Lnduction of Polarity in Fucoid Zygotes
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3 Embryology and Development
BIOL 6505 − INTRODUCTION TO FETAL MEDICINE 3. EMBRYOLOGY AND DEVELOPMENT Arlet G. Kurkchubasche, M.D. INTRODUCTION Embryology – the field of study that pertains to the developing organism/human Basic embryology –usually taught in the chronologic sequence of events. These events are the basis for understanding the congenital anomalies that we encounter in the fetus, and help explain the relationships to other organ system concerns. Below is a synopsis of some of the critical steps in embryogenesis from the anatomic rather than molecular basis. These concepts will be more intuitive and evident in conjunction with diagrams and animated sequences. This text is a synopsis of material provided in Langman’s Medical Embryology, 9th ed. First week – ovulation to fertilization to implantation Fertilization restores 1) the diploid number of chromosomes, 2) determines the chromosomal sex and 3) initiates cleavage. Cleavage of the fertilized ovum results in mitotic divisions generating blastomeres that form a 16-cell morula. The dense morula develops a central cavity and now forms the blastocyst, which restructures into 2 components. The inner cell mass forms the embryoblast and outer cell mass the trophoblast. Consequences for fetal management: Variances in cleavage, i.e. splitting of the zygote at various stages/locations - leads to monozygotic twinning with various relationships of the fetal membranes. Cleavage at later weeks will lead to conjoined twinning. Second week: the week of twos – marked by bilaminar germ disc formation. Commences with blastocyst partially embedded in endometrial stroma Trophoblast forms – 1) cytotrophoblast – mitotic cells that coalesce to form 2) syncytiotrophoblast – erodes into maternal tissues, forms lacunae which are critical to development of the uteroplacental circulation. -
Pelvetia Canaliculata Channel Wrack Ecology and Similar Identification Species
Ecology and Similar species identification Found slightly High shore alga higher than often forming a Fucus spiralis. clear zone on Fronds in more sheltered F.spiralis are shores. flat and twisted. Evenly forked fronds up to 15cm long that are rolled to give a channel on one side. Pelvetia canaliculata Channel Wrack Ecology and Similar identification species High shore alga Fucus often forming vesiculosus a clear zone which has below Pelvetia distinctive air on more bladders sheltered shores. Fronds in F.spiralis are flat and Fucus spiralis twisted and up Spiral Wrack to 20cm long. NO air bladders. Ecology and Similar identification species Most Fucus characteristic vesiculosus mid shore which has alga in shelter. paired circular air Leathery bladders fronds up to a metre long, no mid-rib and single egg-shaped Ascophyllum nodosum air-bladders Egg or Knotted Wrack Ecology and Similar identification species The F. spiralis characteristic and alga of the A.nodosum mid-shore in moderate exposure. The fronds have a prominent mid-rib and Fucus vesiculosus paired air Bladder Wrack bladders. Ecology and Similar identification species Can be Other Fucus abundant in species the low and lower mid- shore. Fronds have a serrated edge. Fucus serratus Serrated Wrack. Ecology and Similar species identification. This is the Laminaria commonest of hyperborea, the the kelps and can forest kelp, dominate around which has a low water. Each round cross plant may reach section to the 1.5m long. stem and stands erect at The stem has an low tide. oval cross section that causes the plant to droop over at low water. -
Algae & Marine Plants of Point Reyes
Algae & Marine Plants of Point Reyes Green Algae or Chlorophyta Genus/Species Common Name Acrosiphonia coalita Green rope, Tangled weed Blidingia minima Blidingia minima var. vexata Dwarf sea hair Bryopsis corticulans Cladophora columbiana Green tuft alga Codium fragile subsp. californicum Sea staghorn Codium setchellii Smooth spongy cushion, Green spongy cushion Trentepohlia aurea Ulva californica Ulva fenestrata Sea lettuce Ulva intestinalis Sea hair, Sea lettuce, Gutweed, Grass kelp Ulva linza Ulva taeniata Urospora sp. Brown Algae or Ochrophyta Genus/Species Common Name Alaria marginata Ribbon kelp, Winged kelp Analipus japonicus Fir branch seaweed, Sea fir Coilodesme