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Reyna-Blanco CS, Caduff M, Galimberti M, Leuenberger C, Wegmann D. Inference of Locus-Specific Population Mixtures from Linked Genome-Wide Allele Frequencies. Mol Biol Evol 2024; 41:msae137. [PMID: 38958167 PMCID: PMC11255385 DOI: 10.1093/molbev/msae137] [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: 11/06/2023] [Revised: 06/26/2024] [Accepted: 06/27/2024] [Indexed: 07/04/2024] Open
Abstract
Admixture between populations and species is common in nature. Since the influx of new genetic material might be either facilitated or hindered by selection, variation in mixture proportions along the genome is expected in organisms undergoing recombination. Various graph-based models have been developed to better understand these evolutionary dynamics of population splits and mixtures. However, current models assume a single mixture rate for the entire genome and do not explicitly account for linkage. Here, we introduce TreeSwirl, a novel method for inferring branch lengths and locus-specific mixture proportions by using genome-wide allele frequency data, assuming that the admixture graph is known or has been inferred. TreeSwirl builds upon TreeMix that uses Gaussian processes to estimate the presence of gene flow between diverged populations. However, in contrast to TreeMix, our model infers locus-specific mixture proportions employing a hidden Markov model that accounts for linkage. Through simulated data, we demonstrate that TreeSwirl can accurately estimate locus-specific mixture proportions and handle complex demographic scenarios. It also outperforms related D- and f-statistics in terms of accuracy and sensitivity to detect introgressed loci.
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Affiliation(s)
- Carlos S Reyna-Blanco
- Department of Biology, University of Fribourg, Fribourg 1700, Switzerland
- Swiss Institute of Bioinformatics, Fribourg 1700, Switzerland
| | - Madleina Caduff
- Department of Biology, University of Fribourg, Fribourg 1700, Switzerland
- Swiss Institute of Bioinformatics, Fribourg 1700, Switzerland
| | - Marco Galimberti
- Department of Biology, University of Fribourg, Fribourg 1700, Switzerland
- Swiss Institute of Bioinformatics, Fribourg 1700, Switzerland
- Department of Psychiatry, Yale University School of Medicine, New Haven, CT, USA
- Veterans Affairs Connecticut Healthcare System, West Haven, CT, USA
| | | | - Daniel Wegmann
- Department of Biology, University of Fribourg, Fribourg 1700, Switzerland
- Swiss Institute of Bioinformatics, Fribourg 1700, Switzerland
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Thomas NE, Hailer F, Bruford MW, Chadwick EA. Country-wide genetic monitoring over 21 years reveals lag in genetic recovery despite spatial connectivity in an expanding carnivore (Eurasian otter, Lutra lutra) population. Evol Appl 2022; 15:2125-2141. [PMID: 36540646 PMCID: PMC9753835 DOI: 10.1111/eva.13505] [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: 02/10/2022] [Revised: 08/05/2022] [Accepted: 10/06/2022] [Indexed: 11/16/2022] Open
Abstract
Numerous terrestrial mammal species have experienced extensive population declines during past centuries, due largely to anthropogenic pressures. For some species, including the Eurasian otter (Lutra lutra), environmental and legal protection has more recently led to population growth and recolonization of parts of their historic ranges. While heralded as conservation success, only few such recoveries have been examined from a genetic perspective, i.e. whether genetic variability and connectivity have been restored. We here use large-scale and long-term genetic monitoring data from UK otters, whose population underwent a well-documented population decline between the 1950s and 1970s, to explore the dynamics of a population re-expansion over a 21-year period. We genotyped otters from across Wales and England at five time points between 1994 and 2014 using 15 microsatellite loci. We used this combination of long-term temporal and large-scale spatial sampling to evaluate 3 hypotheses relating to genetic recovery that (i) gene flow between subpopulations would increase over time, (ii) genetic diversity of previously isolated populations would increase and that (iii) genetic structuring would weaken over time. Although we found an increase in inter-regional gene flow and admixture levels among subpopulations, there was no significant temporal change in either heterozygosity or allelic richness. Genetic structuring among the main subpopulations hence remained strong and showed a clear historical continuity. These findings highlight an underappreciated aspect of population recovery of endangered species: that genetic recovery may often lag behind the processes of spatial and demographic recovery. In other words, the restoration of the physical connectivity of populations does not necessarily lead to genetic connectivity. Our findings emphasize the need for genetic data as an integral part of conservation monitoring, to enable the potential vulnerability of populations to be evaluated.
