1
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Schiebelhut LM, Giakoumis M, Castilho R, Duffin PJ, Puritz JB, Wares JP, Wessel GM, Dawson MN. Minor Genetic Consequences of a Major Mass Mortality: Short-Term Effects in Pisaster ochraceus. THE BIOLOGICAL BULLETIN 2022; 243:328-338. [PMID: 36716481 PMCID: PMC10668074 DOI: 10.1086/722284] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
AbstractMass mortality events are increasing globally in frequency and magnitude, largely as a result of human-induced change. The effects of these mass mortality events, in both the long and short term, are of imminent concern because of their ecosystem impacts. Genomic data can be used to reveal some of the population-level changes associated with mass mortality events. Here, we use reduced-representation sequencing to identify potential short-term genetic impacts of a mass mortality event associated with a sea star wasting outbreak. We tested for changes in the population for genetic differentiation, diversity, and effective population size between pre-sea star wasting and post-sea star wasting populations of Pisaster ochraceus-a species that suffered high sea star wasting-associated mortality (75%-100% at 80% of sites). We detected no significant population-based genetic differentiation over the spatial scale sampled; however, the post-sea star wasting population tended toward more differentiation across sites than the pre-sea star wasting population. Genetic estimates of effective population size did not detectably change, consistent with theoretical expectations; however, rare alleles were lost. While we were unable to detect significant population-based genetic differentiation or changes in effective population size over this short time period, the genetic burden of this mass mortality event may be borne by future generations, unless widespread recruitment mitigates the population decline. Prior results from P. ochraceus indicated that natural selection played a role in altering allele frequencies following this mass mortality event. In addition to the role of selection found in a previous study on the genomic impacts of sea star wasting on P. ochraceus, our current study highlights the potential role the stochastic loss of many individuals plays in altering how genetic variation is structured across the landscape. Future genetic monitoring is needed to determine long-term genetic impacts in this long-lived species. Given the increased frequency of mass mortality events, it is important to implement demographic and genetic monitoring strategies that capture baselines and background dynamics to better contextualize species' responses to large perturbations.
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Affiliation(s)
- Lauren M. Schiebelhut
- Life and Environmental Sciences, University of California, Merced, 5200 N. Lake Road, Merced, California 95343
| | - Melina Giakoumis
- Graduate Center, City University of New York, 365 5th Avenue, New York, New York 10016
- Department of Biology, City College of New York, 160 Convent Avenue, New York, New York 10031
| | - Rita Castilho
- University of Algarve, Campus de Gambelas, Faro, Portugal
- Center of Marine Sciences (CCMAR), Campus de Gambelas, Faro, Portugal
| | - Paige J. Duffin
- Odum School of Ecology and Department of Genetics, University of Georgia, 120 Green Street, Athens, Georgia 30602
| | - Jonathan B. Puritz
- Department of Biological Sciences, University of Rhode Island, 120 Flagg Road, Kingston, Rhode Island 02881
| | - John P. Wares
- Odum School of Ecology and Department of Genetics, University of Georgia, 120 Green Street, Athens, Georgia 30602
| | - Gary M. Wessel
- Department of Molecular Biology, Cell Biology, and Biochemistry, Brown University, Providence, Rhode Island 02912
| | - Michael N Dawson
- Life and Environmental Sciences, University of California, Merced, 5200 N. Lake Road, Merced, California 95343
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2
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Oulhen N, Byrne M, Duffin P, Gomez-Chiarri M, Hewson I, Hodin J, Konar B, Lipp EK, Miner BG, Newton AL, Schiebelhut LM, Smolowitz R, Wahltinez SJ, Wessel GM, Work TM, Zaki HA, Wares JP. A Review of Asteroid Biology in the Context of Sea Star Wasting: Possible Causes and Consequences. THE BIOLOGICAL BULLETIN 2022; 243:50-75. [PMID: 36108034 PMCID: PMC10642522 DOI: 10.1086/719928] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
AbstractSea star wasting-marked in a variety of sea star species as varying degrees of skin lesions followed by disintegration-recently caused one of the largest marine die-offs ever recorded on the west coast of North America, killing billions of sea stars. Despite the important ramifications this mortality had for coastal benthic ecosystems, such as increased abundance of prey, little is known about the causes of the disease or the mechanisms of its progression. Although there have been studies indicating a range of causal mechanisms, including viruses and environmental effects, the broad spatial and depth range of affected populations leaves many questions remaining about either infectious or non-infectious mechanisms. Wasting appears to start with degradation of mutable connective tissue in the body wall, leading to disintegration of the epidermis. Here, we briefly review basic sea star biology in the context of sea star wasting and present our current knowledge and hypotheses related to the symptoms, the microbiome, the viruses, and the associated environmental stressors. We also highlight throughout the article knowledge gaps and the data needed to better understand sea star wasting mechanistically, its causes, and potential management.
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Affiliation(s)
- Nathalie Oulhen
- Department of Molecular and Cell Biology and Biochemistry, Brown University, Providence, Rhode Island
| | - Maria Byrne
- School of Life and Environmental Sciences, University of Sydney, Sydney, New South Wales, Australia
| | - Paige Duffin
- Department of Genetics, University of Georgia, Athens, Georgia
| | - Marta Gomez-Chiarri
- Department of Fisheries, Animal, and Veterinary Science, University of Rhode Island, Kingston, Rhode Island
| | - Ian Hewson
- Department of Microbiology, Cornell University, Ithaca, New York
| | - Jason Hodin
- Friday Harbor Labs, University of Washington, Friday Harbor, Washington
| | - Brenda Konar
- College of Fisheries and Ocean Sciences, University of Alaska, Fairbanks, Alaska
| | - Erin K. Lipp
- Department of Environmental Health Science, University of Georgia, Athens, Georgia
| | - Benjamin G. Miner
- Department of Biology, Western Washington University, Bellingham, Washington
| | | | - Lauren M. Schiebelhut
- Department of Life and Environmental Sciences, University of California, Merced, California
| | - Roxanna Smolowitz
- Department of Biology and Marine Biology, Roger Williams University, Bristol, Rhode Island
| | - Sarah J. Wahltinez
- Department of Comparative, Diagnostic, and Population Medicine, College of Veterinary Medicine, University of Florida, Gainesville, Florida
| | - Gary M. Wessel
- Department of Molecular and Cell Biology and Biochemistry, Brown University, Providence, Rhode Island
| | - Thierry M. Work
- US Geological Survey, National Wildlife Health Center, Honolulu Field Station, Honolulu, Hawaii
| | - Hossam A. Zaki
- Department of Molecular and Cell Biology and Biochemistry, Brown University, Providence, Rhode Island
| | - John P. Wares
- Department of Genetics, University of Georgia, Athens, Georgia
- Odum School of Ecology, University of Georgia, Athens, Georgia
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3
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Liu Z, Bisoyi HK, Huang Y, Wang M, Yang H, Li Q. Thermo‐ and Mechanochromic Camouflage and Self‐Healing in Biomimetic Soft Actuators Based on Liquid Crystal Elastomers. Angew Chem Int Ed Engl 2021. [DOI: 10.1002/ange.202115755] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Zhongcheng Liu
- Institute of Advanced Materials School of Chemistry and Chemical Engineering and Jiangsu Province Hi-Tech Key Laboratory for Biomedical Research Southeast University Nanjing 211189 China
| | - Hari Krishna Bisoyi
- Advanced Materials and Liquid Crystal Institute and Chemical Physics Interdisciplinary Program Kent State University Kent OH 44242 USA
| | - Yinliang Huang
- Institute of Advanced Materials School of Chemistry and Chemical Engineering and Jiangsu Province Hi-Tech Key Laboratory for Biomedical Research Southeast University Nanjing 211189 China
