The Silicon Isotopic Composition of Choanoflagellates: Implications for a Mechanistic Understanding of Isotopic Fractionation During Biosilicification
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The Diatoms Big Significance of Tiny Glass Houses
GENERAL ¨ ARTICLE The Diatoms Big Significance of Tiny Glass Houses Aditi Kale and Balasubramanian Karthick Diatoms are unique microscopic algae having intricate cell walls made up of silica. They are the major phytoplankton in aquatic ecosystems and account for 20–25% of the oxygen release and carbon fixation in the world. Their most charac- teristic features are mechanisms they have evolved to utilize silica. Due to their distinctive adaptations and ecology, they (left) Aditi Kale is a PhD student with the are used in various fields like biomonitoring, paleoecology, Biodiversity and nanotechnology and forensics. Paleobiology group of Agharkar Research Introduction Institute. She is studying the biogeography of Diatoms (Class: Bacillariophyceae) are unique microscopic al- freshwater diatoms in gae containing silica and having distinct geometrical shapes. Western Ghats for her They are unicellular, eukaryotic and photosynthetic organisms. thesis. Their cell size ranges between 5 µm–0.5 mm. They occur in wet (right) Balasubramanian or moist places where photosynthesis is possible. Diatoms are Karthick is Scientist with Biodiversity and either planktonic (free-floating) or benthic (attached to a substra- Paleobiology group of tum) in Nature (Figure 1). The individuals are solitary or some- Agharkar Research times form colonies. Diatoms are mostly non-motile; however, Institute. His interests some benthic diatoms have a specialized raphe system1 that include diatom taxonomy and ecology, microbial secretes mucilage to attach or glide along a surface. They are also biogeography,andaquatic known to form biofilms, i. e., layers of tightly attached cells of ecology. microorganisms. Biofilms are formed on a solid surface and are often surrounded by extra-cellular fluids. -
1 Lessons from Simple Marine Models on the Bacterial Regulation
bioRxiv preprint doi: https://doi.org/10.1101/211797; this version posted October 31, 2017. The copyright holder for this preprint (which was not certified by peer review) is the author/funder, who has granted bioRxiv a license to display the preprint in perpetuity. It is made available under aCC-BY-NC-ND 4.0 International license. Lessons from simple marine models on the bacterial regulation of eukaryotic development Arielle Woznicaa and Nicole Kinga,1 a Howard Hughes Medical Institute and Department of Molecular and Cell Biology, University of California, Berkeley, California 94720, United States 1 Corresponding author, [email protected]. 1 bioRxiv preprint doi: https://doi.org/10.1101/211797; this version posted October 31, 2017. The copyright holder for this preprint (which was not certified by peer review) is the author/funder, who has granted bioRxiv a license to display the preprint in perpetuity. It is made available under aCC-BY-NC-ND 4.0 International license. 1 Highlights 2 - Cues from environmental bacteria influence the development of many marine 3 eukaryotes 4 5 - The molecular cues produced by environmental bacteria are structurally diverse 6 7 - Eukaryotes can respond to many different environmental bacteria 8 9 - Some environmental bacteria act as “information hubs” for diverse eukaryotes 10 11 - Experimentally tractable systems, like the choanoflagellate S. rosetta, promise to 12 reveal molecular mechanisms underlying these interactions 13 14 Abstract 15 Molecular cues from environmental bacteria influence important developmental 16 decisions in diverse marine eukaryotes. Yet, relatively little is understood about the 17 mechanisms underlying these interactions, in part because marine ecosystems are 18 dynamic and complex. -
Bacterial Cues Regulate Multicellular Development and Mating in the Choanoflagellate, S
