1
|
Borg M, Krueger-Hadfield SA, Destombe C, Collén J, Lipinska A, Coelho SM. Red macroalgae in the genomic era. THE NEW PHYTOLOGIST 2023; 240:471-488. [PMID: 37649301 DOI: 10.1111/nph.19211] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/25/2023] [Accepted: 07/24/2023] [Indexed: 09/01/2023]
Abstract
Rhodophyta (or red algae) are a diverse and species-rich group that forms one of three major lineages in the Archaeplastida, a eukaryotic supergroup whose plastids arose from a single primary endosymbiosis. Red algae are united by several features, such as relatively small intron-poor genomes and a lack of cytoskeletal structures associated with motility like flagella and centrioles, as well as a highly efficient photosynthetic capacity. Multicellular red algae (or macroalgae) are one of the earliest diverging eukaryotic lineages to have evolved complex multicellularity, yet despite their ecological, evolutionary, and commercial importance, they have remained a largely understudied group of organisms. Considering the increasing availability of red algal genome sequences, we present a broad overview of fundamental aspects of red macroalgal biology and posit on how this is expected to accelerate research in many domains of red algal biology in the coming years.
Collapse
Affiliation(s)
- Michael Borg
- Department of Algal Development and Evolution, Max Planck Institute for Biology, 72076, Tübingen, Germany
| | - Stacy A Krueger-Hadfield
- Department of Biology, The University of Alabama at Birmingham, Birmingham, AL, 35294, USA
- Virginia Institute of Marine Science Eastern Shore Laboratory, Wachapreague, VA, 23480, USA
| | - Christophe Destombe
- International Research Laboratory 3614 (IRL3614) - Evolutionary Biology and Ecology of Algae, Centre National de la Recherche Scientifique (CNRS), Sorbonne Université, Pontificia Universidad Católica de Chile, Universidad Austral de Chile, Roscoff, 29680, France
| | - Jonas Collén
- CNRS, Integrative Biology of Marine Models (LBI2M, UMR8227), Station Biologique de Roscoff, Sorbonne Université, Roscoff, 29680, France
| | - Agnieszka Lipinska
- Department of Algal Development and Evolution, Max Planck Institute for Biology, 72076, Tübingen, Germany
| | - Susana M Coelho
- Department of Algal Development and Evolution, Max Planck Institute for Biology, 72076, Tübingen, Germany
| |
Collapse
|
2
|
Krueger-Hadfield SA, Oetterer AP, Lees LE, Hoffman JM, Sotka EE, Murren CJ. Phenology and thallus size in a non-native population of Gracilaria vermiculophylla. JOURNAL OF PHYCOLOGY 2023; 59:926-938. [PMID: 37729054 DOI: 10.1111/jpy.13371] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/25/2023] [Revised: 06/13/2023] [Accepted: 07/03/2023] [Indexed: 09/22/2023]
Abstract
Phenology, or seasonal variation in life cycle events, is poorly described for many macroalgal species. We describe the phenology of a non-native population of Gracilaria vermiculophylla whose thalli are free-living or anchored by decorating polychaetes to tube caps. At a site in South Carolina, USA, we sampled 100 thalli approximately every month from January 2014 to January 2015. We assessed the reproductive state and measured thallus size based on wet weight, thallus length, and thallus surface area from herbarium mounts. Because life cycle stage cannot be assigned using morphology, we implemented a PCR assay to determine the life cycle stage-tetrasporophyte, female gametophyte, or male gametophyte-of each thallus. Tetrasporophytes dominated throughout the year, making up 81%-100% of thalli sampled per month. Reproductive tetrasporophytes varied between 0% and 65% of monthly samples and were most common in warm summer months (July through September) when thalli also tended to be larger. The vast majority of the reproductive thalli were worm-anchored and not fixed to hard substratum via a holdfast. Thus, free-living thalli can be reproductive and potentially seed new non-native populations. Given G. vermiculophylla reproduction seems tied closely to temperature, our work suggests phenology may change with climate-related changes in seawater temperatures. We also highlight the importance of understanding the natural history of macroalgae to better understand the consequence of range expansions on population dynamics.
