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Galla SJ, Moraga R, Brown L, Cleland S, Hoeppner MP, Maloney RF, Richardson A, Slater L, Santure AW, Steeves TE. A comparison of pedigree, genetic and genomic estimates of relatedness for informing pairing decisions in two critically endangered birds: Implications for conservation breeding programmes worldwide. Evol Appl 2020; 13:991-1008. [PMID: 32431748 PMCID: PMC7232769 DOI: 10.1111/eva.12916] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2019] [Revised: 12/27/2019] [Accepted: 01/02/2020] [Indexed: 12/18/2022] Open
Abstract
Conservation management strategies for many highly threatened species include conservation breeding to prevent extinction and enhance recovery. Pairing decisions for these conservation breeding programmes can be informed by pedigree data to minimize relatedness between individuals in an effort to avoid inbreeding, maximize diversity and maintain evolutionary potential. However, conservation breeding programmes struggle to use this approach when pedigrees are shallow or incomplete. While genetic data (i.e., microsatellites) can be used to estimate relatedness to inform pairing decisions, emerging evidence indicates this approach may lack precision in genetically depauperate species, and more effective estimates will likely be obtained from genomic data (i.e., thousands of genome-wide single nucleotide polymorphisms, or SNPs). Here, we compare relatedness estimates and subsequent pairing decisions using pedigrees, microsatellites and SNPs from whole-genome resequencing approaches in two critically endangered birds endemic to New Zealand: kakī/black stilt (Himantopus novaezelandiae) and kākāriki karaka/orange-fronted parakeet (Cyanoramphus malherbi). Our findings indicate that SNPs provide more precise estimates of relatedness than microsatellites when assessing empirical parent-offspring and full sibling relationships. Further, our results show that relatedness estimates and subsequent pairing recommendations using PMx are most similar between pedigree- and SNP-based approaches. These combined results indicate that in lieu of robust pedigrees, SNPs are an effective tool for informing pairing decisions, which has important implications for many poorly pedigreed conservation breeding programmes worldwide.
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Affiliation(s)
- Stephanie J. Galla
- School of Biological SciencesUniversity of CanterburyChristchurchNew Zealand
| | - Roger Moraga
- Tea Break Bioinformatics, LtdPalmerston NorthNew Zealand
| | - Liz Brown
- New Zealand Department of ConservationTwizelNew Zealand
| | | | - Marc P. Hoeppner
- Institute for Clinical Molecular BiologyChristian‐Albrechts‐University KielKielGermany
| | | | - Anne Richardson
- The Isaac Conservation and Wildlife TrustChristchurchNew Zealand
| | - Lyndon Slater
- New Zealand Department of ConservationRangioraNew Zealand
| | - Anna W. Santure
- School of Biological SciencesUniversity of AucklandAucklandNew Zealand
| | - Tammy E. Steeves
- School of Biological SciencesUniversity of CanterburyChristchurchNew Zealand
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Moss JB, Gerber GP, Welch ME. Heterozygosity-Fitness Correlations Reveal Inbreeding Depression in Neonatal Body Size in a Critically Endangered Rock Iguana. J Hered 2019; 110:818-829. [PMID: 31617903 DOI: 10.1093/jhered/esz060] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2019] [Accepted: 10/09/2019] [Indexed: 01/16/2023] Open
Abstract
Inbreeding depression, though challenging to identify in nature, may play an important role in regulating the dynamics of small and isolated populations. Conversely, greater expression of genetic load can enhance opportunities for natural selection. Conditional expression concentrates these opportunities for selection and may lead to failure of detection. This study investigates the possibility for age-dependent expression of inbreeding depression in a critically endangered population of rock iguanas, Cyclura nubila caymanensis. We employ heterozygote-fitness correlations to examine the contributions of individual genetic factors to body size, a fitness-related trait. Nonsignificant reductions in homozygosity (up to 7%) were detected between neonates and individuals surviving past their first year, which may reflect natural absorption of inbreeding effects by this small, fecund population. The majority of variation in neonate body size was attributed to maternal or environmental effects (i.e., clutch identity and incubation length); however, heterozygosity across 22 microsatellite loci also contributed significantly and positively to model predictions. Conversely, effects of heterozygosity on fitness were not detectable when adults were examined, suggesting that inbreeding depression in body size may be age dependent in this taxon. Overall, these findings emphasize the importance of taking holistic, cross-generational approaches to genetic monitoring of endangered populations.
