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Buthasane W, Shotelersuk V, Chetruengchai W, Srichomthong C, Assawapitaksakul A, Tangphatsornruang S, Pootakham W, Sonthirod C, Tongsima S, Wangkumhang P, Wilantho A, Thongphakdee A, Sanannu S, Poksawat C, Nipanunt T, Kasorndorkbua C, Koepfli KP, Pukazhenthi BS, Suriyaphol P, Wongsurawat T, Jenjaroenpun P, Suriyaphol G. Comprehensive genome assembly reveals genetic diversity and carcass consumption insights in critically endangered Asian king vultures. Sci Rep 2024; 14:9455. [PMID: 38658744 PMCID: PMC11043450 DOI: 10.1038/s41598-024-59990-9] [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: 11/23/2023] [Accepted: 04/17/2024] [Indexed: 04/26/2024] Open
Abstract
The Asian king vulture (AKV), a vital forest scavenger, is facing globally critical endangerment. This study aimed to construct a reference genome to unveil the mechanisms underlying its scavenger abilities and to assess the genetic relatedness of the captive population in Thailand. A reference genome of a female AKV was assembled from sequencing reads obtained from both PacBio long-read and MGI short-read sequencing platforms. Comparative genomics with New World vultures (NWVs) and other birds in the Family Accipitridae revealed unique gene families in AKV associated with retroviral genome integration and feather keratin, contrasting with NWVs' genes related to olfactory reception. Expanded gene families in AKV were linked to inflammatory response, iron regulation and spermatogenesis. Positively selected genes included those associated with anti-apoptosis, immune response and muscle cell development, shedding light on adaptations for carcass consumption and high-altitude soaring. Using restriction site-associated DNA sequencing (RADseq)-based genome-wide single nucleotide polymorphisms (SNPs), genetic relatedness and inbreeding status of five captive AKVs were determined, revealing high genomic inbreeding in two females. In conclusion, the AKV reference genome was established, providing insights into its unique characteristics. Additionally, the potential of RADseq-based genome-wide SNPs for selecting AKV breeders was demonstrated.
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Affiliation(s)
- Wannapol Buthasane
- Biochemistry Unit, Department of Physiology, Faculty of Veterinary Science, Chulalongkorn University, Bangkok, 10330, Thailand
| | - Vorasuk Shotelersuk
- Center of Excellence for Medical Genomics, Department of Pediatrics, Faculty of Medicine, Chulalongkorn University, Henri Dunant Road, Pathumwan, Bangkok, 10330, Thailand
- Excellence Center for Genomics and Precision Medicine, King Chulalongkorn Memorial Hospital, The Thai Red Cross Society, Bangkok, 10330, Thailand
| | - Wanna Chetruengchai
- Center of Excellence for Medical Genomics, Department of Pediatrics, Faculty of Medicine, Chulalongkorn University, Henri Dunant Road, Pathumwan, Bangkok, 10330, Thailand
- Excellence Center for Genomics and Precision Medicine, King Chulalongkorn Memorial Hospital, The Thai Red Cross Society, Bangkok, 10330, Thailand
| | - Chalurmpon Srichomthong
- Center of Excellence for Medical Genomics, Department of Pediatrics, Faculty of Medicine, Chulalongkorn University, Henri Dunant Road, Pathumwan, Bangkok, 10330, Thailand
- Excellence Center for Genomics and Precision Medicine, King Chulalongkorn Memorial Hospital, The Thai Red Cross Society, Bangkok, 10330, Thailand
| | - Adjima Assawapitaksakul
- Center of Excellence for Medical Genomics, Department of Pediatrics, Faculty of Medicine, Chulalongkorn University, Henri Dunant Road, Pathumwan, Bangkok, 10330, Thailand
- Excellence Center for Genomics and Precision Medicine, King Chulalongkorn Memorial Hospital, The Thai Red Cross Society, Bangkok, 10330, Thailand
| | - Sithichoke Tangphatsornruang
- National Center for Genetic Engineering and Biotechnology (BIOTEC), National Science and Technology Development Agency, Pathum Thani, 12120, Thailand
| | - Wirulda Pootakham
- National Center for Genetic Engineering and Biotechnology (BIOTEC), National Science and Technology Development Agency, Pathum Thani, 12120, Thailand
| | - Chutima Sonthirod
- National Center for Genetic Engineering and Biotechnology (BIOTEC), National Science and Technology Development Agency, Pathum Thani, 12120, Thailand
| | - Sissades Tongsima
- National Center for Genetic Engineering and Biotechnology (BIOTEC), National Science and Technology Development Agency, Pathum Thani, 12120, Thailand
| | - Pongsakorn Wangkumhang
- National Center for Genetic Engineering and Biotechnology (BIOTEC), National Science and Technology Development Agency, Pathum Thani, 12120, Thailand
| | - Alisa Wilantho
- National Center for Genetic Engineering and Biotechnology (BIOTEC), National Science and Technology Development Agency, Pathum Thani, 12120, Thailand
| | - Ampika Thongphakdee
- Animal Conservation and Research Institute, The Zoological Park Organization of Thailand under the Royal Patronage of H.M. The King, Bangkok, 10300, Thailand
| | - Saowaphang Sanannu
- Animal Conservation and Research Institute, The Zoological Park Organization of Thailand under the Royal Patronage of H.M. The King, Bangkok, 10300, Thailand
| | - Chaianan Poksawat
- Animal Conservation and Research Institute, The Zoological Park Organization of Thailand under the Royal Patronage of H.M. The King, Bangkok, 10300, Thailand
| | - Tarasak Nipanunt
- Huai Kha Khaeng Wildlife Breeding Center, Department of National Parks, Wildlife and Plant Conservation, Uthai Thani, 61160, Thailand
| | - Chaiyan Kasorndorkbua
- Laboratory of Raptor Research and Conservation Medicine, Department of Pathology, Faculty of Veterinary Medicine, Kasetsart University, Bangkok, 10900, Thailand
| | - Klaus-Peter Koepfli
- Smithsonian-Mason School of Conservation, George Mason University, Front Royal, VA, 22630, USA
- Center for Species Survival, Smithsonian Conservation Biology Institute, National Zoological Park, Front Royal, VA, 22630, USA
| | - Budhan S Pukazhenthi
- Center for Species Survival, Smithsonian Conservation Biology Institute, National Zoological Park, Front Royal, VA, 22630, USA
| | - Prapat Suriyaphol
- Division of Medical Bioinformatics, Department of Research and Development, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, 10700, Thailand
| | - Thidathip Wongsurawat
- Division of Medical Bioinformatics, Department of Research and Development, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, 10700, Thailand
| | - Piroon Jenjaroenpun
- Division of Medical Bioinformatics, Department of Research and Development, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, 10700, Thailand
| | - Gunnaporn Suriyaphol
- Biochemistry Unit, Department of Physiology, Faculty of Veterinary Science, Chulalongkorn University, Bangkok, 10330, Thailand.
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2
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Furlan EM, Baumgartner LJ, Duncan M, Ellis I, Gruber B, Harrisson K, Michie L, Thiem JD, Stuart I. Swinging back from the brink? Polygamous mating strategies revealed for an iconic threatened freshwater fish. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 919:170808. [PMID: 38336046 DOI: 10.1016/j.scitotenv.2024.170808] [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: 11/07/2023] [Revised: 02/05/2024] [Accepted: 02/06/2024] [Indexed: 02/12/2024]
Abstract
Catastrophic fish death events are increasing in frequency and severity globally. A series of major recent fish deaths in the semi-arid lower Darling-Baaka river system (LDBR) of Australia are emblematic of these issues with tens of millions of native fish perishing. In 2018-2019 there was a major death event for Australia's largest freshwater fish, Murray cod (Maccullochella peelii). To aid the recovery and guide restoration activities of local Murray cod populations, it is essential to gather information on the mating strategies and effective population size following the fish death event. After the fish deaths, we collected larvae during the 2020 and 2021 breeding seasons and used single nucleotide polymorphisms (SNPs) to provide insight mating strategies and to estimate effective population size. Larvae were detected in both years along the entire length of the LDBR. Sixteen percent of the inferred breeding individuals were found to contribute to multiple pairings, confirming a complex and polygamous mating system. A high frequency of polygamy was evident both within and between years with 100 % polygamy identified among parents that produced offspring in both 2020 and 2021 and 95 % polygamy identified among parents involved in multiple spawning events within years. Post-larval Murray cod samples collected between 2016 and 2021 were co-analysed to further inform kinship patterns. Again, monogamy was rare with no confirmed cases of the same male-female pair contributing to multiple breeding events within or between seasons. Effective population size based on Murray cod collected after the fish death event was estimated at 721.6 (CI 471-1486), though this has likely declined following a subsequent catastrophic fish death event in the LDBR in March 2023. Our data provide insight into the variability of Murray cod mating strategies, and we anticipate that this knowledge will assist in planning conservation actions to ultimately help recover a species in crisis.
