85 research outputs found
Sources and uses of genetic material in the study of Petrogale (rock wallabies) and other mammals
Microsatellite DNA fingerprinting confirms dizygotic twinning and paternity in the allied rock-wallaby, Petrogale assimilis (Marsupialia: Macropodidae)
The complete mitochondrial genome of the Australian Common Rock Rat, Zyzomys argurus
The Common Rock Rat Zyzomys argurus is an abundant small- to medium-sized Murid rodent that is endemic to Australia. It is a nocturnal mammal with a mostly herbivorous diet. This species is native to the wet/dry tropics of Northern Australia and can be identified from other rock rats on the basis of its small size and its tail length (which is at least equivalent to its head-body length). Here, we describe the complete mitochondrial genome of Z. argurus and compare it to other Rodentia. The Z. argurus circular mitogenome was 16,261 bp and contained 13 protein-coding genes, two rRNA genes, 22 tRNAs and a control region (D-loop) of 859 bp. Phylogenetic analysis of selected, published sequenced mitogenomes reveal it is most closely related to the Lakeland Downs mouse Leggadina lakedownensis in the order Rodentia
The complete mitochondrial genome of the vulnerable Australian crest-tailed mulgara (Dasycercus cristicauda)
In this announcement, we report the complete mitogenome of the vulnerable Crest-tailed Mulgara (Dasycercus cristicauda) (Krefft, 1867). The mitogenome was 17,085 bp in length and contained 13 protein-coding genes, two rRNA genes, 22 tRNAs and a 1583 bp variable control region (D-loop). The features of the D. cristicauda mitogenome are consistent with other vertebrate mitogenomes but, in contrast to other marsupials, appears to contain a functional tRNA-Lysine with a UUU anticodon. Phylogenetic analysis of available entire mitogenomes reveals it forms a cluster with other marsupials in the Dasyuromorphia order within the Australidelphian clade, being most closely related to the Northern Quoll and the Tasmanian Devil
Genetic consequences of multiple translocations of the banded hare-qallaby in Western Australia
Many Australian mammal species now only occur on islands and fenced mainland havens free from invasive predators. The range of one species, the banded hare-wallaby (Lagostrophus fasciatus), had contracted to two offshore islands in Western Australia. To improve survival, four conservation translocations have been attempted with mixed success, and all occurred in the absence of genetic information. Here, we genotyped seven polymorphic microsatellite markers in two source (Bernier Island and Dorre Island), two historic captive, and two translocated L. fasciatus populations to determine the impact of multiple translocations on genetic diversity. Subsequently, we used population viability analysis (PVA) and gene retention modelling to determine scenarios that will maximise demographic resilience and genetic richness of two new populations that are currently being established. One translocated population (Wadderin) has undergone a genetic bottleneck and lost 8.1% of its source population’s allelic diversity, while the other (Faure Island) may be inbred. We show that founder number is a key parameter when establishing new L. fasciatus populations and 100 founders should lead to high survival probabilities. Our modelling predicts that during periodic droughts, the recovery of source populations will be slower post-harvest, while 75% more animals—about 60 individuals—are required to retain adequate allelic diversity in the translocated population. Our approach demonstrates how genetic data coupled with simulations of stochastic environmental events can address central questions in translocation programmes
Comparative Erythrocyte Metabolism in Marsupials and Monotremes
Concentrations of ATP and DPG, activities of 10 enzymes and the glycolytic rates were measured in the erythrocytes of 11 species of marsupials and two species of monotremes. Mean DPG concentrations were greater in the erythrocytes of marsupials than those of eutherian mammals. The opposite is true of ATP. Significant findings from the results of enzyme activities were: high activity of hexokinase (7.39 + 0.82 EU/g Hb) in the short-beaked echidna, pyruvate kinase (37.49 + 1.0 EU/g) Hb in bridled nailtail wallaby and glucose-6-phosphate dehydrogenase (G6PD; 41.66 + 1.24 EU/g Rb) in black-striped wallaby. About 6- to 7-fold difference in the activity of G6PD levels between the two species of wombats was confirmed. Glucose phosphate isomerase activity was also shown to be twice as high in the red cells of the common wombat compared with those of the southern hairy nosed wombat. There were wide variations in the glycolytic rate among the species examined
