• A demonstration of conservation genomics for threatened species management

      Wright, Belinda R.; Farquharson, Katherine A.; McLennan, Elspeth A.; Belov, Katherine; Hogg, Carolyn J.; Grueber, Catherine E. (2020)
      ... We conducted whole genome sequencing (WGS) of 25 individuals from the captive breeding programme and reduced‐representation sequencing (RRS) of 98 founders of the same programme. A subset of the WGS samples was also sequenced by RRS, allowing us to directly compare genome‐wide heterozygosity with estimates from RRS data. We found good congruence in interindividual variation and gene‐ontology classifications between the two data sets, indicating that our RRS data reflect the genome well....
    • A meta-analysis of birth-origin effects on reproduction in diverse captive environments

      Farquharson, Katherine A.; Hogg, Carolyn J.; Grueber, Catherine E. (2018)
      Successfully establishing captive breeding programs is a priority across diverse industries to address food security, demand for ethical laboratory research animals, and prevent extinction. Differences in reproductive success due to birth origin may threaten the long-term sustainability of captive breeding. Our meta-analysis examining 115 effect sizes from 44 species of invertebrates, fish, birds, and mammals shows that, overall, captive-born animals have a 42% decreased odds of reproductive success in captivity compared to their wild-born counterparts. The largest effects are seen in commercial aquaculture, relative to conservation or laboratory settings, and offspring survival and offspring quality were the most sensitive traits. Although a somewhat weaker trend, reproductive success in conservation and laboratory research breeding programs is also in a negative direction for captive-born animals. Our study provides the foundation for future investigation of non-genetic and genetic drivers of change in captivity, and reveals areas for the urgent improvement of captive breeding.
    • Are any populations ‘safe’? Unexpected reproductive decline in a population of Tasmanian devils free of devil facial tumour disease

      Farquharson, Katherine A.; Gooley, Rebecca M.; Fox, S.; Huxtable, Stewart J.; Belov, Katherine; Pemberton, David; Hogg, Carolyn J.; Grueber, Catherine E. (2018)
      Conservation management relies on baseline demographic data of natural populations. For Tasmanian devils (Sarcophilus harrisii), threatened in the wild by two fatal and transmissible cancers (devil facial tumour disease DFTD: DFT1 and DFT2), understanding the characteristics of healthy populations is crucial for developing adaptive management strategies to bolster populations in the wild....
    • Deciphering genetic mate choice: Not so simple in group-housed conservation breeding programs

      Farquharson, Katherine A.; Hogg, Carolyn J.; Belov, Katherine; Grueber, Catherine E. (2020)
      Incorporating mate choice into conservation breeding programs can improve reproduction and the retention of natural behaviors. However, different types of genetic-based mate choice can have varied consequences for genetic diversity management. As a result, it is important to examine mechanisms of mate choice in captivity to assess its costs and benefits. Most research in this area has focused on experimental pairing trials; however, this resource-intensive approach is not always feasible in captive settings and can interfere with other management constraints. We used generalized linear mixed models and permutation approaches to investigate overall breeding success in group-housed Tasmanian devils at three nonmutually exclusive mate choice hypotheses: (a) advantage of heterozygous individuals, (b) advantage of dissimilar mates, and (c) optimum genetic distance, using both 1,948 genome-wide SNPs and 12 MHC-linked microsatellites. The managed devil insurance population is the largest such breeding program in Australia and is known to have high variance in reproductive success. We found that nongenetic factors such as age were the best predictors of breeding success in a competitive breeding scenario, with younger females and older males being more successful. We found no evidence of mate choice under the hypotheses tested. Mate choice varies among species and across environments, so we advocate for more studies in realistic captive management contexts as experimental or wild studies may not apply. Conservation managers must weigh up the need to wait for adequate sample sizes to detect mate choice with the risk that genetic changes may occur during this time in captivity. Our study shows that examining and integrating mate choice into the captive management of species housed in realistic, semi-natural group-based contexts may be more difficult than previously considered.
    • From reference genomes to population genomics: comparing three reference-aligned reduced-representation sequencing pipelines in two wildlife species

      Wright, Belinda R.; Farquharson, Katherine A.; McLennan, Elspeth A.; Belov, Katherine; Hogg, Carolyn J.; Grueber, Catherine E. (2019)
      Recent advances in genomics have greatly increased research opportunities for non-model species. For wildlife, a growing availability of reference genomes means that population genetics is no longer restricted to a small set of anonymous loci. When used in conjunction with a reference genome, reduced-representation sequencing (RRS) provides a cost-effective method for obtaining reliable diversity information for population genetics. Many software tools have been developed to process RRS data, though few studies of non-model species incorporate genome alignment in calling loci. A commonly-used RRS analysis pipeline, Stacks, has this capacity and so it is timely to compare its utility with existing software originally designed for alignment and analysis of whole genome sequencing data. Here we examine population genetic inferences from two species for which reference-aligned reduced-representation data have been collected. Our two study species are a threatened Australian marsupial (Tasmanian devil Sarcophilus harrisii; declining population) and an Arctic-circle migrant bird (pink-footed goose Anser brachyrhynchus; expanding population). Analyses of these data are compared using Stacks versus two widely-used genomics packages, SAMtools and GATK. We also introduce a custom R script to improve the reliability of single nucleotide polymorphism (SNP) calls in all pipelines and conduct population genetic inferences for non-model species with reference genomes.
    • Pedigree analysis reveals a generational decline in reproductive success of captive Tasmanian devil (Sarcophilus harrisii): implications for captive management of threatened species

      Farquharson, Katherine A.; Hogg, Carolyn J.; Grueber, Catherine E. (2017)
      Captive breeding programs are an increasingly popular tool to augment the conservation of threatened wild populations. Many programs keep detailed pedigrees, which are used to prescribe breeding targets to meet demographic and genetic goals....