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Affiliation(s)
- Elise M Furlan
- Centre for Conservation Ecology and Genomics, Institute for Applied Ecology, University of Canberra, University Drive, Bruce, ACT 2617, Australia; Gulbali Institute for Agriculture, Water and Environment, Charles Sturt University, P.O. Box 789, Albury, NSW 2640, Australia.
| | - Lee J Baumgartner
- Gulbali Institute for Agriculture, Water and Environment, Charles Sturt University, P.O. Box 789, Albury, NSW 2640, Australia
| | - Meaghan Duncan
- Department of Primary Industries, Narrandera Fisheries Centre, Narrandera, New South Wales, Australia
| | - Iain Ellis
- Department of Primary Industries, Buronga, New South Wales, Australia
| | - Bernd Gruber
- Centre for Conservation Ecology and Genomics, Institute for Applied Ecology, University of Canberra, University Drive, Bruce, ACT 2617, Australia
| | - Katherine Harrisson
- Department of Environment and Genetics, La Trobe University, Melbourne, Australia; Research Centre for Future Landscapes, La Trobe University, Melbourne, Australia; Arthur Rylah Institute for Environmental Research, Department of Energy, Environment and Climate Action, Victoria, Australia
| | - Laura Michie
- Department of Primary Industries, Narrandera Fisheries Centre, Narrandera, New South Wales, Australia
| | - Jason D Thiem
- Department of Primary Industries, Narrandera Fisheries Centre, Narrandera, New South Wales, Australia
| | - Ivor Stuart
- Gulbali Institute for Agriculture, Water and Environment, Charles Sturt University, P.O. Box 789, Albury, NSW 2640, Australia
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3
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Pavlova A, Schneller NM, Lintermans M, Beitzel M, Robledo‐Ruiz DA, Sunnucks P. Planning and implementing genetic rescue of an endangered freshwater fish population in a regulated river, where low flow reduces breeding opportunities and may trigger inbreeding depression. Evol Appl 2024; 17:e13679. [PMID: 38617824 PMCID: PMC11009430 DOI: 10.1111/eva.13679] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2023] [Revised: 02/11/2024] [Accepted: 02/26/2024] [Indexed: 04/16/2024] Open
Abstract
Augmenting depleted genetic diversity can improve the fitness and evolutionary potential of wildlife populations, but developing effective management approaches requires genetically monitored test cases. One such case is the small, isolated and inbred Cotter River population of an endangered Australian freshwater fish, the Macquarie perch Macquaria australasica, which over 3 years (2017-2019) received 71 translocated migrants from a closely related, genetically more diverse population. We used genetic monitoring to test whether immigrants bred, interbred with local fish and augmented population genetic diversity. We also investigated whether levels of river flow affected recruitment, inbreeding depression and juvenile dispersal. Fish length was used to estimate the age, birth year cohort and growth of 524 individuals born between 2016 and 2020 under variable flow conditions. DArT genome-wide genotypes were used to assess individual ancestry, heterozygosity, short-term effective population size and identify parent-offspring and full-sibling families. Of 442 individuals born after translocations commenced, only two (0.45%) were of mixed ancestry; these were half-sibs with one translocated parent in common. Numbers of breeders and genetic diversity for five birth year cohorts of the Cotter River fish were low, especially in low-flow years. Additionally, individuals born in the year of lowest flow evidently suffered from inbreeding depression for juvenile growth. The year of highest flow was associated with the largest number of breeders, lowest inbreeding in the offspring and greatest juvenile dispersal distances. Genetic diversity decreased in the upstream direction, flagging restricted access of breeders to the most upstream breeding sites, exacerbated by low river flow. Our results suggest that the effectiveness of translocations could be increased by focussing on upstream sites and moving more individuals per year; using riverine sources should be considered. Our results indicate that river flow sufficient to facilitate fish movement through the system would increase the number of breeders, promote individuals' growth, reduce inbreeding depression and promote genetic rescue.
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Affiliation(s)
- Alexandra Pavlova
- School of Biological SciencesMonash UniversityMelbourneVictoriaAustralia
| | - Nadja M. Schneller
- School of Biological SciencesMonash UniversityMelbourneVictoriaAustralia
| | - Mark Lintermans
- Centre for Applied Water ScienceInstitute for Applied Ecology, University of CanberraCanberraAustralian Capital TerritoryAustralia
| | - Matt Beitzel
- Environment, Planning & Sustainable Development Directorate (ACT Government)CanberraAustralian Capital TerritoryAustralia
| | | | - Paul Sunnucks
- School of Biological SciencesMonash UniversityMelbourneVictoriaAustralia
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4
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Schmidt TL, Thia JA, Hoffmann AA. How Can Genomics Help or Hinder Wildlife Conservation? Annu Rev Anim Biosci 2024; 12:45-68. [PMID: 37788416 DOI: 10.1146/annurev-animal-021022-051810] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/05/2023]
Abstract
Genomic data are becoming increasingly affordable and easy to collect, and new tools for their analysis are appearing rapidly. Conservation biologists are interested in using this information to assist in management and planning but are typically limited financially and by the lack of genomic resources available for non-model taxa. It is therefore important to be aware of the pitfalls as well as the benefits of applying genomic approaches. Here, we highlight recent methods aimed at standardizing population assessments of genetic variation, inbreeding, and forms of genetic load and methods that help identify past and ongoing patterns of genetic interchange between populations, including those subjected to recent disturbance. We emphasize challenges in applying some of these methods and the need for adequate bioinformatic support. We also consider the promises and challenges of applying genomic approaches to understand adaptive changes in natural populations to predict their future adaptive capacity.
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Affiliation(s)
- Thomas L Schmidt
- School of BioSciences, Bio21 Institute, University of Melbourne, Parkville, Victoria, Australia;
| | - Joshua A Thia
- School of BioSciences, Bio21 Institute, University of Melbourne, Parkville, Victoria, Australia;
| | - Ary A Hoffmann
- School of BioSciences, Bio21 Institute, University of Melbourne, Parkville, Victoria, Australia;
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5
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Bossu CM, Rodriguez M, Rayne C, Chromczak DA, Higgins PG, Trulio LA, Ruegg KC. Genomic approaches to mitigating genetic diversity loss in declining populations. Mol Ecol 2023; 32:5228-5240. [PMID: 37610278 DOI: 10.1111/mec.17109] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2023] [Revised: 07/17/2023] [Accepted: 08/04/2023] [Indexed: 08/24/2023]
Abstract
The accelerating pace of global biodiversity loss is exacerbated by habitat fragmentation and subsequent inbreeding in small populations. To address this problem, conservation practitioners often turn to assisted breeding programmes with the aim of enhancing genetic diversity in declining populations. Although genomic information is infrequently included in these efforts, it has the potential to significantly enhance the success of such programmes. In this study, we showcase the value of genomic approaches for increasing genetic diversity in assisted breeding efforts, specifically focusing on a highly inbred population of Western burrowing owls. To maximize genetic diversity in the resulting offspring, we begin by creating an optimal pairing decision tree based on sex, kinship and patterns of homozygosity across the genome. To evaluate the effectiveness of our strategy, we compare genetic diversity, brood size and nestling success rates between optimized and non-optimized pairs. Additionally, we leverage recently discovered correlations between telomere length and fitness across species to investigate whether genomic optimization could have long-term fitness benefits. Our results indicate that pairing individuals with contrasting patterns of homozygosity across the genome is an effective way to increase genetic diversity in offspring. Although short-term field-based metrics of success did not differ significantly between optimized and non-optimized pairs, offspring from optimized pairs had significantly longer telomeres, suggesting that genetic optimization can help reduce the risk of inbreeding depression. These findings underscore the importance of genomic tools for informing efforts to preserve the adaptive potential of small, inbred populations at risk of further decline.
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Affiliation(s)
- Christen M Bossu
- Department of Biology, Colorado State University, Colorado, Fort Collins, USA
| | - Marina Rodriguez
- Department of Biology, Colorado State University, Colorado, Fort Collins, USA
| | - Christine Rayne
- Department of Biology, Colorado State University, Colorado, Fort Collins, USA
| | - Debra A Chromczak
- Burrowing Owl Researcher & Consultant, Riegelsville, Pennsylvania, USA
| | | | - Lynne A Trulio
- Department of Environmental Studies, San José State University, San Jose, California, USA
| | - Kristen C Ruegg
- Department of Biology, Colorado State University, Colorado, Fort Collins, USA
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6
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Tenger-Trolander A. Environmental and genetic effects of captivity - are there lessons for monarch butterfly conservation? CURRENT OPINION IN INSECT SCIENCE 2023; 59:101088. [PMID: 37500011 DOI: 10.1016/j.cois.2023.101088] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/26/2023] [Revised: 07/17/2023] [Accepted: 07/17/2023] [Indexed: 07/29/2023]
Abstract
Rearing monarch butterflies in captivity for later release is a popular but contentious activity due to concerns about its potential negative effects on the wild population. In this review, I discuss how captive rearing and breeding could impact monarch fitness in the wild, the current evidence for such impacts in monarchs and other captive-reared/released organisms, and how this should inform our efforts to conserve monarchs and other species.
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7
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Hudson DW, McKinley TJ, Benton CH, Delahay R, McDonald RA, Hodgson DJ. Multi-locus homozygosity promotes actuarial senescence in a wild mammal. J Anim Ecol 2023; 92:1881-1892. [PMID: 37427855 DOI: 10.1111/1365-2656.13979] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2022] [Accepted: 06/05/2023] [Indexed: 07/11/2023]
Abstract
Genome-wide homozygosity, caused for example by inbreeding, is expected to have deleterious effects on survival and/or reproduction. Evolutionary theory predicts that any fitness costs are likely to be detected in late life because natural selection will filter out negative impacts on younger individuals with greater reproductive value. Here we infer associations between multi-locus homozygosity (MLH), sex, disease and age-dependent mortality risks using Bayesian analysis of the life histories of wild European badgers Meles meles in a population naturally infected with Mycobacterium bovis (the causative agent of bovine tuberculosis [bTB]). We find important effects of MLH on all parameters of the Gompertz-Makeham mortality hazard function, but particularly in later life. Our findings confirm the predicted association between genomic homozygosity and actuarial senescence. Increased homozygosity is particularly associated with an earlier onset, and greater rates of actuarial senescence, regardless of sex. The association between homozygosity and actuarial senescence is further amplified among badgers putatively infected with bTB. These results recommend further investigation into the ecological and behavioural processes that result in genome-wide homozygosity, and focused work on whether homozygosity is harmful or beneficial during early life-stages.