| | - Meng Wang
- Institute of Advanced Materials School of Chemistry and Chemical Engineering and Jiangsu Province Hi-Tech Key Laboratory for Biomedical Research Southeast University Nanjing 211189 China
| | - Hong Yang
- Institute of Advanced Materials School of Chemistry and Chemical Engineering and Jiangsu Province Hi-Tech Key Laboratory for Biomedical Research Southeast University Nanjing 211189 China
| | - Quan Li
- Institute of Advanced Materials School of Chemistry and Chemical Engineering and Jiangsu Province Hi-Tech Key Laboratory for Biomedical Research Southeast University Nanjing 211189 China
- Advanced Materials and Liquid Crystal Institute and Chemical Physics Interdisciplinary Program Kent State University Kent OH 44242 USA
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4
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Liu Z, Bisoyi HK, Huang Y, Wang M, Yang H, Li Q. Thermo- and Mechanochromic Camouflage and Self-Healing in Biomimetic Soft Actuators Based on Liquid Crystal Elastomers. Angew Chem Int Ed Engl 2021; 61:e202115755. [PMID: 34904346 DOI: 10.1002/anie.202115755] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2021] [Indexed: 12/15/2022]
Abstract
In nature, many mysterious creatures capable of deformation camouflage, color camouflage, and self-healing have inspired scientists to develop various biomimetic soft robots. However, the systematic integration of all the above functionalities into a single soft actuator system still remains a challenge. Here we chemically introduce a multi-stimuli-responsive tetraarylsuccinonitrile (TASN) chromophore into a liquid crystal elastomer (LCE) network through a facile thiol-ene photoaddition method. The obtained TASN-LCE soft actuators not only exhibit reversible shape-morphing and reversible color-changing behavior in response to heat and mechanical compression, but also show excellent self-healing, reprogramming and recycling characteristics. We hope that such a TASN-LCE actuator system endowed with dynamic distortion, thermo- and mechano-chromic camouflage, and self-healing functionalities would pave the way for further development of multifunctional biomimetic soft robotic devices.
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Affiliation(s)
- Zhongcheng Liu
- Institute of Advanced Materials, School of Chemistry and Chemical Engineering, and Jiangsu Province Hi-Tech Key Laboratory for Biomedical Research, Southeast University, Nanjing, 211189, China
| | - Hari Krishna Bisoyi
- Advanced Materials and Liquid Crystal Institute and Chemical, Physics Interdisciplinary Program, Kent State University, Kent, OH 44242, USA
| | - Yinliang Huang
- Institute of Advanced Materials, School of Chemistry and Chemical Engineering, and Jiangsu Province Hi-Tech Key Laboratory for Biomedical Research, Southeast University, Nanjing, 211189, China
| | - Meng Wang
- Institute of Advanced Materials, School of Chemistry and Chemical Engineering, and Jiangsu Province Hi-Tech Key Laboratory for Biomedical Research, Southeast University, Nanjing, 211189, China
| | - Hong Yang
- Institute of Advanced Materials, School of Chemistry and Chemical Engineering, and Jiangsu Province Hi-Tech Key Laboratory for Biomedical Research, Southeast University, Nanjing, 211189, China
| | - Quan Li
- Institute of Advanced Materials, School of Chemistry and Chemical Engineering, and Jiangsu Province Hi-Tech Key Laboratory for Biomedical Research, Southeast University, Nanjing, 211189, China.,Advanced Materials and Liquid Crystal Institute and Chemical, Physics Interdisciplinary Program, Kent State University, Kent, OH 44242, USA
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5
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Parker E, Dornburg A, Struthers CD, Jones CD, Near TJ. Phylogenomic species delimitation dramatically reduces species diversity in an Antarctic adaptive radiation. Syst Biol 2021; 71:58-77. [PMID: 34247239 DOI: 10.1093/sysbio/syab057] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2020] [Revised: 07/06/2021] [Accepted: 06/30/2021] [Indexed: 11/14/2022] Open
Abstract
Application of genetic data to species delimitation often builds confidence in delimitations previously hypothesized using morphological, ecological, and geographic data and frequently yields recognition of previously-undescribed cryptic diversity. However, a recent critique of genomic data-based species delimitation approaches is that they have the potential to conflate population structure with species diversity, resulting in taxonomic oversplitting. The need for an integrative approach to species delimitation, in which molecular, morphological, ecological, and geographic lines of evidence are evaluated together, is becoming increasingly apparent. Here, we integrate phylogenetic, population genetic, and coalescent analyses of genome-wide sequence data with investigation of variation in multiple morphological traits to delimit species within the Antarctic barbeled plunderfishes (Artedidraconidae: Pogonophryne). Pogonophryne currently comprises 29 valid species, most of which are distinguished solely by variation in ornamentation of the mental barbel that projects from the lower jaw, a structure previously shown to vary widely within a single species. However, our genomic and phenotypic analyses result in a dramatic reduction in the number of distinct species recognized within the clade, providing evidence to support the recognition of no more than six species. We propose to synonymize 24 of the currently recognized species with five species of Pogonophryne. We find genomic and phenotypic evidence for a new species of Pogonophryne from specimens collected in the Ross Sea. Our findings represent a rare example in which application of molecular data provides evidence of taxonomic oversplitting on the basis of morphology, clearly demonstrating the utility of an integrative species delimitation framework.
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Affiliation(s)
- Elyse Parker
- Department of Ecology & Evolutionary Biology, Yale University, P.O. Box 208106, New Haven, CT 06520, USA
| | - Alex Dornburg
- Department of Bioinformatics and Genomics, University of North Carolina, Charlotte, Charlotte, NC 28223, USA
| | - Carl D Struthers
- Museum of New Zealand Te Papa Tongarewa, Wellington, New Zealand
| | - Christopher D Jones
- Antarctic Ecosystem Research Division, NOAA Southwest Fisheries Science Center, La Jolla, CA 92037, USA
| | - Thomas J Near
- Department of Ecology & Evolutionary Biology, Yale University, P.O. Box 208106, New Haven, CT 06520, USA.,Peabody Museum of Natural History, Yale University, New Haven, CT 06520, USA
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6
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Work TM, Weatherby TM, DeRito CM, Besemer RM, Hewson I. Sea star wasting disease pathology in Pisaster ochraceus shows a basal-to-surface process affecting color phenotypes differently. DISEASES OF AQUATIC ORGANISMS 2021; 145:21-33. [PMID: 34080580 DOI: 10.3354/dao03598] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Sea star wasting disease (SSWD) refers to a suite of poorly described non-specific clinical signs including abnormal posture, epidermal ulceration, and limb autotomy (sloughing) causing mortalities of over 20 species of sea stars and subsequent ecological shifts throughout the northeastern Pacific. While SSWD is widely assumed to be infectious, with environmental conditions facilitating disease progression, few data exist on cellular changes associated with the disease. This is unfortunate, because such observations could inform mechanisms of disease pathogenesis and host susceptibility. Here, we replicated SSWD by exposing captive Pisaster ochraceus to a suite of non-infectious organic substances and show that development of gross lesions is a basal-to-surface process involving inflammation (e.g. infiltration of coelomocytes) of ossicles and mutable collagenous tissue, leading to epidermal ulceration. Affected sea stars also manifest increases in a heretofore undocumented coelomocyte type, spindle cells, that might be a useful marker of inflammation in this species. Finally, compared to purple morphs, orange P. ochraceus developed more severe lesions but survived longer. Longer-lived, and presumably more visible, severely-lesioned orange sea stars could have important demographic implications in terms of detectability of lesioned animals in the wild and measures of apparent prevalence of disease.
