Faecal DNA analysis enables genetic monitoring of the species recovery program for an arid-dwelling marsupial
Steve Smith A C D , Peter McRae B and Jane Hughes AA Griffith School of Environment, Griffith University, 170 Kessels Road, Nathan, Qld 4111, Australia.
B Queensland Parks and Wildlife Service, PO Box 149, Charleville, Qld 4470, Australia.
C Present address: Research Institute for Wildlife Ecology, Savoyenstraße 1, A-1160 Vienna, Austria.
D Corresponding author. Email: steve.smith@fiwi.at
Australian Journal of Zoology 57(2) 139-148 https://doi.org/10.1071/ZO09035
Submitted: 3 April 2009 Accepted: 6 July 2009 Published: 13 August 2009
Abstract
The greater bilby, Macrotis lagotis, is a species of conservation significance in the arid and semiarid zones of Australia. A species recovery program has been underway since the mid-1990s but the incorporation of molecular genetic data within the program has been difficult due to the problems of obtaining regular, population-wide samples of this trap-shy and sparsely distributed species. In this study, we demonstrate that faecal pellets collected from around burrows in the dry, arid habitat of western Queensland provide a viable source for DNA extraction and analysis. Faecal DNA was used to generate population-level estimates of microsatellite and mtDNA diversity for comparison with previous estimates for the natural population derived from tissue samples. Data were used to assess both the reliability of faecal-derived genotypes and the extent of any diversity loss since the previous study. Microsatellite diversity recorded from eight polymorphic markers for the natural population (A = 4.31 ± 0.30, HE = 0.76 ± 0.03) was comparable with the previous study, indicating little change in genetic diversity for the natural population in the 10-year interim. Faecal genotypes generated for the recently reintroduced population matched the known number of founders as well as a known genotype, providing support for the reliability of the faecal DNA approach. The captive and reintroduced populations had significantly lower diversity levels than the natural population (A = 3.59 ± 0.28, HE = 0.68 ± 0.03; A = 3.57 ± 0.20, HE = 0.65 ± 0.03 respectively). Mitochondrial control region analysis, incorporating nested clade phylogeographic analysis (NCPA), agrees with earlier findings that populations of bilbies across the arid zone in Australia have only recently become fragmented, but the case for Queensland bilbies being strongly differentiated from other regions is diminished. Implications from this study include the need to further supplement the captive and reintroduced populations with additional out-bred individuals and that faecal DNA can be used effectively for ongoing monitoring and management of this species.
Additional keywords: bilby, captive breeding, Macrotis lagotis, microsatellites, mtDNA, non-invasive samples, reintroduction.
Acknowledgements
We thank Doug Shooter for his assistance in sample collection and two anonymous reviewers for helpful comments that improved the quality of this manuscript. This study was partly funded by the Queensland Government’s ‘Smartstate PhD Research Grant Scheme’ grant to SS. The study was conducted with the approval of the Griffith University Animal Ethics Committee (GU Ref No. AES/03/03/AEC).
Adams, J. R. , and Waits, L. P. (2007). An efficient method for screening faecal DNA genotypes and detecting new individuals and hybrids in the red wolf (Canis rufus) experimental population area. Conservation Genetics 8, 123–131.
| Crossref | GoogleScholarGoogle Scholar |
Ballou, J. D. (1984). Strategies for maintaining genetic diversity in captive populations through reproductive technology. Zoo Biology 3, 311–323.
| Crossref | GoogleScholarGoogle Scholar |
Balloux, F. , Amos, W. , and Coulson, T. (2004). Does heterozygosity estimate inbreeding in real populations? Molecular Ecology 13, 3021–3031.
| Crossref | GoogleScholarGoogle Scholar | PubMed |
Garrick, R. C. , Dyer, R. J. , Beheregaray, L. B. , and Sunnucks, P. (2008). Babies and bathwater: a comment on the premature obituary for nested clade phylogeographical analysis. Molecular Ecology 17, 1401–1403.
| Crossref | GoogleScholarGoogle Scholar | PubMed |
Jarman, S. N. , Gales, N. J. , Tierney, M. , Gill, P. C. , and Elliott, N. G. (2002). A DNA-based method for identification of krill species and its application to analysing the diet of marine vertebrate predators. Molecular Ecology 11, 2679–2690.
