1
|
Beckett SJ, Demory D, Coenen AR, Casey JR, Dugenne M, Follett CL, Connell P, Carlson MCG, Hu SK, Wilson ST, Muratore D, Rodriguez-Gonzalez RA, Peng S, Becker KW, Mende DR, Armbrust EV, Caron DA, Lindell D, White AE, Ribalet F, Weitz JS. Disentangling top-down drivers of mortality underlying diel population dynamics of Prochlorococcus in the North Pacific Subtropical Gyre. Nat Commun 2024; 15:2105. [PMID: 38453897 PMCID: PMC10920773 DOI: 10.1038/s41467-024-46165-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2023] [Accepted: 02/16/2024] [Indexed: 03/09/2024] Open
Abstract
Photosynthesis fuels primary production at the base of marine food webs. Yet, in many surface ocean ecosystems, diel-driven primary production is tightly coupled to daily loss. This tight coupling raises the question: which top-down drivers predominate in maintaining persistently stable picocyanobacterial populations over longer time scales? Motivated by high-frequency surface water measurements taken in the North Pacific Subtropical Gyre (NPSG), we developed multitrophic models to investigate bottom-up and top-down mechanisms underlying the balanced control of Prochlorococcus populations. We find that incorporating photosynthetic growth with viral- and predator-induced mortality is sufficient to recapitulate daily oscillations of Prochlorococcus abundances with baseline community abundances. In doing so, we infer that grazers in this environment function as the predominant top-down factor despite high standing viral particle densities. The model-data fits also reveal the ecological relevance of light-dependent viral traits and non-canonical factors to cellular loss. Finally, we leverage sensitivity analyses to demonstrate how variation in life history traits across distinct oceanic contexts, including variation in viral adsorption and grazer clearance rates, can transform the quantitative and even qualitative importance of top-down controls in shaping Prochlorococcus population dynamics.
Collapse
Affiliation(s)
- Stephen J Beckett
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA, USA.
- Department of Biology, University of Maryland, College Park, MD, USA.
| | - David Demory
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA, USA.
- Sorbonne Université, CNRS, USR 3579, Laboratoire de Biodiversité et Biotechnologies Microbiennes (LBBM), Observatoire Océanologique, Banyuls-sur-Mer, France.
| | - Ashley R Coenen
- School of Physics, Georgia Institute of Technology, Atlanta, GA, USA
| | - John R Casey
- Daniel K. Inouye Center for Microbial Oceanography: Research and Education, University of Hawai'i at Mānoa, Honolulu, HI, USA
- Department of Oceanography, University of Hawai'i at Mānoa, Honolulu, HI, USA
- Department of Earth, Atmospheric, and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, MA, USA
- Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, CA, USA
| | - Mathilde Dugenne
- Daniel K. Inouye Center for Microbial Oceanography: Research and Education, University of Hawai'i at Mānoa, Honolulu, HI, USA
- Department of Oceanography, University of Hawai'i at Mānoa, Honolulu, HI, USA
- Sorbonne Université, CNRS, UMR 7093, Laboratoire d'Océanographie de Villefranche-sur-Mer (LOV), Villefranche-sur-Mer, France
| | - Christopher L Follett
- Department of Earth, Atmospheric, and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, MA, USA
- Department of Earth, Ocean and Ecological Sciences, University of Liverpool, Liverpool, UK
| | - Paige Connell
- Department of Biological Sciences, University of Southern California, Los Angeles, CA, USA
- Biology Department, San Diego Mesa College, San Diego, CA, USA
| | - Michael C G Carlson
- Faculty of Biology, Technion - Israel Institute of Technology, Haifa, Israel
- Department of Biological Sciences, California State University, Long Beach, CA, USA
| | - Sarah K Hu
- Department of Biological Sciences, University of Southern California, Los Angeles, CA, USA
- Department of Marine Chemistry and Geochemistry, Woods Hole Oceanographic Institution, Woods Hole, MA, USA
- Department of Oceanography, Texas A&M University, College Station, TX, USA
| | - Samuel T Wilson
- Daniel K. Inouye Center for Microbial Oceanography: Research and Education, University of Hawai'i at Mānoa, Honolulu, HI, USA
- Department of Oceanography, University of Hawai'i at Mānoa, Honolulu, HI, USA
- School of Natural and Environmental Sciences, Newcastle University, Newcastle upon Tyne, UK
| | - Daniel Muratore
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA, USA
- Santa Fe Institute, Santa Fe, NM, USA
| | | | - Shengyun Peng
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA, USA
- Adobe, San Jose, CA, USA
| | - Kevin W Becker
- Department of Marine Chemistry and Geochemistry, Woods Hole Oceanographic Institution, Woods Hole, MA, USA
- GEOMAR Helmholtz Centre for Ocean Research, Kiel, Germany
| | - Daniel R Mende
- Daniel K. Inouye Center for Microbial Oceanography: Research and Education, University of Hawai'i at Mānoa, Honolulu, HI, USA
- Department of Oceanography, University of Hawai'i at Mānoa, Honolulu, HI, USA
- Laboratory of Applied Evolutionary Biology, Department of Medical Microbiology, Academic Medical Centre, University of Amsterdam, Amsterdam, The Netherlands
| | | | - David A Caron
- Department of Biological Sciences, University of Southern California, Los Angeles, CA, USA
| | - Debbie Lindell
- Faculty of Biology, Technion - Israel Institute of Technology, Haifa, Israel
| | - Angelicque E White
- Daniel K. Inouye Center for Microbial Oceanography: Research and Education, University of Hawai'i at Mānoa, Honolulu, HI, USA
- Department of Oceanography, University of Hawai'i at Mānoa, Honolulu, HI, USA
| | - François Ribalet
- School of Oceanography, University of Washington, Seattle, WA, USA
| | - Joshua S Weitz
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA, USA.
- Department of Biology, University of Maryland, College Park, MD, USA.
- School of Physics, Georgia Institute of Technology, Atlanta, GA, USA.
- Institut de Biologie, École Normale Supérieure, Paris, France.
| |
Collapse
|
2
|
Hu SK, Anderson RE, Pachiadaki MG, Edgcomb VP, Serres MH, Sylva SP, German CR, Seewald JS, Lang SQ, Huber JA. Microbial eukaryotic predation pressure and biomass at deep-sea hydrothermal vents. ISME J 2024; 18:wrae004. [PMID: 38366040 PMCID: PMC10939315 DOI: 10.1093/ismejo/wrae004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/02/2023] [Revised: 12/22/2023] [Accepted: 01/12/2024] [Indexed: 02/18/2024]
Abstract
Deep-sea hydrothermal vent geochemistry shapes the foundation of the microbial food web by fueling chemolithoautotrophic microbial activity. Microbial eukaryotes (or protists) play a critical role in hydrothermal vent food webs as consumers and hosts of symbiotic bacteria, and as a nutritional source to higher trophic levels. We measured microbial eukaryotic cell abundance and predation pressure in low-temperature diffuse hydrothermal fluids at the Von Damm and Piccard vent fields along the Mid-Cayman Rise in the Western Caribbean Sea. We present findings from experiments performed under in situ pressure that show cell abundances and grazing rates higher than those done at 1 atmosphere (shipboard ambient pressure); this trend was attributed to the impact of depressurization on cell integrity. A relationship between the protistan grazing rate, prey cell abundance, and temperature of end-member hydrothermal vent fluid was observed at both vent fields, regardless of experimental approach. Our results show substantial protistan biomass at hydrothermally fueled microbial food webs, and when coupled with improved grazing estimates, suggest an important contribution of grazers to the local carbon export and supply of nutrient resources to the deep ocean.