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Affiliation(s)
- Thierry M Work
- US Geological Survey, National Wildlife Health Center, Honolulu Field Station, Honolulu, HI 96850, USA
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7
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Brock KM, Baeckens S, Donihue CM, Martín J, Pafilis P, Edwards DL. Trait differences among discrete morphs of a color polymorphic lizard, Podarcis erhardii. PeerJ 2020; 8:e10284. [PMID: 33194436 PMCID: PMC7649010 DOI: 10.7717/peerj.10284] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2020] [Accepted: 10/09/2020] [Indexed: 12/24/2022] Open
Abstract
Color polymorphism defies evolutionary expectations as striking phenotypic variation is maintained within a single species. Color and other traits mediate social interactions, and stable polymorphism within a population is hypothesized to be related to correlational selection of other phenotypic traits among color morphs. Here, we report on a previously unknown throat color polymorphism in the Aegean Wall Lizard (Podarcis erhardii) and examine morph-correlated differences in traits important to social behavior and communication: maximum bite force capacity and chemical signal profile. We find that both sexes of P. erhardii have three color morphs: orange, yellow, and white. Moreover, orange males are significantly larger and tend to bite harder than yellow and white males. Although the established color polymorphism only partially matches the observed intraspecific variation in chemical signal signatures, the chemical profile of the secretions of orange males is significantly divergent from that of white males. Our findings suggest that morph colors are related to differences in traits that are crucial for social interactions and competitive ability, illustrating the need to look beyond color when studying polymorphism evolution.
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Affiliation(s)
- Kinsey M Brock
- Department of Life & Environmental Sciences, School of Natural Sciences, University of California, Merced, Merced, CA, United States of America.,Quantitative and Systems Biology Graduate Group, School of Natural Sciences, University of California, Merced, Merced, CA, United States of America
| | - Simon Baeckens
- Laboratory of Functional Morphology, Department of Biology, University of Antwerp, Wilrijk, Belgium.,Department of Biology, Macquarie University, Sydney, Australia
| | - Colin M Donihue
- Department of Biology, Washington University in St. Louis, St. Louis, MO, United States of America
| | - José Martín
- Department of Evolutionary Ecology, Museo Nacional de Ciencias Naturales, CSIC, Madrid, Spain
| | - Panayiotis Pafilis
- Department of Zoology and Marine Biology, National and Kapodistrian University of Athens, Panepistimioupolis, Athens, Greece.,Zoological Museum, National and Kapodistrian University of Athens, Athens, Greece
| | - Danielle L Edwards
- Department of Life & Environmental Sciences, School of Natural Sciences, University of California, Merced, Merced, CA, United States of America
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8
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Kay SWC, Gehman ALM, Harley CDG. Reciprocal abundance shifts of the intertidal sea stars, Evasterias troschelii and Pisaster ochraceus, following sea star wasting disease. Proc Biol Sci 2020; 286:20182766. [PMID: 31014216 DOI: 10.1098/rspb.2018.2766] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Disease emergence occurs within the context of ecological communities, and disease driven declines in host populations can lead to complex direct and indirect ecological effects. Varying effects of a single disease among multiple susceptible hosts could benefit relatively resistant species. Beginning in 2013, an outbreak of sea star wasting disease (SSWD) led to population declines of many sea star species along the west coast of North America. Through field surveys and laboratory experiments, we investigated how and why the relative abundances of two co-occurring sea star species, Evasterias troschelii and Pisaster ochraceus, shifted during the ongoing wasting epidemic in Burrard Inlet, British Columbia, Canada. We hypothesized that Evasterias is competitively inferior to Pisaster but more resistant to SSWD. Thus, we predicted that SSWD-induced declines of Pisaster could mitigate the negative effects of SSWD on Evasterias, as the latter would experience competitive release. We document shifts in sea star abundance from 2008-2017: Pisaster abundance and mean size declined during the outbreak, while Evasterias abundance increased from relatively rare to numerically dominant within the intertidal. When exposed to symptomatic sea stars, Pisaster and Evasterias both showed signs of SSWD, but transmission and susceptibility was lower in Evasterias. Despite diet overlap documented in our field surveys, Evasterias was not outcompeted by Pisaster in laboratory trails conducted with the relatively small Pisaster available after the outbreak. Interference competition with larger Pisaster, or prey exploitation by Pisaster during the summer when Evasterias is primarily subtidal, may explain the rarity of Evasterias prior to Pisaster declines. Our results suggest that indirect effects mediated by competition can mask some of the direct effects of disease outbreaks, and the combination of direct and indirect effects will determine the restructuring of a community after disturbance.
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Affiliation(s)
- Sharon W C Kay
- 1 Department of Zoology, University of British Columbia , Vancouver, British Columbia , Canada
| | - Alyssa-Lois M Gehman
- 1 Department of Zoology, University of British Columbia , Vancouver, British Columbia , Canada.,3 Hakai Institute , End of Kwakshua Channel, Calvert Island, British Columbia , Canada
| | - Christopher D G Harley
- 1 Department of Zoology, University of British Columbia , Vancouver, British Columbia , Canada.,2 Institute for the Oceans and Fisheries, University of British Columbia , Vancouver, British Columbia , Canada
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9
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Ruiz-Ramos DV, Schiebelhut LM, Hoff KJ, Wares JP, Dawson MN. An initial comparative genomic autopsy of wasting disease in sea stars. Mol Ecol 2020; 29:1087-1102. [PMID: 32069379 DOI: 10.1111/mec.15386] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2019] [Revised: 01/28/2020] [Accepted: 02/05/2020] [Indexed: 12/18/2022]
Abstract
Beginning in 2013, sea stars throughout the Eastern North Pacific were decimated by wasting disease, also known as "asteroid idiopathic wasting syndrome" (AIWS) due to its elusive aetiology. The geographic extent and taxonomic scale of AIWS meant events leading up to the outbreak were heterogeneous, multifaceted, and oftentimes unobserved; progression from morbidity to death was rapid, leaving few tell-tale symptoms. Here, we take a forensic genomic approach to discover candidate genes that may help explain sea star wasting syndrome. We report the first genome and annotation for Pisaster ochraceus, along with differential gene expression (DGE) analyses in four size classes, three tissue types, and in symptomatic and asymptomatic individuals. We integrate nucleotide polymorphisms associated with survivors of the wasting disease outbreak, DGE associated with temperature treatments in P. ochraceus, and DGE associated with wasting in another asteroid Pycnopodia helianthoides. In P. ochraceus, we found DGE across all tissues, among size classes, and between asymptomatic and symptomatic individuals; the strongest wasting-associated DGE signal was in pyloric caecum. We also found previously identified outlier loci co-occur with differentially expressed genes. In cross-species comparisons of symptomatic and asymptomatic individuals, consistent responses distinguish genes associated with invertebrate innate immunity and chemical defence, consistent with context-dependent stress responses, defensive apoptosis, and tissue degradation. Our analyses thus highlight genomic constituents that may link suspected environmental drivers (elevated temperature) with intrinsic differences among individuals (age/size, alleles associated with susceptibility) that elicit organismal responses (e.g., coelomocyte proliferation) and manifest as sea star wasting mass mortality.
