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Peters C, Geary M, Hosie C, Nelson H, Rusk B, Muir A. Non-invasive sampling reveals low mitochondrial genetic diversity for an island endemic species: The critically endangered Grenada Dove Leptotila wellsi. Ecol Evol 2023; 13:e10767. [PMID: 38020693 PMCID: PMC10667608 DOI: 10.1002/ece3.10767] [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: 07/31/2023] [Revised: 10/30/2023] [Accepted: 11/07/2023] [Indexed: 12/01/2023] Open
Abstract
As an island endemic with a decreasing population, the critically endangered Grenada Dove Leptotila wellsi is threatened by accelerated loss of genetic diversity resulting from ongoing habitat fragmentation. Small, threatened populations are difficult to sample directly but advances in molecular methods mean that non-invasive samples can be used. We performed the first assessment of genetic diversity of populations of Grenada Dove by (a) assessing mtDNA genetic diversity in the only two areas of occupancy on Grenada, (b) defining the number of haplotypes present at each site and (c) evaluating evidence of isolation between sites. We used non-invasively collected samples from two locations: Mt Hartman (n = 18) and Perseverance (n = 12). DNA extraction and PCR were used to amplify 1751 bps of mtDNA from two mitochondrial markers: NADH dehydrogenase 2 (ND2) and Cytochrome b (Cyt b). Haplotype diversity (h) of 0.4, a nucleotide diversity (π) of 0.00023 and two unique haplotypes were identified within the ND2 sequences; a single haplotype was identified within the Cyt b sequences. Of the two haplotypes identified, the most common haplotype (haplotype A = 73.9%) was observed at both sites and the other (haplotype B = 26.1%) was unique to Perseverance. Our results show low mitochondrial genetic diversity and clear evidence for genetically isolated populations. The Grenada Dove needs urgent conservation action, including habitat protection and potentially augmentation of gene flow by translocation in order to increase genetic resilience and diversity with the ultimate aim of securing the long-term survival of this critically endangered species.
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Affiliation(s)
- Catherine Peters
- Conservation Biology Research Group, Department of Biological SciencesUniversity of ChesterChesterUK
| | - Matthew Geary
- Conservation Biology Research Group, Department of Biological SciencesUniversity of ChesterChesterUK
| | - Charlotte Hosie
- Conservation Biology Research Group, Department of Biological SciencesUniversity of ChesterChesterUK
| | | | - Bonnie Rusk
- Grenada Dove Conservation ProgrammeSt GeorgesGrenada
| | - Anna Muir
- Conservation Biology Research Group, Department of Biological SciencesUniversity of ChesterChesterUK
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Arantes LS, Caccavo JA, Sullivan JK, Sparmann S, Mbedi S, Höner OP, Mazzoni CJ. Scaling-up RADseq methods for large datasets of non-invasive samples: Lessons for library construction and data preprocessing. Mol Ecol Resour 2023. [PMID: 37646753 DOI: 10.1111/1755-0998.13859] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2023] [Revised: 08/12/2023] [Accepted: 08/16/2023] [Indexed: 09/01/2023]
Abstract
Genetic non-invasive sampling (gNIS) is a critical tool for population genetics studies, supporting conservation efforts while imposing minimal impacts on wildlife. However, gNIS often presents variable levels of DNA degradation and non-endogenous contamination, which can incur considerable processing costs. Furthermore, the use of restriction-site-associated DNA sequencing methods (RADseq) for assessing thousands of genetic markers introduces the challenge of obtaining large sets of shared loci with similar coverage across multiple individuals. Here, we present an approach to handling large-scale gNIS-based datasets using data from the spotted hyena population inhabiting the Ngorongoro Crater in Tanzania. We generated 3RADseq data for more than a thousand individuals, mostly from faecal mucus samples collected non-invasively and varying in DNA degradation and contamination level. Using small-scale sequencing, we screened samples for endogenous DNA content, removed highly contaminated samples, confirmed overlap fragment length between libraries, and balanced individual representation in a sequencing pool. We evaluated the impact of (1) DNA degradation and contamination of non-invasive samples, (2) PCR duplicates and (3) different SNP filters on genotype accuracy based on Mendelian error estimated for parent-offspring trio datasets. Our results showed that when balanced for sequencing depth, contaminated samples presented similar genotype error rates to those of non-contaminated samples. We also showed that PCR duplicates and different SNP filters impact genotype accuracy. In summary, we showed the potential of using gNIS for large-scale genetic monitoring based on SNPs and demonstrated how to improve control over library preparation by using a weighted re-pooling strategy that considers the endogenous DNA content.