californica Dactylosiphon bullosus Desmarestia herbacea Desmarestia latifrons Egregia menziesii Feather boa Fucus distichus Bladderwrack, Rockweed Haplogloia andersonii Anderson's gooey brown Laminaria setchellii Southern stiff-stiped kelp Laminaria sinclairii Leathesia marina Sea cauliflower Melanosiphon intestinalis Twisted sea tubes Nereocystis luetkeana Bull kelp, Bullwhip kelp, Bladder wrack, Edible kelp, Ribbon kelp Pelvetiopsis limitata Petalonia fascia False kelp Petrospongium rugosum Phaeostrophion irregulare Sand-scoured false kelp Pterygophora californica Woody-stemmed kelp, Stalked kelp, Walking kelp Ralfsia sp. Silvetia compressa Rockweed Stephanocystis osmundacea Page 1 of 4 Red Algae or Rhodophyta Genus/Species Common Name Ahnfeltia fastigiata Bushy Ahnfelt's seaweed Ahnfeltiopsis linearis Anisocladella pacifica Bangia sp. Bossiella dichotoma Bossiella -
The Marine Life Information Network® for Britain and Ireland (Marlin)
The Marine Life Information Network® for Britain and Ireland (MarLIN) Description, temporal variation, sensitivity and monitoring of important marine biotopes in Wales. Volume 1. Background to biotope research. Report to Cyngor Cefn Gwlad Cymru / Countryside Council for Wales Contract no. FC 73-023-255G Dr Harvey Tyler-Walters, Charlotte Marshall, & Dr Keith Hiscock With contributions from: Georgina Budd, Jacqueline Hill, Will Rayment and Angus Jackson DRAFT / FINAL REPORT January 2005 Reference: Tyler-Walters, H., Marshall, C., Hiscock, K., Hill, J.M., Budd, G.C., Rayment, W.J. & Jackson, A., 2005. Description, temporal variation, sensitivity and monitoring of important marine biotopes in Wales. Report to Cyngor Cefn Gwlad Cymru / Countryside Council for Wales from the Marine Life Information Network (MarLIN). Marine Biological Association of the UK, Plymouth. [CCW Contract no. FC 73-023-255G] Description, sensitivity and monitoring of important Welsh biotopes Background 2 Description, sensitivity and monitoring of important Welsh biotopes Background The Marine Life Information Network® for Britain and Ireland (MarLIN) Description, temporal variation, sensitivity and monitoring of important marine biotopes in Wales. Contents Executive summary ............................................................................................................................................5 Crynodeb gweithredol ........................................................................................................................................6 -
The Valorisation of Sargassum from Beach Inundations
Journal of Marine Science and Engineering Review Golden Tides: Problem or Golden Opportunity? The Valorisation of Sargassum from Beach Inundations John J. Milledge * and Patricia J. Harvey Algae Biotechnology Research Group, School of Science, University of Greenwich, Central Avenue, Chatham Maritime, Kent ME4 4TB, UK; [email protected] * Correspondence: [email protected]; Tel.: +44-0208-331-8871 Academic Editor: Magnus Wahlberg Received: 12 August 2016; Accepted: 7 September 2016; Published: 13 September 2016 Abstract: In recent years there have been massive inundations of pelagic Sargassum, known as golden tides, on the beaches of the Caribbean, Gulf of Mexico, and West Africa, causing considerable damage to the local economy and environment. Commercial exploration of this biomass for food, fuel, and pharmaceutical products could fund clean-up and offset the economic impact of these golden tides. This paper reviews the potential uses and obstacles for exploitation of pelagic Sargassum. Although Sargassum has considerable potential as a source of biochemicals, feed, food, fertiliser, and fuel, variable and undefined composition together with the possible presence of marine pollutants may make golden tides unsuitable for food, nutraceuticals, and pharmaceuticals and limit their use in feed and fertilisers. Discontinuous and unreliable supply of Sargassum also presents considerable challenges. Low-cost methods of preservation such as solar drying and ensiling may address the problem of discontinuity. The use of processes that can handle a variety of biological and waste feedstocks in addition to Sargassum is a solution to unreliable supply, and anaerobic digestion for the production of biogas is one such process. -
The Physical Mechanisms of Drosophila Gastrulation: Mesoderm and Endoderm Invagination