Collapse
Affiliation(s)
| | - Alexis P Oetterer
- Department of Biology, University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Lauren E Lees
- Department of Biology, College of Charleston, Charleston, South Carolina, USA
| | - Jessica M Hoffman
- Department of Biology, University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Erik E Sotka
- Department of Biology, College of Charleston, Charleston, South Carolina, USA
| | - Courtney J Murren
- Department of Biology, College of Charleston, Charleston, South Carolina, USA
| |
Collapse
|
3
|
Heiser S, Amsler CD, Stoeckel S, McClintock JB, Baker BJ, Krueger-Hadfield SA. Tetrasporophytic bias coupled with heterozygote deficiency in Antarctic Plocamium sp. (Florideophyceae, Rhodophyta). JOURNAL OF PHYCOLOGY 2023; 59:681-697. [PMID: 37114881 DOI: 10.1111/jpy.13339] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/21/2022] [Revised: 02/11/2023] [Accepted: 03/29/2023] [Indexed: 05/05/2023]
Abstract
Meiosis and syngamy generate an alternation between two ploidy stages, but the timing of these two processes varies widely across taxa, thereby generating life cycle diversity. One hypothesis suggests that life cycles with long-lived haploid stages are correlated with selfing, asexual reproduction, or both. Though mostly studied in angiosperms, selfing and asexual reproduction are often associated with marginal habitats. Yet, in haploid-diploid macroalgae, these two reproductive modes have subtle but unique consequences whereby predictions from angiosperms may not apply. Along the western Antarctic Peninsula, there is a thriving macroalgal community, providing an opportunity to explore reproductive system variation in haploid-diploid macroalgae at high latitudes where endemism is common. Plocamium sp. is a widespread and abundant red macroalga observed within this ecosystem. We sampled 12 sites during the 2017 and 2018 field seasons and used 10 microsatellite loci to describe the reproductive system. Overall genotypic richness and evenness were high, suggesting sexual reproduction. Eight sites were dominated by tetrasporophytes, but there was strong heterozygote deficiency, suggesting intergametophytic selfing. We observed slight differences in the prevailing reproductive mode among sites, possibly due to local conditions (e.g., disturbance) that may contribute to site-specific variation. It remains to be determined whether high levels of selfing are characteristic of macroalgae more generally at high latitudes, due to the haploid-diploid life cycle, or both. Further investigations of algal life cycles will likely reveal the processes underlying the maintenance of sexual reproduction more broadly across eukaryotes, but more studies of natural populations are required.
Collapse
Affiliation(s)
- Sabrina Heiser
- Department of Biology, University of Alabama, Birmingham, Alabama, USA
| | - Charles D Amsler
- Department of Biology, University of Alabama, Birmingham, Alabama, USA
| | - Solenn Stoeckel
- IGEPP, INRAE, Institut Agro, Université de Rennes, Le Rheu, France
| | | | - Bill J Baker
- Department of Chemistry, University of South Florida, Tampa, Florida, USA
| | | |
Collapse
|
4
|
Xiang JX, Saha M, Zhong KL, Zhang QS, Zhang D, Jueterbock A, Krueger-Hadfield SA, Wang GG, Weinberger F, Hu ZM. Genome-scale signatures of adaptive gene expression changes in an invasive seaweed Gracilaria vermiculophylla. Mol Ecol 2023; 32:613-627. [PMID: 36355347 DOI: 10.1111/mec.16776] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2022] [Revised: 11/02/2022] [Accepted: 11/08/2022] [Indexed: 11/12/2022]
Abstract
Invasive species can successfully and rapidly colonize new niches and expand ranges via founder effects and enhanced tolerance towards environmental stresses. However, the underpinning molecular mechanisms (i.e., gene expression changes) facilitating rapid adaptation to harsh environments are still poorly understood. The red seaweed Gracilaria vermiculophylla, which is native to the northwest Pacific but invaded North American and European coastal habitats over the last 100 years, provides an excellent model to examine whether enhanced tolerance at the level of gene expression contributed to its invasion success. We collected G. vermiculophylla from its native range in Japan and from two non-native regions along the Delmarva Peninsula (Eastern United States) and in Germany. Thalli were reared in a common garden for 4 months at which time we performed comparative transcriptome (mRNA) and microRNA (miRNA) sequencing. MRNA-expression profiling identified 59 genes that were differently expressed between native and non-native thalli. Of these genes, most were involved in metabolic pathways, including photosynthesis, abiotic stress, and biosynthesis of products and hormones in all four non-native sites. MiRNA-based target-gene correlation analysis in native/non-native pairs revealed that some target genes are positively or negatively regulated via epigenetic mechanisms. Importantly, these genes are mostly associated with metabolism and defence capability (e.g., metal transporter Nramp5, senescence-associated protein, cell wall-associated hydrolase, ycf68 protein and cytochrome P450-like TBP). Thus, our gene expression results indicate that resource reallocation to metabolic processes is most likely a predominant mechanism contributing to the range-wide persistence and adaptation of G. vermiculophylla in the invaded range. This study, therefore, provides molecular insight into the speed and nature of invasion-mediated rapid adaption.