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Affiliation(s)
- Dave W Hudson
- Centre for Ecology and Conservation, University of Exeter, Penryn, UK
| | | | - Clare H Benton
- National Wildlife Management Centre, Animal and Plant Health Agency, Sand Hutton, UK
| | - Richard Delahay
- National Wildlife Management Centre, Animal and Plant Health Agency, Sand Hutton, UK
| | - Robbie A McDonald
- Environment and Sustainability Institute, University of Exeter, Penryn, UK
| | - Dave J Hodgson
- Centre for Ecology and Conservation, University of Exeter, Penryn, UK
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8
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Genomic diversity and signals of selection processes in wild and farm-reared red-legged partridges (Alectoris rufa). Genomics 2023; 115:110591. [PMID: 36849018 DOI: 10.1016/j.ygeno.2023.110591] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2022] [Revised: 02/18/2023] [Accepted: 02/22/2023] [Indexed: 02/27/2023]
Abstract
The genetic dynamics of wild populations with releases of farm-reared reinforcements are very complex. These releases can endanger wild populations through genetic swamping or by displacing them. We assessed the genomic differences between wild and farm-reared red-legged partridges (Alectoris rufa) and described differential selection signals between both populations. We sequenced the whole genome of 30 wild and 30 farm-reared partridges. Both partridges had similar nucleotide diversity (π). Farm-reared partridges had a more negative Tajima's D and more and longer regions of extended haplotype homozygosity than wild partridges. We observed higher inbreeding coefficients (FIS and FROH) in wild partridges. Selective sweeps (Rsb) were enriched with genes that contribute to the reproductive, skin and feather colouring, and behavioural differences between wild and farm-reared partridges. The analysis of genomic diversity should inform future decisions for the preservation of wild populations.
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9
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Duntsch L, Whibley A, de Villemereuil P, Brekke P, Bailey S, Ewen JG, Santure AW. Genomic signatures of inbreeding depression for a threatened Aotearoa New Zealand passerine. Mol Ecol 2023; 32:1893-1907. [PMID: 36655901 DOI: 10.1111/mec.16855] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2022] [Revised: 11/19/2022] [Accepted: 01/16/2023] [Indexed: 01/20/2023]
Abstract
For small and isolated populations, the increased chance of mating between related individuals can result in a substantial reduction in individual and population fitness. Despite the increasing availability of genomic data to measure inbreeding accurately across the genome, inbreeding depression studies for threatened species are still scarce due to the difficulty of measuring fitness in the wild. Here, we investigate inbreeding and inbreeding depression for the extensively monitored Tiritiri Mātangi island population of a threatened Aotearoa New Zealand passerine, the hihi (Notiomystis cincta). First, using a custom 45 k single nucleotide polymorphism (SNP) array, we explore genomic inbreeding patterns by inferring homozygous segments across the genome. Although all individuals have similar levels of ancient inbreeding, highly inbred individuals are affected by recent inbreeding, which can probably be explained by bottleneck effects such as habitat loss after European arrival and their translocation to the island in the 1990s. Second, we investigate genomic inbreeding effects on fitness, measured as lifetime reproductive success, and its three components, juvenile survival, adult annual survival and annual reproductive success, in 363 hihi. We find that global inbreeding significantly affects juvenile survival but none of the remaining fitness traits. Finally, we employ a genome-wide association approach to test the locus-specific effects of inbreeding on fitness, and identify 13 SNPs significantly associated with lifetime reproductive success. Our findings suggest that inbreeding depression does impact hihi, but at different genomic scales for different traits, and that purging has therefore failed to remove all variants with deleterious effects from this population of conservation concern.
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Affiliation(s)
- Laura Duntsch
- Centre for Biodiversity and Biosecurity (CBB), School of Biological Sciences, University of Auckland, Auckland, New Zealand
| | - Annabel Whibley
- Centre for Biodiversity and Biosecurity (CBB), School of Biological Sciences, University of Auckland, Auckland, New Zealand
| | - Pierre de Villemereuil
- Institut de Systématique, Évolution, Biodiversité (ISYEB), École Pratique des Hautes Études, PSL, MNHN, CNRS, SU, UA, Paris, France
| | - Patricia Brekke
- Institute of Zoology, Zoological Society of London, London, UK
| | - Sarah Bailey
- Centre for Biodiversity and Biosecurity (CBB), School of Biological Sciences, University of Auckland, Auckland, New Zealand
| | - John G Ewen
- Institute of Zoology, Zoological Society of London, London, UK
| | - Anna W Santure
- Centre for Biodiversity and Biosecurity (CBB), School of Biological Sciences, University of Auckland, Auckland, New Zealand
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10
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Sundell T, Kammonen JI, Mustanoja E, Biard V, Kunnasranta M, Niemi M, Nykänen M, Nyman T, Palo JU, Valtonen M, Paulin L, Jernvall J, Auvinen P. Genomic evidence uncovers inbreeding and supports translocations in rescuing the genetic diversity of a landlocked seal population. CONSERV GENET 2023. [DOI: 10.1007/s10592-022-01497-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
AbstractFragmentation of isolated populations increases the risk of inbreeding and loss of genetic diversity. The endemic Saimaa ringed seal (Pusa hispida saimensis) is one of the most endangered pinnipeds in the world with a population of only ~ 400 individuals. The current genetic diversity of this subspecies, isolated in Lake Saimaa in Finland for ca. 1000 generations, is alarmingly low. We performed whole-genome sequencing on Saimaa ringed seals (N = 30) and analyzed the level of homozygosity and genetic composition across the individual genomes. Our results show that the Saimaa ringed seal population has a high number of runs of homozygosity (RoH) compared with the neighboring Baltic ringed seal (Pusa hispida botnica) reference population (p < 0.001). There is also a tendency for stillborn seal pups to have more pronounced RoH. Since the population is divided into semi-isolated subpopulations within the Lake Saimaa exposing the population to deleterious genomic effects, our results support augmented gene flow as a genetic conservation action. Based on our results suggesting inbreeding depression in the population, we recommend Pihlajavesi as a potential source and Southern Saimaa as a potential recipient subpopulation for translocating individuals. The Saimaa ringed seal is a recognized subspecies and therefore translocations should be considered only within the lake to avoid an unpredictable risk of disease, the introduction of deleterious alleles, and severe ecological issues for the population.
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11
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Babarinde IA, Adeola AC, Djagoun CAMS, Nneji LM, Okeyoyin AO, Niba G, Wanzie NK, Oladipo OC, Adebambo AO, Bello SF, Ng'ang'a SI, Olaniyi WA, Okoro VMO, Adedeji BE, Olatunde O, Ayoola AO, Matouke MM, Wang YY, Sanke OJ, Oseni SO, Nwani CD, Murphy RW. Population structure and evolutionary history of the greater cane rat ( Thryonomys swinderianus) from the Guinean Forests of West Africa. Front Genet 2023; 14:1041103. [PMID: 36923796 PMCID: PMC10010571 DOI: 10.3389/fgene.2023.1041103] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2022] [Accepted: 02/07/2023] [Indexed: 03/02/2023] Open
Abstract
Grasscutter (Thryonomys swinderianus) is a large-body old world rodent found in sub-Saharan Africa. The body size and the unique taste of the meat of this major crop pest have made it a target of intense hunting and a potential consideration as a micro-livestock. However, there is insufficient knowledge on the genetic diversity of its populations across African Guinean forests. Herein, we investigated the genetic diversity, population structures and evolutionary history of seven Nigerian wild grasscutter populations together with individuals from Cameroon, Republic of Benin, and Ghana, using five mitochondrial fragments, including D-loop and cytochrome b (CYTB). D-loop haplotype diversity ranged from 0.571 (± 0.149) in Republic of Benin to 0.921 (± 0.013) in Ghana. Within Nigeria, the haplotype diversity ranged from 0.659 (± 0.059) in Cross River to 0.837 (± 0.075) in Ondo subpopulation. The fixation index (FST), haplotype frequency distribution and analysis of molecular variance revealed varying levels of population structures across populations. No significant signature of population contraction was detected in the grasscutter populations. Evolutionary analyses of CYTB suggests that South African population might have diverged from other populations about 6.1 (2.6-10.18, 95% CI) MYA. Taken together, this study reveals the population status and evolutionary history of grasscutter populations in the region.