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Affiliation(s)
- Jeanette B Moss
- Biological Sciences Department, Mississippi State University, Mississippi State, MS
| | - Glenn P Gerber
- Institute for Conservation Research, San Diego Zoo Global, Escondido, CA
| | - Mark E Welch
- Biological Sciences Department, Mississippi State University, Mississippi State, MS
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McAliley LR, Willis RE, Ivanyi C, Densmore LD. Captive breeding of the endangered San Esteban Chuckwalla, Sauromalus varius: Effects of a decade of captive breeding on maintaining genetic diversity. SOUTHWEST NAT 2016. [DOI: 10.1894/0038-4909-61.4.279] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Affiliation(s)
- L. Rex McAliley
- Department of Natural Sciences, Northwest Missouri State University, Maryville, MO 64468 (LRM)
| | - Ray E. Willis
- College of Science and Mathematics, Midwestern State University, Wichita Falls, TX 76308 (REW)
| | - Craig Ivanyi
- Arizona Sonora Desert Museum, Tucson, AZ 85743 (CI)
- Department of Biological Sciences, Texas Tech University, Lubbock, TX 79409 (LDD)
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Attard CRM, Brauer CJ, Van Zoelen JD, Sasaki M, Hammer MP, Morrison L, Harris JO, Möller LM, Beheregaray LB. Multi-generational evaluation of genetic diversity and parentage in captive southern pygmy perch (Nannoperca australis). CONSERV GENET 2016. [DOI: 10.1007/s10592-016-0873-y] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Hinkson KM, Henry NL, Hensley NM, Richter SC. Initial founders of captive populations are genetically representative of natural populations in critically endangered dusky gopher frogs, Lithobates sevosus. Zoo Biol 2016; 35:378-384. [PMID: 27383748 DOI: 10.1002/zoo.21309] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2015] [Revised: 03/11/2016] [Accepted: 06/28/2016] [Indexed: 11/11/2022]
Abstract
The rapid rate of decline in amphibian populations has urged many researchers and conservationists to establish captive, or ex situ, populations. Such populations are guarded against effects of habitat loss and degradation, and if actively managed, can serve as a reservoir for rare alleles that might be lost in the wild. Without proper management, ex situ population sizes can dwindle and will no longer perform this function. The dusky gopher frog, Lithobates sevosus, is a critically endangered species, imperiled by habitat loss and population isolation. To assist in recovery of the species and prevent further genetic erosion, a captive breeding program was initiated. We investigated how well natural genetic variation was captured within the ex situ population and determined relatedness within each ex situ population. We genotyped individuals from two natural populations and two founding, captive populations to compare metrics of genetic variation and relatedness. The data show the initial founder populations are genetically representative of the natural populations, although variation is low in each, and that relatedness values are similar. Therefore, founding captive populations were successful at capturing genetic variation in the wild. Future research should continue to compare genetic variation of captive and natural populations to monitor efficacy of their management programs. Zoo Biol. 35:378-384, 2016. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Kristin M Hinkson
- Department of Biological Sciences, Eastern Kentucky University, Richmond, Kentucky
| | - Natochia L Henry
- Department of Biological Sciences, Eastern Kentucky University, Richmond, Kentucky
| | - Nina M Hensley
- Department of Biological Sciences, Eastern Kentucky University, Richmond, Kentucky
| | - Stephen C Richter
- Department of Biological Sciences, Eastern Kentucky University, Richmond, Kentucky. .,Division of Natural Areas, Eastern Kentucky University, Richmond, Kentucky.
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Ivy JA, Putnam AS, Navarro AY, Gurr J, Ryder OA. Applying SNP-Derived Molecular Coancestry Estimates to Captive Breeding Programs. J Hered 2016; 107:403-12. [PMID: 27208150 DOI: 10.1093/jhered/esw029] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2015] [Accepted: 04/22/2016] [Indexed: 12/24/2022] Open
Abstract
Captive breeding programs for wildlife species typically rely on pedigrees to inform genetic management. Although pedigree-based breeding strategies are quite effective at retaining long-term genetic variation, management of zoo-based breeding programs continues to be hampered when pedigrees are poorly known. The objective of this study was to evaluate 2 options for generating single nucleotide polymorphism (SNP) data to resolve unknown relationships within captive breeding programs. We generated SNP data for a zoo-based population of addax (Addax nasomasculatus) using both the Illumina BovineHD BeadChip and double digest restriction site-associated DNA (ddRAD) sequencing. Our results demonstrated that estimates of allele sharing (AS) between pairs of individuals exhibited low variances. Average AS variances were highest when using 50 loci (SNPchipall = 0.00159; ddRADall = 0.0249), but fell below 0.0003 for the SNP chip dataset when sampling ≥250 loci and below 0.0025 for the ddRAD dataset when sampling ≥500 loci. Furthermore, the correlation between the SNPchipall and ddRADall AS datasets was 0.88 (95%CI = 0.84-0.91) when subsampling 500 loci. Collectively, our results indicated that both SNP genotyping methods produced sufficient data for accurately estimating relationships, even within an extremely bottlenecked population. Our results also suggested that analytic assumptions historically integrated into the addax pedigree are not adversely impacting long-term pedigree-based management; kinships calculated from the analytic pedigree were significantly correlated (P << 0.001) with AS estimates. Overall, our conclusions are intended to serve as both a proof of concept and a model for applying molecular data to the genetic management of captive breeding programs.