Collapse
Affiliation(s)
| | - Mahasweta Saha
- Marine Ecology Division, GEOMAR Helmholtz-Zentrum für Ozeanforschung Kiel, Kiel, Germany
- Marine Ecology and Biodiversity, Plymouth Marine Laboratory, Plymouth, UK
| | - Kai-Le Zhong
- Key Laboratory of Experimental Marine Biology, Center for Ocean Mega-Science, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China
| | | | - Di Zhang
- Ocean School, YanTai University, Yantai, China
| | - Alexander Jueterbock
- Algal and Microbial Biotechnology Division, Faculty of Biosciences and Aquaculture, Nord University, Bodø, Norway
| | | | - Gao-Ge Wang
- Institute of Evolution and Marine Biodiversity, College of Marine Life Sciences, Ocean University of China, Qingdao, China
| | - Florian Weinberger
- Marine Ecology Division, GEOMAR Helmholtz-Zentrum für Ozeanforschung Kiel, Kiel, Germany
| | - Zi-Min Hu
- Ocean School, YanTai University, Yantai, China
| |
Collapse
|
5
|
Individuals from non-native populations are stronger and bigger than individuals from native populations of a widespread seaweed. Biol Invasions 2022. [DOI: 10.1007/s10530-022-02766-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
6
|
Flanagan BA, Krueger-Hadfield SA, Murren CJ, Nice CC, Strand AE, Sotka EE. Founder effects shape linkage disequilibrium and genomic diversity of a partially clonal invader. Mol Ecol 2021; 30:1962-1978. [PMID: 33604965 DOI: 10.1111/mec.15854] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2020] [Revised: 01/18/2021] [Accepted: 02/01/2021] [Indexed: 12/20/2022]
Abstract
The genomic variation of an invasive species may be affected by complex demographic histories and evolutionary changes during the invasion. Here, we describe the relative influence of bottlenecks, clonality, and population expansion in determining genomic variability of the widespread red macroalga Agarophyton vermiculophyllum. Its introduction from mainland Japan to the estuaries of North America and Europe coincided with shifts from predominantly sexual to partially clonal reproduction and rapid adaptive evolution. A survey of 62,285 SNPs for 351 individuals from 35 populations, aligned to 24 chromosome-length scaffolds indicate that linkage disequilibrium (LD), observed heterozygosity (Ho ), Tajima's D, and nucleotide diversity (Pi) were greater among non-native than native populations. Evolutionary simulations indicate LD and Tajima's D were consistent with a severe population bottleneck. Also, the increased rate of clonal reproduction in the non-native range could not have produced the observed patterns by itself but may have magnified the bottleneck effect on LD. Elevated marker diversity in the genetic source populations could have contributed to the increased Ho and Pi observed in the non-native range. We refined the previous invasion source region to a ~50 km section of northeastern Honshu Island. Outlier detection methods failed to reveal any consistently differentiated loci shared among invaded regions, probably because of the complex A. vermiculophyllum demographic history. Our results reinforce the importance of demographic history, specifically founder effects, in driving genomic variation of invasive populations, even when localized adaptive evolution and reproductive system shifts are observed.