| Crossref | GoogleScholarGoogle Scholar | PubMed |
Montgomery, M. E. , Ballou, J. D. , Nurthen, R. K. , England, P. R. , Briscoe, D. A. , and Frankham, R. (1997). Minimizing kinship in captive breeding programs. Zoo Biology 16, 377–389.
| Crossref | GoogleScholarGoogle Scholar |
Morin, P. A. , Chambers, K. E. , Boesch, C. , and Vigilant, L. (2001). Quantitative polymerase chain reaction analysis of DNA from noninvasive samples for accurate microsatellite genotyping of wild chimpanzees (Pan troglodytes verus). Molecular Ecology 10, 1835–1844.
| Crossref | GoogleScholarGoogle Scholar | PubMed |
Peakall, R. , and Smouse, P. E. (2006). GENALEX 6: genetic analysis in Excel. Population genetic software for teaching and research. Molecular Ecology Notes 6, 288–295.
| Crossref | GoogleScholarGoogle Scholar |
Petit, R. J. (2008). The coup de grace for the nested clade phylogeographic analysis? Molecular Ecology 17, 516–518.
| Crossref | GoogleScholarGoogle Scholar | PubMed |
Southgate, R. (2005). Age classes of the greater bilby (Macrotis lagotis) based on track and faecal pellet size. Wildlife Research 32, 625–630.
| Crossref | GoogleScholarGoogle Scholar |
Southgate, R. , and Adams, M. (1993). Genetic variation in the greater bilby. Pacific Conservation Biology 1, 46–52.
Southgate, R. , and Carthew, S. M. (2006). Diet of the bilby (Macrotis lagotis) in relation to substrate, fire and rainfall characteristics in the Tanami Desert. Wildlife Research 33, 507–519.
| Crossref | GoogleScholarGoogle Scholar |
Southgate, R. , and Possingham, H. (1995). Modelling the reintroduction of the greater bilby Macrotis lagotis using the metapopulation model Analysis of the Likelihood of Extinction (ALEX). Biological Conservation 73, 151–160.
| Crossref | GoogleScholarGoogle Scholar |
Southgate, R. I. , McRae, P. , and Atherton, R. (1995). Trapping techniques and a pen design for the greater bilby, Macrotis lagotis. Australian Mammalogy 18, 101–104.
Southgate, R. I. , Christie, P. , and Bellchambers, K. (2000). Breeding biology of captive, reintroduced and wild greater bilbies, Macrotis lagotis (Marsupialia: Peramelidae). Wildlife Research 27, 621–628.
| Crossref | GoogleScholarGoogle Scholar |
Taberlet, P. , Griffin, S. , Goossens, B. , Questiau, S. , Manceau, V. , Escaravage, N. , Waits, L. P. , and Bouvet, J. (1996). Reliable genotyping of samples with very low DNA quantities using PCR. Nucleic Acids Research 24, 3189–3194.
| Crossref | GoogleScholarGoogle Scholar | PubMed |
Templeton, A. R. (2008). Nested clade analysis: an extensively validated method for strong phylogeographic inference. Molecular Ecology 17, 1877–1880.
| Crossref | GoogleScholarGoogle Scholar | PubMed |
Templeton, A. R. (2009). Why does a method that fails continue to be used? The answer. Evolution 63, 807–812.
| Crossref | GoogleScholarGoogle Scholar | PubMed |
Templeton, A. R. , Boerwinkle, E. , and Sing, C. F. (1987). A cladistic analysis of phenotypic associations with haplotypes inferred from restriction endonuclease mapping. 1. Basic theory and an analysis of alcohol dehydrogenase activity in Drosophila. Genetics 117, 343–351.
| PubMed |
Waits, L. P. , and Paetkau, D. (2005). Noninvasive genetic sampling tools for wildlife biologists: a review of applications and recommendations for accurate data collection. Journal of Wildlife Management 69, 1419–1433.
| Crossref | GoogleScholarGoogle Scholar |
Waples, R. S. (1989). A generalized approach for estimating effective population size from temporal changes in allele frequency. Genetics 121, 379–391.
| PubMed |
Woodworth, L. M. , Montgomery, M. E. , Briscoe, D. A. , and Frankham, R. (2002). Rapid genetic deterioration in captive populations: causes and conservation implications. Conservation Genetics 3, 277–288.
| Crossref | GoogleScholarGoogle Scholar |