses and mediates temperature adaptation in Drosophila. eLife 2019; 8:44642. [PMID: 31702556 PMCID: PMC6890466 DOI: 10.7554/elife.44642] [Citation(s) in RCA: 44] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2018] [Accepted: 11/07/2019] [Indexed: 12/31/2022] Open
Abstract
Circadian rhythms are generated by the cyclic transcription, translation, and degradation of clock gene products, including timeless (tim), but how the circadian clock senses and adapts to temperature changes is not completely understood. Here, we show that temperature dramatically changes the splicing pattern of tim in Drosophila. We found that at 18°C, TIM levels are low because of the induction of two cold-specific isoforms: tim-cold and tim-short and cold. At 29°C, another isoform, tim-medium, is upregulated. Isoform switching regulates the levels and activity of TIM as each isoform has a specific function. We found that tim-short and cold encodes a protein that rescues the behavioral defects of tim01 mutants, and that flies in which tim-short and cold is abrogated have abnormal locomotor activity. In addition, miRNA-mediated control limits the expression of some of these isoforms. Finally, data that we obtained using minigenes suggest that tim alternative splicing might act as a thermometer for the circadian clock.
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Affiliation(s)
| | - Naveh Evantal
- Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, Jerusalem, Israel
| | | | - Osnat Bartok
- Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Ron Weiss
- Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Sebastian Kadener
- Biology Department, Brandeis University, Waltham, United States.,Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, Jerusalem, Israel
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47
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Renschler G, Richard G, Valsecchi CIK, Toscano S, Arrigoni L, Ramírez F, Akhtar A. Hi-C guided assemblies reveal conserved regulatory topologies on X and autosomes despite extensive genome shuffling. Genes Dev 2019; 33:1591-1612. [PMID: 31601616 PMCID: PMC6824461 DOI: 10.1101/gad.328971.119] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2019] [Accepted: 09/09/2019] [Indexed: 11/30/2022]
Abstract
In this study, Renschler et al. set out to analyze the impact of genomic rearrangements on genome topology using the Drosophila genus and X chromosome dosage compensation as a model. The authors developed a scaffolding algorithm and generated chromosome-length assemblies from Hi-C data for studying genome topology in three distantly related Drosophila species. Their data provides unique insights into genome topology evolution. RA Genome rearrangements that occur during evolution impose major challenges on regulatory mechanisms that rely on three-dimensional genome architecture. Here, we developed a scaffolding algorithm and generated chromosome-length assemblies from Hi-C data for studying genome topology in three distantly related Drosophila species. We observe extensive genome shuffling between these species with one synteny breakpoint after approximately every six genes. A/B compartments, a set of large gene-dense topologically associating domains (TADs), and spatial contacts between high-affinity sites (HAS) located on the X chromosome are maintained over 40 million years, indicating architectural conservation at various hierarchies. Evolutionary conserved genes cluster in the vicinity of HAS, while HAS locations appear evolutionarily flexible, thus uncoupling functional requirement of dosage compensation from individual positions on the linear X chromosome. Therefore, 3D architecture is preserved even in scenarios of thousands of rearrangements highlighting its relevance for essential processes such as dosage compensation of the X chromosome.
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Affiliation(s)
- Gina Renschler
- Max Planck Institute of Immunobiology and Epigenetics, 79108 Freiburg im Breisgau, Germany.,Faculty of Biology, University of Freiburg, 79104 Freiburg, Germany
| | - Gautier Richard
- Max Planck Institute of Immunobiology and Epigenetics, 79108 Freiburg im Breisgau, Germany.,IGEPP, INRA, Agrocampus Ouest, Université Rennes, 35600 Le Rheu, France
| | | | - Sarah Toscano
- Max Planck Institute of Immunobiology and Epigenetics, 79108 Freiburg im Breisgau, Germany
| | - Laura Arrigoni
- Max Planck Institute of Immunobiology and Epigenetics, 79108 Freiburg im Breisgau, Germany
| | - Fidel Ramírez
- Max Planck Institute of Immunobiology and Epigenetics, 79108 Freiburg im Breisgau, Germany
| | - Asifa Akhtar
- Max Planck Institute of Immunobiology and Epigenetics, 79108 Freiburg im Breisgau, Germany
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48
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Chong J, Amourda C, Saunders TE. Temporal development of Drosophila embryos is highly robust across a wide temperature range. J R Soc Interface 2019; 15:rsif.2018.0304. [PMID: 29997261 PMCID: PMC6073635 DOI: 10.1098/rsif.2018.0304] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2018] [Accepted: 06/18/2018] [Indexed: 11/12/2022] Open
Abstract
Development is a process precisely coordinated in both space and time. Spatial precision has been quantified in a number of developmental systems, and such data have contributed significantly to our understanding of, for example, morphogen gradient interpretation. However, comparatively little quantitative analysis has been performed on timing and temporal coordination during development. Here, we use Drosophila to explore the temporal robustness of embryonic development within physiologically normal temperatures. We find that development is temporally very precise across a wide range of temperatures in the three Drosophila species investigated. However, we find temperature dependence in the timing of developmental events. A simple model incorporating history dependence can explain the developmental temporal trajectories. Interestingly, history dependence is temperature-specific, with either effective negative or positive feedback at different temperatures. We also find that embryos are surprisingly robust to shifting temperatures during embryogenesis. We further identify differences between tropical and temperate species, potentially due to different mechanisms regulating temporal development that depend on the local environment. Our data show that Drosophila embryonic development is temporally robust across a wide range of temperatures. This robustness shows interesting species-specific differences that are suggestive of different sensitivity to temperature fluctuations between Drosophila species.