Collapse
Affiliation(s)
- Ben A Flanagan
- Department of Biology, College of Charleston, Charleston, SC, USA.,Department of Biological Sciences, University of Southern California, Los Angeles, CA, USA
| | - Stacy A Krueger-Hadfield
- Department of Biology, College of Charleston, Charleston, SC, USA.,Department of Biology, University of Alabama at Birmingham, Birmingham, AL, USA
| | | | - Chris C Nice
- Department of Biology, Population and Conservation Biology Program, Texas State University, San Marcos, TX, USA
| | - Allan E Strand
- Department of Biology, College of Charleston, Charleston, SC, USA
| | - Erik E Sotka
- Department of Biology, College of Charleston, Charleston, SC, USA
| |
Collapse
|
7
|
Vieira VM, Engelen AH, Huanel OR, Guillemin M. Differential Frond Growth in the Isomorphic Haploid-diploid Red Seaweed Agarophyton chilense by Long-term In Situ Monitoring. JOURNAL OF PHYCOLOGY 2021; 57:592-605. [PMID: 33249614 PMCID: PMC8247958 DOI: 10.1111/jpy.13110] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/19/2020] [Revised: 10/18/2020] [Accepted: 10/29/2020] [Indexed: 06/12/2023]
Abstract
Conditional differentiation between haploids and diploids has been proposed to drive the evolutionary stability of isomorphic biphasic life cycles. The cost of producing and maintaining genetic information has been posed as a possible driver of this conditional differentiation. Under this hypothesis, haploids benefit over diploids in resource-limited environments by halving the costs of producing and maintaining DNA. Spared resources can be allocated to enhance survival, growth or fertility. Here we test in the field whether indeed haploids have higher growth rates than diploids. Individuals of the red seaweed Agarophyton chilense, were mapped and followed during 2 years with 4-month census intervals across different stands within the Valdivia River estuary, Chile. As hypothesized, haploids grew larger and faster than diploids, but this was sex-dependent. Haploid (gametophyte) females grew twice as large and 15% faster than diploids (tetrasporophytes), whereas haploid males only grew as large and as fast as the maximum obtained by diploids in summer. However, haploid males maintained their maximum sizes and growth rates constant year-round, while diploids were smaller and had lower growth rates during the winter. In conclusion, our results confirm the conditional differentiation in size and growth between haploids and diploids but also identified important differences between males and females. Besides understanding life cycle evolution, the dynamics of A. chilense frond growth reported informs algal farmers regarding production optimization and should help in determining best planting and harvesting strategies.
Collapse
Affiliation(s)
- Vasco M.N.C.S. Vieira
- MARETECInstituto Superior TécnicoUniversidade Técnica de LisboaAv. Rovisco Pais1049‐001LisboaPortugal
| | - Aschwin H. Engelen
- CCMARCenter of Marine ScienceUniversity of AlgarveCampus Gambelas8005‐139FaroPortugal
| | - Oscar R. Huanel
- Departamento de EcologíaFacultad de Ciencias BiológicasPontificia Universidad Católica de ChileSantiagoChile
- CNRSUMI 3614Evolutionary Biology and Ecology of AlgaeSorbonne UniversitésUPMC University Paris VIStation Biologique de RoscoffCS 90074Place G. Tessier296888RoscoffFrance
| | - Marie‐Laure Guillemin
- CNRSUMI 3614Evolutionary Biology and Ecology of AlgaeSorbonne UniversitésUPMC University Paris VIStation Biologique de RoscoffCS 90074Place G. Tessier296888RoscoffFrance
- Instituto de Ciencias Ambientales y EvolutivasFacultad de CienciasUniversidad Austral de ChileCasilla 567ValdiviaChile
| |
Collapse
|
8
|
Krueger-Hadfield SA, Flanagan BA, Godfroy O, Hill-Spanik KM, Nice CC, Murren CJ, Strand AE, Sotka EE. Using RAD-seq to develop sex-linked markers in a haplodiplontic alga. JOURNAL OF PHYCOLOGY 2021; 57:279-294. [PMID: 33098662 DOI: 10.1111/jpy.13088] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/03/2020] [Accepted: 10/05/2020] [Indexed: 06/11/2023]
Abstract