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Affiliation(s)
- Dannise V Ruiz-Ramos
- Department of Life and Environmental Sciences, University of California, Merced, CA, USA
| | - Lauren M Schiebelhut
- Department of Life and Environmental Sciences, University of California, Merced, CA, USA
| | - Katharina J Hoff
- Institute for Computer Science and Mathematics, University of Greifswald, Greifswald, Germany.,Center for Functional Genomics of Microbes, University of Greifswald, Greifswald, Germany
| | - John P Wares
- Department of Genetics and the Odum School of Ecology, University of Georgia, Athens, GA, USA
| | - Michael N Dawson
- Department of Life and Environmental Sciences, University of California, Merced, CA, USA
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10
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Correlates of color polymorphism in coconut crabs Birgus latro. ZOOLOGY 2018; 129:1-8. [DOI: 10.1016/j.zool.2018.06.002] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2018] [Revised: 06/02/2018] [Accepted: 06/04/2018] [Indexed: 11/23/2022]
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11
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Decimation by sea star wasting disease and rapid genetic change in a keystone species, Pisaster ochraceus. Proc Natl Acad Sci U S A 2018; 115:7069-7074. [PMID: 29915091 DOI: 10.1073/pnas.1800285115] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Standing genetic variation enables or restricts a population's capacity to respond to changing conditions, including the extreme disturbances expected to increase in frequency and intensity with continuing anthropogenic climate change. However, we know little about how populations might respond to extreme events with rapid genetic shifts, or how population dynamics may influence and be influenced by population genomic change. We use a range-wide epizootic, sea star wasting disease, that onset in mid-2013 and caused mass mortality in Pisaster ochraceus to explore how a keystone marine species responded to an extreme perturbation. We integrated field surveys with restriction site-associated DNA sequencing data to (i) describe the population dynamics of mortality and recovery, and (ii) compare allele frequencies in mature P. ochraceus before the disease outbreak with allele frequencies in adults and new juveniles after the outbreak, to identify whether selection may have occurred. We found P. ochraceus suffered 81% mortality in the study region between 2012 and 2015, and experienced a concurrent 74-fold increase in recruitment beginning in late 2013. Comparison of pre- and postoutbreak adults revealed significant allele frequency changes at three loci, which showed consistent changes across the large majority of locations. Allele frequency shifts in juvenile P. ochraceus (spawned from premortality adults) were consistent with those seen in adult survivors. Such parallel shifts suggest detectable signals of selection and highlight the potential for persistence of this change in subsequent generations, which may influence the resilience of this keystone species to future outbreaks.
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12
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Moritsch MM, Raimondi PT. Reduction and recovery of keystone predation pressure after disease-related mass mortality. Ecol Evol 2018; 8:3952-3964. [PMID: 29721271 PMCID: PMC5916292 DOI: 10.1002/ece3.3953] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2017] [Revised: 02/08/2018] [Accepted: 02/11/2018] [Indexed: 11/23/2022] Open
Abstract
Disturbances such as disease can reshape communities through interruption of ecological interactions. Changes to population demographics alter how effectively a species performs its ecological role. While a population may recover in density, this may not translate to recovery of ecological function. In 2013, a sea star wasting syndrome outbreak caused mass mortality of the keystone predator Pisaster ochraceus on the North American Pacific coast. We analyzed sea star counts, biomass, size distributions, and recruitment from long‐term intertidal monitoring sites from San Diego to Alaska to assess regional trends in sea star recovery following the outbreak. Recruitment, an indicator of population recovery, has been spatially patchy and varied within and among regions of the coast. Despite sea star counts approaching predisease numbers, sea star biomass, a measure of predation potential on the mussel Mytilus californianus, has remained low. This indicates that post‐outbreak populations have not regained their full predation pressure. The regional variability in percent of recovering sites suggested differences in factors promoting sea star recovery between regions but did not show consistent patterns in postoutbreak recruitment on a coast‐wide scale. These results shape predictions of where changes in community composition are likely to occur in years following the disease outbreak and provide insight into how populations of keystone species resume their ecological roles following mortality‐inducing disturbances.
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Affiliation(s)
- Monica M Moritsch
- Department of Ecology and Evolutionary Biology University of California Santa Cruz Long Marine Laboratory Santa Cruz CA USA
| | - Peter T Raimondi
- Department of Ecology and Evolutionary Biology University of California Santa Cruz Long Marine Laboratory Santa Cruz CA USA
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13
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Large-scale impacts of sea star wasting disease (SSWD) on intertidal sea stars and implications for recovery. PLoS One 2018; 13:e0192870. [PMID: 29558484 PMCID: PMC5860697 DOI: 10.1371/journal.pone.0192870] [Citation(s) in RCA: 59] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2017] [Accepted: 01/31/2018] [Indexed: 12/26/2022] Open
Abstract
Disease outbreaks can have substantial impacts on wild populations, but the often patchy or anecdotal evidence of these impacts impedes our ability to understand outbreak dynamics. Recently however, a severe disease outbreak occurred in a group of very well-studied organisms–sea stars along the west coast of North America. We analyzed nearly two decades of data from a coordinated monitoring effort at 88 sites ranging from southern British Columbia to San Diego, California along with 2 sites near Sitka, Alaska to better understand the effects of sea star wasting disease (SSWD) on the keystone intertidal predator, Pisaster ochraceus. Quantitative surveys revealed unprecedented declines of P. ochraceus in 2014 and 2015 across nearly the entire geographic range of the species. The intensity of the impact of SSWD was not uniform across the affected area, with proportionally greater population declines in the southern regions relative to the north. The degree of population decline was unrelated to pre-outbreak P. ochraceus density, although these factors have been linked in other well-documented disease events. While elevated seawater temperatures were not broadly linked to the initial emergence of SSWD, anomalously high seawater temperatures in 2014 and 2015 might have exacerbated the disease’s impact. Both before and after the onset of the SSWD outbreak, we documented higher recruitment of P. ochraceus in the north than in the south, and while some juveniles are surviving (as evidenced by transition of recruitment pulses to larger size classes), post-SSWD survivorship is lower than during pre-SSWD periods. In hindsight, our data suggest that the SSWD event defied prediction based on two factors found to be important in other marine disease events, sea water temperature and population density, and illustrate the importance of surveillance of natural populations as one element of an integrated approach to marine disease ecology. Low levels of SSWD-symptomatic sea stars are still present throughout the impacted range, thus the outlook for population recovery is uncertain.