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Affiliation(s)
- Isaac A Babarinde
- Shenzhen Key Laboratory of Gene Regulation and Systems Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen, China.,Department of Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen, China
| | - Adeniyi C Adeola
- State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, China.,Sino-Africa Joint Research Centre, Chinese Academy of Sciences, Kunming, China.,Centre for Biotechnology Research, Bayero University, Kano, Nigeria
| | - Chabi A M S Djagoun
- Laboratory of Applied Ecology, Faculty of Agronomic Sciences, University of Abomey-Calavi, Cotonou, Benin
| | - Lotanna M Nneji
- Department of Ecology and Evolutionary Biology, Princeton University, Princeton, NJ, United States
| | - Agboola O Okeyoyin
- National Park Service Headquarters, Federal Capital Territory, Abuja, Nigeria
| | - George Niba
- National Centre for Animal Husbandry and Veterinary Training, Jakiri, North West Region, Cameroon
| | - Ndifor K Wanzie
- Department of Zoology, University of Douala, Douala, Cameroon.,Department of Zoology, Faculty of Life Sciences, University of Ilorin, Ilorin, Kwara State, Nigeria
| | | | - Ayotunde O Adebambo
- Animal Genetics & Biotechnology, Federal University of Agriculture, Abeokuta, Nigeria
| | - Semiu F Bello
- Department of Animal Genetics, Breeding and Reproduction, College of Animal Science, South China Agricultural University, Guangzhou, China
| | - Said I Ng'ang'a
- State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, China
| | - Wasiu A Olaniyi
- Department of Animal Science, Faculty of Agriculture, Adekunle Ajasin University, Akungba-Akoko, Ondo State, Nigeria
| | - Victor M O Okoro
- Department of Animal Science and Technology, School of Agriculture and Agricultural Technology, Federal University of Technology, Owerri, Nigeria
| | | | - Omotoso Olatunde
- Department of Zoology, University of Ibadan, Ibadan, Oyo State, Nigeria
| | - Adeola O Ayoola
- State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, China.,Sino-Africa Joint Research Centre, Chinese Academy of Sciences, Kunming, China
| | - Moise M Matouke
- Department of Fisheries and Aquatic Resources Management, University of Buea, Buea, Cameroon
| | | | - Oscar J Sanke
- Taraba State Ministry of Agriculture and Natural Resources, Jalingo, Nigeria
| | - Saidu O Oseni
- Department of Animal Sciences, Faculty of Agriculture, Obafemi Awolowo University, Ile-Ife, Nigeria
| | - Christopher D Nwani
- Department of Zoology and Environmental Biology, Faculty of Biological Sciences, University of Nigeria, Nsukka, Nigeria
| | - Robert W Murphy
- Centre for Biodiversity and Conservation Biology, Royal Ontario Museum, Toronto, ON, Canada
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12
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Byeun DG, Moon BS, Lee S, Choi JK. Germ Cell Isolation and Cryopreservation from Reproductive Organs of Brown Mealworm. INSECTS 2022; 13:1108. [PMID: 36555018 PMCID: PMC9783178 DOI: 10.3390/insects13121108] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/28/2022] [Revised: 11/28/2022] [Accepted: 11/28/2022] [Indexed: 06/17/2023]
Abstract
This study aimed to isolate and freeze germ cells from the superior brown mealworm. Styrofoam diet changes were observed for 20 days to determine whether mealworms were useful insects for decomposing Styrofoam. The average weight of mealworms before the Styrofoam diet was 500 mg, which decreased to 336 mg at D20 after their diet. To preserve mealworms with excellent Styrofoam-degrading ability, we first isolated the reproductive organs of mealworms, testes, ovaries, sperms, and ovarioles. Morphologically, male and female adult brown mealworms were distinguished according to the presence or absence of a protrusion at the tip of the fifth segment of the abdomen. Sperms and ovarioles were observed in anatomically isolated testes and ovaries. We compared mechanical and enzymatic (collagenase I) methods to effectively isolate ovarioles from adult female brown mealworms. For the enzymatic method, most were torn and burst as the membrane of the ovarioles was damaged by collagenase I, unlike the mechanical method. To preserve the superior genetic resources of mealworms, we cryopreserved the ovaries of female brown mealworms using slow-freezing and vitrification. Histological analysis showed that the yolk sac was completely damaged in the ovaries after slow-freezing. However, only partial damage was achieved in the vitrification group compared to the control group (no freezing). The newly developed vitrification method with alginate-encapsulated ovarioles maintained the yolk sac in the ovarioles but was evenly distributed. These results provide basic data for reproductive studies of other useful insects and contribute to the biobanking and fertility preservation of superior mealworm germ cells and endangered insects.
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Affiliation(s)
- Do Gyeung Byeun
- Department of Biotechnology, College of Life and Applied Sciences, Yeungnam University, Gyeongsan 38541, Republic of Korea
| | - Byoung-San Moon
- Department of Biotechnology, Chonnam National University, Yeosu 59626, Republic of Korea
| | - Seungki Lee
- Biological and Genetic Resources Assessment Division, National Institute of Biological Resources, Incheon 404-708, Republic of Korea
| | - Jung Kyu Choi
- Department of Biotechnology, College of Life and Applied Sciences, Yeungnam University, Gyeongsan 38541, Republic of Korea
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13
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Tian D, Patton AH, Turner BJ, Martin CH. Severe inbreeding, increased mutation load and gene loss-of-function in the critically endangered Devils Hole pupfish. Proc Biol Sci 2022; 289:20221561. [PMID: 36321496 PMCID: PMC9627712 DOI: 10.1098/rspb.2022.1561] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Small populations with limited range are often threatened by inbreeding and reduced genetic diversity, which can reduce fitness and exacerbate population decline. One of the most extreme natural examples is the Devils Hole pupfish (Cyprinodon diabolis), an iconic and critically endangered species with the smallest known range of any vertebrate. This species has experienced severe declines in population size over the last 30 years and suffered major bottlenecks in 2007 and 2013, when the population shrunk to 38 and 35 individuals, respectively. Here, we analysed 30 resequenced genomes of desert pupfishes from Death Valley, Ash Meadows and surrounding areas to examine the genomic consequences of small population size. We found extremely high levels of inbreeding (FROH = 0.34–0.81) and an increased amount of potentially deleterious genetic variation in the Devils Hole pupfish as compared to other species, including unique, fixed loss-of-function alleles and deletions in genes associated with sperm motility and hypoxia. Additionally, we successfully resequenced a formalin-fixed museum specimen from 1980 and found that the population was already highly inbred prior to recent known bottlenecks. We thus document severe inbreeding and increased mutation load in the Devils Hole pupfish and identify candidate deleterious variants to inform management of this conservation icon.
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Affiliation(s)
- David Tian
- Department of Integrative Biology, University of California, Berkeley, CA 94720, USA
- Museum of Vertebrate Zoology, University of California, Berkeley, CA 94720, USA
| | - Austin H. Patton
- Department of Integrative Biology, University of California, Berkeley, CA 94720, USA
- Museum of Vertebrate Zoology, University of California, Berkeley, CA 94720, USA
| | - Bruce J. Turner
- Museum of Vertebrate Zoology, University of California, Berkeley, CA 94720, USA
| | - Christopher H. Martin
- Department of Integrative Biology, University of California, Berkeley, CA 94720, USA
- Museum of Vertebrate Zoology, University of California, Berkeley, CA 94720, USA
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14
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Zander KK, Burton M, Pandit R, Gunawardena A, Pannell D, Garnett ST. How public values for threatened species are affected by conservation strategies. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2022; 319:115659. [PMID: 35820310 DOI: 10.1016/j.jenvman.2022.115659] [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: 02/15/2022] [Revised: 06/28/2022] [Accepted: 06/29/2022] [Indexed: 06/15/2023]
Abstract
While the imminent extinction of many species is predicted, prevention is expensive, and decision-makers often have to prioritise funding. In democracies, it can be argued that conservation using public funds should be influenced by the values placed on threatened species by the public, and that community views should also affect the conservation management approaches adopted. We conducted on online survey with 2400 respondents from the general Australian public to determine 1) the relative values placed on a diverse set of 12 threatened Australian animal species and 2) whether those values changed with the approach proposed to conserve them. The survey included a contingent valuation and a choice experiment. Three notable findings emerged: 1) respondents were willing to pay $60/year on average for a species (95% confidence interval: $23 to $105) to avoid extinction in the next 20 years based on the contingent valuation, and $29 to $100 based on the choice experiment, 2) respondents were willing to pay to reduce the impact of feral animals on almost all presented threatened species, 3) for few species and respondents, WTP was lower when genetic modification to reduce inbreeding in the remaining population was proposed.
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Affiliation(s)
| | - Michael Burton
- School of Agriculture and Environment, University of Western Australia, Australia
| | - Ram Pandit
- School of Agriculture and Environment, University of Western Australia, Australia
| | - Asha Gunawardena
- School of Agriculture and Environment, University of Western Australia, Australia
| | - David Pannell
- School of Agriculture and Environment, University of Western Australia, Australia
| | - Stephen T Garnett
- Research Institute for the Environment and Livelihoods, Charles Darwin University, Australia
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15
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Grueber CE, Sunnucks P. Using genomics to fight extinction. Science 2022; 376:574-575. [PMID: 35511984 DOI: 10.1126/science.abp9874] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Quantifying fitness of wild organisms from genomic data alone is a challenging frontier.
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Affiliation(s)
- Catherine E Grueber
- School of Life and Environmental Sciences, Faculty of Science, The University of Sydney, Sydney, NSW, Australia
| | - Paul Sunnucks
- School of Biological Sciences, Monash University, Melbourne, VIC, Australia
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16
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Lamka GF, Harder AM, Sundaram M, Schwartz TS, Christie MR, DeWoody JA, Willoughby JR. Epigenetics in Ecology, Evolution, and Conservation. Front Ecol Evol 2022. [DOI: 10.3389/fevo.2022.871791] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Epigenetic variation is often characterized by modifications to DNA that do not alter the underlying nucleotide sequence, but can influence behavior, morphology, and physiological phenotypes by affecting gene expression and protein synthesis. In this review, we consider how the emerging field of ecological epigenetics (eco-epi) aims to use epigenetic variation to explain ecologically relevant phenotypic variation and predict evolutionary trajectories that are important in conservation. Here, we focus on how epigenetic data have contributed to our understanding of wild populations, including plants, animals, and fungi. First, we identified published eco-epi literature and found that there was limited taxonomic and ecosystem coverage and that, by necessity of available technology, these studies have most often focused on the summarized epigenome rather than locus- or nucleotide-level epigenome characteristics. We also found that while many studies focused on adaptation and heritability of the epigenome, the field has thematically expanded into topics such as disease ecology and epigenome-based ageing of individuals. In the second part of our synthesis, we discuss key insights that have emerged from the epigenetic field broadly and use these to preview the path toward integration of epigenetics into ecology. Specifically, we suggest moving focus to nucleotide-level differences in the epigenome rather than whole-epigenome data and that we incorporate several facets of epigenome characterization (e.g., methylation, chromatin structure). Finally, we also suggest that incorporation of behavior and stress data will be critical to the process of fully integrating eco-epi data into ecology, conservation, and evolutionary biology.
