Genetics of Shoot Meristem and Shoot Regeneration

2021 ◽  
Vol 55 (1) ◽  
Author(s):  
Leor Eshed Williams
Keyword(s):  
Shoot Regeneration ◽  
Developmental Plasticity ◽  
Genetic Network ◽  
Shoot Meristem ◽  
Annual Review ◽  
Publication Date ◽  
Cell Specification ◽  
Future Challenges ◽  
Gene Regulatory ◽  
Stochastic Events

Plants exhibit remarkable lineage plasticity, allowing them to regenerate organs that differ from their respective origins. Such developmental plasticity is dependent on the activity of pluripotent founder cells or stem cells residing in meristems. At the shoot apical meristem (SAM), the constant flow of cells requires continuing cell specification governed by a complex genetic network, with the WUSCHEL transcription factor and phytohormone cytokinin at its core. In this review, I discuss some intriguing recent discoveries that expose new principles and mechanisms of patterning and cell specification acting both at the SAM and, prior to meristem organogenesis during shoot regeneration. I also highlight unanswered questions and future challenges in the study of SAM and meristem regeneration. Finally, I put forward a model describing stochastic events mediated by epigenetic factors to explain how the gene regulatory network might be initiated at the onset of shoot regeneration. Expected final online publication date for the Annual Review of Genetics, Volume 55 is November 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

Dissecting Organismal Morphogenesis by Bridging Genetics and Biophysics

2021 ◽  
Vol 55 (1) ◽  
Author(s):  
Nikhil Mishra ◽  
Carl-Philipp Heisenberg
Keyword(s):  
Cell Fate ◽  
Regulatory Networks ◽  
Annual Review ◽  
Publication Date ◽  
Technological Advances ◽  
Complex Shapes ◽  
Gene Regulatory ◽  
And Mathematics ◽  
Multicellular Organisms ◽  
Shape Changes

Multicellular organisms develop complex shapes from much simpler, single-celled zygotes through a process commonly called morphogenesis. Morphogenesis involves an interplay between several factors, ranging from the gene regulatory networks determining cell fate and differentiation to the mechanical processes underlying cell and tissue shape changes. Thus, the study of morphogenesis has historically been based on multidisciplinary approaches at the interface of biology with physics and mathematics. Recent technological advances have further improved our ability to study morphogenesis by bridging the gap between the genetic and biophysical factors through the development of new tools for visualizing, analyzing, and perturbing these factors and their biochemical intermediaries. Here, we review how a combination of genetic, microscopic, biophysical, and biochemical approaches has aided our attempts to understand morphogenesis and discuss potential approaches that may be beneficial to such an inquiry in the future. Expected final online publication date for the Annual Review of Genetics, Volume 55 is November 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

Sepsis-Induced Immunosuppression

2021 ◽  
Vol 84 (1) ◽  
Author(s):  
Lisa K. Torres ◽  
Peter Pickkers ◽  
Tom van der Poll
Keyword(s):  
Organ Transplant ◽  
Annual Review ◽  
Publication Date ◽  
Predisposing Factor ◽  
Substantial Impact ◽  
Immunomodulatory Agents ◽  
Secondary Infections ◽  
Future Challenges ◽  
Treatment Paradigm ◽  
New Treatment

Sepsis is expected to have a substantial impact on public health and cost as its prevalence increases. Factors contributing to increased prevalence include a progressively aging population, advances in the use of immunomodulatory agents to treat a rising number of diseases, and immune-suppressing therapies in organ transplant recipients and cancer patients. It is now recognized that sepsis is associated with profound and sustained immunosuppression, which has been implicated as a predisposing factor in the increased susceptibility of patients to secondary infections and mortality. In this review, we discuss mechanisms of sepsis-induced immunosuppression and biomarkers that identify a state of impaired immunity. We also highlight immune-enhancing strategies that have been evaluated in patients with sepsis, as well as therapeutics under current investigation. Finally, we describe future challenges and the need for a new treatment paradigm, integrating predictive enrichment with patient factors that may guide the future selection of tailored immunotherapy. Expected final online publication date for the Annual Review of Physiology, Volume 84 is February 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

scholarly journals Physiologically Based Modeling of Food Digestion and Intestinal Microbiota: State of the Art and Future Challenges. An INFOGEST Review