Bacterial cues regulate multicellular development and mating in the choanoflagellate, S. rosetta By Arielle Woznica A dissertation submitted in partial satisfaction of the requirements for the degree of Doctor of Philosophy in Molecular and Cell Biology in the Graduate Division of the University of California, Berkeley Committee in charge: Professor Nicole King, Chair Professor Russell Vance Professor Diana Bautista Professor Brian Staskawicz Spring 2017 Abstract Bacterial cues regulate multicellular development and mating in the choanoflagellate, S. rosetta By Arielle Woznica Doctor of Philosophy in Molecular and Cell Biology University of California, Berkeley Professor Nicole King, Chair Animals first diverged from their unicellular ancestors in oceans dominated by bacteria, and have lived in close association with bacteria ever since. Interactions with bacteria critically shape diverse aspects of animal biology today, including developmental processes that were long thought to be autonomous. Yet, the multicellularity of animals and the often-complex communities of bacteria with which they are associated make it challenging to characterize the mechanisms underlying many bacterial-animal interactions. Thus, developing experimentally tractable host-microbe model systems will be essential for revealing the molecules and mechanisms by which bacteria influence animal development. The choanoflagellate Salpingoeca rosetta, one of the closest living relatives of animals, has emerged as an attractive model for studying host-microbe interactions. Like all choanoflagellates, S. rosetta feeds on bacteria; however, we have found that interactions between S. rosetta and bacteria extend beyond those of predator and prey. In fact, two key transitions in the life history of S. rosetta, multicellular “rosette” development and sexual reproduction, are regulated by environmental bacteria. -
23.3 Groups of Protists
Chapter 23 | Protists 639 cysts that are a protective, resting stage. Depending on habitat of the species, the cysts may be particularly resistant to temperature extremes, desiccation, or low pH. This strategy allows certain protists to “wait out” stressors until their environment becomes more favorable for survival or until they are carried (such as by wind, water, or transport on a larger organism) to a different environment, because cysts exhibit virtually no cellular metabolism. Protist life cycles range from simple to extremely elaborate. Certain parasitic protists have complicated life cycles and must infect different host species at different developmental stages to complete their life cycle. Some protists are unicellular in the haploid form and multicellular in the diploid form, a strategy employed by animals. Other protists have multicellular stages in both haploid and diploid forms, a strategy called alternation of generations, analogous to that used by plants. Habitats Nearly all protists exist in some type of aquatic environment, including freshwater and marine environments, damp soil, and even snow. Several protist species are parasites that infect animals or plants. A few protist species live on dead organisms or their wastes, and contribute to their decay. 23.3 | Groups of Protists By the end of this section, you will be able to do the following: • Describe representative protist organisms from each of the six presently recognized supergroups of eukaryotes • Identify the evolutionary relationships of plants, animals, and fungi within the six presently recognized supergroups of eukaryotes • Identify defining features of protists in each of the six supergroups of eukaryotes. In the span of several decades, the Kingdom Protista has been disassembled because sequence analyses have revealed new genetic (and therefore evolutionary) relationships among these eukaryotes. -
Synthetic Morphogenesis
Downloaded from http://cshperspectives.cshlp.org/ on September 24, 2021 - Published by Cold Spring Harbor Laboratory Press Synthetic Morphogenesis Brian P. Teague, Patrick Guye, and Ron Weiss Synthetic Biology Center, Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 Correspondence: [email protected] Throughout biology, function is intimately linked with form. Across scales ranging from subcellular to multiorganismal, the identity and organization of a biological structure’s subunits dictate its properties. The field of molecular morphogenesis has traditionally been concerned with describing these links, decoding the molecular mechanisms that give rise to the shape and structure of cells, tissues, organs, and organisms. Recent advances in synthetic biology promise unprecedented control over these molecular mechanisms; this opens the path to not just probing morphogenesis but directing it. This review explores several frontiers in the nascent field of synthetic morphogenesis, including programmable tissues and organs, synthetic biomaterials and programmable matter, and engineering complex morphogenic systems de novo. We will discuss each frontier’s objectives, current approaches, constraints and challenges, and future potential. hat is the underlying basis of biological 2014). As the mechanistic underpinnings of Wstructure? Speculations were based on these processes are elucidated, opportunities macroscopic observation until the 17th century, arise to use this knowledge to direct mor- when Antonie van Leeuwenhoek and Robert phogenesis toward novel, useful ends. We call Hooke discovered that organisms were com- this emerging field of endeavor “synthetic mor- posed of microscopic cells (Harris 1999), and phogenesis.” Inspired by and based on natural that the size and shape of the cells affected the morphogenic systems, synthetic morphogenesis properties of the structures they formed. -
