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Connolly JB, Burt A, Christophides G, Diabate A, Habtewold T, Hancock PA, James AA, Kayondo JK, Lwetoijera DW, Manjurano A, McKemey AR, Santos MR, Windbichler N, Randazzo F. Considerations for first field trials of low-threshold gene drive for malaria vector control. Malar J 2024; 23:156. [PMID: 38773487 PMCID: PMC11110314 DOI: 10.1186/s12936-024-04952-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2023] [Accepted: 04/15/2024] [Indexed: 05/23/2024] Open
Abstract
Sustainable reductions in African malaria transmission require innovative tools for mosquito control. One proposal involves the use of low-threshold gene drive in Anopheles vector species, where a 'causal pathway' would be initiated by (i) the release of a gene drive system in target mosquito vector species, leading to (ii) its transmission to subsequent generations, (iii) its increase in frequency and spread in target mosquito populations, (iv) its simultaneous propagation of a linked genetic trait aimed at reducing vectorial capacity for Plasmodium, and (v) reduced vectorial capacity for parasites in target mosquito populations as the gene drive system reaches fixation in target mosquito populations, causing (vi) decreased malaria incidence and prevalence. Here the scope, objectives, trial design elements, and approaches to monitoring for initial field releases of such gene dive systems are considered, informed by the successful implementation of field trials of biological control agents, as well as other vector control tools, including insecticides, Wolbachia, larvicides, and attractive-toxic sugar bait systems. Specific research questions to be addressed in initial gene drive field trials are identified, and adaptive trial design is explored as a potentially constructive and flexible approach to facilitate testing of the causal pathway. A fundamental question for decision-makers for the first field trials will be whether there should be a selective focus on earlier points of the pathway, such as genetic efficacy via measurement of the increase in frequency and spread of the gene drive system in target populations, or on wider interrogation of the entire pathway including entomological and epidemiological efficacy. How and when epidemiological efficacy will eventually be assessed will be an essential consideration before decisions on any field trial protocols are finalized and implemented, regardless of whether initial field trials focus exclusively on the measurement of genetic efficacy, or on broader aspects of the causal pathway. Statistical and modelling tools are currently under active development and will inform such decisions on initial trial design, locations, and endpoints. Collectively, the considerations here advance the realization of developer ambitions for the first field trials of low-threshold gene drive for malaria vector control within the next 5 years.
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Affiliation(s)
- John B Connolly
- Department of Life Sciences, Silwood Park, Imperial College London, London, UK.
| | - Austin Burt
- Department of Life Sciences, Silwood Park, Imperial College London, London, UK
| | - George Christophides
- Department of Life Sciences, South Kensington Campus, Imperial College London, London, UK
| | - Abdoulaye Diabate
- Institut de Recherche en Sciences de la Santé/Centre Muraz, Bobo-Dioulasso, Burkina Faso
| | - Tibebu Habtewold
- Department of Life Sciences, South Kensington Campus, Imperial College London, London, UK
- Environmental Health and Ecological Science Department, Ifakara Health Institute, Ifakara, Tanzania
| | - Penelope A Hancock
- MRC Centre for Global Infectious Disease Analysis, St. Mary's Campus, Imperial College London, London, UK
| | - Anthony A James
- Departments of Microbiology & Molecular Genetics and Molecular Biology & Biochemistry, University of California, Irvine, USA
| | - Jonathan K Kayondo
- Entomology Department, Uganda Virus Research Institute (UVRI), Entebbe, Uganda
| | | | - Alphaxard Manjurano
- Malaria Research Unit and Laboratory Sciences, Mwanza Medical Research Centre, National Institute for Medical Research, Mwanza, Tanzania
| | - Andrew R McKemey
- Department of Life Sciences, Silwood Park, Imperial College London, London, UK
| | - Michael R Santos
- Foundation for the National Institutes of Health, North Bethesda, MD, USA
| | - Nikolai Windbichler
- Department of Life Sciences, South Kensington Campus, Imperial College London, London, UK
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Duprey J, Gallego R, Klinger T, Kelly RP. Environmental DNA reveals patterns of biological invasion in an inland sea. PLoS One 2023; 18:e0281525. [PMID: 38150426 PMCID: PMC10752502 DOI: 10.1371/journal.pone.0281525] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2023] [Accepted: 11/28/2023] [Indexed: 12/29/2023] Open
Abstract
Non-native species have the potential to cause ecological and economic harm to coastal and estuarine ecosystems. Understanding which habitat types are most vulnerable to biological invasions, where invasions originate, and the vectors by which they arrive can help direct limited resources to prevent or mitigate ecological and socio-economic harm. Information about the occurrence of non-native species can help guide interventions at all stages of invasion, from first introduction, to naturalization and invasion. However, monitoring at relevant scales requires considerable investment of time, resources, and taxonomic expertise. Environmental DNA (eDNA) metabarcoding methods sample coastal ecosystems at broad spatial and temporal scales to augment established monitoring methods. We use COI mtDNA eDNA sampling to survey a diverse assemblage of species across distinct habitats in the Salish Sea in Washington State, USA, and classify each as non-native, native, or indeterminate in origin. The non-native species detected include both well-documented invaders and species not previously reported within the Salish Sea. We find a non-native assemblage dominated by shellfish and algae with native ranges in the temperate western Pacific, and find more-retentive estuarine habitats to be invaded at far higher levels than better-flushed rocky shores. Furthermore, we find an increase in invasion level with higher water temperatures in spring and summer across habitat types. This analysis contributes to a growing understanding of the biotic and abiotic factors that influence invasion level, and underscores the utility of eDNA surveys to monitor biological invasions and to better understand the factors that drive these invasions.