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14
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Layton KKS, Gosliner TM, Wilson NG. Flexible colour patterns obscure identification and mimicry in Indo-Pacific Chromodoris nudibranchs (Gastropoda: Chromodorididae). Mol Phylogenet Evol 2018; 124:27-36. [PMID: 29476907 DOI: 10.1016/j.ympev.2018.02.008] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2017] [Revised: 02/08/2018] [Accepted: 02/10/2018] [Indexed: 01/18/2023]
Abstract
Chromodoris is a genus of colourful nudibranchs that feed on sponges and is found across the Indo-Pacific. While this was once the most diverse chromodorid genus, recent work has shown that the genus should be restricted to a monophyletic lineage that contains only 22 species, all of which exhibit black pigmentation and planar spawning behaviour. Earlier phylogenies of this group are poorly resolved and thus additional work is needed to clarify species boundaries within Chromodoris. This study presents a maximum-likelihood phylogeny based on mitochondrial loci (COI, 16S) for 345 Chromodoris specimens, including data from 323 new specimens and 22 from GenBank, from across the Indo-Pacific. Species hypotheses and phylogenetic analysis uncovered 39 taxa in total containing 18 undescribed species, with only five of 39 taxa showing stable colour patterns and distinct morphotypes. This study also presents the first evidence for regional mimicry in this genus, with C. colemani and C. joshi displaying geographically-based variation in colour patterns which appear to match locally abundant congenerics, highlighting the flexibility of these colour patterns in Chromodoris nudibranchs. The current phylogeny contains short branch lengths, polytomies and poor support at interior nodes, which is indicative of a recent radiation. As such, future work will employ a transcriptome-based exon capture approach for resolving the phylogeny of this group. In all, this study included 21 of the 22 described species in the Chromodoris sensu stricto group with broad sampling coverage from across the Indo-Pacific, constituting the most comprehensive sampling of this group to date. This work highlights several cases of undocumented diversity, ultimately expanding our knowledge of species boundaries in this group, while also demonstrating the limitations of colour patterns for species identification in this genus.
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Affiliation(s)
- Kara K S Layton
- School of Biological Sciences, The University of Western Australia, Perth, WA 6009, Australia; Aquatic Zoology & Molecular Systematics Unit, Western Australian Museum, Welshpool, WA 6106, Australia.
| | - Terrence M Gosliner
- Department of Invertebrate Zoology & Geology, California Academy of Sciences, San Francisco, CA 94118, USA
| | - Nerida G Wilson
- School of Biological Sciences, The University of Western Australia, Perth, WA 6009, Australia; Aquatic Zoology & Molecular Systematics Unit, Western Australian Museum, Welshpool, WA 6106, Australia
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15
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Reijnen BT, van der Meij SET. Coat of many colours-DNA reveals polymorphism of mantle patterns and colouration in Caribbean Cyphoma Röding, 1798 (Gastropoda, Ovulidae). PeerJ 2017; 5:e3018. [PMID: 28265504 PMCID: PMC5337085 DOI: 10.7717/peerj.3018] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2016] [Accepted: 01/23/2017] [Indexed: 11/20/2022] Open
Abstract
The iconic gastropod genus Cyphoma is commonly observed in the Caribbean, where it lives in association with various octocorallian hosts. Each species in the genus Cyphoma has a unique, characteristic mantle pattern and colouration, which separates the valid taxa. Because of its abundance and recognisability Cyphoma gibbosum has been used as a model organism in several studies concerning allelochemicals, reef degradation, and physical defence mechanisms. Molecular analyses based on four molecular markers (COI, 16S, H3 and 28S) for three Cyphoma species (C. gibbosum, C. mcgintyi, C. signatum) and an unidentified black morph, collected from three localities in the Caribbean, show that they represent morphological varieties of a single, genetically homogeneous species. This outcome is in agreement with previous anatomical studies. As a result C. mcgintyi and C. signatum are synonymised with C. gibbosum, which is a key result for future work using C. gibbosum as a model organism. The striking morphological differences in mantle pattern and colouration are hypothesised to be the result of one of three possible scenarios: rapid divergence, supergenes (including balanced polymorphism), or incipient speciation.
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Affiliation(s)
| | - Sancia E T van der Meij
- Naturalis Biodiversity Center, Leiden, The Netherlands; Oxford University Museum of Natural History, University of Oxford, Oxford, United Kingdom; Linacre College, Oxford, United Kingdom
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16
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Dating and biogeographical patterns in the sea slug genus Acanthodoris Gray, 1850 (Mollusca, Gastropoda, Nudibranchia). Mol Phylogenet Evol 2016; 97:19-31. [DOI: 10.1016/j.ympev.2015.12.018] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2014] [Revised: 12/25/2015] [Accepted: 12/27/2015] [Indexed: 01/23/2023]
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17
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Wares JP, Schiebelhut LM. What doesn't kill them makes them stronger: an association between elongation factor 1-α overdominance in the sea star Pisaster ochraceus and "sea star wasting disease". PeerJ 2016; 4:e1876. [PMID: 27069810 PMCID: PMC4824914 DOI: 10.7717/peerj.1876] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2016] [Accepted: 03/10/2016] [Indexed: 11/20/2022] Open
Abstract
In recent years, a massive mortality event has killed millions of sea stars, of many different species, along the Pacific coast of North America. This disease event, known as 'sea star wasting disease' (SSWD), is linked to viral infection. In one affected sea star (Pisaster ochraceus), previous work had identified that the elongation factor 1-α locus (EF1A) harbored an intronic insertion allele that is lethal when homozygous yet appears to be maintained at moderate frequency in populations through increased fitness for heterozygotes. The environmental conditions supporting this increased fitness are unknown, but overdominance is often associated with disease. Here, we evaluate populations of P. ochraceus to identify the relationship between SSWD and EF1A genotype. Our data suggest that there may be significantly decreased occurrence of SSWD in individuals that are heterozygous at this locus. These results suggest further studies are warranted to understand the functional relationship between diversity at EF1A and survival in P. ochraceus.
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Affiliation(s)
- John P. Wares
- Department of Genetics and the Odum School of Ecology, University of Georgia, Athens, GA, United States
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18
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Eisenlord ME, Groner ML, Yoshioka RM, Elliott J, Maynard J, Fradkin S, Turner M, Pyne K, Rivlin N, van Hooidonk R, Harvell CD. Ochre star mortality during the 2014 wasting disease epizootic: role of population size structure and temperature. Philos Trans R Soc Lond B Biol Sci 2016; 371:20150212. [PMID: 26880844 PMCID: PMC4760142 DOI: 10.1098/rstb.2015.0212] [Citation(s) in RCA: 70] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/15/2015] [Indexed: 11/18/2022] Open
Abstract
Over 20 species of asteroids were devastated by a sea star wasting disease (SSWD) epizootic, linked to a densovirus, from Mexico to Alaska in 2013 and 2014. For Pisaster ochraceus from the San Juan Islands, South Puget Sound and Washington outer coast, time-series monitoring showed rapid disease spread, high mortality rates in 2014, and continuing levels of wasting in the survivors in 2015. Peak prevalence of disease at 16 sites ranged to 100%, with an overall mean of 61%. Analysis of longitudinal data showed disease risk was correlated with both size and temperature and resulted in shifts in population size structure; adult populations fell to one quarter of pre-outbreak abundances. In laboratory experiments, time between development of disease signs and death was influenced by temperature in adults but not juveniles and adult mortality was 18% higher in the 19 °C treatment compared to the lower temperature treatments. While larger ochre stars developed disease signs sooner than juveniles, diseased juveniles died more quickly than diseased adults. Unusual 2-3 °C warm temperature anomalies were coincident with the summer 2014 mortalities. We suggest these warm waters could have increased the disease progression and mortality rates of SSWD in Washington State.