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Affiliation(s)
- Nia E. Thomas
- Organisms and Environment Research Division, School of BiosciencesCardiff UniversityCardiffWalesUK
| | - Frank Hailer
- Organisms and Environment Research Division, School of BiosciencesCardiff UniversityCardiffWalesUK
| | - Michael W. Bruford
- Organisms and Environment Research Division, School of BiosciencesCardiff UniversityCardiffWalesUK
| | - Elizabeth A. Chadwick
- Organisms and Environment Research Division, School of BiosciencesCardiff UniversityCardiffWalesUK
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Mantiquilla JA, Shiao MS, Lu HY, Sridith K, Sidique SNM, Liyanage WK, Chu YL, Shih HC, Chiang YC. Deep structured populations of geographically isolated nipa ( Nypa fruticans Wurmb.) in the Indo-West Pacific revealed using microsatellite markers. FRONTIERS IN PLANT SCIENCE 2022; 13:1038998. [PMID: 36388479 PMCID: PMC9641285 DOI: 10.3389/fpls.2022.1038998] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/07/2022] [Accepted: 09/28/2022] [Indexed: 06/16/2023]
Abstract
Nipa (Nypa fruticans Wurmb.) is an important mangrove palm species, but it is understudied due to lack of information on genetic patterns within its distribution range. In this study, we identified 18 informative microsatellite markers to assess genetic variations among local populations in the Indo-West Pacific (IWP). Results showed population stratification based on high genetic differentiation (FST = 0.22131) with the Mantel test indicating significance to isolation-by-distance. We found a pronounced differentiation between the west populations in Sri Lanka and east populations in Southeast Asia. The east populations around the South China Sea were more genetically similar than those along the Malacca Strait and Java Sea. These genetic clines were shaped by ocean circulations and seasonal monsoon reversals as plausible factors. The Malacca Strait was confirmed as both a genetic and a geographic barrier rather than a corridor according to the Monmonier plot. Simulations of directional migration indicated a statistically strong contemporary genetic connectivity from west to east where Sri Lankan immigrants were detected as far as central Philippines via long-distance dispersal. This is the first report on the recent migration patterns of nipa using microsatellites. Assignment of first-generation (F0) immigrants suggested Mainland Southeast Asia as a melting pot due to the admixture associated with excess of homozygosity. The western populations were recent expansions that emerged in rapid succession based on a phylogram as supported by footprints of genetic drift based on bottleneck tests.