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Steven Le Feunteun ◽  
Ahmed Al-Razaz ◽  
Matthijs Dekker ◽  
Erwin George ◽  
Beatrice Laroche ◽  
...  
Keyword(s):  
Gastrointestinal Tract ◽  
Historical Background ◽  
Annual Review ◽  
Publication Date ◽  
Physiologically Based ◽  
The Future ◽  
Future Challenges ◽  
Full Picture ◽  
Food Digestion

This review focuses on modeling methodologies of the gastrointestinal tract during digestion that have adopted a systems-view approach and, more particularly, on physiologically based compartmental models of food digestion and host–diet–microbiota interactions. This type of modeling appears very promising for integrating the complex stream of mechanisms that must be considered and retrieving a full picture of the digestion process from mouth to colon. We may expect these approaches to become more and more accurate in the future and to serve as a useful means of understanding the physicochemical processes occurring in the gastrointestinal tract, interpreting postprandial in vivo data, making relevant predictions, and designing healthier foods. This review intends to provide a scientific and historical background of this field of research, before discussing the future challenges and potential benefits of the establishment of such a model to study and predict food digestion and absorption in humans. Expected final online publication date for the Annual Review of Food Science and Technology, Volume 12 is March 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

Single-Cell Epigenomics Reveals Mechanisms of Cancer Progression

2022 ◽  
Vol 6 (1) ◽  
Author(s):  
Lindsay M. LaFave ◽  
Rachel Savage ◽  
Jason D. Buenrostro
Keyword(s):  
Single Cell ◽  
Cancer Progression ◽  
Cancer Biology ◽  
Annual Review ◽  
Publication Date ◽  
Cancer Evolution ◽  
Regulatory State ◽  
Cellular Functions ◽  
Cancer Initiation ◽  
Gene Regulatory

Cancer initiation is driven by the cooperation between genetic and epigenetic aberrations that disrupt gene regulatory programs critical to maintain specialized cellular functions. After initiation, cells acquire additional genetic and epigenetic alterations influenced by tumor-intrinsic and -extrinsic mechanisms, which increase intratumoral heterogeneity, reshape the cell's underlying gene regulatory network, and promote cancer evolution. Furthermore, environmental or therapeutic insults drive the selection of heterogeneous cell states, with implications for cancer initiation, maintenance, and drug resistance. The advancement of single-cell genomics has begun to uncover the full repertoire of chromatin and gene expression states (cell states) that exist within individual tumors. These single-cell analyses suggest that cells diversify in their regulatory states upon transformation by co-opting damage-induced and nonlineage regulatory programs that can lead to epigenomic plasticity. Here, we review these recent studies related to regulatory state changes in cancer progression and highlight the growing single-cell epigenomics toolkit poised to address unresolved questions in the field. Expected final online publication date for the Annual Review of Cancer Biology, Volume 6 is April 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

The Making of Plant Armor: The Periderm

2022 ◽  
Vol 73 (1) ◽  
Author(s):  
Olga Serra ◽  
Ari Pekka Mähönen ◽  
Alexander J. Hetherington ◽  
Laura Ragni
Keyword(s):  
Regulatory Networks ◽  
Plant Biology ◽  
Raw Material ◽  
Industrial Processes ◽  
Annual Review ◽  
Publication Date ◽  
Biotic And Abiotic Stress ◽  
Meristematic Tissue ◽  
Future Challenges ◽  
Periderm Formation