Collapse
Affiliation(s)
- Sarah K Hu
- Department of Oceanography, Texas A&M University, College Station, TX 77843, United States
- Department of Marine Chemistry and Geochemistry, Woods Hole Oceanographic Institution, Woods Hole, MA 02543, United States
| | - Rika E Anderson
- Biology Department, Carleton College, Northfield, MN 55057, United States
| | - Maria G Pachiadaki
- Biology Department, Woods Hole Oceanographic Institution, Woods Hole, MA 02543, United States
| | - Virginia P Edgcomb
- Department of Geology & Geophysics, Woods Hole Oceanographic Institution, Woods Hole, MA 02543, United States
| | - Margrethe H Serres
- Department of Marine Chemistry and Geochemistry, Woods Hole Oceanographic Institution, Woods Hole, MA 02543, United States
| | - Sean P Sylva
- Department of Marine Chemistry and Geochemistry, Woods Hole Oceanographic Institution, Woods Hole, MA 02543, United States
| | - Christopher R German
- Department of Geology & Geophysics, Woods Hole Oceanographic Institution, Woods Hole, MA 02543, United States
| | - Jeffrey S Seewald
- Department of Marine Chemistry and Geochemistry, Woods Hole Oceanographic Institution, Woods Hole, MA 02543, United States
| | - Susan Q Lang
- Department of Geology & Geophysics, Woods Hole Oceanographic Institution, Woods Hole, MA 02543, United States
| | - Julie A Huber
- Department of Marine Chemistry and Geochemistry, Woods Hole Oceanographic Institution, Woods Hole, MA 02543, United States
| |
Collapse
|
3
|
Gleich SJ, Hu SK, Krinos AI, Caron DA. Protistan community composition and metabolism in the North Pacific Subtropical Gyre: Influences of mesoscale eddies and depth. Environ Microbiol 2024; 26:e16556. [PMID: 38081167 DOI: 10.1111/1462-2920.16556] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2023] [Accepted: 11/27/2023] [Indexed: 01/30/2024]
Abstract
Marine protists and their metabolic activities are intricately tied to the cycling of nutrients and the flow of energy through microbial food webs. Physiochemical changes in the environment, such as those that result from mesoscale eddies, may impact protistan communities, but the effects that such changes have on protists are poorly known. A metatranscriptomic study was conducted to investigate how eddies affected protists at adjacent cyclonic and anticyclonic eddy sites in the oligotrophic ocean at four depths from 25 to 250 m. Eddy polarity impacted protists at all depths sampled, although the effects of eddy polarity were secondary to the impact of depth across the depth range. Eddy-induced vertical shifts in the water column yielded differences in the cyclonic and anticyclonic eddy protistan communities, and these differences were the most pronounced at and just below the deep chlorophyll maximum. An analysis of transcripts associated with protistan nutritional physiology at 150 m revealed that cyclonic eddies may support a more heterotrophic community, while anticyclonic eddies promote a more phototrophic community. The results of this study indicate that eddies alter the metabolism of protists particularly in the lower euphotic zone and may therefore impact carbon export from the euphotic zone.
Collapse
Affiliation(s)
- Samantha J Gleich
- Department of Biological Sciences, University of Southern California, Los Angeles, California, USA
| | - Sarah K Hu
- Department of Oceanography, Texas A&M University, College Station, Texas, USA
| | - Arianna I Krinos
- MIT-WHOI Joint Program in Oceanography and Applied Ocean Science and Engineering, Cambridge and Woods Hole, Cambridge, Massachusetts, USA
- Department of Biology, Woods Hole Oceanographic Institution, Woods Hole, Massachusetts, USA
- Department of Earth, Atmospheric, and Planetary Science, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
| | - David A Caron
- Department of Biological Sciences, University of Southern California, Los Angeles, California, USA
| |
Collapse
|
4
|
Hu SK, Smith AR, Anderson RE, Sylva SP, Setzer M, Steadmon M, Frank KL, Chan EW, Lim DSS, German CR, Breier JA, Lang SQ, Butterfield DA, Fortunato CS, Seewald JS, Huber JA. Globally-distributed microbial eukaryotes exhibit endemism at deep-sea hydrothermal vents. Mol Ecol 2023; 32:6580-6598. [PMID: 36302092 DOI: 10.1111/mec.16745] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2022] [Revised: 09/21/2022] [Accepted: 10/06/2022] [Indexed: 11/30/2022]
Abstract
Single-celled microbial eukaryotes inhabit deep-sea hydrothermal vent environments and play critical ecological roles in the vent-associated microbial food web. 18S rRNA amplicon sequencing of diffuse venting fluids from four geographically- and geochemically-distinct hydrothermal vent fields was applied to investigate community diversity patterns among protistan assemblages. The four vent fields include Axial Seamount at the Juan de Fuca Ridge, Sea Cliff and Apollo at the Gorda Ridge, all in the NE Pacific Ocean, and Piccard and Von Damm at the Mid-Cayman Rise in the Caribbean Sea. We describe species diversity patterns with respect to hydrothermal vent field and sample type, identify putative vent endemic microbial eukaryotes, and test how vent fluid geochemistry may influence microbial community diversity. At a semi-global scale, microbial eukaryotic communities at deep-sea vents were composed of similar proportions of dinoflagellates, ciliates, Rhizaria, and stramenopiles. Individual vent fields supported distinct and highly diverse assemblages of protists that included potentially endemic or novel vent-associated strains. These findings represent a census of deep-sea hydrothermal vent protistan communities. Protistan diversity, which is shaped by the hydrothermal vent environment at a local scale, ultimately influences the vent-associated microbial food web and the broader deep-sea carbon cycle.
