Green Algal Models for Multicellularity

2021 ◽  
Vol 55 (1) ◽  
Author(s):  
James Umen ◽  
Matthew D. Herron
Keyword(s):  
Single Cells ◽  
Model Organisms ◽  
Annual Review ◽  
Publication Date ◽  
Freshwater Algae ◽  
Green Algal ◽  
Photosynthetic Eukaryotes ◽  
Volvocine Algae ◽  
Repeated Evolution ◽  
Life On Earth

The repeated evolution of multicellularity across the tree of life has profoundly affected the ecology and evolution of nearly all life on Earth. Many of these origins were in different groups of photosynthetic eukaryotes, or algae. Here, we review the evolution and genetics of multicellularity in several groups of green algae, which include the closest relatives of land plants. These include millimeter-scale, motile spheroids of up to 50,000 cells in the volvocine algae; decimeter-scale seaweeds in the genus Ulva (sea lettuce); and very plantlike, meter-scale freshwater algae in the genus Chara (stoneworts). We also describe algae in the genus Caulerpa, which are giant, multinucleate, morphologically complex single cells. In each case, we review the life cycle, phylogeny, and genetics of traits relevant to the evolution of multicellularity, and genetic and genomic resources available for the group in question. Finally, we suggest routes toward developing these groups as model organisms for the evolution of multicellularity. 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.

Chemistry Under Shock Conditions

2021 ◽  
Vol 51 (1) ◽  
Author(s):  
Brenden W. Hamilton ◽  
Michael N. Sakano ◽  
Chunyu Li ◽  
Alejandro Strachan
Keyword(s):  
Materials Science ◽  
Low Frequency ◽  
Annual Review ◽  
Publication Date ◽  
Energy Localization ◽  
Ambient Conditions ◽  
Static Loads ◽  
Nonequilibrium Conditions ◽  
Life On Earth ◽  
Modes Coupling

Shock loading takes materials from ambient conditions to extreme conditions of temperature and nonhydrostatic stress on picosecond timescales. In molecular materials the fast loading results in temporary nonequilibrium conditions with overheated low-frequency modes and relatively cold, high-frequency, intramolecular modes; coupling the shock front with the material's microstructure and defects results in energy localization in hot spots. These processes can conspire to lead to a material response not observed under quasi-static loads. This review focuses on chemical reactions induced by dynamical loading, the understanding of which requires bringing together materials science, shock physics, and condensed matter chemistry. Recent progress in experiments and simulations holds the key to the answer of long-standing grand challenges with implications for the initiation of detonation and life on Earth. Expected final online publication date for the Annual Review of Materials Science, Volume 51 is August 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

Growth and Division of the Peptidoglycan Matrix

2021 ◽  
Vol 75 (1) ◽  
Author(s):  
Patricia D.A. Rohs ◽  
Thomas G. Bernhardt
Keyword(s):  
Cell Wall ◽  
Bacterial Infections ◽  
Model Organisms ◽  
Annual Review ◽  
Publication Date ◽  
Drug Resistant ◽  
Peptidoglycan Cell Wall ◽  
Integral Role ◽  
Osmotic Lysis ◽  
Peptidoglycan Layer

Most bacteria are surrounded by a peptidoglycan cell wall that defines their shape and protects them from osmotic lysis. The expansion and division of this structure therefore plays an integral role in bacterial growth and division. Additionally, the biogenesis of the peptidoglycan layer is the target of many of our most effective antibiotics. Thus, a better understanding of how the cell wall is built will enable the development of new therapies to combat the rise of drug-resistant bacterial infections. This review covers recent advances in defining the mechanisms involved in assembling the peptidoglycan layer with an emphasis on discoveries related to the function and regulation of the cell elongation and division machineries in the model organisms Escherichia coli and Bacillus subtilis. Expected final online publication date for the Annual Review of Microbiology, Volume 75 is October 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

The Complex Genetic Basis and Multilayered Regulatory Control of Yeast Pseudohyphal Growth