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Affiliation(s)
- Morgan E Eisenlord
- Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, NY 14850, USA
| | - Maya L Groner
- Department of Health Management, University of Prince Edward Island, Atlantic Veterinary College, Charlottetown, Prince Edward Island, Canada C1A 4P3
| | - Reyn M Yoshioka
- Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, NY 14850, USA
| | - Joel Elliott
- Department of Biology, University of Puget Sound, Tacoma, WA 98416, USA
| | - Jeffrey Maynard
- Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, NY 14850, USA Laboratoire d'Excellence «CORAIL» USR 3278 CNRS-EPHE, CRIOBE, Papetoai, Moorea, Polynésie Française
| | - Steven Fradkin
- Lake Crescent Laboratory, Olympic National Park, Port Angeles, WA 98362, USA
| | - Margaret Turner
- Marine Science Center, Northeastern University, Nahant, MA 01908, USA
| | - Katie Pyne
- Department of Biology, University of Puget Sound, Tacoma, WA 98416, USA
| | - Natalie Rivlin
- Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, NY 14850, USA
| | - Ruben van Hooidonk
- Atlantic Oceanographic and Meteorological Laboratory, NOAA, 4301 Rickenbacker Causeway, Miami, FL 33149, USA Cooperative Institute for Marine and Atmospheric Studies, Rosenstiel School of Marine and Atmospheric Science, University of Miami, 4600 Rickenbacker Causeway, Miami, FL 33149, USA
| | - C Drew Harvell
- Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, NY 14850, USA
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Gooding RA, Harley CDG. Quantifying the Effects of Predator and Prey Body Size on Sea Star Feeding Behaviors. THE BIOLOGICAL BULLETIN 2015; 228:192-200. [PMID: 26124446 DOI: 10.1086/bblv228n3p192] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Body size plays a crucial role in determining the strength of species interactions, population dynamics, and community structure. We measured how changes in body size affect the trophic relationship between the sea star Pisaster ochraceus and its prey, the mussel Mytilus trossulus. We tested the effects of a wide range of predator and prey sizes on sea stars' prey-size preference, feeding rate, and prey tissue consumption. We found that preferred prey size increased with sea star size. Pisaster consumption rate (mussels consumed per day) and tissue intake rate (grams of tissue consumed per day) also increased with sea star size. Pisaster consumption rate, but not tissue intake rate, decreased with increasing mussel size. Juvenile sea stars preferred the most profitable prey sizes-that is, those that maximized tissue consumed per unit handling time. When adult sea stars were offered larger, more profitable mussels, tissue intake rates (grams per day) tended to increase, although this relationship was not statistically significant. Our results indicate that the Pisaster-Mytilus interaction depends on the sizes of both predator and prey, that predation rates are sensitive to even small changes in body size, and that shifts in size distributions may affect predator energetics and prey numbers differently depending on the factors that limit tissue consumption rates.
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Affiliation(s)
- Rebecca A Gooding
- Department of Zoology, University of British Columbia, 6270 University Blvd, Vancouver, British Columbia V6T1Z4 Canada
| | - Christopher D G Harley
- Department of Zoology, University of British Columbia, 6270 University Blvd, Vancouver, British Columbia V6T1Z4 Canada
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20
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Sunday JM, Popovic I, Palen WJ, Foreman MGG, Hart MW. Ocean circulation model predicts high genetic structure observed in a long-lived pelagic developer. Mol Ecol 2014; 23:5036-47. [DOI: 10.1111/mec.12924] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2013] [Revised: 09/09/2014] [Accepted: 09/12/2014] [Indexed: 01/06/2023]
Affiliation(s)
- J. M. Sunday
- Biodiversity Research Centre; University of British Columbia; 2212 Main Mall Vancouver British Columbia Canada
- Department of Biological Sciences; Simon Fraser University; 8888 University Drive Burnaby British Columbia Canada
| | - I. Popovic
- Department of Biological Sciences; Simon Fraser University; 8888 University Drive Burnaby British Columbia Canada
| | - W. J. Palen
- Department of Biological Sciences; Simon Fraser University; 8888 University Drive Burnaby British Columbia Canada
| | - M. G. G. Foreman
- Institute of Ocean Sciences; Fisheries and Oceans Canada; 9860 West Saanich Road Sidney British Columbia Canada
| | - M. W. Hart
- Department of Biological Sciences; Simon Fraser University; 8888 University Drive Burnaby British Columbia Canada
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21
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Popovic I, Marko PB, Wares JP, Hart MW. Selection and demographic history shape the molecular evolution of the gamete compatibility protein bindin in Pisaster sea stars. Ecol Evol 2014; 4:1567-88. [PMID: 24967076 PMCID: PMC4063459 DOI: 10.1002/ece3.1042] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2013] [Revised: 02/15/2014] [Accepted: 02/26/2014] [Indexed: 12/18/2022] Open
Abstract
Reproductive compatibility proteins have been shown to evolve rapidly under positive selection leading to reproductive isolation, despite the potential homogenizing effects of gene flow. This process has been implicated in both primary divergence among conspecific populations and reinforcement during secondary contact; however, these two selective regimes can be difficult to discriminate from each other. Here, we describe the gene that encodes the gamete compatibility protein bindin for three sea star species in the genus Pisaster. First, we compare the full-length bindin-coding sequence among all three species and analyze the evolutionary relationships between the repetitive domains of the variable second bindin exon. The comparison suggests that concerted evolution of repetitive domains has an effect on bindin divergence among species and bindin variation within species. Second, we characterize population variation in the second bindin exon of two species: We show that positive selection acts on bindin variation in Pisaster ochraceus but not in Pisaster brevispinus, which is consistent with higher polyspermy risk in P. ochraceus. Third, we show that there is no significant genetic differentiation among populations and no apparent effect of sympatry with congeners that would suggest selection based on reinforcement. Fourth, we combine bindin and cytochrome c oxidase 1 data in isolation-with-migration models to estimate gene flow parameter values and explore the historical demographic context of our positive selection results. Our findings suggest that positive selection on bindin divergence among P. ochraceus alleles can be accounted for in part by relatively recent northward population expansions that may be coupled with the potential homogenizing effects of concerted evolution.
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Affiliation(s)
- Iva Popovic
- Department of Biological Sciences, Simon Fraser UniversityBurnaby, British Columbia, Canada
| | - Peter B Marko
- Department of Biology, University of Hawai'iMānoa, Hawaii
| | - John P Wares
- Department of Genetics, University of GeorgiaAthens, Georgia
| | - Michael W Hart
- Department of Biological Sciences, Simon Fraser UniversityBurnaby, British Columbia, Canada
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22
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Nokelainen O, Valkonen J, Lindstedt C, Mappes J. Changes in predator community structure shifts the efficacy of two warning signals in Arctiid moths. J Anim Ecol 2014; 83:598-605. [PMID: 24164666 DOI: 10.1111/1365-2656.12169] [Citation(s) in RCA: 92] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2013] [Accepted: 10/21/2013] [Indexed: 11/27/2022]
Abstract
Polymorphism in warning coloration is puzzling because positive frequency-dependent selection by predators is expected to promote monomorphic warning signals in defended prey. We studied predation on the warning-coloured wood tiger moth (Parasemia plantaginis) by using artificial prey resembling white and yellow male colour morphs in five separate populations with different naturally occurring morph frequencies. We tested whether predation favours one of the colour morphs over the other and whether that is influenced either by local, natural colour morph frequencies or predator community composition. We found that yellow specimens were attacked less than white ones regardless of the local frequency of the morphs indicating frequency-independent selection, but predation did depend on predator community composition: yellows suffered less attacks when Paridae were abundant, whereas whites suffered less attacks when Prunellidae were abundant. Our results suggest that spatial heterogeneity in predator community composition can generate a geographical mosaic of selection facilitating the evolution of polymorphic warning signals. This is the first time this mechanism gains experimental support. Altogether, this study sheds light on the evolution of adaptive coloration in heterogeneous environments.