The Choanoflagellate S. Rosetta Integrates Cues from Diverse Bacteria to Enhance Multicellular Development
The choanoflagellate S. rosetta integrates cues from diverse bacteria to enhance multicellular development By Ella Victoria Ireland A dissertation submitted in partial satisfaction of the requirements for the degree of Doctor of Philosophy in Molecular and Cell Biology in the Graduate Division of the University of California, Berkeley Committee in charge: Professor Nicole King, Chair Professor Russell Vance Professor Iswar Hariharan Professor Brian Staskawicz Fall 2019 Abstract The choanoflagellate S. rosetta integrates cues from diverse bacteria to enhance multicellular development By Ella Victoria Ireland Doctor of Philosophy in Molecular and Cell Biology University of California, Berkeley Professor Nicole King, Chair Bacteria play critical roles in regulating animal development, homeostasis and disease. Animals are often hosts to hundreds of different species of bacteria, which produce thousands of different molecules with the potential to influence animal biology. Direct interactions between different species of bacteria, as well as the environmental context of the animal-bacteria interaction, can have a significant impact on the outcome for the animal (Chapter 1). While we are beginning to understand the role of context in bacteria-animal interactions, surprisingly little is known about how animals integrate multiple distinct bacterial inputs. In my doctoral research I studied the choanoflagellate Salpingoeca rosetta, one of the closest living relatives of animals, to learn more about how eukaryotes integrate diverse bacterial cues. As with animals, bacteria regulate critical aspects of S. rosetta biology. The bacterium Algoriphagus machipongonensis produces sulfonolipid Rosette Inducing Factors (RIFs), which induce multicellular “rosette” development in S. rosetta. In contrast, the bacterium Vibrio fischeri produces a chondroitinase, EroS, which acts as an aphrodisiac and induces S. -
Brown Algae and 4) the Oomycetes (Water Molds)
Protista Classification Excavata The kingdom Protista (in the five kingdom system) contains mostly unicellular eukaryotes. This taxonomic grouping is polyphyletic and based only Alveolates on cellular structure and life styles not on any molecular evidence. Using molecular biology and detailed comparison of cell structure, scientists are now beginning to see evolutionary SAR Stramenopila history in the protists. The ongoing changes in the protest phylogeny are rapidly changing with each new piece of evidence. The following classification suggests 4 “supergroups” within the Rhizaria original Protista kingdom and the taxonomy is still being worked out. This lab is looking at one current hypothesis shown on the right. Some of the organisms are grouped together because Archaeplastida of very strong support and others are controversial. It is important to focus on the characteristics of each clade which explains why they are grouped together. This lab will only look at the groups that Amoebozoans were once included in the Protista kingdom and the other groups (higher plants, fungi, and animals) will be Unikonta examined in future labs. Opisthokonts Protista Classification Excavata Starting with the four “Supergroups”, we will divide the rest into different levels called clades. A Clade is defined as a group of Alveolates biological taxa (as species) that includes all descendants of one common ancestor. Too simplify this process, we have included a cladogram we will be using throughout the SAR Stramenopila course. We will divide or expand parts of the cladogram to emphasize evolutionary relationships. For the protists, we will divide Rhizaria the supergroups into smaller clades assigning them artificial numbers (clade1, clade2, clade3) to establish a grouping at a specific level. -