2021 ◽  
Vol 55 (1) ◽  
Author(s):  
Anuj Kumar
Keyword(s):  
Cell Growth ◽  
Signaling Pathways ◽  
Single Cells ◽  
Regulatory Control ◽  
Yeast Cells ◽  
Regulatory Mechanisms ◽  
Annual Review ◽  
Publication Date ◽  
Yeast Saccharomyces Cerevisiae ◽  
Pseudohyphal Growth

Eukaryotic cells are exquisitely responsive to external and internal cues, achieving precise control of seemingly diverse growth processes through a complex interplay of regulatory mechanisms. The budding yeast Saccharomyces cerevisiae provides a fascinating model of cell growth in its stress-responsive transition from planktonic single cells to a filamentous pseudohyphal growth form. During pseudohyphal growth, yeast cells undergo changes in morphology, polarity, and adhesion to form extended and invasive multicellular filaments. This pseudohyphal transition has been studied extensively as a model of conserved signaling pathways regulating cell growth and for its relevance in understanding the pathogenicity of the related opportunistic fungus Candida albicans, wherein filamentous growth is required for virulence. This review highlights the broad gene set enabling yeast pseudohyphal growth, signaling pathways that regulate this process, the role and regulation of proteins conferring cell adhesion, and interesting regulatory mechanisms enabling the pseudohyphal transition. 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.

The Molecular Basis for Life in Extreme Environments

2021 ◽  
Vol 50 (1) ◽  
Author(s):  
Nozomi Ando ◽  
Blanca Barquera ◽  
Douglas H. Bartlett ◽  
Eric Boyd ◽  
Audrey A. Burnim ◽  
...  
Keyword(s):  
Molecular Basis ◽  
Structural Changes ◽  
Extreme Environments ◽  
Annual Review ◽  
Publication Date ◽  
Extreme Conditions ◽  
Future Directions ◽  
Environmental Genomics ◽  
Life On Earth ◽  
Diversity Of Life

Sampling and genomic efforts over the past decade have revealed an enormous quantity and diversity of life in Earth's extreme environments. This new knowledge of life on Earth poses the challenge of understanding its molecular basis in such inhospitable conditions, given that such conditions lead to loss of structural changes and of function in biomolecules from mesophiles. In this review, we discuss the physicochemical properties of extreme environments. We present the state of recent progress in extreme environmental genomics. We then present an overview of our current understanding of the biomolecular adaptation to extreme conditions. As our current and future understanding of biomolecular structure–function relationships in extremophiles requires methodologies adapted to extremes of pressure, temperature, and chemical composition, advances in instrumentation for probing biophysical properties under extreme conditions are presented. Finally, we briefly discuss possible future directions in extreme biophysics. Expected final online publication date for the Annual Review of Biophysics, Volume 50 is May 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

Advances in the Evolution and Ecology of 13- and 17-Year Periodical Cicadas

2021 ◽  
Vol 67 (1) ◽  
Author(s):  
Chris Simon ◽  
John R. Cooley ◽  
Richard Karban ◽  
Teiji Sota
Keyword(s):  
Character Displacement ◽  
Prime Numbers ◽  
Life Cycles ◽  
Model Organisms ◽  
Annual Review ◽  
Publication Date ◽  
Reproductive Character Displacement ◽  
Temporal Isolation ◽  
Periodical Cicadas ◽  
Major Review