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Affiliation(s)
- Jeronica Chong
- Mechanobiology Institute, National University of Singapore, Singapore, Republic of Singapore
| | - Christopher Amourda
- Mechanobiology Institute, National University of Singapore, Singapore, Republic of Singapore
| | - Timothy E Saunders
- Mechanobiology Institute, National University of Singapore, Singapore, Republic of Singapore .,Department of Biological Sciences, National University of Singapore, Singapore, Republic of Singapore.,Institute of Molecular and Cell Biology, A*Star, Proteos, Singapore, Republic of Singapore
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49
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Repressive Gene Regulation Synchronizes Development with Cellular Metabolism. Cell 2019; 178:980-992.e17. [PMID: 31353220 DOI: 10.1016/j.cell.2019.06.023] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2019] [Revised: 05/06/2019] [Accepted: 06/12/2019] [Indexed: 01/06/2023]
Abstract
Metabolic conditions affect the developmental tempo of animals. Developmental gene regulatory networks (GRNs) must therefore synchronize their dynamics with a variable timescale. We find that layered repression of genes couples GRN output with variable metabolism. When repressors of transcription or mRNA and protein stability are lost, fewer errors in Drosophila development occur when metabolism is lowered. We demonstrate the universality of this phenomenon by eliminating the entire microRNA family of repressors and find that development to maturity can be largely rescued when metabolism is reduced. Using a mathematical model that replicates GRN dynamics, we find that lowering metabolism suppresses the emergence of developmental errors by curtailing the influence of auxiliary repressors on GRN output. We experimentally show that gene expression dynamics are less affected by loss of repressors when metabolism is reduced. Thus, layered repression provides robustness through error suppression and may provide an evolutionary route to a shorter reproductive cycle.
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50
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Wunderlich Z, Fowlkes CC, Eckenrode KB, Bragdon MDJ, Abiri A, DePace AH. Quantitative Comparison of the Anterior-Posterior Patterning System in the Embryos of Five Drosophila Species. G3 (BETHESDA, MD.) 2019; 9:2171-2182. [PMID: 31048401 PMCID: PMC6643877 DOI: 10.1534/g3.118.200953] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/07/2018] [Accepted: 05/01/2019] [Indexed: 11/18/2022]
Abstract
Complex spatiotemporal gene expression patterns direct the development of the fertilized egg into an adult animal. Comparisons across species show that, in spite of changes in the underlying regulatory DNA sequence, developmental programs can be maintained across millions of years of evolution. Reciprocally, changes in gene expression can be used to generate morphological novelty. Distinguishing between changes in regulatory DNA that lead to changes in gene expression and those that do not is therefore a central goal of evolutionary developmental biology. Quantitative, spatially-resolved measurements of developmental gene expression patterns play a crucial role in this goal, enabling the detection of subtle phenotypic differences between species and the development of computations models that link the sequence of regulatory DNA to expression patterns. Here we report the generation of two atlases of cellular resolution gene expression measurements for the primary anterior-posterior patterning genes in Drosophila simulans and Drosophila virilis By combining these data sets with existing atlases for three other Drosophila species, we detect subtle differences in the gene expression patterns and dynamics driving the highly conserved axis patterning system and delineate inter-species differences in the embryonic morphology. These data sets will be a resource for future modeling studies of the evolution of developmental gene regulatory networks.
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Affiliation(s)
- Zeba Wunderlich
- Department of Developmental and Cell Biology, University of California, Irvine, CA, 92697
| | - Charless C Fowlkes
- Department of Computer Science, University of California, Irvine, CA, 92697
| | - Kelly B Eckenrode
- Department of Systems Biology, Harvard Medical School, Boston, MA, 20115
| | - Meghan D J Bragdon
- Department of Systems Biology, Harvard Medical School, Boston, MA, 20115
| | - Arash Abiri
- Department of Developmental and Cell Biology, University of California, Irvine, CA, 92697
| | - Angela H DePace
- Department of Systems Biology, Harvard Medical School, Boston, MA, 20115
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