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Affiliation(s)
- Joe Duprey
- School of Marine and Environmental Affairs, University of Washington, Seattle, WA, United States of America
| | - Ramón Gallego
- School of Marine and Environmental Affairs, University of Washington, Seattle, WA, United States of America
- Universidad Autónoma de Madrid—Unidad de Genética, Madrid, Spain
| | - Terrie Klinger
- School of Marine and Environmental Affairs, University of Washington, Seattle, WA, United States of America
| | - Ryan P. Kelly
- School of Marine and Environmental Affairs, University of Washington, Seattle, WA, United States of America
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De León LF, Silva B, Avilés-Rodríguez KJ, Buitrago-Rosas D. Harnessing the omics revolution to address the global biodiversity crisis. Curr Opin Biotechnol 2023; 80:102901. [PMID: 36773576 DOI: 10.1016/j.copbio.2023.102901] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2022] [Revised: 01/10/2023] [Accepted: 01/18/2023] [Indexed: 02/12/2023]
Abstract
Human disturbances are altering global biodiversity in unprecedented ways. We identify three fundamental challenges underpinning our understanding of global biodiversity (namely discovery, loss, and preservation), and discuss how the omics revolution (e.g. genomics, transcriptomics, proteomics, metabolomics, and meta-omics) can help address these challenges. We also discuss how omics tools can illuminate the major drivers of biodiversity loss, including invasive species, pollution, urbanization, overexploitation, and climate change, with a special focus on highly diverse tropical environments. Although omics tools are transforming the traditional toolkit of biodiversity research, their application to addressing the current biodiversity crisis remains limited and may not suffice to offset current rates of biodiversity loss. Despite technical and logistical challenges, omics tools need to be fully integrated into global biodiversity research, and better strategies are needed to improve their translation into biodiversity policy and practice. It is also important to recognize that although the omics revolution can be considered the biologist's dream, socioeconomic disparity limits their application in biodiversity research.
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Affiliation(s)
- Luis F De León
- Department of Biology, University of Massachusetts Boston, Boston, MA 02125, USA.
| | - Bruna Silva
- Department of Biology, University of Massachusetts Boston, Boston, MA 02125, USA
| | - Kevin J Avilés-Rodríguez
- Department of Biology, University of Massachusetts Boston, Boston, MA 02125, USA; Department of Biology, Fordham University, Bronx, NY, USA
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Gold Z, Wall AR, Schweizer TM, Pentcheff ND, Curd EE, Barber PH, Meyer RS, Wayne R, Stolzenbach K, Prickett K, Luedy J, Wetzer R. A manager's guide to using eDNA metabarcoding in marine ecosystems. PeerJ 2022; 10:e14071. [PMID: 36405018 PMCID: PMC9673773 DOI: 10.7717/peerj.14071] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2022] [Accepted: 08/27/2022] [Indexed: 11/16/2022] Open
Abstract
Environmental DNA (eDNA) metabarcoding is a powerful tool that can enhance marine ecosystem/biodiversity monitoring programs. Here we outline five important steps managers and researchers should consider when developing eDNA monitoring program: (1) select genes and primers to target taxa; (2) assemble or develop comprehensive barcode reference databases; (3) apply rigorous site occupancy based decontamination pipelines; (4) conduct pilot studies to define spatial and temporal variance of eDNA; and (5) archive samples, extracts, and raw sequence data. We demonstrate the importance of each of these considerations using a case study of eDNA metabarcoding in the Ports of Los Angeles and Long Beach. eDNA metabarcoding approaches detected 94.1% (16/17) of species observed in paired trawl surveys while identifying an additional 55 native fishes, providing more comprehensive biodiversity inventories. Rigorous benchmarking of eDNA metabarcoding results improved ecological interpretation and confidence in species detections while providing archived genetic resources for future analyses. Well designed and validated eDNA metabarcoding approaches are ideally suited for biomonitoring applications that rely on the detection of species, including mapping invasive species fronts and endangered species habitats as well as tracking range shifts in response to climate change. Incorporating these considerations will enhance the utility and efficacy of eDNA metabarcoding for routine biomonitoring applications.