Collapse
Affiliation(s)
- Sarah K Hu
- Department of Marine Chemistry and Geochemistry, Woods Hole Oceanographic Institution, Woods Hole, Massachusetts, USA
| | - Amy R Smith
- Department of Marine Chemistry and Geochemistry, Woods Hole Oceanographic Institution, Woods Hole, Massachusetts, USA
- Bard College at Simon's Rock, Great Barrington, Massachusetts, USA
| | - Rika E Anderson
- Biology Department, Carleton College, Northfield, Minnesota, USA
| | - Sean P Sylva
- Department of Marine Chemistry and Geochemistry, Woods Hole Oceanographic Institution, Woods Hole, Massachusetts, USA
| | - Michaela Setzer
- Pacific Biosciences Research Center, Kewalo Marine Laboratory, University of Hawai'i at Mānoa, Honolulu, Hawai'i, USA
- Department of Oceanography, University of Hawaii at Mānoa, Honolulu, Hawai'i, USA
| | - Maria Steadmon
- Pacific Biosciences Research Center, Kewalo Marine Laboratory, University of Hawai'i at Mānoa, Honolulu, Hawai'i, USA
- Department of Oceanography, University of Hawaii at Mānoa, Honolulu, Hawai'i, USA
| | - Kiana L Frank
- Pacific Biosciences Research Center, Kewalo Marine Laboratory, University of Hawai'i at Mānoa, Honolulu, Hawai'i, USA
| | - Eric W Chan
- School of Earth, Environmental, and Marine Sciences, The University of Texas Rio Grande Valley, Edinburg, Texas, USA
| | | | - Christopher R German
- Department of Geology & Geophysics, Woods Hole Oceanographic Institution, Woods Hole, Massachusetts, USA
| | - John A Breier
- School of Earth, Environmental, and Marine Sciences, The University of Texas Rio Grande Valley, Edinburg, Texas, USA
| | - Susan Q Lang
- Department of Geology & Geophysics, Woods Hole Oceanographic Institution, Woods Hole, Massachusetts, USA
- School of the Earth, Ocean, and Environment, University of South Carolina, Columbia, South Carolina, USA
| | - David A Butterfield
- Cooperative Institute for Climate, Ocean, and Ecosystem Studies, University of Washington and NOAA/PMEL, Seattle, Washington, USA
| | | | - Jeffrey S Seewald
- Department of Marine Chemistry and Geochemistry, Woods Hole Oceanographic Institution, Woods Hole, Massachusetts, USA
| | - Julie A Huber
- Department of Marine Chemistry and Geochemistry, Woods Hole Oceanographic Institution, Woods Hole, Massachusetts, USA
| |
Collapse
|
5
|
Alexander H, Hu SK, Krinos AI, Pachiadaki M, Tully BJ, Neely CJ, Reiter T. Eukaryotic genomes from a global metagenomic data set illuminate trophic modes and biogeography of ocean plankton. mBio 2023; 14:e0167623. [PMID: 37947402 PMCID: PMC10746220 DOI: 10.1128/mbio.01676-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2023] [Accepted: 09/27/2023] [Indexed: 11/12/2023] Open
Abstract
Metagenomics is a powerful method for interpreting the ecological roles and physiological capabilities of mixed microbial communities. Yet, many tools for processing metagenomic data are neither designed to consider eukaryotes nor are they built for an increasing amount of sequence data. EukHeist is an automated pipeline to retrieve eukaryotic and prokaryotic metagenome-assembled genomes (MAGs) from large-scale metagenomic sequence data sets. We developed the EukHeist workflow to specifically process large amounts of both metagenomic and/or metatranscriptomic sequence data in an automated and reproducible fashion. Here, we applied EukHeist to the large-size fraction data (0.8-2,000 µm) from Tara Oceans to recover both eukaryotic and prokaryotic MAGs, which we refer to as TOPAZ (Tara Oceans Particle-Associated MAGs). The TOPAZ MAGs consisted of >900 environmentally relevant eukaryotic MAGs and >4,000 bacterial and archaeal MAGs. The bacterial and archaeal TOPAZ MAGs expand upon the phylogenetic diversity of likely particle- and host-associated taxa. We use these MAGs to demonstrate an approach to infer the putative trophic mode of the recovered eukaryotic MAGs. We also identify ecological cohorts of co-occurring MAGs, which are driven by specific environmental factors and putative host-microbe associations. These data together add to a number of growing resources of environmentally relevant eukaryotic genomic information. Complementary and expanded databases of MAGs, such as those provided through scalable pipelines like EukHeist, stand to advance our understanding of eukaryotic diversity through increased coverage of genomic representatives across the tree of life.IMPORTANCESingle-celled eukaryotes play ecologically significant roles in the marine environment, yet fundamental questions about their biodiversity, ecological function, and interactions remain. Environmental sequencing enables researchers to document naturally occurring protistan communities, without culturing bias, yet metagenomic and metatranscriptomic sequencing approaches cannot separate individual species from communities. To more completely capture the genomic content of mixed protistan populations, we can create bins of sequences that represent the same organism (metagenome-assembled genomes [MAGs]). We developed the EukHeist pipeline, which automates the binning of population-level eukaryotic and prokaryotic genomes from metagenomic reads. We show exciting insight into what protistan communities are present and their trophic roles in the ocean. Scalable computational tools, like EukHeist, may accelerate the identification of meaningful genetic signatures from large data sets and complement researchers' efforts to leverage MAG databases for addressing ecological questions, resolving evolutionary relationships, and discovering potentially novel biodiversity.
Collapse
Affiliation(s)
- Harriet Alexander
- Biology Department, Woods Hole Oceanographic Institution, Woods Hole, Massachusetts, USA
| | - Sarah K. Hu
- Marine Chemistry and Geochemistry, Woods Hole Oceanographic Institution, Woods Hole, Massachusetts, USA
| | - Arianna I. Krinos
- Biology Department, Woods Hole Oceanographic Institution, Woods Hole, Massachusetts, USA
- MIT-WHOI Joint Program in Oceanography/Applied Ocean Science and Engineering, Cambridge and Woods Hole, Massachusetts, USA
| | - Maria Pachiadaki
- Biology Department, Woods Hole Oceanographic Institution, Woods Hole, Massachusetts, USA
| | - Benjamin J. Tully
- Department of Biological Sciences, University of Southern California, Los Angeles, California, USA
| | - Christopher J. Neely
- Department of Quantitative and Computational Biology, University of Southern California, Los Angeles, California, USA
| | - Taylor Reiter
- Population Health and Reproduction, University of California, Davis, Davis, California, USA
| |
Collapse
|
6
|
Ollison GA, Hu SK, Hopper JV, Stewart BP, Smith J, Beatty JL, Rink LK, Caron DA. Daily dynamics of contrasting spring algal blooms in Santa Monica Bay (central Southern California Bight). Environ Microbiol 2022; 24:6033-6051. [PMID: 35880671 PMCID: PMC10087728 DOI: 10.1111/1462-2920.16137] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2021] [Revised: 07/11/2022] [Accepted: 07/13/2022] [Indexed: 01/12/2023]
Abstract
Protistan algae (phytoplankton) dominate coastal upwelling ecosystems where they form massive blooms that support the world's most important fisheries and constitute an important sink for atmospheric CO2 . Bloom initiation is well understood, but the biotic and abiotic forces that shape short-term dynamics in community composition are still poorly characterized. Here, high-frequency (daily) changes in relative abundance dynamics of the metabolically active protistan community were followed via expressed 18S V4 rRNA genes (RNA) throughout two algal blooms during the spring of 2018 and 2019 in Santa Monica Bay (central Southern California Bight). A diatom bloom formed after wind-driven, nutrient upwelling events in both years, but different taxa dominated each year. Whereas diatoms bloomed following elevated nutrients and declined after depletion each year, a massive dinoflagellate bloom manifested under relatively low inorganic nitrogen conditions following diatom bloom senescence in 2019 but not 2018. Network analysis revealed associations between diatoms and cercozoan putative parasitic taxa and syndinean parasites during 2019 that may have influenced the demise of the diatoms, and the transition to a dinoflagellate-dominated bloom.