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Affiliation(s)
- Junaldo A. Mantiquilla
- Department of Biological Sciences, National Sun Yat-sen University, Kaohsiung City, Taiwan
- Department of Biological Sciences and Environmental Studies, University of the Philippines Mindanao, Davao City, Philippines
| | - Meng-Shin Shiao
- Research Center, Faculty of Medicine Ramathibodi Hospital, Mahidol University, Bangkok, Thailand
| | - Hsueh-Yu Lu
- Department of Biological Sciences, National Sun Yat-sen University, Kaohsiung City, Taiwan
| | | | - Siti Nordahliawate M. Sidique
- Laboratory for Pest, Disease and Microbial Biotechnology (LAPDiM), School of Food Science and Technology, Universiti Malaysia Terengganu, Kuala Terengganu, Malaysia
| | - Wasantha Kumara Liyanage
- Department of Agricultural Biology, Faculty of Agriculture, University of Ruhuna, Kamburupitiya, Sri Lanka
| | - Ya-Ling Chu
- Department of Biological Sciences, National Sun Yat-sen University, Kaohsiung City, Taiwan
| | | | - Yu-Chung Chiang
- Department of Biological Sciences, National Sun Yat-sen University, Kaohsiung City, Taiwan
- Department of Biomedical Science and Environment Biology, Kaohsiung Medical University, Kaohsiung, Taiwan
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4
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Stuckert AMM, Matute DR. Using neutral loci to quantify reproductive isolation and speciation: a commentary on Westram et al., 2022. J Evol Biol 2022; 35:1169-1174. [PMID: 36063155 DOI: 10.1111/jeb.14057] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2022] [Accepted: 06/20/2022] [Indexed: 01/23/2023]
Affiliation(s)
- Adam M M Stuckert
- Biology Department, University of North Carolina, Chapel Hill, North Carolina, USA
| | - Daniel R Matute
- Biology Department, University of North Carolina, Chapel Hill, North Carolina, USA
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Poommouang A, Kriangwanich W, Buddhachat K, Brown JL, Piboon P, Chomdej S, Kampuansai J, Mekchay S, Kaewmong P, Kittiwattanawong K, Nganvongpanit K. Genetic diversity in a unique population of dugong (Dugong dugon) along the sea coasts of Thailand. Sci Rep 2021; 11:11624. [PMID: 34078973 PMCID: PMC8172547 DOI: 10.1038/s41598-021-90947-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2021] [Accepted: 05/12/2021] [Indexed: 11/09/2022] Open
Abstract
Dugong (Dugong dugon) populations have been shrinking globally, due in large part to habitat fragmentation, degradation and ocean pollution, and today are listed as Vulnerable by the IUCN. Thus, determining genetic diversity in the remaining populations is essential for conservation planning and protection. In this study, measures of inter-simple sequence repeat (ISSR) markers and mtDNA D-loop typing were used to evaluate the genetic diversity of 118 dugongs from skin samples of deceased dugongs collected in Thai waters over a 29-year period. Thirteen ISSR primers revealed that dugongs from the Andaman Sea and Gulf of Thailand exhibited more genetic variation in the first 12 years of the study (1990-2002) compared to the last decade (2009-2019). Dugongs from the Andaman Sea, Trang, Satun and some areas of Krabi province exhibited greater diversity compared to other coastal regions of Thailand. Eleven haplotypes were identified, and when compared to other parts of the world (235 sequences obtained from NCBI), five clades were apparent from a total 353 sequences. Moreover, dugongs from the Andaman Sea were genetically distinct, with a separate haplotype belonging to two clades found only in Thai waters that separated from other groups around 1.2 million years ago. Genetic diversity of dugongs in present times was less than that of past decades, likely due to increased population fragmentation. Because dugongs are difficult to keep and breed in captivity, improved in situ conservation actions are needed to sustain genetically healthy wild populations, and in particular, the specific genetic group found only in the Andaman Sea.
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Affiliation(s)
- Anocha Poommouang
- Animal Bone and Joint Research Laboratory, Department of Veterinary Biosciences and Public Health, Faculty of Veterinary Medicine, Chiang Mai University, Chiang Mai, 50100, Thailand
| | - Wannapimol Kriangwanich
- Animal Bone and Joint Research Laboratory, Department of Veterinary Biosciences and Public Health, Faculty of Veterinary Medicine, Chiang Mai University, Chiang Mai, 50100, Thailand
| | - Kittisak Buddhachat
- Excellence Center in Veterinary Bioscience, Chiang Mai, 50100, Thailand
- Department of Biology, Faculty of Science, Naresuan University, Phitsanulok, 65000, Thailand
| | - Janine L Brown
- Smithsonian Conservation Biology Institute, Center for Species Survival, 1500 Remount Road, Front Royal, VA, 22630, USA
| | - Promporn Piboon
- Animal Bone and Joint Research Laboratory, Department of Veterinary Biosciences and Public Health, Faculty of Veterinary Medicine, Chiang Mai University, Chiang Mai, 50100, Thailand
| | - Siriwadee Chomdej
- Department of Biology, Faculty of Science, Chiang Mai University, Chiang Mai, 50200, Thailand
| | - Jatupol Kampuansai
- Department of Biology, Faculty of Science, Chiang Mai University, Chiang Mai, 50200, Thailand
| | - Supamit Mekchay
- Department of Animal and Aquatic Sciences, Faculty of Agriculture, Chiang Mai University, Chiang Mai, 50200, Thailand
| | | | | | - Korakot Nganvongpanit
- Animal Bone and Joint Research Laboratory, Department of Veterinary Biosciences and Public Health, Faculty of Veterinary Medicine, Chiang Mai University, Chiang Mai, 50100, Thailand.