Marine Ecology Progress Series 601:77
Vol. 601: 77–95, 2018 MARINE ECOLOGY PROGRESS SERIES Published August 9 https://doi.org/10.3354/meps12685 Mar Ecol Prog Ser OPENPEN ACCESSCCESS Remarkable structural resistance of a nanoflagellate- dominated plankton community to iron fertilization during the Southern Ocean experiment LOHAFEX Isabelle Schulz1,2,3, Marina Montresor4, Christine Klaas1, Philipp Assmy1,2,5, Sina Wolzenburg1, Mangesh Gauns6, Amit Sarkar6,7, Stefan Thiele8,9, Dieter Wolf-Gladrow1, Wajih Naqvi6, Victor Smetacek1,6,* 1Alfred-Wegener-Institut Helmholtz-Zentrum für Polar- und Meeresforschung, 27570 Bremerhaven, Germany 2MARUM − Center for Marine Environmental Sciences, University of Bremen, 28359 Bremen, Germany 3Biological and Environmental Science and Engineering Division, Red Sea Research Center, King Abdullah University of Science and Technology, 23955-6900 Thuwal, Kingdom of Saudi Arabia 4Stazione Zoologica Anton Dohrn, 80121 Naples, Italy 5Norwegian Polar Institute, Fram Centre, 9296 Tromsø, Norway 6CSIR National Institute of Oceanography, 403 004 Goa, India 7National Centre for Antarctic and Ocean Research, 403 804 Goa, India 8Max Planck Institute for Marine Microbiology, 28359 Bremen, Germany 9Institute for Inorganic and Analytical Chemistry, Friedrich Schiller University, 07743 Jena, Germany ABSTRACT: The genesis of phytoplankton blooms and the fate of their biomass in iron-limited, high-nutrient−low-chlorophyll regions can be studied under natural conditions with ocean iron fertilization (OIF) experiments. The Indo-German OIF experiment LOHAFEX was carried out over 40 d in late summer 2009 within the cold core of a mesoscale eddy in the productive south- west Atlantic sector of the Southern Ocean. Silicate concentrations were very low, and phyto- plankton biomass was dominated by autotrophic nanoflagellates (ANF) in the size range 3−10 µm. -
Physical, Chemical, and Genetic Techniques for Diatom Frustule Modification: Applications in Nanotechnology
applied sciences Review Physical, Chemical, and Genetic Techniques for Diatom Frustule Modification: Applications in Nanotechnology Alessandra Rogato 1,2 and Edoardo De Tommasi 3,* 1 Institute of Biosciences and Bioresources, National Research Council, Via P. Castellino 111, 80131 Naples, Italy; [email protected] 2 Department of Integrative Marine Ecology, Stazione Zoologica Anton Dohrn, 80121 Naples, Italy; 3 Institute of Applied Sciences and Intelligent Systems, National Research Council, Via P. Castellino 111, 80131 Naples, Italy * Correspondence: [email protected] Received: 29 September 2020; Accepted: 3 December 2020; Published: 6 December 2020 Abstract: Diatom frustules represent one of the most complex examples of micro- and nano-structured materials found in nature, being the result of a biomineralization process refined through tens of milions of years of evolution. They are constituted by an intricate, ordered porous silica matrix which recently found several applications in optoelectronics, sensing, solar light harvesting, filtering, and drug delivery, to name a few. The possibility to modify the composition and the structure of frustules can further broaden the range of potential applications, adding new functions and active features to the material. In the present work the most remarkable physical and chemical techniques aimed at frustule modification are reviewed, also examining the most recent genetic techniques developed for its controlled morphological mutation. Keywords: diatoms; biomaterials; biomineralization; hybrid nanomaterials; surface functionalization; nanotechnologies; sensing; genetic engineering 1. Introduction Many living organisms, from unicellular to multicellular ones (e.g., bacteria, protists, plants, invertebrates and vertebrates), are able to produce minerals to develop peculiar features such as shells, bones, teeth or exoskeleton. -
Hsp70 Sequences Indicate That Choanoflagellates Are Closely Related to Animals Elizabeth A