| FLYBOOK DEVELOPMENT AND GROWTH The Physical Mechanisms of Drosophila Gastrulation: Mesoderm and Endoderm Invagination Adam C. Martin1 Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts 02142 ORCID ID: 0000-0001-8060-2607 (A.C.M.) ABSTRACT A critical juncture in early development is the partitioning of cells that will adopt different fates into three germ layers: the ectoderm, the mesoderm, and the endoderm. This step is achieved through the internalization of specified cells from the outermost surface layer, through a process called gastrulation. In Drosophila, gastrulation is achieved through cell shape changes (i.e., apical constriction) that change tissue curvature and lead to the folding of a surface epithelium. Folding of embryonic tissue results in mesoderm and endoderm invagination, not as individual cells, but as collective tissue units. The tractability of Drosophila as a model system is best exemplified by how much we know about Drosophila gastrulation, from the signals that pattern the embryo to the molecular components that generate force, and how these components are organized to promote cell and tissue shape changes. For mesoderm invagination, graded signaling by the morphogen, Spätzle, sets up a gradient in transcriptional activity that leads to the expression of a secreted ligand (Folded gastrulation) and a transmembrane protein (T48). Together with the GPCR Mist, which is expressed in the mesoderm, and the GPCR Smog, which is expressed uniformly, these signals activate heterotrimeric G-protein and small Rho-family G-protein signaling to promote apical contractility and changes in cell and tissue shape. A notable feature of this signaling pathway is its intricate organization in both space and time. -
First Report of the Asian Seaweed Sargassum Filicinum Harvey (Fucales) in California, USA
First Report of the Asian Seaweed Sargassum filicinum Harvey (Fucales) in California, USA Kathy Ann Miller1, John M. Engle2, Shinya Uwai3, Hiroshi Kawai3 1University Herbarium, University of California, Berkeley, California, USA 2 Marine Science Institute, University of California, Santa Barbara, California, USA 3 Research Center for Inland Seas, Kobe University, Rokkodai, Kobe 657–8501, Japan correspondence: Kathy Ann Miller e-mail: [email protected] fax: 1-510-643-5390 telephone: 510-387-8305 1 ABSTRACT We report the occurrence of the brown seaweed Sargassum filicinum Harvey in southern California. Sargassum filicinum is native to Japan and Korea. It is monoecious, a trait that increases its chance of establishment. In October 2003, Sargassum filicinum was collected in Long Beach Harbor. In April 2006, we discovered three populations of this species on the leeward west end of Santa Catalina Island. Many of the individuals were large, reproductive and senescent; a few were small, young but precociously reproductive. We compared the sequences of the mitochondrial cox3 gene for 6 individuals from the 3 sites at Catalina with 3 samples from 3 sites in the Seto Inland Sea, Japan region. The 9 sequences (469 bp in length) were identical. Sargassum filicinum may have been introduced through shipping to Long Beach; it may have spread to Catalina via pleasure boats from the mainland. Key words: California, cox3, invasive seaweed, Japan, macroalgae, Sargassum filicinum, Sargassum horneri INTRODUCTION The brown seaweed Sargassum muticum (Yendo) Fensholt, originally from northeast Asia, was first reported on the west coast of North America in the early 20th c. (Scagel 1956), reached southern California in 1970 (Setzer & Link 1971) and has become a common component of California intertidal and subtidal communities (Ambrose and Nelson 1982, Deysher and Norton 1982, Wilson 2001, Britton-Simmons 2004). -
Stages of Embryonic Development of the Zebrafish