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Affiliation(s)
- Ossi Nokelainen
- Department of Biological and Environmental Science, Centre of Excellence in Biological Interactions, University of Jyväskylä, Jyväskylä, P.O. Box 35, 40014, Finland
| | - Janne Valkonen
- Department of Biological and Environmental Science, Centre of Excellence in Biological Interactions, University of Jyväskylä, Jyväskylä, P.O. Box 35, 40014, Finland
| | - Carita Lindstedt
- Department of Biological and Environmental Science, Centre of Excellence in Biological Interactions, University of Jyväskylä, Jyväskylä, P.O. Box 35, 40014, Finland
| | - Johanna Mappes
- Department of Biological and Environmental Science, Centre of Excellence in Biological Interactions, University of Jyväskylä, Jyväskylä, P.O. Box 35, 40014, Finland
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23
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Barley AJ, White J, Diesmos AC, Brown RM. THE CHALLENGE OF SPECIES DELIMITATION AT THE EXTREMES: DIVERSIFICATION WITHOUT MORPHOLOGICAL CHANGE IN PHILIPPINE SUN SKINKS. Evolution 2013; 67:3556-72. [DOI: 10.1111/evo.12219] [Citation(s) in RCA: 99] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2013] [Accepted: 07/08/2013] [Indexed: 12/01/2022]
Affiliation(s)
- Anthony J. Barley
- Department of Ecology and Evolutionary Biology; University of Kansas; Lawrence Kansas 66045
| | - Jordan White
- Department of Ecology and Evolutionary Biology; University of Kansas; Lawrence Kansas 66045
| | | | - Rafe M. Brown
- Department of Ecology and Evolutionary Biology; University of Kansas; Lawrence Kansas 66045
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24
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Shell polymorphism in the land-snail Cepaea nemoralis (L.) along a West-East transect in continental Europe. FOLIA MALACOLOGICA 2012. [DOI: 10.2478/v10125-012-0015-1] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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25
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Balakirev ES, Krupnova TN, Ayala FJ. Symbiotic associations in the phenotypically-diverse brown alga Saccharina japonica. PLoS One 2012; 7:e39587. [PMID: 22745792 PMCID: PMC3379999 DOI: 10.1371/journal.pone.0039587] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2012] [Accepted: 05/23/2012] [Indexed: 02/08/2023] Open
Abstract
The brown alga Saccharina japonica (Areschoug) Lane, Mayes, Druehl et Saunders is a highly polymorphic representative of the family Laminariaceae, inhabiting the northwest Pacific region. We have obtained 16S rRNA sequence data in symbiont microorganisms of the typical form (TYP) of S. japonica and its common morphological varieties, known as "longipes" (LON) and "shallow-water" (SHA), which show contrasting bathymetric distribution and sharp morphological, life history traits, and ecological differences. Phylogenetic analysis of the 16S rRNA sequences shows that the microbial communities are significantly different in the three forms studied and consist of mosaic sets of common and form-specific bacterial lineages. The divergence in bacterial composition is substantial between the TYP and LON forms in spite of their high genetic similarity. The symbiont distribution in the S. japonica forms and in three other laminarialean species is not related to the depth or locality of the algae settlements. Combined with our previous results on symbiont associations in sea urchins and taking into account the highly specific character of bacteria-algae associations, we propose that the TYP and LON forms may represent incipient species passing through initial steps of reproductive isolation. We suggest that phenotype differences between genetically similar forms may be caused by host-symbiont interactions that may be a general feature of evolution in algae and other eukaryote organisms. Bacterial symbionts could serve as sensitive markers to distinguish genetically similar algae forms and also as possible growth-promoting inductors to increase algae productivity.
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Affiliation(s)
- Evgeniy S Balakirev
- Department of Ecology and Evolutionary Biology, University of California Irvine, Irvine, California, United States of America.
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26
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Chatti N, Zitari-Chatti R, Attia MH, Khadra YB, Said K. Very low mitochondrial diversity and genetic homogeneity in the starfish Echinaster sepositus along the Tunisian coast. Biochem Genet 2011; 50:45-51. [PMID: 21892776 DOI: 10.1007/s10528-011-9457-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2010] [Accepted: 04/21/2011] [Indexed: 10/17/2022]
Affiliation(s)
- Noureddine Chatti
- Unité de Recherche Génétique, Biodiversité et Valorisation des Bioressources, UR03ES09, Institut Supérieur de Biotechnologie de Monastir, Av. Tahar Haddad, 5000, Monastir, Tunisia.
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27
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BINKS RACHELM, EVANS JONATHANP, PRINCE JANE, KENNINGTON WJASON. Fine-scale patterns of genetic divergence within and between morphologically variable subspecies of the sea urchin Heliocidaris erythrogramma (Echinometridae). Biol J Linn Soc Lond 2011. [DOI: 10.1111/j.1095-8312.2011.01663.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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28
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Pedroza LSRA, Sauma MFLC, Vasconcelos JM, Takeshita LYC, Ribeiro-Rodrigues EM, Sastre D, Barbosa CM, Chies JAB, Veit TD, Lima CPS, Oliveira LF, Henderson BL, Castro APG, Maia MHT, Barbosa FB, Santos SEB, Guerreiro JF, Sena L, Santos EJM. Systemic lupus erythematosus: association with KIR and SLC11A1 polymorphisms, ethnic predisposition and influence in clinical manifestations at onset revealed by ancestry genetic markers in an urban Brazilian population. Lupus 2011; 20:265-73. [PMID: 21233146 DOI: 10.1177/0961203310385266] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Systemic lupus erythematosus (SLE) is an autoimmune disorder of the connective tissue with a wide and heterogeneous spectrum of manifestations, with renal and neurological involvement usually related to worse prognosis. SLE more frequently affects females of reproductive age, and a high prevalence and renal manifestation seem to be associated with non-European ethnicity. The present study aims to investigate candidate loci to SLE predisposition and evaluate the influence of ethnic ancestry in the disease risk and clinical phenotypic heterogeneity of lupus at onset. Samples represented by 111 patients and 345 controls, originated from the city of Belém, located in the Northern Region of Brazil, were investigated for polymorphisms in HLA-G, HLA-C, SLC11A1, MTHFR, CASP8 and 15 KIR genes, in addition to 89 Amerindian samples genotyped for SLC11A1. We also investigated 48 insertion/deletion ancestry markers to characterize individual African, European and Amerindian ancestry proportions in the samples. Predisposition to SLE was associated with GTGT deletion at the SLC11A1 3'UTR, presence of KIR2DS2 +/KIR2DS5 +/KIR3DS1 + profile, increased number of stimulatory KIR genes, and European and Amerindian ancestries. The ancestry analysis ruled out ethnic differences between controls and patients as the source of the observed associations. Moreover, the African ancestry was associated with renal manifestations.