- Excellence Center in Veterinary Bioscience, Chiang Mai, 50100, Thailand.
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Pylidis C, Anijalg P, Saarma U, Dawson DA, Karaiskou N, Butlin R, Mertzanis Y, Giannakopoulos A, Iliopoulos Y, Krupa A, Burke TA. Multisource noninvasive genetics of brown bears ( Ursus arctos) in Greece reveals a highly structured population and a new matrilineal contact zone in southern Europe. Ecol Evol 2021; 11:6427-6443. [PMID: 34141229 PMCID: PMC8207399 DOI: 10.1002/ece3.7493] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2018] [Revised: 02/14/2021] [Accepted: 02/22/2021] [Indexed: 11/21/2022] Open
Abstract
In human-dominated landscapes, connectivity is crucial for maintaining demographically stable mammalian populations. Here, we provide a comprehensive noninvasive genetic study for the brown bear population in the Hellenic Peninsula. We analyze its population structuring and connectivity, estimate its population size throughout its distribution, and describe its phylogeography in detail for the first time. Our results, based on 150 multilocus genotypes and on 244-bp sequences of the mtDNA control region, show the population is comprised by three highly differentiated genetic clusters, consistent with geographical populations of Pindos, Peristeri, and Rhodope. By detecting two male bears with Rhodopean ancestry in the western demes, we provide strong evidence for the ongoing genetic connectivity of the geographically fragmented eastern and western distributions, which suggests connectivity of the larger East Balkan and Pindos-Dinara populations. Total effective population size (N e) was estimated to be 199 individuals, and total combined population size (N C) was 499, with each cluster showing a relatively high level of genetic variability, suggesting that migration has been sufficient to counteract genetic erosion. The mtNDA results were congruent with the microsatellite data, and the three genetic clusters were matched predominantly with an equal number of mtDNA haplotypes that belong to the brown bear Western mitochondrial lineage (Clade 1), with two haplotypes being globally new and endemic. The detection of a fourth haplotype that belongs to the Eastern lineage (Clade 3a1) in three bears from the western distribution places the southernmost secondary contact zone between the Eastern and Western lineages in Greece and generates new hypotheses about postglacial maxima migration routes. This work indicates that the genetic composition and diversity of Europe's low-latitude fringe population are the outcome of ancient and historical events and highlight its importance for the connectivity and long-term persistence of the species in the Balkans.