Apart from model organisms, 13- and 17-year periodical cicadas (Hemiptera: Cicadidae: Magicicada) are among the most studied insects in evolution and ecology. They are attractive subjects because they predictably emerge in large numbers; have a complex biogeography shaped by both spatial and temporal isolation; and include three largely sympatric, parallel species groups that are, in a sense, evolutionary replicates. Magicicada are also relatively easy to capture and manipulate, and their spectacular, synchronized mass emergences facilitate outreach and citizen science opportunities. Since the last major review, studies of Magicicada have revealed insights into reproductive character displacement and the nature of species boundaries, provided additional examples of allochronic speciation, found evidence for repeated and parallel (but noncontemporaneous) evolution of 13- and 17-year life cycles, quantified the amount and direction of gene flow through time, revealed phylogeographic patterning resulting from paleoclimate change, studied the timing of juvenile development, and created hypotheses for the evolution of life-cycle control and the future effects of climate change on Magicicada life cycles. New ecological studies have supported and questioned the role of prime numbers in Magicicada ecology and evolution, found bidirectional shifts in population size over generations, quantified the contribution of Magicicada to nutrient flow in forest ecosystems, and examined behavioral and biochemical interactions between Magicicada and their fungal parasites and bacterial endosymbionts. Expected final online publication date for the Annual Review of Entomology, Volume 67 is January 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

scholarly journals Applications of Single-Cell DNA Sequencing

2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Gilad D. Evrony ◽  
Anjali Gupta Hinch ◽  
Chongyuan Luo
Keyword(s):  
Dna Sequencing ◽  
Single Cell ◽  
Human Genetics ◽  
Single Cells ◽  
Annual Review ◽  
Publication Date ◽  
Genomic Analyses ◽  
Somatic Mutagenesis ◽  
Organismal Development ◽  
Fundamental Units

Over the past decade, genomic analyses of single cells—the fundamental units of life—have become possible. Single-cell DNA sequencing has shed light on biological questions that were previously inaccessible across diverse fields of research, including somatic mutagenesis, organismal development, genome function, and microbiology. Single-cell DNA sequencing also promises significant future biomedical and clinical impact, spanning oncology, fertility, and beyond. While single-cell approaches that profile RNA and protein have greatly expanded our understanding of cellular diversity, many fundamental questions in biology and important biomedical applications require analysis of the DNA of single cells. Here, we review the applications and biological questions for which single-cell DNA sequencing is uniquely suited or required. We include a discussion of the fields that will be impacted by single-cell DNA sequencing as the technology continues to advance. Expected final online publication date for the Annual Review of Genomics and Human Genetics Volume 22 is August 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

Genomic and Epigenetic Foundations of Neocentromere Formation

2021 ◽  
Vol 55 (1) ◽  
Author(s):  
Evon M. DeBose-Scarlett ◽  
Beth A. Sullivan
Keyword(s):  
Genome Instability ◽  
Genome Project ◽  
Model Organisms ◽  
Annual Review ◽  
Publication Date ◽  
Open Chromatin ◽  
Developmental Defects ◽  
Active Transcription ◽  
Genomic Locations ◽  
The Human Genome Project

Centromeres are essential to genome inheritance, serving as the site of kinetochore assembly and coordinating chromosome segregation during cell division. Abnormal centromere function is associated with birth defects, infertility, and cancer. Normally, centromeres are assembled and maintained at the same chromosomal location. However, ectopic centromeres form spontaneously at new genomic locations and contribute to genome instability and developmental defects as well as to acquired and congenital human disease. Studies in model organisms have suggested that certain regions of the genome, including pericentromeres, heterochromatin, and regions of open chromatin or active transcription, support neocentromere activation. However, there is no universal mechanism that explains neocentromere formation. This review focuses on recent technological and intellectual advances in neocentromere research and proposes future areas of study. Understanding neocentromere biology will provide a better perspective on chromosome and genome organization and functional context for information generated from the Human Genome Project, ENCODE, and other large genomic consortia. 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.