For many taxa, including isomorphic haplodiplontic macroalgae, determining sex and ploidy is challenging, thereby limiting the scope of some population demographic and genetic studies. Here, we used double-digest restriction site-associated DNA sequencing (ddRAD-seq) to identify sex-linked molecular markers in the widespread red alga Agarophyton vermiculophyllum. In the ddRAD-seq library, we included 10 female gametophytes, 10 male gametophytes, and 16 tetrasporophytes from one native and one non-native site (N = 40 gametophytes and N = 32 tetrasporophytes total). We identified seven putatively female-linked and 19 putatively male-linked sequences. Four female- and eight male-linked markers amplified in all three life cycle stages. Using one female- and one male-linked marker that were sex-specific, we developed a duplex PCR and tested the efficacy of this assay on a subset of thalli sampled at two sites in the non-native range. We confirmed ploidy based on the visual observation of reproductive structures and previous microsatellite genotyping at 10 polymorphic loci. For 32 vegetative thalli, we were able to assign sex and confirm ploidy in these previously genotyped thalli. These markers will be integral to ongoing studies of A. vermiculophyllum invasion. We discuss the utility of RAD-seq over other approaches previously used, such as RAPDs (random amplified polymorphic DNA), for future work designing sex-linked markers in other haplodiplontic macroalgae for which genomes are lacking.
Collapse
Affiliation(s)
- Stacy A Krueger-Hadfield
- Department of Biology, University of Alabama at Birmingham, 1300 University Blvd, Birmingham, Alabama, 35294, USA
| | - Ben A Flanagan
- Department of Biological Sciences, University of Southern California, Los Angeles, California, 90089, USA
| | - Olivier Godfroy
- Sorbonne Université, CNRS, Integrative Biology of Marine Models (LBI2M), Station Biologique de Roscoff (SBR), 29680, Roscoff, France
| | - Kristina M Hill-Spanik
- Department of Biology and Grice Marine Lab, College of Charleston, 205 Fort Johnson Road, Charleston, South Carolina, 29412, USA
| | - Chris C Nice
- Department of Biology, Population and Conservation Biology Program, Texas State University, San Marcos, Texas, 78666, USA
| | - Courtney J Murren
- Department of Biology, College of Charleston, 66 George Street, Charleston, South Carolina, 29424, USA
| | - Allan E Strand
- Department of Biology and Grice Marine Lab, College of Charleston, 205 Fort Johnson Road, Charleston, South Carolina, 29412, USA
| | - Erik E Sotka
- Department of Biology and Grice Marine Lab, College of Charleston, 205 Fort Johnson Road, Charleston, South Carolina, 29412, USA
| |
Collapse
|
9
|
Krueger-Hadfield SA, Ryan WH. Influence of nutrients on ploidy-specific performance in an invasive, haplodiplontic red macroalga. JOURNAL OF PHYCOLOGY 2020; 56:1114-1120. [PMID: 32348550 DOI: 10.1111/jpy.13011] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/30/2019] [Accepted: 04/21/2020] [Indexed: 06/11/2023]
Abstract
Worldwide, macroalgae have invaded near-shore marine ecosystems. However, their haplodiplontic life cycles have complicated efforts to predict patterns of growth and spread, particularly since most theoretical predictions are derived from diplontic taxa (i.e., animals). To complete one revolution of the life cycle, two separate ploidy stages, often including separate haploid sexes, must pass through development and reproduction. In the case of the invasive, red macroalga Agarophyton vermiculophyllum, during the invasion of soft-sediment estuaries throughout the Northern Hemisphere, diploid tetrasporophytes came to dominate all free-floating populations and haploid gametophytes were consistently lost. The ecological hypothesis of nutrient limitation might contribute to an explanation of this pattern of tetrasporophytic dominance in free-floating populations. Under this hypothesis, gametophytes should outperform tetrasporophytes under nutrient limited conditions, but tetrasporophytes should be better able to exploit optimal or even abundant nutrient conditions, such as in eutrophic estuaries. We sampled tetrasporophytes, male gametophytes, and female gametophytes from two sites each located on either side of the Delmarva Peninsula that separates the Chesapeake Bay from the Atlantic Ocean. We subjected apices excised from multiple thalli from each life cycle stage to a nutrient-enriched and a nutrient-poor seawater treatment and assessed growth and survival. While nutrient addition increased growth rates, there was no significant difference among ploidies or sexes. Gametophytes did, however, suffer higher mortality than tetrasporophytes. We discuss how nutrient-dependent differences in growth and survival may contribute to observed patterns of tetrasporophytic dominance in soft-sediment A. vermiculophyllum populations.