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Affiliation(s)
- Charilaos Pylidis
- School of Biological SciencesUniversity of BristolBristolUK
- NERC Biomolecular Analysis FacilityDepartment of Animal and Plant SciencesUniversity of SheffieldUK
- Callisto Wildlife and Nature Conservation SocietyThessalonikiGreece
| | - Peeter Anijalg
- Department of ZoologyInstitute of Ecology and Earth SciencesUniversity of TartuTartuEstonia
| | - Urmas Saarma
- Department of ZoologyInstitute of Ecology and Earth SciencesUniversity of TartuTartuEstonia
| | - Deborah A. Dawson
- NERC Biomolecular Analysis FacilityDepartment of Animal and Plant SciencesUniversity of SheffieldUK
| | - Nikoleta Karaiskou
- Department of Genetics, Developmental and Molecular BiologySchool of BiologyAristotle University of ThessalonikiThessalonikiGreece
| | - Roger Butlin
- Department of Animal and Plant SciencesUniversity of SheffieldSheffieldUK
| | - Yorgos Mertzanis
- Callisto Wildlife and Nature Conservation SocietyThessalonikiGreece
| | | | | | - Andrew Krupa
- Department of Animal and Plant SciencesUniversity of SheffieldSheffieldUK
| | - Terence A. Burke
- NERC Biomolecular Analysis FacilityDepartment of Animal and Plant SciencesUniversity of SheffieldUK
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Genetic composition of queen conch (Lobatus gigas) population on Pedro Bank, Jamaica and its use in fisheries management. PLoS One 2021; 16:e0245703. [PMID: 33819265 PMCID: PMC8021194 DOI: 10.1371/journal.pone.0245703] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2020] [Accepted: 03/11/2021] [Indexed: 11/19/2022] Open
Abstract
The queen conch fishery in Jamaica is sustained by Pedro Bank, which is the main harvesting site located approximately 80 km south-west from Kingston. Due to its relative size, Pedro Bank has been subdivided into zones for management purposes by the Fisheries Division and the Veterinary Services Division. Understanding whether these sub-divisions reflect different sub-populations is critical for managing exploitation levels because fisheries management must demonstrate that harvesting does not endanger the future viability of the population as queen conch are on Appendix II of the Convention in Trade in Endangered Species of Wild Fauna and Flora (CITES). This determination is essential for the continued export to international markets such as the European Union. Two hundred and eight samples were collected across the entire Pedro Bank and were genetically characterized using nine polymorphic microsatellite loci. Population structure analysis for Lobatus gigas from Pedro Bank yielded low but significant values (FST = 0.009: p = 0.006) and suggested a high magnitude of gene flow indicative of a fit and viable population throughout the bank. Analysis of molecular variance (AMOVA) indicated a 100% variation within individual samples with little variation (0.9%) between populations. In contrast pairwise genetic comparisons identified significant differences between populations located to the south eastern and eastern region of the bank to those in the central and western locations. Bayesian clustering analysis also indicated the likelihood of two population sub-divisions (K = 2) on Pedro Bank. The results provided evidence of a weak but significant population structure which has crucial implications for the fishing industry as it suggests the use of ecosystem based management (EBM) in setting quotas to promote sustainable harvesting of L. gigas within each monitoring zone on Pedro Bank.
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The influence of a priori grouping on inference of genetic clusters: simulation study and literature review of the DAPC method. Heredity (Edinb) 2020; 125:269-280. [PMID: 32753664 PMCID: PMC7553915 DOI: 10.1038/s41437-020-0348-2] [Citation(s) in RCA: 49] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2019] [Revised: 07/19/2020] [Accepted: 07/20/2020] [Indexed: 11/20/2022] Open
Abstract
Inference of genetic clusters is a key aim of population genetics, sparking development of numerous analytical methods. Within these, there is a conceptual divide between finding de novo structure versus assessment of a priori groups. Recently developed, Discriminant Analysis of Principal Components (DAPC), combines discriminant analysis (DA) with principal component (PC) analysis. When applying DAPC, the groups used in the DA (specified a priori or described de novo) need to be carefully assessed. While DAPC has rapidly become a core technique, the sensitivity of the method to misspecification of groups and how it is being empirically applied, are unknown. To address this, we conducted a simulation study examining the influence of a priori versus de novo group designations, and a literature review of how DAPC is being applied. We found that with a priori groupings, distance between genetic clusters reflected underlying FST. However, when migration rates were high and groups were described de novo there was considerable inaccuracy, both in terms of the number of genetic clusters suggested and placement of individuals into those clusters. Nearly all (90.1%) of 224 studies surveyed used DAPC to find de novo clusters, and for the majority (62.5%) the stated goal matched the results. However, most studies (52.3%) omit key run parameters, preventing repeatability and transparency. Therefore, we present recommendations for standard reporting of parameters used in DAPC analyses. The influence of groupings in genetic clustering is not unique to DAPC, and researchers need to consider their goal and which methods will be most appropriate.