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17
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Inbreeding is associated with shorter early-life telomere length in a wild passerine. CONSERV GENET 2022. [DOI: 10.1007/s10592-022-01441-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
AbstractInbreeding can have negative effects on survival and reproduction, which may be of conservation concern in small and isolated populations. However, the physiological mechanisms underlying inbreeding depression are not well-known. The length of telomeres, the DNA sequences protecting chromosome ends, has been associated with health or fitness in several species. We investigated effects of inbreeding on early-life telomere length in two small island populations of wild house sparrows (Passer domesticus) known to be affected by inbreeding depression. Using genomic measures of inbreeding we found that inbred nestling house sparrows (n = 371) have significantly shorter telomeres. Using pedigree-based estimates of inbreeding we found a tendency for inbred nestling house sparrows to have shorter telomeres (n = 1195). This negative effect of inbreeding on telomere length may have been complemented by a heterosis effect resulting in longer telomeres in individuals that were less inbred than the population average. Furthermore, we found some evidence of stronger effects of inbreeding on telomere length in males than females. Thus, telomere length may reveal subtle costs of inbreeding in the wild and demonstrate a route by which inbreeding negatively impacts the physiological state of an organism already at early life-history stages.
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18
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Robledo-Ruiz DA, Gan HM, Kaur P, Dudchenko O, Weisz D, Khan R, Lieberman Aiden E, Osipova E, Hiller M, Morales HE, Magrath MJL, Clarke RH, Sunnucks P, Pavlova A. Chromosome-length genome assembly and linkage map of a critically endangered Australian bird: the helmeted honeyeater. Gigascience 2022; 11:6554768. [PMID: 35348671 PMCID: PMC8963300 DOI: 10.1093/gigascience/giac025] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2021] [Revised: 01/13/2022] [Accepted: 02/14/2022] [Indexed: 11/17/2022] Open
Abstract
Background The helmeted honeyeater (Lichenostomus melanops cassidix) is a Critically Endangered bird endemic to Victoria, Australia. To aid its conservation, the population is the subject of genetic rescue. To understand, monitor, and modulate the effects of genetic rescue on the helmeted honeyeater genome, a chromosome-length genome and a high-density linkage map are required. Results We used a combination of Illumina, Oxford Nanopore, and Hi-C sequencing technologies to assemble a chromosome-length genome of the helmeted honeyeater, comprising 906 scaffolds, with length of 1.1 Gb and scaffold N50 of 63.8 Mb. Annotation comprised 57,181 gene models. Using a pedigree of 257 birds and 53,111 single-nucleotide polymorphisms, we obtained high-density linkage and recombination maps for 25 autosomes and Z chromosome. The total sex-averaged linkage map was 1,347 cM long, with the male map being 6.7% longer than the female map. Recombination maps revealed sexually dimorphic recombination rates (overall higher in males), with average recombination rate of 1.8 cM/Mb. Comparative analyses revealed high synteny of the helmeted honeyeater genome with that of 3 passerine species (e.g., 32 Hi-C scaffolds mapped to 30 zebra finch autosomes and Z chromosome). The genome assembly and linkage map suggest that the helmeted honeyeater exhibits a fission of chromosome 1A into 2 chromosomes relative to zebra finch. PSMC analysis showed a ∼15-fold decline in effective population size to ∼60,000 from mid- to late Pleistocene. Conclusions The annotated chromosome-length genome and high-density linkage map provide rich resources for evolutionary studies and will be fundamental in guiding conservation efforts for the helmeted honeyeater.
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Affiliation(s)
| | - Han Ming Gan
- Deakin Genomics Centre, Deakin University, Geelong, VIC 3220, Australia.,GeneSEQ Sdn Bhd, 48300 Rawang, Selangor, Malaysia
| | - Parwinder Kaur
- UWA School of Agriculture and Environment, The University of Western Australia, Perth WA 6009,Australia
| | - Olga Dudchenko
- The Center for Genome Architecture, Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA.,Center for Theoretical Biological Physics and Department of Computer Science, Rice University, Houston, TX 77030, USA
| | - David Weisz
- The Center for Genome Architecture, Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
| | - Ruqayya Khan
- The Center for Genome Architecture, Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
| | - Erez Lieberman Aiden
- UWA School of Agriculture and Environment, The University of Western Australia, Perth WA 6009,Australia.,The Center for Genome Architecture, Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA.,Center for Theoretical Biological Physics and Department of Computer Science, Rice University, Houston, TX 77030, USA.,Broad Institute of MIT and Harvard, Cambridge, MA 02139, USA.,Shanghai Institute for Advanced Immunochemical Studies, ShanghaiTech, Pudong 201210, China
| | - Ekaterina Osipova
- Max Planck Institute of Molecular Cell Biology and Genetics, Pfotenhauerstr 108, 101307 Dresden, Germany.,LOEWE Centre for Translational Biodiversity Genomics, Senckenberganlage 25, 60325 Frankfurt, Germany.,Senckenberg Research Institute, Senckenberganlage 25, 60325 Frankfurt, Germany.,Goethe-University, Faculty of Biosciences, Max-von-Laue-Str. 9, 60438 Frankfurt, Germany
| | - Michael Hiller
- Max Planck Institute of Molecular Cell Biology and Genetics, Pfotenhauerstr 108, 101307 Dresden, Germany.,LOEWE Centre for Translational Biodiversity Genomics, Senckenberganlage 25, 60325 Frankfurt, Germany.,Senckenberg Research Institute, Senckenberganlage 25, 60325 Frankfurt, Germany.,Goethe-University, Faculty of Biosciences, Max-von-Laue-Str. 9, 60438 Frankfurt, Germany
| | - Hernán E Morales
- Section for Evolutionary Genomics, GLOBE Institute, University of Copenhagen, Denmark
| | - Michael J L Magrath
- Department of Wildlife Conservation and Science, Zoos Victoria, Parkville, VIC 3052, Australia
| | - Rohan H Clarke
- School of Biological Sciences, Monash University, Clayton, VIC 3800, Australia
| | - Paul Sunnucks
- School of Biological Sciences, Monash University, Clayton, VIC 3800, Australia
| | - Alexandra Pavlova
- School of Biological Sciences, Monash University, Clayton, VIC 3800, Australia
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19
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Brockett B, Banks S, Neaves LE, Gordon IJ, Pierson JC, Manning AD. Establishment, persistence and the importance of longitudinal monitoring in multi‐source reintroductions. Anim Conserv 2022. [DOI: 10.1111/acv.12764] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Affiliation(s)
- B. Brockett
- Fenner School of Environment and Society The Australian National University Canberra ACT Australia
| | - S. Banks
- College of Engineering, IT and the Environment Charles Darwin University Darwin NT Australia
| | - L. E. Neaves
- Fenner School of Environment and Society The Australian National University Canberra ACT Australia
| | - I. J. Gordon
- Fenner School of Environment and Society The Australian National University Canberra ACT Australia
- James Hutton Institute Dundee UK
- Central Queensland University Townsville QLD Australia
- Land & Water CSIRO Townsville QLD Australia
- Protected Places Mission NERP2, Reef and Rainforest Research Center Cairns QLD Australia
| | - J. C. Pierson
- ACT Parks and Conservation Service Canberra Australia
| | - A. D. Manning
- Fenner School of Environment and Society The Australian National University Canberra ACT Australia
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20
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Flanagan AM, Masuda B, Grueber CE, Sutton JT. Moving from trends to benchmarks by using regression tree analysis to find inbreeding thresholds in a critically endangered bird. CONSERVATION BIOLOGY : THE JOURNAL OF THE SOCIETY FOR CONSERVATION BIOLOGY 2021; 35:1278-1287. [PMID: 33025666 DOI: 10.1111/cobi.13650] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/25/2020] [Revised: 09/03/2020] [Accepted: 10/02/2020] [Indexed: 06/11/2023]
Abstract
Understanding how inbreeding affects endangered species in conservation breeding programs is essential for their recovery. The Hawaiian Crow ('Alalā) (Corvus hawaiiensis) is one of the world's most endangered birds. It went extinct in the wild in 2002, and, until recent release efforts starting in 2016, nearly all of the population remained under human care for conservation breeding. Using pedigree inbreeding coefficients (F), we evaluated the effects of inbreeding on Hawaiian Crow offspring survival and reproductive success. We used regression tree analysis to identify the level of inbreeding (i.e., inbreeding threshold) that explains a substantial decrease in 'Alalā offspring survival to recruitment. Similar to a previous study of inbreeding in 'Alalā, we found that inbreeding had a negative impact on offspring survival but that parental (vs. artificial) egg incubation improved offspring survival to recruitment. Furthermore, we found that inbreeding did not substantially affect offspring reproductive success, based on the assumption that offspring that survive to adulthood breed with distantly related mates. Our novel application of regression tree analysis showed that offspring with inbreeding levels exceeding F = 0.098 were 69% less likely to survive to recruitment than more outbred offspring, providing a specific threshold value for ongoing population management. Our results emphasize the importance of assessing inbreeding depression across all life history stages, confirm the importance of prioritizing parental over artificial egg incubation in avian conservation breeding programs, and demonstrate the utility of regression tree analysis as a tool for identifying inbreeding thresholds, if present, in any pedigree-managed population.