Collapse
Affiliation(s)
- Gerid A Ollison
- Department of Biological Sciences, University of Southern California, Los Angeles, California, USA
| | - Sarah K Hu
- Woods Hole Oceanographic Institution, Marine Chemistry and Geochemistry, Woods Hole, Massachusetts, USA
| | - Julie V Hopper
- Department of Biological Sciences, University of Southern California, Los Angeles, California, USA
| | - Brittany P Stewart
- Department of Biological Sciences, University of Southern California, Los Angeles, California, USA
| | - Jayme Smith
- Southern California Coastal Water Research Project, Costa Mesa, California, USA
| | - Jennifer L Beatty
- Department of Biological Sciences, University of Southern California, Los Angeles, California, USA
| | - Laura K Rink
- Heal the Bay Aquarium, Santa Monica, California, USA
| | - David A Caron
- Department of Biological Sciences, University of Southern California, Los Angeles, California, USA
| |
Collapse
|
7
|
Hammond SW, Lodolo L, Hu SK, Pasulka AL. Methodological 'lenses' influence the characterization of phytoplankton dynamics in a coastal upwelling ecosystem. Environ Microbiol Rep 2022; 14:897-906. [PMID: 36071313 DOI: 10.1111/1758-2229.13116] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Accepted: 08/01/2022] [Indexed: 06/15/2023]
Abstract
New technologies enable the opportunity to improve our monitoring and understanding of marine phytoplankton communities. However, careful consideration for how different methodological approaches, or 'lenses', influence our interpretation of phytoplankton ecology is important, particularly when drawing conclusions about change over time or space. Using both high-throughput 18S rRNA gene sequencing and microscopy, we explored how phytoplankton community structure varied over the course of a year within a nearshore semi-enclosed coastal embayment along the Central Coast of California. The seasonal shift in the relative community dominance (i.e., diatom vs. dinoflagellate dominance) was captured in the microscopy results but not effectively captured in the molecular-based findings. However, the molecular approach explained more of the variability in composition across seasons relative to the microscopy approach. Temporal dynamics of specific bloom-forming taxa also differed between the molecular and microscopy results. Overall, the observed differences between the molecular- and microscopy-derived characterization of phytoplankton dynamics suggest that the approaches are best suited to answer different research questions. Moreover, the approaches complement each other for a more comprehensive perspective of a coastal phytoplankton ecosystem. Therefore, identifying the biases of each approach within natural communities is necessary to effectively and accurately characterize phytoplankton communities.
Collapse
Affiliation(s)
- S William Hammond
- Biological Sciences Department, California Polytechnic State University, San Luis Obispo, California, USA
| | - Laura Lodolo
- Biological Sciences Department, California Polytechnic State University, San Luis Obispo, California, USA
| | - Sarah K Hu
- Marine Chemistry & Geochemistry, Woods Hole Oceanographic Institution, Woods Hole, Massachusetts, USA
| | - Alexis L Pasulka
- Biological Sciences Department, California Polytechnic State University, San Luis Obispo, California, USA
| |
Collapse
|
8
|
Xuan DD, Li YL, Zhang GN, Ding LW, Cao PP, Jia RJ, Zheng YA, Zhou XJ, Pan LY, Hu SK, Niu LN. [Analysis of intestinal microbial diversity in Leopoldamys edwardsi based on illumina sequencing technique]. Zhonghua Yu Fang Yi Xue Za Zhi 2022; 56:512-518. [PMID: 35488552 DOI: 10.3760/cma.j.cn112150-20210915-00892] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
To explore the composition and diversity of the intestinal microflora of Leopoldamys edwardsi in Hainan Island. In November 2019, DNA was extracted from fecal samples of 25 adult Leopoldamys edwardsi (14 males and 11 females) in Hainan Island at the Joint Laboratory of tropical infectious diseases of Hainan Medical College and Hong Kong University. Based on the IonS5TMXL sequencing platform, single-end sequencing (Single-End) was used to construct a small fragment library for single-end sequencing. Based on Reads shear filtration and OTUs clustering. The species annotation and abundance analysis of OTUs were carried out by using mothur method and SSUrRNA database, and further conducted α diversity and β diversity analysis. A total of 1481842 high quality sequences, belonging to 14 Phyla, 85 families and 186 Genera, were obtained from 25 intestinal excrement samples of Leopoldamys edwardsi. At the level of phyla classification, the main core biota of the Leopoldamys edwardsi contained Firmicutes (46.04%),Bacteroidetes (25.34%), Proteobacteria (17.09%), Tenericutes (7.38%) and Actinobacteria (1.67%), these five phyla account for 97.52% of all phyla. The ratio of Helicobacter which occupied the largest proportion at the genus level was 12.44%, followed by Lactobacillus (11.39%), Clostridium (6.19%),Mycoplasma (4.23%) and Flavonifractor (3.52%). High throughput sequencing analysis showed that the intestinal flora of Leopoldamys edwardsi in Hainan Island was complex and diverse, which had the significance of further research.