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Rojas A, Dvir E, Farkas R, Sarma K, Borthakur S, Jabbar A, Markovics A, Otranto D, Baneth G. Phylogenetic analysis of Spirocerca lupi and Spirocerca vulpis reveal high genetic diversity and intra-individual variation. Parasit Vectors 2018; 11:639. [PMID: 30547850 PMCID: PMC6295112 DOI: 10.1186/s13071-018-3202-0] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2018] [Accepted: 11/19/2018] [Indexed: 12/12/2022] Open
Abstract
Background Spirocerca lupi is a parasitic nematode of canids that can lead to a severe and potentially fatal disease. Recently, a new species, Spirocerca vulpis, was described from red foxes in Europe, suggesting a high genetic diversity of the Spirocerca spp. infecting canids. The genetic variation and phylogenetic relationships of S. lupi collected from naturally-infected domestic dogs from Australia, Hungary, Israel, Italy, India and South Africa, and S. vulpis from red foxes from Bosnia and Herzegovina, Italy and Spain, was studied using mitochondrial and rDNA markers. Results A high intra-individual variation was found in the first internal transcribed spacer (ITS1) locus in all Spirocerca spp., ranging between 0.37–2.84%, with up to six haplotypes per specimen. In addition, a combination of phylogenetic and haplotype analyses revealed a large variability between S. lupi specimens collected from different geographical locations using the ITS1 (0.37–9.33%) and the cytochrome c oxidase subunit 1 (cox1) gene (1.42–6.74%). This genetic diversity led to the identification of two S. lupi genotypes circulating among dogs (PTP support > 0.829), including genotype 1 found in S. lupi from Australia, India, Israel and South Africa, and genotype 2 represented by specimens from Hungary and Italy. These genotypes presented pairwise nucleotide distances of 0.14%, 8.06% and 6.48 ± 0.28% in the small rDNA subunit (18S), ITS1 and cox1 loci, respectively. Additionally, Nei’s genetic distance in the ITS1 showed a further subdivision of genotype 1 worms into 1A (Israel and South Africa) and 1B (Australia and India). A morphological analysis of the anterior and posterior extremities of genotype 1 and genotype 2 worms using scanning electron microscopy did not show any differences between the specimens, contrary to the morphological differences between S. lupi and S. vulpis. Conclusions These findings demonstrate the high genetic variability among Spirocerca spp. from different geographical locations, thereby expanding our understanding of the epidemiology, evolution and phylogenetic variability within the genus. Electronic supplementary material The online version of this article (10.1186/s13071-018-3202-0) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Alicia Rojas
- Koret School of Veterinary Medicine, The Hebrew University of Jerusalem, Rehovot, Israel
| | - Eran Dvir
- Department of Animal Sciences, Tel-Hai Academic College, Upper Galilee, Israel
| | - Róbert Farkas
- Department of Parasitology and Zoology, University of Veterinary Medicine, Budapest, Hungary
| | - Kalyan Sarma
- Department of Veterinary Medicine, College of Veterinary Sciences and Animal Husbandry, Central Agricultural University, Mizoram, India
| | - Sonjoy Borthakur
- Department of Veterinary Parasitology, College of Veterinary Sciences and Animal Husbandry, Central Agricultural University, Mizoram, India
| | - Abdul Jabbar
- Department of Veterinary Biosciences, Melbourne Veterinary School, The University of Melbourne, Victoria, Australia
| | | | - Domenico Otranto
- Department of Veterinary Medicine, University of Bari, Valenzano, Italy
| | - Gad Baneth
- Koret School of Veterinary Medicine, The Hebrew University of Jerusalem, Rehovot, Israel.