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Affiliation(s)
- Alison M Flanagan
- Hawaii Endangered Bird Conservation Program, Institute for Conservation Research, San Diego Zoo Global, P.O. Box 39, Volcano, HI, 96785, U.S.A
| | - Bryce Masuda
- Hawaii Endangered Bird Conservation Program, Institute for Conservation Research, San Diego Zoo Global, P.O. Box 39, Volcano, HI, 96785, U.S.A
| | - Catherine E Grueber
- School of Life and Environmental Sciences, The University of Sydney, Sydney, NSW, 2006, Australia
| | - Jolene T Sutton
- Department of Biology, University of Hawaii at Hilo, Hilo, HI, 96720, U.S.A
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21
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Nimje PS, Mayer M, Zedrosser A, Sæbø M, Rosell F. Territory acquisition and mate choice in a monogamous mammal, the Eurasian beaver. Anim Behav 2021. [DOI: 10.1016/j.anbehav.2021.06.015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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22
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Robledo-Ruiz DA, Pavlova A, Clarke RH, Magrath MJL, Quin B, Harrisson KA, Gan HM, Low GW, Sunnucks P. A novel framework for evaluating in situ breeding management strategies in endangered populations. Mol Ecol Resour 2021; 22:239-253. [PMID: 34288508 DOI: 10.1111/1755-0998.13476] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Revised: 06/29/2021] [Accepted: 07/15/2021] [Indexed: 11/30/2022]
Abstract
Conservation breeding management aims to reduce inbreeding and maximize the retention of genetic diversity in endangered populations. However, breeding management of wild populations is still rare, and there is a need for approaches that provide data-driven evidence of the likelihood of success of alternative in situ strategies. Here, we provide an analytical framework that uses in silico simulations to evaluate, for real wild populations, (i) the degree of population-level inbreeding avoidance, (ii) the genetic quality of mating pairs, and (iii) the potential genetic benefits of implementing two breeding management strategies. The proposed strategies aim to improve the genetic quality of breeding pairs by splitting detrimental pairs and allowing the members to re-pair in different ways. We apply the framework to the wild population of the Critically Endangered helmeted honeyeater by combining genomic data and field observations to estimate the inbreeding (i.e., pair-kinship) and genetic quality (i.e., Mate Suitability Index) of all mating pairs for seven consecutive breeding seasons. We found no evidence of population-level inbreeding avoidance and that ~91.6% of breeding pairs were detrimental to the genetic health of the population. Furthermore, the framework revealed that neither proposed management strategy would significantly improve the genetic quality or reduce inbreeding of the mating pairs in this population. Our results demonstrate the usefulness of our analytical framework for testing the efficacy of different in situ breeding management strategies and for making evidence-based management decisions.
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Affiliation(s)
| | - Alexandra Pavlova
- School of Biological Sciences, Monash University, Clayton, Vic., Australia
| | - Rohan H Clarke
- School of Biological Sciences, Monash University, Clayton, Vic., Australia
| | - Michael J L Magrath
- Department of Wildlife Conservation and Science, Zoos Victoria, Parkville, Vic., Australia.,School of BioSciences, University of Melbourne, Parkville, Vic., Australia
| | - Bruce Quin
- Department of Environment, Land, Water and Planning, Woori Yallock, Vic., Australia
| | - Katherine A Harrisson
- Department of Ecology, Environment and Evolution, La Trobe University, Melbourne, Vic., Australia.,Department of Environment, Land, Water and Planning, Arthur Rylah Institute for Environmental Research, Heidelberg, Vic., Australia
| | - Han Ming Gan
- Centre for Integrative Ecology, School of Life and Environmental Sciences, Deakin University, Geelong, Vic., Australia.,Deakin Genomics Centre, Deakin University, Geelong, Vic., Australia
| | - Gabriel W Low
- School of Biological Sciences, Monash University, Clayton, Vic., Australia
| | - Paul Sunnucks
- School of Biological Sciences, Monash University, Clayton, Vic., Australia
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23
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Duntsch L, Whibley A, Brekke P, Ewen JG, Santure AW. Genomic data of different resolutions reveal consistent inbreeding estimates but contrasting homozygosity landscapes for the threatened Aotearoa New Zealand hihi. Mol Ecol 2021; 30:6006-6020. [PMID: 34242449 DOI: 10.1111/mec.16068] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2020] [Accepted: 07/01/2021] [Indexed: 12/19/2022]
Abstract
Inbreeding can lead to a loss of heterozygosity in a population and when combined with genetic drift may reduce the adaptive potential of a species. However, there is uncertainty about whether resequencing data can provide accurate and consistent inbreeding estimates. Here, we performed an in-depth inbreeding analysis for hihi (Notiomystis cincta), an endemic and nationally vulnerable passerine bird of Aotearoa New Zealand. We first focused on subsampling variants from a reference genome male, and found that low-density data sets tend to miss runs of homozygosity (ROH) in some places and overestimate ROH length in others, resulting in contrasting homozygosity landscapes. Low-coverage resequencing and 50 K SNP array densities can yield comparable inbreeding results to high-coverage resequencing approaches, but the results for all data sets are highly dependent on the software settings employed. Second, we extended our analysis to 10 hihi where low-coverage whole genome resequencing, RAD-seq and SNP array genotypes are available. We inferred ROH and individual inbreeding to evaluate the relative effects of sequencing depth versus SNP density on estimating inbreeding coefficients and found that high rates of missingness downwardly bias both the number and length of ROH. In summary, when using genomic data to evaluate inbreeding, studies must consider that ROH estimates are heavily dependent on analysis parameters, data set density and individual sequencing depth.
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Affiliation(s)
- Laura Duntsch
- School of Biological Sciences, University of Auckland, Auckland, New Zealand
| | - Annabel Whibley
- School of Biological Sciences, University of Auckland, Auckland, New Zealand
| | - Patricia Brekke
- Institute of Zoology, Zoological Society of London, London, UK
| | - John G Ewen
- Institute of Zoology, Zoological Society of London, London, UK
| | - Anna W Santure
- School of Biological Sciences, University of Auckland, Auckland, New Zealand
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24
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DeWoody JA, Harder AM, Mathur S, Willoughby JR. The long-standing significance of genetic diversity in conservation. Mol Ecol 2021; 30:4147-4154. [PMID: 34191374 DOI: 10.1111/mec.16051] [Citation(s) in RCA: 71] [Impact Index Per Article: 23.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2021] [Revised: 06/20/2021] [Accepted: 06/28/2021] [Indexed: 12/12/2022]
Abstract
Since allozymes were first used to assess genetic diversity in the 1960s and 1970s, biologists have attempted to characterize gene pools and conserve the diversity observed in domestic crops, livestock, zoos and (more recently) natural populations. Recently, some authors have claimed that the importance of genetic diversity in conservation biology has been greatly overstated. Here, we argue that a voluminous literature indicates otherwise. We address four main points made by detractors of genetic diversity's role in conservation by using published literature to firmly establish that genetic diversity is intimately tied to evolutionary fitness, and that the associated demographic consequences are of paramount importance to many conservation efforts. We think that responsible management in the Anthropocene should, whenever possible, include the conservation of ecosystems, communities, populations and individuals, and their underlying genetic diversity.
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Affiliation(s)
- J Andrew DeWoody
- Department of Forestry and Natural Resources, Department of Biological Sciences, Purdue University, West Lafayette, Indiana, USA
| | - Avril M Harder
- School of Forestry and Wildlife Sciences, Auburn University, Auburn, Alabama, USA
| | - Samarth Mathur
- Department of Evolution, Ecology and Organismal Biology, The Ohio State University, Columbus, Ohio, USA
| | - Janna R Willoughby
- School of Forestry and Wildlife Sciences, Auburn University, Auburn, Alabama, USA
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25
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Stoffel MA, Johnston SE, Pilkington JG, Pemberton JM. Mutation load decreases with haplotype age in wild Soay sheep. Evol Lett 2021; 5:187-195. [PMID: 34136268 PMCID: PMC8190445 DOI: 10.1002/evl3.229] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2021] [Revised: 04/06/2021] [Accepted: 04/13/2021] [Indexed: 01/01/2023] Open
Abstract
Runs of homozygosity (ROH) are pervasive in diploid genomes and expose the effects of deleterious recessive mutations, but how exactly these regions contribute to variation in fitness remains unclear. Here, we combined empirical analyses and simulations to explore the deleterious effects of ROH with varying genetic map lengths in wild Soay sheep. Using a long-term dataset of 4879 individuals genotyped at 417K SNPs, we found that inbreeding depression increases with ROH length. A 1% genomic increase in long ROH (>12.5 cM) reduced the odds of first-year survival by 12.4% compared to only 7.7% for medium ROH (1.56-12.5 cM), whereas short ROH (<1.56 cM) had no effect on survival. We show by forward genetic simulations that this is predicted: compared to shorter ROH, long ROH will have higher densities of deleterious alleles, with larger average effects on fitness and lower population frequencies. Taken together, our results are consistent with the idea that the mutation load decreases in older haplotypes underlying shorter ROH, where purifying selection has had more time to purge deleterious mutations. Finally, our study demonstrates that strong inbreeding depression can persist despite ongoing purging in a historically small population.