Collapse
Affiliation(s)
- Stacy A Krueger-Hadfield
- Department of Biology, The University of Alabama at Birmingham, 1300 University Blvd, Birmingham, Alabama, 35924, USA
| | - Will H Ryan
- Department of Biology, The University of Alabama at Birmingham, 1300 University Blvd, Birmingham, Alabama, 35924, USA
| |
Collapse
|
10
|
Bonthond G, Bayer T, Krueger-Hadfield SA, Barboza FR, Nakaoka M, Valero M, Wang G, Künzel S, Weinberger F. How do microbiota associated with an invasive seaweed vary across scales? Mol Ecol 2020; 29:2094-2108. [PMID: 32408381 DOI: 10.1111/mec.15470] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2019] [Revised: 04/18/2020] [Accepted: 05/05/2020] [Indexed: 01/13/2023]
Abstract
Communities are shaped by scale dependent processes. To study the diversity and variation of microbial communities across scales, the invasive and widespread seaweed Agarophyton vermiculophyllum presents a unique opportunity. We characterized pro- and eukaryotic communities associated with this holobiont across its known distribution range, which stretches over the northern hemisphere. Our data reveal that community composition and diversity in the holobiont vary at local but also larger geographic scales. While processes acting at the local scale (i.e., within population) are the main structuring drivers of associated microbial communities, changes in community composition also depend on processes acting at larger geographic scales. Interestingly, the largest analysed scale (i.e., native and non-native ranges) explained variation in the prevalence of predicted functional groups, which could suggest a functional shift in microbiota occurred over the course of the invasion process. While high variability in microbiota at the local scale supports A. vermiculophyllum to be a generalist host, we also identified a number of core taxa. These geographically independent holobiont members imply that cointroduction of specific microbiota may have additionally promoted the invasion process.
Collapse
Affiliation(s)
- Guido Bonthond
- GEOMAR Helmholtz Centre for Ocean Research Kiel, Kiel, Germany
| | - Till Bayer
- GEOMAR Helmholtz Centre for Ocean Research Kiel, Kiel, Germany
| | | | | | - Masahiro Nakaoka
- Akkeshi Marine Station, Field Science Center for Northern Biosphere, Hokkaido University, Akkeshi, Japan
| | - Myriam Valero
- UMI EBEA 3614, CNRS, UCCh, UACH, Station Biologique de Roscoff, Sorbonne Université, Roscoff, France
| | - Gaoge Wang
- College of Marine Life Sciences, Ocean University of China, Qingdao, China.,Institute of Evolution and Marine Biodiversity, Ocean University of China, Qingdao, China
| | - Sven Künzel
- Max Planck Institute for Evolutionary Biology, Plön, Germany
| | | |
Collapse
|
11
|
Krueger‐Hadfield SA. What's ploidy got to do with it? Understanding the evolutionary ecology of macroalgal invasions necessitates incorporating life cycle complexity. Evol Appl 2020; 13:486-499. [PMID: 32431731 PMCID: PMC7045718 DOI: 10.1111/eva.12843] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2019] [Revised: 06/09/2019] [Accepted: 07/06/2019] [Indexed: 01/04/2023] Open
Abstract
Biological invasions represent grave threats to terrestrial, aquatic, and marine ecosystems, but our understanding of the role of evolution during invasions remains rudimentary. In marine environments, macroalgae account for a large percentage of invaders, but their complicated life cycles render it difficult to move methodologies and predictions wholesale from species with a single, free-living ploidy stage, such as plants or animals. In haplodiplontic macroalgae, meiosis and fertilization are spatiotemporally separated by long-lived, multicellular haploid and diploid stages, and gametes are produced by mitosis, not meiosis. As a consequence, there are unique eco-evolutionary constraints that are not typically considered in invasions. First, selfing can occur in both monoicious (i.e., hermaphroditic) and dioicious (i.e., separate sexes) haplodiplontic macroalgae. In the