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Nykänen M, Dillane E, Englund A, Foote AD, Ingram SN, Louis M, Mirimin L, Oudejans M, Rogan E. Quantifying dispersal between marine protected areas by a highly mobile species, the bottlenose dolphin, Tursiops truncatus. Ecol Evol 2018; 8:9241-9258. [PMID: 30377497 PMCID: PMC6194238 DOI: 10.1002/ece3.4343] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2018] [Revised: 05/31/2018] [Accepted: 06/01/2018] [Indexed: 01/19/2023] Open
Abstract
The functioning of marine protected areas (MPAs) designated for marine megafauna has been criticized due to the high mobility and dispersal potential of these taxa. However, dispersal within a network of small MPAs can be beneficial as connectivity can result in increased effective population size, maintain genetic diversity, and increase robustness to ecological and environmental changes making populations less susceptible to stochastic genetic and demographic effects (i.e., Allee effect). Here, we use both genetic and photo-identification methods to quantify gene flow and demographic dispersal between MPAs of a highly mobile marine mammal, the bottlenose dolphin Tursiops truncatus. We identify three populations in the waters of western Ireland, two of which have largely nonoverlapping core coastal home ranges and are each strongly spatially associated with specific MPAs. We find high site fidelity of individuals within each of these two coastal populations to their respective MPA. We also find low levels of demographic dispersal between the populations, but it remains unclear whether any new gametes are exchanged between populations through these migrants (genetic dispersal). The population sampled in the Shannon Estuary has a low estimated effective population size and appears to be genetically isolated. The second coastal population, sampled outside of the Shannon, may be demographically and genetically connected to other coastal subpopulations around the coastal waters of the UK. We therefore recommend that the methods applied here should be used on a broader geographically sampled dataset to better assess this connectivity.
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Affiliation(s)
- Milaja Nykänen
- School of Biological, Earth and Environmental SciencesUniversity College CorkCorkIreland
| | - Eileen Dillane
- School of Biological, Earth and Environmental SciencesUniversity College CorkCorkIreland
| | - Anneli Englund
- School of Biological, Earth and Environmental SciencesUniversity College CorkCorkIreland
| | - Andrew D. Foote
- School of Biological SciencesMolecular Ecology Fisheries Genetics LabBangor UniversityBangorUK
| | - Simon N. Ingram
- School of Biological and Marine SciencesPlymouth UniversityPlymouthUK
| | - Marie Louis
- Centre d'Etudes Biologiques de ChizéUMR 7372CNRS‐Université de La RochelleLa RochelleFrance
- Observatoire PelagisUMS 3462CNRS‐Université de La RochelleLa RochelleFrance
- Scottish Oceans InstituteUniversity of St AndrewsSt AndrewsUK
| | - Luca Mirimin
- Department of Natural SciencesSchool of Science and ComputingGalway‐Mayo Institute of TechnologyMarine and Freshwater Research CentreGalwayIreland
| | | | - Emer Rogan
- School of Biological, Earth and Environmental SciencesUniversity College CorkCorkIreland
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Landscape determinants of genetic differentiation, inbreeding and genetic drift in the hazel dormouse (Muscardinus avellanarius). CONSERV GENET 2017. [DOI: 10.1007/s10592-017-0999-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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Schregel J, Kopatz A, Eiken HG, Swenson JE, Hagen SB. Sex-specific genetic analysis indicates low correlation between demographic and genetic connectivity in the Scandinavian brown bear (Ursus arctos). PLoS One 2017; 12:e0180701. [PMID: 28672045 PMCID: PMC5495496 DOI: 10.1371/journal.pone.0180701] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2017] [Accepted: 06/20/2017] [Indexed: 11/30/2022] Open
Abstract
The degree of gene flow within and among populations, i.e. genetic population connectivity, may closely track demographic population connectivity. Alternatively, the rate of gene flow may change relative to the rate of dispersal. In this study, we explored the relationship between genetic and demographic population connectivity using the Scandinavian brown bear as model species, due to its pronounced male dispersal and female philopatry. Thus, we expected that females would shape genetic structure locally, whereas males would act as genetic mediators among regions. To test this, we used eight validated microsatellite markers on 1531 individuals sampled noninvasively during country-wide genetic population monitoring in Sweden and Norway from 2006 to 2013. First, we determined sex-specific genetic structure and substructure across the study area. Second, we compared genetic differentiation, migration/gene flow patterns, and spatial autocorrelation results between the sexes both within and among genetic clusters and geographic regions. Our results indicated that demographic connectivity was not a reliable indicator of genetic connectivity. Among regions, we found no consistent difference in long-term gene flow and estimated current migration rates between males and females. Within regions/genetic clusters, only females consistently displayed significant positive spatial autocorrelation, indicating male-biased small-scale dispersal. In one cluster, however, males showed a dispersal pattern similar to females. The Scandinavian brown bear population has experienced substantial recovery over the last decades; however, our results did not show any changes in its large-scale population structure compared to previous studies, suggesting that an increase in population size and dispersal of individuals does not necessary lead to increased genetic connectivity. Thus, we conclude that both genetic and demographic connectivity should be estimated, so as not to make false assumptions about the reality of wildlife populations.