DEVELOPMENTAL DYNAMICS 2032553’10 (1995) Stages of Embryonic Development of the Zebrafish CHARLES B. KIMMEL, WILLIAM W. BALLARD, SETH R. KIMMEL, BONNIE ULLMANN, AND THOMAS F. SCHILLING Institute of Neuroscience, University of Oregon, Eugene, Oregon 97403-1254 (C.B.K., S.R.K., B.U., T.F.S.); Department of Biology, Dartmouth College, Hanover, NH 03755 (W.W.B.) ABSTRACT We describe a series of stages for Segmentation Period (10-24 h) 274 development of the embryo of the zebrafish, Danio (Brachydanio) rerio. We define seven broad peri- Pharyngula Period (24-48 h) 285 ods of embryogenesis-the zygote, cleavage, blas- Hatching Period (48-72 h) 298 tula, gastrula, segmentation, pharyngula, and hatching periods. These divisions highlight the Early Larval Period 303 changing spectrum of major developmental pro- Acknowledgments 303 cesses that occur during the first 3 days after fer- tilization, and we review some of what is known Glossary 303 about morphogenesis and other significant events that occur during each of the periods. Stages sub- References 309 divide the periods. Stages are named, not num- INTRODUCTION bered as in most other series, providing for flexi- A staging series is a tool that provides accuracy in bility and continued evolution of the staging series developmental studies. This is because different em- as we learn more about development in this spe- bryos, even together within a single clutch, develop at cies. The stages, and their names, are based on slightly different rates. We have seen asynchrony ap- morphological features, generally readily identi- pearing in the development of zebrafish, Danio fied by examination of the live embryo with the (Brachydanio) rerio, embryos fertilized simultaneously dissecting stereomicroscope. -
Seedless Plants Key Concept Seedless Plants Do Not Produce Seeds 2 but Are Well Adapted for Reproduction and Survival
Seedless Plants Key Concept Seedless plants do not produce seeds 2 but are well adapted for reproduction and survival. What You Will Learn When you think of plants, you probably think of plants, • Nonvascular plants do not have such as trees and flowers, that make seeds. But two groups of specialized vascular tissues. plants don’t make seeds. The two groups of seedless plants are • Seedless vascular plants have specialized vascular tissues. nonvascular plants and seedless vascular plants. • Seedless plants reproduce sexually and asexually, but they need water Nonvascular Plants to reproduce. Mosses, liverworts, and hornworts do not have vascular • Seedless plants have two stages tissue to transport water and nutrients. Each cell of the plant in their life cycle. must get water from the environment or from a nearby cell. So, Why It Matters nonvascular plants usually live in places that are damp. Also, Seedless plants play many roles in nonvascular plants are small. They grow on soil, the bark of the environment, including helping to form soil and preventing erosion. trees, and rocks. Mosses, liverworts, and hornworts don’t have true stems, roots, or leaves. They do, however, have structures Vocabulary that carry out the activities of stems, roots, and leaves. • rhizoid • rhizome Mosses Large groups of mosses cover soil or rocks with a mat of Graphic Organizer In your Science tiny green plants. Mosses have leafy stalks and rhizoids. A Journal, create a Venn Diagram that rhizoid is a rootlike structure that holds nonvascular plants in compares vascular plants and nonvas- place. Rhizoids help the plants get water and nutrients. -
Development and Function of Plasmodesmata in Zygotes of Fucus Distichus
Botanica Marina 2015; 58(3): 229–238 Chikako Nagasato*, Makoto Terauchi, Atsuko Tanaka and Taizo Motomura Development and function of plasmodesmata in zygotes of Fucus distichus Abstract: Brown algae have plasmodesmata, tiny tubu- Introduction lar cytoplasmic channels connecting adjacent cells. The lumen of plasmodesmata is 10–20 nm wide, and it takes a Multicellular organisms such as animals, fungi, land simple form, without a desmotubule (the inner membrane plants, and brown algae have specific cellular connections. structure consisting of endoplasmic reticulum in the plas- These structures connect the cytoplasm of adjacent cells modesmata of green plants). In this study, we analyzed and provide a route for cell-cell communication. Green the ultrastructure and distribution of plasmodesmata plants, including land plants and certain species of green during development of Fucus distichus zygotes. The first algae (reviewed in Robards and Lucas 1990, Raven 1997), cytokinesis of zygotes in brown algae is not accompanied and brown algae (Bisalputra 1966) possess plasmodes- by plasmodesmata formation. As the germlings develop, mata. These are cytoplasmic canals that pass through the plasmodesmata are found in all septal cell walls, includ- septal cell wall and connect adjacent cells. Plasmodes- ing the first cell division plane. Plasmodesmata are formed mata in green plants and brown algae share similar char- de novo on the existing cell wall. Pit fields, which are clus- acteristics; however, plasmodesmata in brown algae lack ters of plasmodesmata, were observed in germlings with a desmotubule, a tubular strand of connecting endoplas- differentiated cell layers. Apart from the normal plas- mic reticulum (ER) that penetrates the plasmodesmata modesmata, these pit fields had branched plasmodes- of land plants (Terauchi et al. -