View metadata, citation and similar papers at core.ac.uk brought to you by CORE provided by Elsevier - Publisher Connector Brief Communication 967 Hsp70 sequences indicate that choanoflagellates are closely related to animals Elizabeth A. Snell*, Rebecca F. Furlong* and Peter W.H. Holland Over 130 years ago, James-Clark [1, 2] noted a band of 1.4 kb, the predicted size if the hsp70 gene con- remarkable structural similarity between the tains no intron between the priming sites. After cloning feeding cells of sponges (choanocytes) and a group and sequencing, we identified two distinct products. The of free-living protists, the choanoflagellates. Both first has the potential to encode a protein similar to the cell types possess a single flagellum surrounded by nuclear-encoded Hsp70proteins of other eukaryotes and a collar of fine tentacles [3]. The similarity led to dissimilar to Hsp70proteins of organelles and bacteria. the hypothesis that sponges, and, by implication, We conclude that this represents the nuclear hsp70 gene other animals, evolved from choanoflagellate-like of Monosiga ovata (Figure 1). ancestors. Phylogenetic analysis of ribosomal DNA neither supports nor refutes this hypothesis [4–6]. The nucleotide sequence of the second amplified product Here, we report the sequence of an hsp70 gene and also matched hsp70 but did not possess a complete open pseudogene from the freshwater choanoflagellate reading frame throughout the sequence. Alignment with Monosiga ovata. These represent the first nuclear- known hsp70 genes revealed that there is a single nucleo- encoded protein-coding sequences reported for tide deletion in the sequence, resulting in a frame shift. -
Gyrodinium Undulans </Emphasis> Hulburt, a Marine Dinoflagellate
HELGOLANDER MEERESUNTERSUCHUNGEN Helgolfinder Meeresunters. 52, 1-14 (199fll Gyrodinium undulans Hulburt, a marine dinoflagellate feeding on the bloom-forming diatom Odontella aurita, and on copepod and rotifer eggs G. Drebes I & E. Schnepf 2 1Biologische Anstalt Hetgoland, Wattenmeerstation Sytt; D-25992 List/Sylt, Germany 2Zeflentehre, Fakultat fur Biologie, Universit~t Heidelberg; lm Neuenheimer Feld 230, D-fig120 Heidelberg, Germany ABSTRACT: The marine dinoflagellate Gyrodinium undulans was discovered as a feeder on the planktonic diatom Odontella aurita. Every year, during winter and early spring, a certain percent- age of cells of this bloom-forming diatom, in the Wadden Sea along the North Sea coast, was regu- larly found affected by the flagellate. Supplied with the food diatom O. aurita the dinoflagellate could be maintained successfully in clonal culture. The vegetative lite cycle was studied, mainly by light microscopy on live material, with special regard to the mode of food uptake. Food is taken up by a so-called phagopod, emerging from the antapex of the flagellate. Only Iluid or tiny prey mate- rial could be transported through the phagopod. Larger organelles like the chloroplasts of Odontefla are not ingested and are left behind in the diatom cell. Thereafter, the detached dinoflagellate re- produces by ceil division, occasionally followed by a second division. As yet, stages of sexual repro- duction and possible formation of resting cysts could not be recognized, neither from wild material nor from laboratory cultures. Palmelloid stages (sometimes with a delicate wall) occurring in ageing cultures may at least partly function as temporary resting stages. The winter species G. -
Architecture and Material Properties of Diatom Shells Provide Effective
View metadata, citation and similar papers at core.ac.uk brought to you by CORE provided by Electronic Publication Information Center letters to nature .............................................................. diameter, respectively (Fig. 1g). Mechanical strength and size were not only inversely related within a single species but also between Architecture and material properties different species: C. granii cells (130 mm diameter) were crushed at of diatom shells provide effective lower forces (up to 90 mN) than T. punctigera. F. kerguelensis frustules (longest axis 30 mm, Fig. 1d, f) broke at 730 mN (Fig. 1g). mechanical protection Assuming that the glass needle pressed on an area of 100 mm2, the pressures resisted ranged between about 1 and 7 N mm22 (equiva- 22 Christian E. Hamm*, Rudolf Merkel†‡, Olaf Springer§, Piotr Jurkojc§, lent to 100–700 tonnes m ). Much the same forces were required Christian Maier†, Kathrin Prechtel† & Victor Smetacek* to break frustules of individual cells of the same species or size group tested, regardless of where they were applied. * Alfred Wegener Institute for Polar and Marine Research, Am Handelshafen 12, A three-dimensional finite element model (FEM) of the F. 27570 Bremerhaven, Germany kerguelensis frustule (Fig. 2a) was constructed to simulate the † Technische Universita¨tMu¨nchen, Physics Department (Biophysics Group E22), glass needle crush tests and to examine the values and distributions 85748 Garching, Germany of stress within the frustule. Loading the FEM of diatom frustules of ‡ Research