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Affiliation(s)
- Martin A. Stoffel
- School of Biological Sciences, Institute of Evolutionary BiologyUniversity of EdinburghEdinburghEH9 3FLUnited Kingdom
| | - Susan E. Johnston
- School of Biological Sciences, Institute of Evolutionary BiologyUniversity of EdinburghEdinburghEH9 3FLUnited Kingdom
| | - Jill G. Pilkington
- School of Biological Sciences, Institute of Evolutionary BiologyUniversity of EdinburghEdinburghEH9 3FLUnited Kingdom
| | - Josephine M. Pemberton
- School of Biological Sciences, Institute of Evolutionary BiologyUniversity of EdinburghEdinburghEH9 3FLUnited Kingdom
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26
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Farquharson KA, Hogg CJ, Grueber CE. Offspring survival changes over generations of captive breeding. Nat Commun 2021; 12:3045. [PMID: 34031378 PMCID: PMC8144597 DOI: 10.1038/s41467-021-22631-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2020] [Accepted: 03/11/2021] [Indexed: 11/28/2022] Open
Abstract
Conservation breeding programs such as zoos play a major role in preventing extinction, but their sustainability may be impeded by neutral and adaptive population genetic change. These changes are difficult to detect for a single species or context, and impact global conservation efforts. We analyse pedigree data from 15 vertebrate species – over 30,000 individuals – to examine offspring survival over generations of captive breeding. Even accounting for inbreeding, we find that the impacts of increasing generations in captivity are highly variable across species, with some showing substantial increases or decreases in offspring survival over generations. We find further differences between dam and sire effects in first- versus multi-generational analysis. Crucially, our multispecies analysis reveals that responses to captivity could not be predicted from species’ evolutionary (phylogenetic) relationships. Even under best-practice captive management, generational fitness changes that cannot be explained by known processes (such as inbreeding depression), are occurring. Captive breeding could prevent species extinctions, but selection for captivity may decrease fitness. Here the authors analyse pedigree data on 15 long-running vertebrate breeding programs and find generational fitness changes that processes such as inbreeding depression cannot explain.
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Affiliation(s)
- Katherine A Farquharson
- The University of Sydney, School of Life and Environmental Sciences, Faculty of Science, Sydney, NSW, Australia
| | - Carolyn J Hogg
- The University of Sydney, School of Life and Environmental Sciences, Faculty of Science, Sydney, NSW, Australia
| | - Catherine E Grueber
- The University of Sydney, School of Life and Environmental Sciences, Faculty of Science, Sydney, NSW, Australia.
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27
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Hasselgren M, Dussex N, von Seth J, Angerbjörn A, Olsen RA, Dalén L, Norén K. Genomic and fitness consequences of inbreeding in an endangered carnivore. Mol Ecol 2021; 30:2790-2799. [PMID: 33955096 DOI: 10.1111/mec.15943] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2020] [Revised: 03/31/2021] [Accepted: 04/14/2021] [Indexed: 12/28/2022]
Abstract
Reduced fitness through genetic drift and inbreeding is a major threat to small and isolated populations. Although previous studies have generally used genetically verified pedigrees to document effects of inbreeding and gene flow, these often fail to capture the whole inbreeding history of the species. By assembling a draft arctic fox (Vulpes lagopus) genome and resequencing complete genomes of 23 additional foxes born before and after a well-documented immigration event in Scandinavia, we here look into the genomic consequences of inbreeding and genetic rescue. We found a difference in genome-wide diversity, with 18% higher heterozygosity and 81% lower FROH in immigrant F1 compared to native individuals. However, more distant descendants of immigrants (F2, F3) did not show the same pattern. We also found that foxes with lower inbreeding had higher probability to survive their first year of life. Our results demonstrate the important link between genetic variation and fitness as well as the transient nature of genetic rescue. Moreover, our results have implications in conservation biology as they demonstrate that inbreeding depression can effectively be detected in the wild by a genomic approach.
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Affiliation(s)
| | - Nicolas Dussex
- Department of Zoology, Stockholm University, Stockholm, Sweden.,Department of Bioinformatics and Genetics, Swedish Museum of Natural History, Stockholm, Sweden
| | - Johanna von Seth
- Department of Zoology, Stockholm University, Stockholm, Sweden.,Department of Bioinformatics and Genetics, Swedish Museum of Natural History, Stockholm, Sweden
| | | | - Remi-André Olsen
- Science for Life Laboratory, Department of Biochemistry and Biophysics, Stockholm University, Solna, Sweden
| | - Love Dalén
- Department of Bioinformatics and Genetics, Swedish Museum of Natural History, Stockholm, Sweden
| | - Karin Norén
- Department of Zoology, Stockholm University, Stockholm, Sweden
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28
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Stoffel MA, Johnston SE, Pilkington JG, Pemberton JM. Genetic architecture and lifetime dynamics of inbreeding depression in a wild mammal. Nat Commun 2021; 12:2972. [PMID: 34016997 PMCID: PMC8138023 DOI: 10.1038/s41467-021-23222-9] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2020] [Accepted: 03/29/2021] [Indexed: 02/03/2023] Open
Abstract
Inbreeding depression is ubiquitous, but we still know little about its genetic architecture and precise effects in wild populations. Here, we combine long-term life-history data with 417 K imputed SNP genotypes for 5952 wild Soay sheep to explore inbreeding depression on a key fitness component, annual survival. Inbreeding manifests in long runs of homozygosity (ROH), which make up nearly half of the genome in the most inbred individuals. The ROH landscape varies widely across the genome, with islands where up to 87% and deserts where only 4% of individuals have ROH. The fitness consequences of inbreeding are severe; a 10% increase in individual inbreeding FROH is associated with a 60% reduction in the odds of survival in lambs, though inbreeding depression decreases with age. Finally, a genome-wide association scan on ROH shows that many loci with small effects and five loci with larger effects contribute to inbreeding depression in survival.
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Affiliation(s)
- M A Stoffel
- Institute of Evolutionary Biology, School of Biological Sciences, University of Edinburgh, Edinburgh, UK.
| | - S E Johnston
- Institute of Evolutionary Biology, School of Biological Sciences, University of Edinburgh, Edinburgh, UK
| | - J G Pilkington
- Institute of Evolutionary Biology, School of Biological Sciences, University of Edinburgh, Edinburgh, UK
| | - J M Pemberton
- Institute of Evolutionary Biology, School of Biological Sciences, University of Edinburgh, Edinburgh, UK
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29
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Hoffmann AA, Miller AD, Weeks AR. Genetic mixing for population management: From genetic rescue to provenancing. Evol Appl 2021; 14:634-652. [PMID: 33767740 PMCID: PMC7980264 DOI: 10.1111/eva.13154] [Citation(s) in RCA: 60] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2020] [Revised: 10/10/2020] [Accepted: 10/14/2020] [Indexed: 12/21/2022] Open
Abstract
Animal and plant species around the world are being challenged by the deleterious effects of inbreeding, loss of genetic diversity, and maladaptation due to widespread habitat destruction and rapid climate change. In many cases, interventions will likely be needed to safeguard populations and species and to maintain functioning ecosystems. Strategies aimed at initiating, reinstating, or enhancing patterns of gene flow via the deliberate movement of genotypes around the environment are generating growing interest with broad applications in conservation and environmental management. These diverse strategies go by various names ranging from genetic or evolutionary rescue to provenancing and genetic resurrection. Our aim here is to provide some clarification around terminology and to how these strategies are connected and linked to underlying genetic processes. We draw on case studies from the literature and outline mechanisms that underlie how the various strategies aim to increase species fitness and impact the wider community. We argue that understanding mechanisms leading to species decline and community impact is a key to successful implementation of these strategies. We emphasize the need to consider the nature of source and recipient populations, as well as associated risks and trade-offs for the various strategies. This overview highlights where strategies are likely to have potential at population, species, and ecosystem scales, but also where they should probably not be attempted depending on the overall aims of the intervention. We advocate an approach where short- and long-term strategies are integrated into a decision framework that also considers nongenetic aspects of management.
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Affiliation(s)
- Ary A. Hoffmann
- School of BioSciencesBio21 InstituteThe University of MelbourneParkvilleVic.Australia
| | - Adam D. Miller
- School of Life and Environmental SciencesCentre for Integrative EcologyDeakin UniversityWarrnamboolVic.Australia
- Deakin Genomics CentreDeakin UniversityGeelongVic.Australia
| | - Andrew R. Weeks
- School of BioSciencesBio21 InstituteThe University of MelbourneParkvilleVic.Australia
- cesar Pty LtdParkvilleVic.Australia
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30
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Multiple life-stage inbreeding depression impacts demography and extinction risk in an extinct-in-the-wild species. Sci Rep 2021; 11:682. [PMID: 33436770 PMCID: PMC7804286 DOI: 10.1038/s41598-020-79979-4] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2020] [Accepted: 12/09/2020] [Indexed: 11/13/2022] Open
Abstract
Inbreeding can depress individuals’ fitness traits and reduce population viability. However, studies that directly translate inbreeding depression on fitness traits into consequences for population viability, and further, into consequences for management choices, are lacking. Here, we estimated impacts of inbreeding depression (B, lethal equivalents) across life-history stages for an extinct-in-the-wild species, the sihek (Guam kingfisher, Todiramphus cinnamominus). We then projected population growth under different management alternatives with our B estimates incorporated, as well as without inbreeding depression (B = 0) or with a conventional default B. We found that inbreeding depression severely impacted multiple life-history stages, and directly translated into an effect on population viability under management alternatives. Simulations including our B estimates indicated rapid population decline, whereas projections without inbreeding depression or with default B suggested very gradual population decline. Further, our results demonstrate that incorporation of B across life-history stages can influence management decisions, as projections with our B estimates suggested a need to switch to increased breeding management to avoid species extinction and support wild releases. Our results demonstrate that magnitude of B across life-history stages can translate into demographic consequences, such that incorporation of multiple life-stage B into population models can be important for informed conservation management decision-making.