Plants and Ecology 2013:2
Fucus radicans – Reproduction, adaptation & distribution patterns by Ellen Schagerström Plants & Ecology The Department of Ecology, 2013/2 Environment and Plant Sciences Stockholm University Fucus radicans - Reproduction, adaptation & distribution patterns by Ellen Schagerström Supervisors: Lena Kautsky & Sofia Wikström Plants & Ecology The Department of Ecology, 2013/2 Environment and Plant Sciences Stockholm University Plants & Ecology The Department of Ecology, Environment and Plant Sciences Stockholm University S-106 91 Stockholm Sweden © The Department of Ecology, Environment and Plant Sciences ISSN 1651-9248 Printed by FMV Printcenter Cover: Fucus radicans and Fucus vesiculosus together in a tank. Photo by Ellen Schagerström Summary The Baltic Sea is considered an ecological marginal environment, where both marine and freshwater species struggle to adapt to its ever changing conditions. Fucus vesiculosus (bladderwrack) is commonly seen as the foundation species in the Baltic Sea, as it is the only large perennial macroalgae, forming vast belts down to a depth of about 10 meters. The salinity gradient results in an increasing salinity stress for all marine organisms. This is commonly seen in many species as a reduction in size. What was previously described as a low salinity induced dwarf morph of F. vesiculosus was recently proved to be a separate species, when genetic tools were used. This new species, Fucus radicans (narrow wrack) might be the first endemic species to the Baltic Sea, having separated from its mother species F. vesiculosus as recent as 400 years ago. Fucus radicans is only found in the Bothnian Sea and around the Estonian island Saaremaa. The Swedish/Finnish populations have a surprisingly high level of clonality. -
Immuno and Affinity Cytochemical Analysis of Cell Wall Composition in the Moss Physcomitrella Patens Elizabeth A
University of Rhode Island DigitalCommons@URI Biological Sciences Faculty Publications Biological Sciences 2016 Immuno and Affinity Cytochemical Analysis of Cell Wall Composition in the Moss Physcomitrella patens Elizabeth A. Berry Mai L. Tran See next page for additional authors Creative Commons License Creative Commons License This work is licensed under a Creative Commons Attribution 4.0 License. Follow this and additional works at: https://digitalcommons.uri.edu/bio_facpubs Citation/Publisher Attribution Berry, E. A., Tran, M. L., Dimos, C. S., Budziszek Jr., M. J., Scavuzzo-Duggan, T. R., and Roberts, A. W. (2016). Immuno and affinity cytochemical analysis of cell wall composition in the moss Physcomitrella patens. Frontiers in Plant Science, 7, article 248. doi:3389/ fpls.2016.00248 This Article is brought to you for free and open access by the Biological Sciences at DigitalCommons@URI. It has been accepted for inclusion in Biological Sciences Faculty Publications by an authorized administrator of DigitalCommons@URI. For more information, please contact [email protected]. Authors Elizabeth A. Berry, Mai L. Tran, Christos S. Dimos, Michael J. Budziszek Jr., Tess R. Scavuzzo-Duggan, and Alison Roberts This article is available at DigitalCommons@URI: https://digitalcommons.uri.edu/bio_facpubs/82 fpls-07-00248 March 4, 2016 Time: 18:53 # 1 ORIGINAL RESEARCH published: 08 March 2016 doi: 10.3389/fpls.2016.00248 Immuno and Affinity Cytochemical Analysis of Cell Wall Composition in the Moss Physcomitrella patens Elizabeth A. Berry, Mai L. Tran, Christos S. Dimos, Michael J. Budziszek Jr., Tess R. Scavuzzo-Duggan and Alison W. Roberts* Department of Biological Sciences, University of Rhode Island, Kingston, RI, USA In contrast to homeohydric vascular plants, mosses employ a poikilohydric strategy for surviving in the dry aerial environment.