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Affiliation(s)
- Zachary Gold
- Department of Ecology and Evolutionary Biology, University of California, Los Angeles, Los Angeles, CA, United States of America
| | - Adam R. Wall
- Diversity Initiative for the Southern California Ocean (DISCO), Natural History Museum of Los Angeles County, Los Angeles, CA, United States of America
| | - Teia M. Schweizer
- Department of Fish and Wildlife Conservation Biology, Colorado State University, Fort Collins, CO, United States of America
| | - N. Dean Pentcheff
- Diversity Initiative for the Southern California Ocean (DISCO), Natural History Museum of Los Angeles County, Los Angeles, CA, United States of America
| | - Emily E. Curd
- Department of Natural Sciences, Landmark College, Putney, VT, United States of America
| | - Paul H. Barber
- Department of Ecology and Evolutionary Biology, University of California, Los Angeles, Los Angeles, CA, United States of America
| | - Rachel S. Meyer
- Department of Ecology and Evolutionary Biology, University of California, Los Angeles, Los Angeles, CA, United States of America,Department of Ecology and Evolutionary Biology, University of California, Santa Cruz, Santa Cruz, CA, United States of America
| | - Robert Wayne
- Department of Ecology and Evolutionary Biology, University of California, Los Angeles, Los Angeles, CA, United States of America
| | - Kevin Stolzenbach
- Wood Environment and Infrastructure, Inc., San Diego, CA, United States of America
| | - Kat Prickett
- Port of Los Angeles, Los Angeles, CA, United States of America
| | - Justin Luedy
- Port of Long Beach, Long Beach, CA, United States of America
| | - Regina Wetzer
- Diversity Initiative for the Southern California Ocean (DISCO), Natural History Museum of Los Angeles County, Los Angeles, CA, United States of America
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McCartin LJ, Vohsen SA, Ambrose SW, Layden M, McFadden CS, Cordes EE, McDermott JM, Herrera S. Temperature Controls eDNA Persistence across Physicochemical Conditions in Seawater. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2022; 56:8629-8639. [PMID: 35658125 PMCID: PMC9231374 DOI: 10.1021/acs.est.2c01672] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/08/2022] [Revised: 05/21/2022] [Accepted: 05/23/2022] [Indexed: 05/20/2023]
Abstract
Environmental DNA (eDNA) quantification and sequencing are emerging techniques for assessing biodiversity in marine ecosystems. Environmental DNA can be transported by ocean currents and may remain at detectable concentrations far from its source depending on how long it persist. Thus, predicting the persistence time of eDNA is crucial to defining the spatial context of the information derived from it. To investigate the physicochemical controls of eDNA persistence, we performed degradation experiments at temperature, pH, and oxygen conditions relevant to the open ocean and the deep sea. The eDNA degradation process was best explained by a model with two phases with different decay rate constants. During the initial phase, eDNA degraded rapidly, and the rate was independent of physicochemical factors. During the second phase, eDNA degraded slowly, and the rate was strongly controlled by temperature, weakly controlled by pH, and not controlled by dissolved oxygen concentration. We demonstrate that marine eDNA can persist at quantifiable concentrations for over 2 weeks at low temperatures (≤10 °C) but for a week or less at ≥20 °C. The relationship between temperature and eDNA persistence is independent of the source species. We propose a general temperature-dependent model to predict the maximum persistence time of eDNA detectable through single-species eDNA quantification methods.
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Affiliation(s)
- Luke J. McCartin
- Department
of Biological Sciences, Lehigh University, Bethlehem, Pennsylvania 18015-3027, United States
| | - Samuel A. Vohsen
- Department
of Biological Sciences, Lehigh University, Bethlehem, Pennsylvania 18015-3027, United States
| | - Susan W. Ambrose
- Department
of Earth and Environmental Sciences, Lehigh
University, Bethlehem, Pennsylvania 18015-3027, United States
| | - Michael Layden
- Department
of Biological Sciences, Lehigh University, Bethlehem, Pennsylvania 18015-3027, United States
| | - Catherine S. McFadden
- Department
of Biology, Harvey Mudd College, Claremont, California 91711, United States
| | - Erik E. Cordes
- Department
of Biology, Temple University, Philadelphia, Pennsylvania 19122-6008, United States
| | - Jill M. McDermott
- Department
of Earth and Environmental Sciences, Lehigh
University, Bethlehem, Pennsylvania 18015-3027, United States
| | - Santiago Herrera
- Department
of Biological Sciences, Lehigh University, Bethlehem, Pennsylvania 18015-3027, United States
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