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31
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Zilko JP, Harley D, Hansen B, Pavlova A, Sunnucks P. Accounting for cryptic population substructure enhances detection of inbreeding depression with genomic inbreeding coefficients: an example from a critically endangered marsupial. Mol Ecol 2020; 29:2978-2993. [PMID: 32627274 DOI: 10.1111/mec.15540] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2019] [Revised: 05/16/2020] [Accepted: 06/18/2020] [Indexed: 12/21/2022]
Abstract
Characterizing inbreeding depression in wildlife populations can be critical to their conservation. Coefficients of individual inbreeding can be estimated from genome-wide marker data. The degree to which sensitivity of inbreeding coefficients to population genetic substructure alters estimates of inbreeding depression in wild populations is not well understood. Using generalized linear models, we tested the power of two frequently used inbreeding coefficients that are calculated from genome-wide SNP markers, FH and F^III , to predict four fitness traits estimated over two decades in an isolated population of the critically endangered Leadbeater's possum. FH estimates inbreeding as excess observed homozygotes relative to equilibrium expectations, whereas F^III quantifies allelic similarity between the gametes that formed an individual, and upweights rare homozygotes. We estimated FH and F^III from 1,575 genome-wide SNP loci in individuals with fitness trait data (N = 179-237 per trait), and computed revised coefficients, FH by group and F^IIIby group , adjusted for population genetic substructure by calculating them separately within two different genetic groups of individuals identified in the population. Using FH or F^III in the models, inbreeding depression was detected for survival to sexual maturity, longevity and whether individuals bred during their lifetime. F^IIIby group (but not FH by group ) additionally revealed significant inbreeding depression for lifetime reproductive output (total offspring assigned to each individual). Estimates of numbers of lethal equivalents indicated substantial inbreeding load, but differing between inbreeding estimators. Inbreeding depression, declining population size, and low and declining genetic diversity suggest that genetic rescue may assist in preventing extinction of this unique Leadbeater's possum population.
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Affiliation(s)
- Joseph P Zilko
- School of Biological Sciences, Monash University, Clayton, Vic, Australia
| | - Dan Harley
- Zoos Victoria, Parkville, Vic, Australia
| | - Birgita Hansen
- Centre for eResearch and Digital Innovation, Federation University, Ballarat, Vic, Australia
| | - Alexandra Pavlova
- School of Biological Sciences, Monash University, Clayton, Vic, Australia
| | - Paul Sunnucks
- School of Biological Sciences, Monash University, Clayton, Vic, Australia
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32
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Schultz AJ, Cristescu RH, Hanger J, Loader J, de Villiers D, Frère CH. Inbreeding and disease avoidance in a free-ranging koala population. Mol Ecol 2020; 29:2416-2430. [PMID: 32470998 DOI: 10.1111/mec.15488] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2019] [Accepted: 05/11/2020] [Indexed: 11/30/2022]
Abstract
Habitat destruction and fragmentation are increasing globally, forcing surviving species into small, isolated populations. Isolated populations typically experience heightened inbreeding risk and associated inbreeding depression and population decline; although individuals in these populations may mitigate these risks through inbreeding avoidance strategies. For koalas, as dietary specialists already under threat in the northern parts of their range, increased habitat fragmentation and associated inbreeding costs are of great conservation concern. Koalas are known to display passive inbreeding avoidance through sex-biased dispersal, although population isolation will reduce dispersal pathways. We tested whether free-ranging koalas display active inbreeding avoidance behaviours. We used VHF tracking data, parentage reconstruction, and veterinary examination results to test whether free-ranging female koalas avoid mating with (a) more closely related males; and (b) males infected with sexually transmitted Chlamydia pecorum. We found no evidence that female koalas avoid mating with relatively more related available mates. In fact, as the relatedness of potential mates increases, so did inbreeding events. We also found no evidence that female koalas can avoid mating with males infected with C. pecorum. The absence of active inbreeding avoidance mechanisms in koalas is concerning from a conservation perspective, as small, isolated populations may be at even higher risk of inbreeding depression than expected. At risk koala populations may require urgent conservation interventions to augment gene flow and reduce inbreeding risks. Similarly, if koalas are not avoiding mating with individuals with chlamydial disease, populations may be at higher risk from disease than anticipated, further impacting population viability.
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Affiliation(s)
- Anthony J Schultz
- Global Change Ecology Research Group, University of the Sunshine Coast, Sippy Downs, QLD, Australia
| | - Romane H Cristescu
- Global Change Ecology Research Group, University of the Sunshine Coast, Sippy Downs, QLD, Australia
| | - Jon Hanger
- Endeavour Veterinary Ecology Pty Ltd, Toorbul, QLD, Australia
| | - Jo Loader
- Endeavour Veterinary Ecology Pty Ltd, Toorbul, QLD, Australia
| | | | - Celine H Frère
- Global Change Ecology Research Group, University of the Sunshine Coast, Sippy Downs, QLD, Australia
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33
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Major RE, Ewart KM, Portelli DJ, King A, Tsang LR, O’Dwyer T, Carlile N, Haselden C, Bower H, Alquezar‐Planas DE, Johnson RN, Eldridge MDB. Islands within islands: genetic structuring at small spatial scales has implications for long‐term persistence of a threatened species. Anim Conserv 2020. [DOI: 10.1111/acv.12603] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- R. E. Major
- Australian Museum Research Institute Australian Museum Sydney NSW Australia
| | - K. M. Ewart
- Australian Museum Research Institute Australian Museum Sydney NSW Australia
| | - D. J. Portelli
- Department of Environment and Natural Resources Alice Springs NT Australia
| | - A. King
- Australian Museum Research Institute Australian Museum Sydney NSW Australia
| | - L. R. Tsang
- Australian Museum Research Institute Australian Museum Sydney NSW Australia
| | - T. O’Dwyer
- NSW Department of Planning, Industry and Environment Hurstville NSW Australia
| | - N. Carlile
- NSW Department of Planning, Industry and Environment Hurstville NSW Australia
| | - C. Haselden
- Lord Howe Island Board Lord Howe Island NSW Australia
| | - H. Bower
- Lord Howe Island Board Lord Howe Island NSW Australia
| | | | - R. N. Johnson
- Australian Museum Research Institute Australian Museum Sydney NSW Australia
| | - M. D. B. Eldridge
- Australian Museum Research Institute Australian Museum Sydney NSW Australia
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34
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Abstract
Endangered species face a huge array of challenges, including the negative consequences of individuals having to breed with close genetic relatives. But just how costly is inbreeding in small populations? New research from an endangered bird species suggests that considering inbreeding could be crucial for conservation programmes.
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Affiliation(s)
- Lewis G Spurgin
- School of Biological Sciences, University of East Anglia, NR4 7TJ, UK.
| | - Matthew J G Gage
- School of Biological Sciences, University of East Anglia, NR4 7TJ, UK
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35
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Potter S, Neaves LE, Lethbridge M, Eldridge MDB. Understanding Historical Demographic Processes to Inform Contemporary Conservation of an Arid zone Specialist: The Yellow-Footed Rock-Wallaby. Genes (Basel) 2020; 11:E154. [PMID: 32023869 PMCID: PMC7073556 DOI: 10.3390/genes11020154] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2019] [Revised: 01/27/2020] [Accepted: 01/28/2020] [Indexed: 11/16/2022] Open
Abstract
Little genetic research has been undertaken on mammals across the vast expanse of the arid biome in Australia, despite continuing species decline and need for conservation management. Here, we evaluate the contemporary and historical genetic connectivity of the yellow-footed rock-wallaby, Petrogalexanthopusxanthopus, a threatened macropodid which inhabits rocky outcrops across the disconnected mountain range systems of the southern arid biome. We use 17 microsatellite loci together with mitochondrial control region data to determine the genetic diversity of populations and the evolutionary processes shaping contemporary population dynamics on which to base conservation recommendations. Our results indicate the highly fragmented populations have reduced diversity and limited contemporary gene flow, with most populations having been through population bottlenecks. Despite limited contemporary gene flow, the phylogeographic relationships of the mitochondrial control region indicate a lack of structure and suggests greater historical connectivity. This is an emerging outcome for mammals across this arid region. On the basis of our results, we recommend augmentation of populations of P. x.xanthopus, mixing populations from disjunct mountain range systems to reduce the chance of continued diversity loss and inbreeding depression, and therefore maximize the potential for populations to adapt and survive into the future.
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Affiliation(s)
- Sally Potter
- Division of Ecology and Evolution, Research School of Biology, Australian National University, Acton ACT 2601, Australia
- Australian Museum Research Institute, Australian Museum, 1 William Street, Sydney 2010, New South Wales, Australia (M.D.B.E.)
| | - Linda E. Neaves
- Australian Museum Research Institute, Australian Museum, 1 William Street, Sydney 2010, New South Wales, Australia (M.D.B.E.)
- Royal Botanic Garden Edinburgh, 20A Inverleith Row, Edinburgh EH3 5 LR, UK
| | - Mark Lethbridge
- Biological Sciences, Flinders University, Adelaide 5001, Australia;
| | - Mark D. B. Eldridge
- Australian Museum Research Institute, Australian Museum, 1 William Street, Sydney 2010, New South Wales, Australia (M.D.B.E.)
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