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Affiliation(s)
- Jamie A Ivy
- From the Department of Life Sciences, San Diego Zoo Global, San Diego, CA 92112-0551 (Ivy and Putnam); Institute for Conservation Research, San Diego Zoo Global, Escondido, CA 92027-7017 (Navarro and Ryder); and Faculty of Veterinary Science, University of Sydney, Sydney, New South Wales, Australia (Gurr)
| | - Andrea S Putnam
- From the Department of Life Sciences, San Diego Zoo Global, San Diego, CA 92112-0551 (Ivy and Putnam); Institute for Conservation Research, San Diego Zoo Global, Escondido, CA 92027-7017 (Navarro and Ryder); and Faculty of Veterinary Science, University of Sydney, Sydney, New South Wales, Australia (Gurr)
| | - Asako Y Navarro
- From the Department of Life Sciences, San Diego Zoo Global, San Diego, CA 92112-0551 (Ivy and Putnam); Institute for Conservation Research, San Diego Zoo Global, Escondido, CA 92027-7017 (Navarro and Ryder); and Faculty of Veterinary Science, University of Sydney, Sydney, New South Wales, Australia (Gurr)
| | - Jessica Gurr
- From the Department of Life Sciences, San Diego Zoo Global, San Diego, CA 92112-0551 (Ivy and Putnam); Institute for Conservation Research, San Diego Zoo Global, Escondido, CA 92027-7017 (Navarro and Ryder); and Faculty of Veterinary Science, University of Sydney, Sydney, New South Wales, Australia (Gurr)
| | - Oliver A Ryder
- From the Department of Life Sciences, San Diego Zoo Global, San Diego, CA 92112-0551 (Ivy and Putnam); Institute for Conservation Research, San Diego Zoo Global, Escondido, CA 92027-7017 (Navarro and Ryder); and Faculty of Veterinary Science, University of Sydney, Sydney, New South Wales, Australia (Gurr)
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Aplasca AC, Iverson JB, Welch ME, Colosimo G, Hekkala ER. Genetic diversity and structure in the Endangered Allen Cays Rock Iguana, Cyclura cychlura inornata. PeerJ 2016; 4:e1793. [PMID: 26989628 PMCID: PMC4793328 DOI: 10.7717/peerj.1793] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2016] [Accepted: 02/21/2016] [Indexed: 11/26/2022] Open
Abstract
The Endangered Allen Cays Rock Iguana (Cyclura cychlura inornata) is endemic to the Allen Cays, a tiny cluster of islands in the Bahamas. Naturally occurring populations exist on only two cays (<4 ha each). However, populations of unknown origin were recently discovered on four additional cays. To investigate patterns of genetic variation among these populations, we analyzed nuclear and mitochondrial markers for 268 individuals. Analysis of three mitochondrial gene regions (2,328 bp) and data for eight nuclear microsatellite loci indicated low genetic diversity overall. Estimates of effective population sizes based on multilocus genotypes were also extremely low. Despite low diversity, significant population structuring and variation in genetic diversity measures were detected among cays. Genetic data confirm the source population for an experimentally translocated population while raising concerns regarding other, unauthorized, translocations. Reduced heterozygosity is consistent with a documented historical population decline due to overharvest. This study provides the first range-wide genetic analysis of this subspecies. We suggest strategies to maximize genetic diversity during ongoing recovery including additional translocations to establish assurance populations and additional protective measures for the two remaining natural populations.