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Affiliation(s)
- Larissa S Arantes
- Berlin Center for Genomics in Biodiversity Research (BeGenDiv), Berlin, Germany
- Leibniz-Institut für Zoo- und Wildtierforschung (IZW), Berlin, Germany
| | - Jilda A Caccavo
- Laboratoire des Sciences du Climat et de l'Environnement, LSCE/IPSL, CEA-CNRS-UVSQ, Université Paris-Saclay, Gif-sur-Yvette, France
- Laboratoire d'Océanographie et du Climat: Expérimentations et Approches Numériques, LOCEAN/IPSL, UPMC-CNRS-IRD-MNHN, Sorbonne Université, Paris, France
| | - James K Sullivan
- Berlin Center for Genomics in Biodiversity Research (BeGenDiv), Berlin, Germany
- Freie Universität, Berlin, Germany
| | - Sarah Sparmann
- Berlin Center for Genomics in Biodiversity Research (BeGenDiv), Berlin, Germany
- Leibniz-Institut für Gewässerökologie und Binnenfischerei (IGB), Berlin, Germany
| | - Susan Mbedi
- Berlin Center for Genomics in Biodiversity Research (BeGenDiv), Berlin, Germany
- Museum für Naturkunde, Berlin, Germany
| | - Oliver P Höner
- Leibniz-Institut für Zoo- und Wildtierforschung (IZW), Berlin, Germany
| | - Camila J Mazzoni
- Berlin Center for Genomics in Biodiversity Research (BeGenDiv), Berlin, Germany
- Leibniz-Institut für Zoo- und Wildtierforschung (IZW), Berlin, Germany
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Oliveros A, Terraube J, Levengood AL, Powell D, Frère CH. Influence of scat ageing on the gut microbiome: how old is too old? BMC Genomics 2023; 24:427. [PMID: 37525141 PMCID: PMC10388479 DOI: 10.1186/s12864-023-09520-0] [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: 02/13/2023] [Accepted: 07/16/2023] [Indexed: 08/02/2023] Open
Abstract
BACKGROUND The study of the host-microbiome by the collection of non-invasive samples has the potential to become a powerful tool for conservation monitoring and surveillance of wildlife. However, multiple factors can bias the quality of data recovered from scats, particularly when field-collected samples are used given that the time of defecation is unknown. Previous studies using scats have shown that the impact of aerobic exposure on the microbial composition is species-specific, leading to different rates of change in microbial communities. However, the impact that this aging process has on the relationship between the bacterial and fungal composition has yet to be explored. In this study, we measured the effects of time post-defecation on bacterial and fungal compositions in a controlled experiment using scat samples from the endangered koala (Phascolarctos cinereus). RESULTS We found that the bacterial composition remained stable through the scat aging process, while the fungal composition did not. The absence of an increase in facultative anaerobes and the stable population of obligate anaerobic bacteria were likely due to our sampling from the inner portion of the scat. We report a cluster of fungal taxa that colonises scats after defecation which can dilute the genetic material from the autochthonous mycoflora and inhibit recovery. CONCLUSION We emphasize the need to preserve the integrity of scat samples collected in the wild and combat the effects of time and provide strategies for doing so.
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Affiliation(s)
- Alejandro Oliveros
- The School of Biological Sciences, The University of Queensland, St Lucia, QLD, Australia.
- School of Science, Technology and Engineering, University of the Sunshine Coast, Sippy Downs, QLD, Australia.
| | - Julien Terraube
- Vulture Conservation Foundation, Wuhrstrasse 12, Zürich, CH-8003, Switzerland
- School of Science, Technology and Engineering, University of the Sunshine Coast, Sippy Downs, QLD, Australia
| | - Alexis L Levengood
- School of Science, Technology and Engineering, University of the Sunshine Coast, Sippy Downs, QLD, Australia
| | - Daniel Powell
- School of Science, Technology and Engineering, University of the Sunshine Coast, Sippy Downs, QLD, Australia
| | - Céline H Frère
- The School of Biological Sciences, The University of Queensland, St Lucia, QLD, Australia
- School of Science, Technology and Engineering, University of the Sunshine Coast, Sippy Downs, QLD, Australia
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Frère CH, O'Reilly GD, Strickland K, Schultz A, Hohwieler K, Hanger J, de Villiers D, Cristescu R, Powell D, Sherwin W. Evaluating the genetic consequences of population subdivision as it unfolds and how to best mitigate them: A rare story about koalas. Mol Ecol 2023; 32:2174-2185. [PMID: 36756702 DOI: 10.1111/mec.16877] [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: 03/13/2022] [Revised: 01/23/2023] [Accepted: 01/25/2023] [Indexed: 02/10/2023]
Abstract
The genetic consequences of the subdivision of populations are regarded as significant to long-term evolution, and research has shown that the scale and speed at which this is now occurring is critically reducing the adaptive potential of most species which inhabit human-impacted landscapes. Here, we provide a rare and, to our knowledge, the first analysis of this process while it is happening and demonstrate a method of evaluating the effect of mitigation measures such as fauna crossings. We did this by using an extensive genetic data set collected from a koala population which was intensely monitored during the construction of linear transport infrastructure which resulted in the subdivision of their population. First, we found that both allelic richness and effective population size decreased through the process of population subdivision. Second, we predicted the extent to which genetic drift could impact genetic diversity over time and showed that after only 10 generations the resulting two subdivided populations could experience between 12% and 69% loss in genetic diversity. Lastly, using forward simulations we estimated that a minimum of eight koalas would need to disperse from each side of the subdivision per generation to maintain genetic connectivity close to zero but that 16 koalas would ensure that both genetic connectivity and diversity remained unchanged. These results have important consequences for the genetic management of species in human-impacted landscapes by showing which genetic metrics are best to identify immediate loss in genetic diversity and how to evaluate the effectiveness of any mitigation measures.