Collapse
Affiliation(s)
- D D Xuan
- Key Laboratory of Tropical Translational Medicine of Ministry of Education, Hainan Medical University, Hainan Medical University-The University of Hong Kong Joint Laboratory of Tropical Infectious Diseases, Hainan Medical University, Department of Pathogen Biology, Hainan Medical University, Haikou 571101, China
| | - Y L Li
- Sanya People's Hospital, Sanya 572000, China
| | - G N Zhang
- Key Laboratory of Tropical Translational Medicine of Ministry of Education, Hainan Medical University, Hainan Medical University-The University of Hong Kong Joint Laboratory of Tropical Infectious Diseases, Hainan Medical University, Department of Pathogen Biology, Hainan Medical University, Haikou 571101, China
| | - L W Ding
- Key Laboratory of Tropical Translational Medicine of Ministry of Education, Hainan Medical University, Hainan Medical University-The University of Hong Kong Joint Laboratory of Tropical Infectious Diseases, Hainan Medical University, Department of Pathogen Biology, Hainan Medical University, Haikou 571101, China
| | - P P Cao
- Key Laboratory of Tropical Translational Medicine of Ministry of Education, Hainan Medical University, Hainan Medical University-The University of Hong Kong Joint Laboratory of Tropical Infectious Diseases, Hainan Medical University, Department of Pathogen Biology, Hainan Medical University, Haikou 571101, China
| | - R J Jia
- Key Laboratory of Tropical Translational Medicine of Ministry of Education, Hainan Medical University, Hainan Medical University-The University of Hong Kong Joint Laboratory of Tropical Infectious Diseases, Hainan Medical University, Department of Pathogen Biology, Hainan Medical University, Haikou 571101, China
| | - Y A Zheng
- Key Laboratory of Tropical Translational Medicine of Ministry of Education, Hainan Medical University, Hainan Medical University-The University of Hong Kong Joint Laboratory of Tropical Infectious Diseases, Hainan Medical University, Department of Pathogen Biology, Hainan Medical University, Haikou 571101, China
| | - X J Zhou
- Key Laboratory of Tropical Translational Medicine of Ministry of Education, Hainan Medical University, Hainan Medical University-The University of Hong Kong Joint Laboratory of Tropical Infectious Diseases, Hainan Medical University, Department of Pathogen Biology, Hainan Medical University, Haikou 571101, China
| | - L Y Pan
- Key Laboratory of Tropical Translational Medicine of Ministry of Education, Hainan Medical University, Hainan Medical University-The University of Hong Kong Joint Laboratory of Tropical Infectious Diseases, Hainan Medical University, Department of Pathogen Biology, Hainan Medical University, Haikou 571101, China
| | - S K Hu
- Department of Laboratory Medicine, Peking University Shougang Hospital, Beijing 100144, China
| | - L N Niu
- Key Laboratory of Tropical Translational Medicine of Ministry of Education, Hainan Medical University, Hainan Medical University-The University of Hong Kong Joint Laboratory of Tropical Infectious Diseases, Hainan Medical University, Department of Pathogen Biology, Hainan Medical University, Haikou 571101, China
| |
Collapse
|
9
|
Abstract
Time-series can provide critical insights into the structure and function of microbial communities. The analysis of temporal data warrants statistical considerations, distinct from comparative microbiome studies, to address ecological questions. This primer identifies unique challenges and approaches for analyzing microbiome time-series. In doing so, we focus on (1) identifying compositionally similar samples, (2) inferring putative interactions among populations, and (3) detecting periodic signals. We connect theory, code and data via a series of hands-on modules with a motivating biological question centered on marine microbial ecology. The topics of the modules include characterizing shifts in community structure and activity, identifying expression levels with a diel periodic signal, and identifying putative interactions within a complex community. Modules are presented as self-contained, open-access, interactive tutorials in R and Matlab. Throughout, we highlight statistical considerations for dealing with autocorrelated and compositional data, with an eye to improving the robustness of inferences from microbiome time-series. In doing so, we hope that this primer helps to broaden the use of time-series analytic methods within the microbial ecology research community.
Collapse
Affiliation(s)
- Ashley R. Coenen
- School of Physics, Georgia Institute of Technology, Atlanta, GA, United States
| | - Sarah K. Hu
- Woods Hole Oceanographic Institution, Marine Chemistry and Geochemistry, Woods Hole, MA, United States
| | - Elaine Luo
- Daniel K. Inouye Center for Microbial Oceanography: Research and Education, University of Hawaii, Honolulu, HI, United States
| | - Daniel Muratore
- Interdisciplinary Graduate Program in Quantitative Biosciences, Georgia Institute of Technology, Atlanta, GA, United States
| | - Joshua S. Weitz
- School of Physics, Georgia Institute of Technology, Atlanta, GA, United States
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA, United States
| |
Collapse
|
10
|
Pasulka A, Hu SK, Countway PD, Coyne KJ, Cary SC, Heidelberg KB, Caron DA. SSU-rRNA Gene Sequencing Survey of Benthic Microbial Eukaryotes from Guaymas Basin Hydrothermal Vent. J Eukaryot Microbiol 2019; 66:637-653. [PMID: 30620427 DOI: 10.1111/jeu.12711] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2018] [Revised: 12/09/2018] [Accepted: 12/16/2018] [Indexed: 12/21/2022]
Abstract
Microbial eukaryotes have important roles in marine food webs, but their diversity and activities in hydrothermal vent ecosystems are poorly characterized. In this study, we analyzed microbial eukaryotic communities associated with bacterial (Beggiatoa) mats in the 2,000 m deep-sea Guaymas Basin hydrothermal vent system using 18S rRNA gene high-throughput sequencing of the V4 region. We detected 6,954 distinct Operational Taxonomic Units (OTUs) across various mat systems. Of the sequences that aligned with known protistan phylotypes, most were affiliated with alveolates (especially dinoflagellates and ciliates) and cercozoans. OTU richness and community structure differed among sediment habitats (e.g. different mat types and cold sediments away from mats). Additionally, full-length 18S rRNA genes amplified and cloned from single cells revealed the identities of some of the most commonly encountered, active ciliates in this hydrothermal vent ecosystem. Observations and experiments were also conducted to demonstrate that ciliates were trophically active and ingesting fluorescent bacteria or Beggiatoa trichomes. Our work suggests that the active and diverse protistan community at the Guaymas Basin hydrothermal vent ecosystem likely consumes substantial amounts of bacterial biomass, and that the different habitats, often defined by distances of just a few 10s of cm, select for particular assemblages and levels of diversity.
Collapse
Affiliation(s)
- Alexis Pasulka
- Biological Sciences Department, California Polytechnic State University, 1 Grand Avenue, San Luis Obispo, California, USA
| | - Sarah K Hu
- Department of Biological Sciences, University of Southern California, 3616 Trousdale Parkway, AHF 301 Los Angeles, Los Angeles, California, USA
| | - Peter D Countway
- Bigelow Laboratory for Ocean Sciences, 60 Bigelow Drive, East Boothbay, Maine, USA
| | - Kathryn J Coyne
- College of Earth, Ocean, and Environment, University of Delaware, 700 Pilottown Road, Lewes, Delaware, USA
| | - Stephen C Cary
- Department of Biological Sciences, The University of Waikato, Private Bag 3105, Hamilton, New Zealand
| | - Karla B Heidelberg
- Department of Biological Sciences, University of Southern California, 3616 Trousdale Parkway, AHF 301 Los Angeles, Los Angeles, California, USA
| | - David A Caron
- Department of Biological Sciences, University of Southern California, 3616 Trousdale Parkway, AHF 301 Los Angeles, Los Angeles, California, USA
| |
Collapse
|
11
|
Abstract
Documenting the immense diversity of single-celled, eukaryotic organisms (protists) has been a formidable challenge for ecologists. These species were originally defined by morphological criteria, but shortcomings of the morphospecies concept, and a bewildering array of sizes and cellular attributes, has made constructing a taxonomy that is useful for ecologists nearly impossible. Consequently, physiological and genetic information has been integrated to address these shortcomings, and to develop the framework of a unifying taxonomy. DNA sequence information, in particular, has revolutionized studies of protistan diversity. However, the exponential increase in sequence-based protistan species richness published from field surveys in recent years raises the question of whether we have moved beyond characterizing species-level diversity and begun to reveal intraspecies diversity. The answer to that question appears to be 'yes', at least for some protistan lineages. The need to document such microdiversity may be justified, but it is important for protistologists to recognize and acknowledge that possibility, and its consequences.