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Affiliation(s)
- Andrea C Aplasca
- Department of Biological Sciences, Fordham University, New York, NY, United States; Current affiliation: College of Veterinary Medicine, Cornell University, Ithaca, NY, United States
| | - John B Iverson
- Department of Biology, Earlham College , Richmond, IN , United States
| | - Mark E Welch
- Department of Biological Sciences, Mississippi State University , Mississippi, MS , United States
| | - Giuliano Colosimo
- Department of Biological Sciences, Mississippi State University , Mississippi, MS , United States
| | - Evon R Hekkala
- Department of Biological Sciences, Fordham University , New York, NY , United States
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Seddon JM, Lee KE, Johnston SD, Nicolson VN, Pyne M, Carrick FN, Ellis WAH. Testing the regional genetic representativeness of captive koala populations in South-East Queensland. WILDLIFE RESEARCH 2014. [DOI: 10.1071/wr13103] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Context Captive breeding for release back to the wild is an important component of ex situ conservation but requires genetic diversity that is representative of the wild population and has the ultimate goal of producing ecologically sustainable and resilient populations. However, defining and testing for representativeness of captive populations is difficult. Koalas (Phascolarctos cinereus) are bred for educational and tourism purposes in zoos and wildlife parks in South-East Queensland, but there are drastic declines evident in some wild koala populations in this region. Aim We compared genetic diversity at microsatellite loci and mitochondrial DNA in two captive koala populations with that of the local, wild koalas of South-East Queensland, determining the degree to which genetic diversity of neutral loci had been preserved and was represented in the captive populations. Key results The expected heterozygosity and the allelic richness was significantly greater in one captive colony than one wild South-East Queensland population. There was low but significant differentiation of the captive from wild populations using FST, with greater differentiation described by Jost’s Dest. In contrast, a newly introduced Kullback–Leibler divergence measure, which assesses similarity of allele frequencies, showed no significant divergence of colony and wild populations. The captive koalas lacked many of the mitochondrial haplotypes identified from South-East Queensland koalas and possessed seven other haplotypes. Conclusions Captive colonies of koalas have maintained levels of overall neutral genetic diversity similar to wild populations at microsatellite loci and low but significant differentiation likely resulted from drift and founder effects in small captive colonies or declining wild populations. Mitochondrial DNA suggests that captive founders were from a wider geographic source or that haplotypes have been lost locally. Implications Overall, tested captive koalas maintain sufficient microsatellite diversity to act as an in situ reservoir for neutral genetic diversity of regional populations.
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Robinson SP, Simmons LW, Kennington WJ. Estimating relatedness and inbreeding using molecular markers and pedigrees: the effect of demographic history. Mol Ecol 2013; 22:5779-92. [PMID: 24102888 DOI: 10.1111/mec.12529] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2012] [Revised: 09/06/2013] [Accepted: 09/09/2013] [Indexed: 11/30/2022]
Abstract
Estimates of inbreeding and relatedness are commonly calculated using molecular markers, although the accuracy of such estimates has been questioned. As a further complication, in many situations, such estimates are required in populations with reduced genetic diversity, which is likely to affect their accuracy. We investigated the correlation between microsatellite- and pedigree-based coefficients of inbreeding and relatedness in laboratory populations of Drosophila melanogaster that had passed through bottlenecks to manipulate their genetic diversity. We also used simulations to predict expected correlations between marker- and pedigree-based estimates and to investigate the influence of linkage between loci and null alleles. Our empirical data showed lower correlations between marker- and pedigree-based estimates in our control (nonbottleneck) population than were predicted by our simulations or those found in similar studies. Correlations were weaker in bottleneck populations, confirming that extreme reductions in diversity can compromise the ability of molecular estimates to detect recent inbreeding events. However, this result was highly dependent on the strength of the bottleneck and we did not observe or predict any reduction in correlations in our population that went through a relatively severe bottleneck of N = 10 for one generation. Our results are therefore encouraging, as molecular estimates appeared robust to quite severe reductions in genetic diversity. It should also be remembered that pedigree-based estimates may not capture realized identity-by-decent and that marker-based estimates may actually be more useful in certain situations.
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Affiliation(s)
- S P Robinson
- Centre for Evolutionary Biology, School of Animal Biology (M092), University of Western Australia, Crawley, WA, 6009, Australia
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Putnam AS, Ivy JA. Kinship-based management strategies for captive breeding programs when pedigrees are unknown or uncertain. J Hered 2013; 105:303-11. [PMID: 24143031 DOI: 10.1093/jhered/est068] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Zoo-based captive breeding programs typically rely on accurate pedigrees to maintain long-term population genetic diversity and prevent close inbreeding. For many mixed-sex captive populations, it is difficult to assign parentage of offspring with certainty without conducting DNA-based parentage analyses. Using the demographic parameters of a North American captive population of Arabian oryx (Oryx leucoryx), 2 kinship-based breeding-pair selection strategies were modeled for their performance in handling pedigrees with varying degrees of parentage uncertainty. We also compared these strategies with 2 nonkinship-based methods. Pedigrees simulated under different management strategies were compared for their long-term ability to maintain gene diversity (GD) and avoid inbreeding. For the Arabian oryx, results indicate that recording multiple possible parents instead of removing the unknown genomic portion of the pedigree can more efficiently utilize all animals available for breeding without compromising GD and inbreeding avoidance. Both kinship-based breeding-pair selection strategies significantly outperformed the nonkinship-based strategies.
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Affiliation(s)
- Andrea S Putnam
- the Department of Life Sciences, San Diego Zoo Global, PO Box 120551, San Diego, CA 92112-0551
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