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Affiliation(s)
- L S R A Pedroza
- 1Instituto de Ciências Biológicas, Universidade Federal do Pará, Belém, Pará, Brazil
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MARKO PETERB, HOFFMAN JESSICAM, EMME SANDRAA, MCGOVERN TAMARAM, KEEVER CARSONC, NICOLE COX L. The ‘Expansion-Contraction’ model of Pleistocene biogeography: rocky shores suffer a sea change? Mol Ecol 2010; 19:146-69. [DOI: 10.1111/j.1365-294x.2009.04417.x] [Citation(s) in RCA: 166] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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30
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Adaptive shell color plasticity during the early ontogeny of an intertidal keystone snail. Proc Natl Acad Sci U S A 2009; 106:16298-303. [PMID: 19805296 DOI: 10.1073/pnas.0908655106] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
We report a mechanism of crypsis present during the vulnerable early post-metamorphic ontogeny (</=20 mm peristomal length) of the muricid snail Concholepas concholepas, a rocky shore keystone predator characteristic of the southeastern Pacific coast. In the field, we found a significant occurrence (>95%) of specimens bearing patterns of shell coloration (dark or light colored) that matched the background coloration provided by patches of Concholepas' most abundant prey (mussels or barnacles respectively). The variation in shell color was positively associated with the color of the most common prey (r = 0.99). In laboratory experiments, shell coloration of C. concholepas depended on the prey-substrate used to induce metamorphosis and for the post-metamorphic rearing. The snail shell color matched the color of the prey offered during rearing. Laboratory manipulation experiments, switching the prey during rearing, showed a corresponding change in snail shell color along the outermost shell edge. As individuals grew and became increasingly indistinguishable from the surrounding background, cryptic individuals had higher survival (71%) than the non cryptic ones (4%) when they were reared in the presence of the predatory crab Acanthocyclus hassleri. These results suggest that the evolution of shell color plasticity during the early ontogeny of C. concholepas, depends on the color of the more abundant of the consumed prey available in the natural habitat where settlement has taken place; this in turn has important consequences for their fitness and survivorship in the presence of visual predators.
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31
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Keever CC, Sunday J, Puritz JB, Addison JA, Toonen RJ, Grosberg RK, Hart MW. Discordant distribution of populations and genetic variation in a sea star with high dispersal potential. Evolution 2009; 63:3214-27. [PMID: 19663996 DOI: 10.1111/j.1558-5646.2009.00801.x] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Patiria miniata, a broadcast-spawning sea star species with high dispersal potential, has a geographic range in the intertidal zone of the northeast Pacific Ocean from Alaska to California that is characterized by a large range gap in Washington and Oregon. We analyzed spatial genetic variation across the P. miniata range using multilocus sequence data (mtDNA, nuclear introns) and multilocus genotype data (microsatellites). We found a strong phylogeographic break at Queen Charlotte Sound in British Columbia that was not in the location predicted by the geographical distribution of the populations. However, this population genetic discontinuity does correspond to previously described phylogeographic breaks in other species. Northern populations from Alaska and Haida Gwaii were strongly differentiated from all southern populations from Vancouver Island and California. Populations from Vancouver Island and California were undifferentiated with evidence of high gene flow or very recent separation across the range disjunction between them. The surprising and discordant spatial distribution of populations and alleles suggests that historical vicariance (possibly caused by glaciations) and contemporary dispersal barriers (possibly caused by oceanographic conditions) both shape population genetic structure in this species.
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Affiliation(s)
- Carson C Keever
- Department of Biological Sciences, Simon Fraser University, Burnaby, British Columbia V5A 1S6, Canada
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Elevated water temperature and carbon dioxide concentration increase the growth of a keystone echinoderm. Proc Natl Acad Sci U S A 2009; 106:9316-21. [PMID: 19470464 DOI: 10.1073/pnas.0811143106] [Citation(s) in RCA: 179] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Anthropogenic climate change poses a serious threat to biodiversity. In marine environments, multiple climate variables, including temperature and CO(2) concentration ([CO(2)]), are changing simultaneously. Although temperature has well-documented ecological effects, and many heavily calcified marine organisms experience reduced growth with increased [CO(2)], little is known about the combined effects of temperature and [CO(2)], particularly on species that are less dependent on calcified shells or skeletons. We manipulated water temperature and [CO(2)] to determine the effects on the sea star Pisaster ochraceus, a keystone predator. We found that sea star growth and feeding rates increased with water temperature from 5 degrees C to 21 degrees C. A doubling of current [CO(2)] also increased growth rates both with and without a concurrent temperature increase from 12 degrees C to 15 degrees C. Increased [CO(2)] also had a positive but nonsignificant effect on sea star feeding rates, suggesting [CO(2)] may be acting directly at the physiological level to increase growth rates. As in past studies of other marine invertebrates, increased [CO(2)] reduced the relative calcified mass in sea stars, although this effect was observed only at the lower experimental temperature. The positive relationship between growth and [CO(2)] found here contrasts with previous studies, most of which have shown negative effects of [CO(2)] on marine species, particularly those that are more heavily calcified than P. ochraceus. Our findings demonstrate that increased [CO(2)] will not have direct negative effects on all marine invertebrates, suggesting that predictions of biotic responses to climate change should consider how different types of organisms will respond to changing climatic variables.
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Abstract
When individuals have higher evolutionary fitness because of being heterozygous at a given gene region, it is known as overdominance. Although overdominant selection could represent an important mechanism for maintaining genetic variation within species, the prevalence of this mode of selection appears to be relatively low. Identification of cases of true single-locus heterozygote advantage are thus useful reference points in our overall understanding of how various forms of balancing selection influence and maintain genetic variation in natural populations. Here we report the apparent long-term maintenance of diversity via overdominant selection with homozygous lethality at an elongation factor locus in the sea star Pisaster ochraceus. Observing this pattern in a gene with such major effects on protein assembly indicates that overdominant selection could be a more prevalent factor in maintaining allelic diversity in the wild than previously recognized.
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Affiliation(s)
- M S Pankey
- Department of Genetics, University of Georgia, Athens, GA 30602, USA
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DNA variation and symbiotic associations in phenotypically diverse sea urchin Strongylocentrotus intermedius. Proc Natl Acad Sci U S A 2008; 105:16218-23. [PMID: 18852450 DOI: 10.1073/pnas.0807860105] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Strongylocentrotus intermedius (A. Agassiz, 1863) is an economically important sea urchin inhabiting the northwest Pacific region of Asia. The northern Primorye (Sea of Japan) populations of S. intermedius consist of two sympatric morphological forms, "usual" (U) and "gray" (G). The two forms are significantly different in morphology and preferred bathymetric distribution, the G form prevailing in deeper-water settlements. We have analyzed the genetic composition of the S. intermedius forms using the nucleotide sequences of the mitochondrial gene encoding the cytochrome c oxidase subunit I and the nuclear gene encoding bindin to evaluate the possibility of cryptic species within S. intermedius. We have examined the presence of symbiont microorganisms by means of 16S rRNA sequences. The nucleotide sequence divergence between the morphological forms is low: 0.74% and 0.70% for cytochrome c oxidase subunit I and nuclear gene encoding bindin, respectively, which is significantly below average intrageneric sequence divergence among Strongylocentrotus species. We thus have found no genetic evidence of cryptic species within S. intermedius. Phylogenetic analysis shows that the bacteria symbionts of S. intermedius belong to the phylum Bacteroidetes, but the U and G forms predominantly harbor highly divergent bacterial lineages belonging to two different taxonomic classes, Flavobacteria and Sphingobacteria. We propose that the U and G forms of S. intermedius represent distinct ecomorphological adaptations to contrasting shallow- and deep-water marine environments and might be considered incipient species. We also propose that the symbiotic bacteria likely play an important role in the evolution of morphological divergence of S. intermedius.
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