Collapse
Affiliation(s)
- David A Caron
- Department of Biological Sciences, 3616 Trousdale Parkway, University of Southern California, Los Angeles, CA 90089-0371, USA.
| | - Sarah K Hu
- Department of Biological Sciences, 3616 Trousdale Parkway, University of Southern California, Los Angeles, CA 90089-0371, USA
| |
Collapse
|
12
|
Hu SK, Liu Z, Alexander H, Campbell V, Connell PE, Dyhrman ST, Heidelberg KB, Caron DA. Shifting metabolic priorities among key protistan taxa within and below the euphotic zone. Environ Microbiol 2018; 20:2865-2879. [PMID: 29708635 DOI: 10.1111/1462-2920.14259] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2017] [Revised: 04/24/2018] [Accepted: 04/26/2018] [Indexed: 12/12/2022]
Abstract
A metatranscriptome study targeting the protistan community was conducted off the coast of Southern California, at the San Pedro Ocean Time-series station at the surface, 150 m (oxycline), and 890 m to link putative metabolic patterns to distinct protistan lineages. Comparison of relative transcript abundances revealed depth-related shifts in the nutritional modes of key taxonomic groups. Eukaryotic gene expression in the sunlit surface environment was dominated by phototrophs, such as diatoms and chlorophytes, and high abundances of transcripts associated with synthesis pathways (e.g., photosynthesis, carbon fixation, fatty acid synthesis). Sub-euphotic depths (150 and 890 m) exhibited strong contributions from dinoflagellates and ciliates, and were characterized by transcripts relating to digestion or intracellular nutrient recycling (e.g., breakdown of fatty acids and V-type ATPases). These transcriptional patterns underlie the distinct nutritional modes of ecologically important protistan lineages that drive marine food webs, and provide a framework to investigate trophic dynamics across diverse protistan communities.
Collapse
Affiliation(s)
- Sarah K Hu
- Department of Biological Sciences, University of Southern California, Los Angeles, CA, USA
| | - Zhenfeng Liu
- Department of Biological Sciences, University of Southern California, Los Angeles, CA, USA
| | - Harriet Alexander
- Department of Population Health and Reproduction, University of California Davis, Davis, CA, USA
| | - Victoria Campbell
- Division Allergy and Infectious Diseases, UW Medicine, Seattle, WA, USA
| | - Paige E Connell
- Department of Biological Sciences, University of Southern California, Los Angeles, CA, USA
| | - Sonya T Dyhrman
- Department of Earth and Environmental Sciences, Lamont-Doherty Earth Observatory, Columbia University, Palisades, NY, USA
| | - Karla B Heidelberg
- Department of Biological Sciences, University of Southern California, Los Angeles, CA, USA
| | - David A Caron
- Department of Biological Sciences, University of Southern California, Los Angeles, CA, USA
| |
Collapse
|
13
|
Hu SK, Campbell V, Connell P, Gellene AG, Liu Z, Terrado R, Caron DA. Protistan diversity and activity inferred from RNA and DNA at a coastal ocean site in the eastern North Pacific. FEMS Microbiol Ecol 2016; 92:fiw050. [PMID: 26940085 DOI: 10.1093/femsec/fiw050] [Citation(s) in RCA: 51] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/25/2016] [Indexed: 11/14/2022] Open
Abstract
Microbial eukaryotes fulfill key ecological positions in marine food webs. Molecular approaches that connect protistan diversity and biogeography to their diverse metabolisms will greatly improve our understanding of marine ecosystem function. The majority of molecular-based studies to date use 18S rRNA gene sequencing to characterize natural microbial assemblages, but this approach does not necessarily discriminate between active and non-active cells. We incorporated RNA sequencing into standard 18S rRNA gene sequence surveys with the purpose of assessing those members of the protistan community contributing to biogeochemical cycling (active organisms), using the ratio of cDNA (reverse transcribed from total RNA) to 18S rRNA gene sequences within major protistan taxonomic groups. Trophically important phytoplankton, such as diatoms and chlorophytes exhibited seasonal trends in relative activity. Additionally, both radiolaria and ciliates displayed previously unreported high relative activities below the euphotic zone. This study sheds new light on the relative metabolic activity of specific protistan groups and how microbial communities respond to changing environmental conditions.
Collapse
Affiliation(s)
- Sarah K Hu
- Department of Biological Sciences, University of Southern California, 3616 Trousdale Parkway, Los Angeles, CA 90089-0371, USA
| | - Victoria Campbell
- Department of Biological Sciences, University of Southern California, 3616 Trousdale Parkway, Los Angeles, CA 90089-0371, USA UW Medicine, Division Allergy and Infectious Diseases, 750 Republican St., Seattle, WA 98109, USA
| | - Paige Connell
- Department of Biological Sciences, University of Southern California, 3616 Trousdale Parkway, Los Angeles, CA 90089-0371, USA
| | - Alyssa G Gellene
- Department of Biological Sciences, University of Southern California, 3616 Trousdale Parkway, Los Angeles, CA 90089-0371, USA
| | - Zhenfeng Liu
- Department of Biological Sciences, University of Southern California, 3616 Trousdale Parkway, Los Angeles, CA 90089-0371, USA
| | - Ramon Terrado
- Department of Biological Sciences, University of Southern California, 3616 Trousdale Parkway, Los Angeles, CA 90089-0371, USA
| | - David A Caron
- Department of Biological Sciences, University of Southern California, 3616 Trousdale Parkway, Los Angeles, CA 90089-0371, USA
| |
Collapse
|
14
|
Hu SK, Liu Z, Lie AAY, Countway PD, Kim DY, Jones AC, Gast RJ, Cary SC, Sherr EB, Sherr BF, Caron DA. Estimating Protistan Diversity Using High-Throughput Sequencing. J Eukaryot Microbiol 2015; 62:688-93. [PMID: 25851049 DOI: 10.1111/jeu.12217] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2014] [Revised: 01/17/2015] [Accepted: 01/26/2015] [Indexed: 11/28/2022]
Abstract
Sequencing hypervariable regions from the 18S rRNA gene is commonly employed to characterize protistan biodiversity, yet there are concerns that short reads do not provide the same taxonomic resolution as full-length sequences. A total of 7,432 full-length sequences were used to perform an in silico analysis of how sequences of various lengths and target regions impact downstream ecological interpretations. Sequences that were longer than 400 nucleotides and included the V4 hypervariable region generated results similar to those derived from full-length 18S rRNA gene sequences. Present high-throughput sequencing capabilities are approaching protistan diversity estimation comparable to whole gene sequences.