former, fertilization between gametes produced by the same haploid thallus results in instantaneous, genome-wide homozygosity. In the latter, cross-fertilization between separate male and female haploids that share the same diploid parent is analogous to selfing in plants or animals. Separate sexes, therefore, cannot be used as a proxy for outcrossing. Second, selfing likely facilitates invasions (i.e., Baker's law) and the long-lived haploid stage may enable purging of deleterious mutations, further contributing to invasion success. Third, asexual reproduction will result in the dominance of one ploidy and/or sex and the loss of the other(s). Whether or not sexual reproduction can be recovered depends on which stage is maintained. Finally, fourth, haplodiplontic life cycles are predicted to be maintained through niche differentiation in the haploid and diploid stages. Empirical tests are rare, but fundamental to our understanding of macroalgal invasion dynamics. By highlighting these four phenomena, we can build a framework with which to empirically and theoretically address important gaps in the literature on marine evolutionary ecology, of which biological invasions can serve as unnatural laboratories.
Collapse
|
12
|
Krueger-Hadfield SA, Blakeslee AMH, Fowler AE. Incorporating Ploidy Diversity into Ecological and Community Genetics. JOURNAL OF PHYCOLOGY 2019; 55:1198-1207. [PMID: 31349373 DOI: 10.1111/jpy.12906] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/04/2019] [Accepted: 07/11/2019] [Indexed: 06/10/2023]
Abstract
Studies in ecological and community genetics have advanced our understanding of the role of intraspecific diversity in structuring communities and ecosystems. However, in near-shore marine communities, these studies have mostly been restricted to seagrasses, marsh plants, and oysters. Yet, macroalgae are critically important ecosystem engineers in these communities. Greater intraspecific diversity in a macroalgal ecosystem engineer should result in higher primary and secondary production and community resilience. The paucity of studies investigating the consequences of macroalgal intraspecific genetic variation might be due, in part, to the complexity of macroalgal life cycles. The majority of macroalgae have seemingly subtle, but in actuality, profoundly different life cycles than the more typical animal and angiosperm models. Here, we develop a novel genetic diversity metric, PHD , that incorporates the ratio of gametophytic to sporophytic thalli in natural populations. This metric scales from 0 to 1 like many common genetic diversity metrics, such as genotypic richness, enabling comparisons among metrics. We discuss PHD and examples from the literature, with specific reference to the widespread, red seaweed Agarophyton vermiculophyllum. We also discuss a sex diversity metric, PFM , which also scales from 0 to 1, but fewer studies have identified males and females in natural populations. Nevertheless, by incorporating these novel metrics into the repertoire of diversity metrics, we can explore the role of genetic diversity in community and ecosystem dynamics with an emphasis on the unique biology of many macroalgae, as well as other haplodiplontic taxa such as ferns, foraminiferans, and some fungi.
Collapse
Affiliation(s)
- Stacy A Krueger-Hadfield
- Department of Biology, University of Alabama at Birmingham, 1300 University Blvd CH464, Birmingham, Alabama, 35294, USA
| | - April M H Blakeslee
- Department of Biology, East Carolina University, E 10th Street, Greenville, North Carolina, 27858, USA
| | - Amy E Fowler
- Department of Environmental Science and Policy, George Mason University, 4400 University Dr, Fairfax, Virginia, 22030, USA
| |
Collapse
|
13
|
Robitzch V, Arakaki N, Mauger S, Zapata Rojas JC, Guillemin ML. Stranded alone: The first reported Peruvian population of Agarophyton chilensis is a single-male's clone. ALGAL RES 2019. [DOI: 10.1016/j.algal.2019.101527] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
|