Temporal and Spatial Signaling Mediating the Balance of the Plankton Microbiome

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Yun Deng ◽  
Marine Vallet ◽  
Georg Pohnert
Keyword(s):  
Abiotic Factors ◽  
Algal Growth ◽  
Annual Review ◽  
Publication Date ◽  
Phytoplankton Assemblages ◽  
Metabolic Markers ◽  
Species Succession ◽  
Photosynthetic Eukaryotes ◽  
Temporal And Spatial ◽  
Chemical Mediators

The annual patterns of plankton succession in the ocean determine ecological and biogeochemical cycles. The temporally fluctuating interplay between photosynthetic eukaryotes and the associated microbiota balances the composition of aquatic planktonic ecosystems. In addition to nutrients and abiotic factors, chemical signaling determines the outcome of interactions between phytoplankton and their associated microbiomes. Chemical mediators control essential processes, such as the development of key morphological, physiological, behavioral, and life-history traits during algal growth. These molecules thus impact species succession and community composition across time and space in processes that are highlighted in this review. We focus on spatial, seasonal, and physiological dynamics that occur during the early association of algae with bacteria, the exponential growth of a bloom, and also during its decline and recycling. We also discuss how patterns from field data and global surveys might be linked to the actions of metabolic markers in natural phytoplankton assemblages. Expected final online publication date for the Annual Review of Marine Science, Volume 14 is January 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

Revelations About Aging and Disease from Unconventional Vertebrate Model Organisms

2021 ◽  
Vol 55 (1) ◽  
Author(s):  
Yang Zhao ◽  
Andrei Seluanov ◽  
Vera Gorbunova
Keyword(s):  
Risk Factor ◽  
Animal Species ◽  
Model Organisms ◽  
Annual Review ◽  
Publication Date ◽  
Vertebrate Species ◽  
Associated Diseases ◽  
Vertebrate Model ◽  
Underlying Mechanisms ◽  
Excellent Resource

Aging is a major risk factor for multiple diseases. Understanding the underlying mechanisms of aging would help to delay and prevent age-associated diseases. Short-lived model organisms have been extensively used to study the mechanisms of aging. However, these short-lived species may be missing the longevity mechanisms that are needed to extend the lifespan of an already long-lived species such as humans. Unconventional long-lived animal species are an excellent resource to uncover novel mechanisms of longevity and disease resistance. Here, we review mechanisms that evolved in nonmodel vertebrate species to counteract age-associated diseases. Some antiaging mechanisms are conserved across species; however, various nonmodel species also evolved unique mechanisms to delay aging and prevent disease. This variety of antiaging mechanisms has evolved due to the remarkably diverse habitats and behaviors of these species. We propose that exploring a wider range of unconventional vertebrates will provide important resources to study antiaging mechanisms that are potentially applicable to humans. 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.

Endogenous Retroviruses Drive Resistance and Promotion of Exogenous Retroviral Homologs

2020 ◽  
Vol 9 (1) ◽  
Author(s):  
Elliott S. Chiu ◽  
Sue VandeWoude
Keyword(s):  
Immune Modulation ◽  
Viral Infections ◽  
Viral Evolution ◽  
Endogenous Retroviruses ◽  
Annual Review ◽  
Publication Date ◽  
Biological Functions ◽  
Self Tolerance ◽  
Vertebrate Hosts ◽  
Insight Into

Endogenous retroviruses (ERVs) serve as markers of ancient viral infections and provide invaluable insight into host and viral evolution. ERVs have been exapted to assist in performing basic biological functions, including placentation, immune modulation, and oncogenesis. A subset of ERVs share high nucleotide similarity to circulating horizontally transmitted exogenous retrovirus (XRV) progenitors. In these cases, ERV–XRV interactions have been documented and include ( a) recombination to result in ERV–XRV chimeras, ( b) ERV induction of immune self-tolerance to XRV antigens, ( c) ERV antigen interference with XRV receptor binding, and ( d) interactions resulting in both enhancement and restriction of XRV infections. Whereas the mechanisms governing recombination and immune self-tolerance have been partially determined, enhancement and restriction of XRV infection are virus specific and only partially understood. This review summarizes interactions between six unique ERV–XRV pairs, highlighting important ERV biological functions and potential evolutionary histories in vertebrate hosts. Expected final online publication date for the Annual Review of Animal Biosciences, Volume 9 is February 16, 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

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