Collapse
Affiliation(s)
- Sarah K Hu
- Department of Biological Sciences, University of Southern California, Los Angeles, California, 90089, USA
| | - Zhenfeng Liu
- Department of Biological Sciences, University of Southern California, Los Angeles, California, 90089, USA
| | - Alle A Y Lie
- Department of Biological Sciences, University of Southern California, Los Angeles, California, 90089, USA
| | - Peter D Countway
- Bigelow Laboratory for Ocean Sciences, East Boothbay, Maine, 04544, USA
| | - Diane Y Kim
- Department of Biological Sciences, University of Southern California, Los Angeles, California, 90089, USA
| | - Adriane C Jones
- Mount St. Mary's College, Los Angeles, California, 90049, USA
| | - Rebecca J Gast
- Woods Hole Oceanographic Institution, Woods Hole, Massachusetts, 02543, USA
| | - S Craig Cary
- Environmental Research Institute, School of Science, University of Waikato, Hamilton, 3240, New Zealand.,College of Earth and Ocean Science, University of Delaware, Newark, Delaware, 19716, USA
| | - Evelyn B Sherr
- College of Oceanic and Atmospheric Sciences, Oregon State University, Corvallis, Oregon, 97331, USA
| | - Barry F Sherr
- College of Oceanic and Atmospheric Sciences, Oregon State University, Corvallis, Oregon, 97331, USA
| | - David A Caron
- Department of Biological Sciences, University of Southern California, Los Angeles, California, 90089, USA
| |
Collapse
|
15
|
Hu SK, Li SH, Duan PF. [Rapid propagation of Gynostemma pentaphyllum Makino via tissue culture]. Zhong Yao Tong Bao 1988; 13:17-9, 62. [PMID: 3252985] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
|
16
|
Hu SK, Mitcho YL, Oronsky AL, Kerwar SS. Studies on the effect of methotrexate on macrophage function. J Rheumatol 1988; 15:206-9. [PMID: 3129560] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Time course studies in rat adjuvant arthritis have shown that resident peritoneal macrophages synthesize large amounts of interleukin-1 (IL-1) on Day 10-11 postadjuvant immunization. Expression of Ia antigen on these macrophages increased rapidly between Day 15 to Day 20 postadjuvant treatment and remained at these high levels on Day 25. If these adjuvant immunized rats were treated with low doses of methotrexate, resident peritoneal macrophages appeared to synthesize lower amounts of IL-1 and their Ia expression was decreased. Methotrexate, in vitro, has no effect on lipopolysaccharide induced IL-1 synthesis by resident peritoneal macrophages.
Collapse
Affiliation(s)
- S K Hu
- Department of Inflammation and Immunology, American Cyanamid Company, Pearl River, NY 10965
| | | | | | | |
Collapse
|
17
|
Abstract
The effect of estradiol on interleukin 1 (IL-1) synthesis/secretion by rat peritoneal macrophages was investigated. Peritoneal adherent cells (PAC) from adult female rats secreted greater amounts of IL-1 spontaneously than those from age-matched male rats or prepubescent female rats. Ovariectomy led to reduced synthesis of IL-1 by PAC but estradiol replacement therapy of such rats effectively increased IL-1 synthesis. IL-1 secretion was also stimulated when PAC from male rats was incubated with estradiol. A combination of estradiol and LPS in vitro enhanced secretion of IL-1 by PAC even more than estradiol alone. These data provide new evidence suggesting that estradiol may play an important role in regulating synthesis of IL-1 by macrophages.
Collapse
Affiliation(s)
- S K Hu
- Inflammation and Immunology Research Department, American Cyanamid Company, Lederle Laboratories, Pearl River, NY 10965
| | | | | |
Collapse
|
18
|
Hu SK, Zhou XJ, Zeng XL, Dou ZL, Li XH, Wu J. Morphological changes induced by radix et rhizoma rhei in Wistar rats. J TRADIT CHIN MED 1986; 6:37-42. [PMID: 3736101] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
|
19
|
Hu SK. [Effect of the combination of Codonopsis pilosula and cyclophosphamide on the transplantable tumor and tumor-bearing mice]. Zhong Xi Yi Jie He Za Zhi 1985; 5:618-21, 581. [PMID: 2938803] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
|
20
|
Eardley DD, Hu SK, Gershon RK. Role of Ly-1:Qa1- and Ly-1:Qa1+ inducer T cells in activation of Ly-23 effectors of suppression of antibody production in mice. The Journal of Immunology 1983. [DOI: 10.4049/jimmunol.131.5.2154] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Abstract
Ly-2+ effectors of T cell-mediated suppression require inducing signals from antigen and a helper cell bearing the Ly-1+:Qa1+ surface phenotype. In this report, we have further examined the helper cell requirements for suppressor cell induction of antibody production in mice. By using the T cell subset education procedure in vitro, we have activated T cells to sheep red blood cells (SRBC) antigens and then purified Ly-2 cells before testing for suppressor activity in assay cultures of defined T and B cell subsets. We have confirmed our previous observations that Ly-1+:Qa1+ cells are required for activation of T suppressors, but have found that under the appropriate conditions, there is not a strict requirement for the Ly-123 subset of T cells. Furthermore, if Ly-23 cells are stimulated in the presence of Ly-1+:Qa1- T cells, effective suppressors can be obtained only if a source of Ly-1:Qa1+ inducers is added to the assay culture. If Ly-23 cells are activated by antigen in the absence of Ly-1 cells, subsequent exposure to the Ly-1+:Qa1+ subset under the conditions tested here is not sufficient to activate suppressors. These results show that effectors of suppression, like B cells and cytotoxic T lymphocytes, may respond to two helper cells.
Collapse
|
21
|
Eardley DD, Hu SK, Gershon RK. Role of Ly-1:Qa1- and Ly-1:Qa1+ inducer T cells in activation of Ly-23 effectors of suppression of antibody production in mice. J Immunol 1983; 131:2154-7. [PMID: 6226735] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Ly-2+ effectors of T cell-mediated suppression require inducing signals from antigen and a helper cell bearing the Ly-1+:Qa1+ surface phenotype. In this report, we have further examined the helper cell requirements for suppressor cell induction of antibody production in mice. By using the T cell subset education procedure in vitro, we have activated T cells to sheep red blood cells (SRBC) antigens and then purified Ly-2 cells before testing for suppressor activity in assay cultures of defined T and B cell subsets. We have confirmed our previous observations that Ly-1+:Qa1+ cells are required for activation of T suppressors, but have found that under the appropriate conditions, there is not a strict requirement for the Ly-123 subset of T cells. Furthermore, if Ly-23 cells are stimulated in the presence of Ly-1+:Qa1- T cells, effective suppressors can be obtained only if a source of Ly-1:Qa1+ inducers is added to the assay culture. If Ly-23 cells are activated by antigen in the absence of Ly-1 cells, subsequent exposure to the Ly-1+:Qa1+ subset under the conditions tested here is not sufficient to activate suppressors. These results show that effectors of suppression, like B cells and cytotoxic T lymphocytes, may respond to two helper cells.