The periderm acts as armor protecting the plant's inner tissues from biotic and abiotic stress. It forms during the radial thickening of plant organs such as stems and roots and replaces the function of primary protective tissues such as the epidermis and the endodermis. A wound periderm also forms to heal and protect injured tissues. The periderm comprises a meristematic tissue called the phellogen, or cork cambium, and its derivatives: the lignosuberized phellem and the phelloderm. Research on the periderm has mainly focused on the chemical composition of the phellem due to its relevance as a raw material for industrial processes. Today, there is increasing interest in the regulatory network underlying periderm development as a novel breeding trait to improve plant resilience and to sequester CO2. Here, we discuss our current understanding of periderm formation, focusing on aspects of periderm evolution, mechanisms of periderm ontogenesis, regulatory networks underlying phellogen initiation and cork differentiation, and future challenges of periderm research. Expected final online publication date for the Annual Review of Plant Biology, Volume 73 is May 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

Beyond Casual Resemblances: Rigorous Frameworks for Comparing Regeneration Across Species

2021 ◽  
Vol 37 (1) ◽  
Author(s):  
Mansi Srivastava
Keyword(s):  
Gene Regulatory Networks ◽  
Regulatory Networks ◽  
Evolutionary History ◽  
Adult Stem Cells ◽  
Annual Review ◽  
Publication Date ◽  
Animal Phyla ◽  
History Of ◽  
Gene Regulatory ◽  
Unifying Principles

The majority of animal phyla have species that can regenerate. Comparing regeneration across animals can reconstruct the molecular and cellular evolutionary history of this process. Recent studies have revealed some similarity in regeneration mechanisms, but rigorous comparative methods are needed to assess whether these resemblances are ancestral pathways (homology) or are the result of convergent evolution (homoplasy). This review aims to provide a framework for comparing regeneration across animals, focusing on gene regulatory networks (GRNs), which are substrates for assessing process homology. The homology of the wound-induced activation of Wnt signaling and of adult stem cells are discussed as examples of ongoing studies of regeneration that enable comparisons in a GRN framework. Expanding the study of regeneration GRNs in currently studied species and broadening taxonomic sampling for these approaches will identify processes that are unifying principles of regeneration biology across animals. These insights are important both for evolutionary studies of regeneration and for human regenerative medicine. Expected final online publication date for the Annual Review of Cell and Developmental Biology, Volume 37 is October 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

Gut Microbiota in Intestinal and Liver Disease

2020 ◽  
Vol 16 (1) ◽  
Author(s):  
Rheinallt M. Jones ◽  
Andrew S. Neish
Keyword(s):  
Community Structure ◽  
Liver Disease ◽  
Gastrointestinal Tract ◽  
Gut Microbiota ◽  
Alimentary Tract ◽  
Annual Review ◽  
Publication Date ◽  
Proinflammatory Gene ◽  
Gene Regulatory

It is known that the gut microbiota, the numerically vast and taxonomically diverse microbial communities that thrive in a symbiotic fashion within our alimentary tract, can affect the normal physiology of the gastrointestinal tract and liver. Further, disturbances of the microbiota community structure from both endogenous and exogenous influences as well as the failure of host responsive mechanisms have been implicated in a variety of disease processes. Mechanistically, alterations in intestinal permeability and dysbiosis of the microbiota can result in inflammation, immune activation, and exposure to xenobiotic influences. Additionally, the gut and liver are continually exposed to small molecule products of the microbiota with proinflammatory, gene regulatory, and oxidative properties. Long-term coevolution has led to tolerance and incorporation of these influences into normal physiology and homeostasis; conversely, changes in this equilibrium from either the host or the microbial side can result in a wide variety of immune, inflammatory, metabolic, and neoplastic intestinal and hepatic disorders. Expected final online publication date for the Annual Review of Pathology: Mechanisms of Disease, Volume 16 is January 25, 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

Time-Based Systems Biology Approaches to Capture and Model Dynamic Gene Regulatory Networks