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Affiliation(s)
- C H Frère
- School of Biological Sciences, University of Queensland, St Lucia, Queensland, Australia
| | - G D O'Reilly
- The School of Biological, Earth and Environmental Sciences, University of New South Wales, Sydney, New South Wales, Australia
| | - K Strickland
- Institute of Ecology and Evolution, University of Edinburgh, Edinburgh, UK
| | - A Schultz
- Icelandic Museum of Natural History (Náttúruminjasafn Íslands), Reykjavik, Iceland
| | - K Hohwieler
- School of Science, Technology and Engineering, University of the Sunshine Coast, Queensland, Australia
| | - J Hanger
- Endeavour Veterinary Ecology Pty Ltd, Toorbul, Queensland, Australia
| | - D de Villiers
- Endeavour Veterinary Ecology Pty Ltd, Toorbul, Queensland, Australia
| | - R Cristescu
- School of Science, Technology and Engineering, University of the Sunshine Coast, Queensland, Australia
| | - D Powell
- School of Science, Technology and Engineering, University of the Sunshine Coast, Queensland, Australia
| | - W Sherwin
- The School of Biological, Earth and Environmental Sciences, University of New South Wales, Sydney, New South Wales, Australia
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Tkaczynski A, Rundle‐Thiele S. Koala conservation in South East Queensland: A grey literature review analysis. CONSERVATION SCIENCE AND PRACTICE 2023. [DOI: 10.1111/csp2.12874] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Affiliation(s)
- Aaron Tkaczynski
- Faculty of Business, Economics and Law University of Queensland St Lucia Queensland Australia
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Cristescu RH, Strickland K, Schultz AJ, Kruuk LEB, de Villiers D, Frère CH. Susceptibility to a sexually transmitted disease in a wild koala population shows heritable genetic variance but no inbreeding depression. Mol Ecol 2022; 31:5455-5467. [PMID: 36043238 PMCID: PMC9826501 DOI: 10.1111/mec.16676] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2022] [Revised: 08/19/2022] [Accepted: 08/23/2022] [Indexed: 01/11/2023]
Abstract
The koala, one of the most iconic Australian wildlife species, is facing several concomitant threats that are driving population declines. Some threats are well known and have clear methods of prevention (e.g., habitat loss can be reduced with stronger land-clearing control), whereas others are less easily addressed. One of the major current threats to koalas is chlamydial disease, which can have major impacts on individual survival and reproduction rates and can translate into population declines. Effective management strategies for the disease in the wild are currently lacking, and, to date, we know little about the determinants of individual susceptibility to disease. Here, we investigated the genetic basis of variation in susceptibility to chlamydia using one of the most intensively studied wild koala populations. We combined data from veterinary examinations, chlamydia testing, genetic sampling and movement monitoring. Out of our sample of 342 wild koalas, 60 were found to have chlamydia. Using genotype information on 5007 SNPs to investigate the role of genetic variation in determining disease status, we found no evidence of inbreeding depression, but a heritability of 0.11 (95% CI: 0.06-0.23) for the probability that koalas had chlamydia. Heritability of susceptibility to chlamydia could be relevant for future disease management, as it suggests adaptive potential for the population.
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Affiliation(s)
- Romane H. Cristescu
- Global Change Ecology Research GroupUniversity of the Sunshine CoastSippy DownsQueenslandAustralia
| | - Kasha Strickland
- Institute of Ecology and EvolutionUniversity of EdinburghEdinburghUK
| | - Anthony J. Schultz
- Global Change Ecology Research GroupUniversity of the Sunshine CoastSippy DownsQueenslandAustralia,Icelandic Museum of Natural History (Náttúruminjasafn Íslands)ReykjavikIceland
| | - Loeske E. B. Kruuk
- Institute of Ecology and EvolutionUniversity of EdinburghEdinburghUK,Research School of BiologyAustralian National UniversityCanberraAustralian Capital TerritoryAustralia
| | | | - Céline H. Frère
- School of Biological SciencesUniversity of QueenslandSt LuciaQueenslandAustralia
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