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Affiliation(s)
- Julia Schregel
- Norwegian Institute of Bioeconomy Research, NIBIO - Svanhovd, Svanvik, Norway
- Norwegian University of Life Sciences, Faculty of Environmental Sciences and Natural Resource Management, Ǻs, Norway
- * E-mail: (JS); (SBH)
| | - Alexander Kopatz
- Norwegian Institute of Bioeconomy Research, NIBIO - Svanhovd, Svanvik, Norway
| | - Hans Geir Eiken
- Norwegian Institute of Bioeconomy Research, NIBIO - Svanhovd, Svanvik, Norway
| | - Jon E. Swenson
- Norwegian University of Life Sciences, Faculty of Environmental Sciences and Natural Resource Management, Ǻs, Norway
- Norwegian Institute for Nature Research, Trondheim, Norway
| | - Snorre B. Hagen
- Norwegian Institute of Bioeconomy Research, NIBIO - Svanhovd, Svanvik, Norway
- * E-mail: (JS); (SBH)
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Miller KJ, Gunasekera RM. A comparison of genetic connectivity in two deep sea corals to examine whether seamounts are isolated islands or stepping stones for dispersal. Sci Rep 2017; 7:46103. [PMID: 28393887 PMCID: PMC5385499 DOI: 10.1038/srep46103] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2016] [Accepted: 03/10/2017] [Indexed: 11/09/2022] Open
Abstract
Ecological processes in the deep sea are poorly understood due to the logistical constraints of sampling thousands of metres below the ocean’s surface and remote from most land masses. Under such circumstances, genetic data provides unparalleled insight into biological and ecological relationships. We use microsatellite DNA to compare the population structure, reproductive mode and dispersal capacity in two deep sea corals from seamounts in the Southern Ocean. The solitary coral Desmophyllum dianthus has widespread dispersal consistent with its global distribution and resilience to disturbance. In contrast, for the matrix-forming colonial coral Solenosmilia variabilis asexual reproduction is important and the dispersal of sexually produced larvae is negligible, resulting in isolated populations. Interestingly, despite the recognised impacts of fishing on seamount communities, genetic diversity on fished and unfished seamounts was similar for both species, suggesting that evolutionary resilience remains despite reductions in biomass. Our results provide empirical evidence that a group of seamounts can function either as isolated islands or stepping stones for dispersal for different taxa. Furthermore different strategies will be required to protect the two sympatric corals and consequently the recently declared marine reserves in this region may function as a network for D. dianthus, but not for S. variabilis.
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Affiliation(s)
- Karen J Miller
- Australian Institute of Marine Science, Indian Ocean Marine Research Centre, The University of Western Australia (MO96), 35 Stirling Hwy, Crawley, Western Australia 6009, Australia
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15
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Ganzhorn SM, Perez-Sweeney B, Thomas WW, Gaiotto FA, Lewis JD. Effects of fragmentation on density and population genetics of a threatened tree species in a biodiversity hotspot. ENDANGER SPECIES RES 2015. [DOI: 10.3354/esr00645] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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Stroganov AN. Formation of genetic diversity in populations of pacific cod (Gadus macrocephalus Tilesius) (Gadidae). RUSS J GENET+ 2013. [DOI: 10.1134/s102279541309010x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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