2021 ◽  
Vol 72 (1) ◽  
Author(s):  
Jose M. Alvarez ◽  
Matthew D. Brooks ◽  
Joseph Swift ◽  
Gloria M. Coruzzi
Keyword(s):  
Systems Biology ◽  
Gene Regulatory Networks ◽  
Regulatory Networks ◽  
Environmental Changes ◽  
Annual Review ◽  
Publication Date ◽  
Learning Approaches ◽  
Dynamic Events ◽  
Genome Wide ◽  
Gene Regulatory

All aspects of transcription and its regulation involve dynamic events. However, capturing these dynamic events in gene regulatory networks (GRNs) offers both a promise and a challenge. The promise is that capturing and modeling the dynamic changes in GRNs will allow us to understand how organisms adapt to a changing environment. The ability to mount a rapid transcriptional response to environmental changes is especially important in nonmotile organisms such as plants. The challenge is to capture these dynamic, genome-wide events and model them in GRNs. In this review, we cover recent progress in capturing dynamic interactions of transcription factors with their targets—at both the local and genome-wide levels—and using them to learn how GRNs operate as a function of time. We also discuss recent advances that employ time-based machine learning approaches to forecast gene expression at future time points, a key goal of systems biology. Expected final online publication date for the Annual Review of Plant Biology, Volume 72 is May 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

Olfactory Sensing and Navigation in Turbulent Environments

2021 ◽  
Vol 13 (1) ◽  
Author(s):  
Gautam Reddy ◽  
Venkatesh N. Murthy ◽  
Massimo Vergassola
Keyword(s):  
Turbulent Flows ◽  
Molecular Diffusion ◽  
Turbulent Transport ◽  
Annual Review ◽  
Publication Date ◽  
Pheromone Communication ◽  
Fluid Turbulence ◽  
Turbulent Environments ◽  
Future Challenges ◽  
Olfactory Organs

Fluid turbulence is a double-edged sword for the navigation of macroscopic animals, such as birds, insects, and rodents. On one hand, turbulence enables pheromone communication among mates and the possibility of locating food by their odors from long distances. Molecular diffusion would indeed be unable to spread odors over relevant distances in natural conditions. On the other hand, turbulent flows are hard to predict, and learning effective maneuvers to navigate them is challenging, as we discuss in this review. We first provide a summary of the olfactory organs that sense airborne or surface-bound odors, as well as the computational tasks that animals face when extracting information useful for navigation from an olfactory signal. A compendium of the dynamics of turbulent transport emphasizes those aspects that directly impact animals’ behavior. The state of the art on navigational strategies is discussed, followed by a concluding section dedicated to future challenges in the field. Expected final online publication date for the Annual Review of Condensed Matter Physics, Volume 13 is March 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

Estimating DSGE Models: Recent Advances and Future Challenges

2021 ◽  
Vol 13 (1) ◽  
Author(s):  
Jesús Fernández-Villaverde ◽  
Pablo A. Guerrón-Quintana
Keyword(s):  
Likelihood Function ◽  
Space Representation ◽  
Annual Review ◽  
Publication Date ◽  
Dsge Models ◽  
State Space Representation ◽  
Current State ◽  
Recent Advances ◽  
Future Challenges ◽  
Dynamic Stochastic

We review the current state of the estimation of dynamic stochastic general equilibrium (DSGE) models. After introducing a general framework for dealing with DSGE models, the state-space representation, we discuss how to evaluate moments or the likelihood function implied by such a structure. We discuss, in varying degrees of detail, recent advances in the field, such as the tempered particle filter, approximated Bayesian computation, Hamiltonian Monte Carlo, variational inference, and machine learning. These methods show much promise but have not been fully explored by the DSGE community yet. We conclude by outlining three future challenges for this line of research. Expected final online publication date for the Annual Review of Economics, Volume 13 is August 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

Sign in / Sign up

Export Citation Format

Share Document