Collapse
|
22
|
Liu ML, Li ML, Hu SK. Study of antibacterial and antiinflammatory components of Achillea alpina. J TRADIT CHIN MED 1983; 3:213-6. [PMID: 6556407] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/05/2023]
|
23
|
Abstract
Antigen-stimulated Ly1 cells induce T cells from nonimmune donors to develop potent feedback suppressive activity. Suppression is mediated by Ly23 suppressor T (Ts) cells, which are generated from either Ly23 or Ly123 precursors. Ts activity generated from Ly23 precursors requires a strong inducer signal and is rapidly expressed but short lived. In contrast, Ts activity from Ly123 precursors is relatively long lived and is efficiently generated by relatively low levels of inducer signals. Induction of both Ly123 and Ly23 precursors to become Ts cells requires that both cells share genes linked to the Ig-H locus.
Collapse
|
24
|
Hall NR, McClure JE, Hu SK, Tare NS, Seals CM, Goldstein AL. Effects of 6-hydroxydopamine upon primary and secondary thymus dependent immune responses. Immunopharmacology 1982; 5:39-48. [PMID: 6813289 DOI: 10.1016/0162-3109(82)90035-2] [Citation(s) in RCA: 58] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Adult male mice were treated with various doses of 6-hydroxydopamine in order to assess the effects of this drug upon thymic dependent immunity. A consistent decrease in primary antibody titers to sheep erythrocytes was observed following treatment with this drug. Serum levels of thymosin alpha 1 were increased by day three after 6-OHDA with a return to normal by day five. Thymocyte terminal deoxynucleotidyl transferase changes were biphasic with an initial decrease after 6-OHDA followed by an increase. Changes in mitogen responsiveness were observed but were not consistently reproducible. Involvement of both catecholamines and corticosteroids in bringing about these observed changes was discussed.
Collapse
|
25
|
Abstract
Thymosin fraction 5, a family of acidic polypeptides isolated from bovine thymus, contains several hormonal-like factors which have been shown to influence the maturation, differentiation and functions of T-cells. Some of these peptides have been chemically defined. Two of them, thymosin alpha 1 (M.W. 3108) and thymosin beta 4 (M.W. 4982) have been sequenced. In murine systems, terminal deoxynucleotidyl transferase (TdT) has been shown to be T-cell specific and to be present primarily in the cortisone sensitive immature T-cell populations. The daily injection of thymosin fraction 5 and two of its components, thymosin beta 3 and beta 4, significantly increases TdT activity in immune suppressed mice as compared to control groups. This study indicates that thymosin can act on prothymocytes and influence the early stages of T-cell differentiation. In an in vivo system, thymosin fraction 5 and the purified peptide, thymosin alpha 1, have high activities in decreasing TdT in normal murine thymocytes after a 22-h incubation. This effect suggests that thymosin can also act on thymocytes and regulate the later biochemical processes during T-cell differentiation.
Collapse
|
26
|
Low TL, Hu SK, Goldstein AL. Complete amino acid sequence of bovine thymosin beta 4: a thymic hormone that induces terminal deoxynucleotidyl transferase activity in thymocyte populations. Proc Natl Acad Sci U S A 1981; 78:1162-6. [PMID: 6940133 PMCID: PMC319967 DOI: 10.1073/pnas.78.2.1162] [Citation(s) in RCA: 238] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
The amino acid sequence of thymosin beta 4, a polypeptide isolated from calf thymus, was determined. Thymosin beta 4 is composed of 43 amino acid residues and has a molecular weight of 4982 and an isoelectric point of 5.1. The NH2 terminus of the peptide is blocked by an acetyl group. This molecule induces expression of terminal deoxynucleotidyl transferase (DNA nucleotidylexotransferase, EC 2.7.7.31) in transferase-negative murine thymocytes in vivo and in citro. Thus, it appears that thymosin beta 4 acts on lymphoid stem cells and may control the early stages of the maturation process of thymus-dependent lymphocytes. This peptide is one of several present in thymosin fraction 5 that participates in the regulation, differentiation, and function of thymus-dependent thymocytes.
Collapse
|
27
|
Goldstein AL, Low TL, Thurman GB, Zatz MM, Hall N, Chen J, Hu SK, Naylor PB, McClure JE. Current status of thymosin and other hormones of the thymus gland. Recent Prog Horm Res 1981; 37:369-415. [PMID: 7025134 DOI: 10.1016/b978-0-12-571137-1.50012-8] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
|
28
|
Low TL, Thurman GB, Chincarini C, McClure JE, Marshall GD, Hu SK, Goldstein AL. Current status of thymosin research: evidence for the existence of a family of thymic factors that control T-cell maturation. Ann N Y Acad Sci 1979; 332:33-48. [PMID: 394636 DOI: 10.1111/j.1749-6632.1979.tb47095.x] [Citation(s) in RCA: 78] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Thymosin fraction 5 contains several distinct hormonal-like factors which are effective in partially or fully inducing and maintaining immune function. Several of the peptide components of fraction 5 have been purified, sequenced and studied in assay systems designed to measure T-cell differentiation and function. These studied indicate that a number of the purified peptides act on different subpopulations of T-cells (see Figure 1). Thymosin beta 3 and beta 4 peptides act on terminal deoxynucleotidyl transferase (TdT) negative precursor T-cells to induce TdT positive cells. Thymosin alpha 1 induces the formation of functional helper cells and conversion of Lyt- cells to Lyt 1+, 2+, 3+ cells. Thymosin alpha 7 induces the formation of functional suppressor T-cells and also converts Lyt- cells to Lyt 1+, 2+, 3+ cells. These studies have provided further evidence that the thymus secretes a family of distinct peptides which act at various sites of the maturation sequence of T-cells to induce and maintain immune function. Phase I and Phase II clinical studied with thymosin in the treatment of primary immunodeficiency diseases, autoimmune diseases, and cancer point to a major role of the endocrine thymus in the maintenance of immune balance and in the treatment of diseases characterized by thymic malfunction. It is becoming increasingly clear that immunological maturation is a process involving a complex number of steps and that a single factor initiating a single cellular event might not be reflected in any meaningful immune reconstitution unless it is the only peptide lacking. Given the complexity of the maturation sequence of T-cells and the increasing numbers of T-cell subpopulations that are being identified, it would be surprising if a single thymic factor could control all of the steps and populations involved. Rather, it would appear that the control of T-cell maturation and function involves a complex number of thymic-specific factors and other molecules that rigidly control the intermediary steps in the differentiation process.
Collapse
|
29
|
Marshall GD, Low TL, Thurman GB, Hu SK, Rossio JL, Trivers G, Goldstein AL. Overview of thymosin activity. Cancer Treat Rep 1978; 62:1731-7. [PMID: 215305] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Our current research program centers around the biologic and chemical characterization of the family of polypeptides present in thymosin fraction 5. A system of nomenclature has been developed and the peptides are being systematically isolated and chemically characterized. Thymosin fraction 5 and its component parts influence a variety of lymphocyte properties including cyclic nucleotide levels, migration inhibitory factor production, T-dependent antibody production, and expression of certain surface markers. Thymosin is being used in clinical trials to investigate its effects on immunodeficiency diseases, malignant diseases, and autoimmune diseases.
Collapse
|