Population genomics of a predatory mammal reveals patterns of decline and impacts of exposure to toxic toads
Mammal declines across northern Australia are one of the major biodiversity loss events occurring globally. There has been no regional assessment of the implications of these species declines for genomic diversity. To address this, we conducted a species-wide assessment of genomic diversity in the northern quoll (Dasyurus hallucatus), an Endangered marsupial carnivore. We used next generation sequencing methods to genotype 10,191 single nucleotide polymorphisms (SNPs) in 352 individuals from across a 3220-km length of the continent, investigating patterns of population genomic structure and diversity, and identifying loci showing signals of putative selection. We found strong heterogeneity in the distribution of genomic diversity across the continent, characterized by (i) biogeographical barriers driving hierarchical population structure through long-term isolation, and (ii) severe reductions in diversity resulting from population declines, exacerbated by the spread of introduced toxic cane toads (Rhinella marina). These results warn of a large ongoing loss of genomic diversity and associated adaptive capacity as mammals decline across northern Australia. Encouragingly, populations of the northern quoll established on toad-free islands by translocations appear to have maintained most of the initial genomic diversity after 16 years. By mapping patterns of genomic diversity within and among populations, and investigating these patterns in the context of population declines, we can provide conservation managers with data critical to informed decision-making. This includes the identification of populations that are candidates for genetic management, the importance of remnant island and insurance/translocated populations for the conservation of genetic diversity, and the characterization of putative evolutionarily significant units
Comparative Study Of The Antioxidant Defence Systems In The Erythrocytes Of Australian Marsupials And Monotremes
A comparison of the erythrocyte (RBC) antioxidant metabolites and enzymes in nine marsupial and two monotreme species was carried out. Reduced glutathione (GSH) concentrations were comparable with those reported for other marsupial and eutherian species. An important finding was that the erythrocytes of the southern hairy nosed wombat regenerated GSH faster than the erythrocytes from its close relative, the common wombat. The activities of glutathione-S-transferase, NADH methaemoglobin reductase, superoxide dismutase, and glutathione peroxidase (GSH-Px), showed similar levels and extents of variation as those observed in other marsupial and eutherian species. Catalase activities in the marsupials were lower than those measured in the two monotreme species and much lower than those reported in eutherian species. A negative correlation, significant at P < 0.05, was observed between GSH-PX and catalase activities in the RBC of the marsupials. Since both these enzymes "detoxify" H202, there appears to be a reciprocal relationship between the activities of these enzymes in marsupial RB
Food forensics in the human and pet-food industry: Use of a simple technology to identify commercially important species of kangaroos from Western Australia
The kangaroos and wallabies are iconic fauna that are immediately identifiable with the Australian landscape. The group belong to the superfamily Macropodoidea (or macropods), which contain about 45 living species in Australia [1]. These species are found naturally in the wild only in Australia and New Guinea, although some feral populations have been introduced in New Zealand, Great Britain and Hawaii. Of these, four are commercially harvested in an internationally recognised sustainable industry (red kangaroo, common wallaroo, western and eastern grey kangaroos; [2]). None of the commercial species is threatened or endangered and the red kangaroo remains the sole example of a national emblem that is harvested for human consumption. The Red kangaroo, Eastern grey and Western grey kangaroo are the most abundant species on mainland Australia and make up over 90 per cent of the commercial harvest. In the harvested areas, and depending on seasonal conditions, their combined population sizes have fluctuated between 15 and 50 million animals over the past 20 years. The intensity of harvest is relative to the population size and determined on a quota basis that is reviewed annually (see: http://www.environment.gov.au/biodiversity/trade-use/). These quotas are set on the basis of population size/trends and long-term climate predictions. The proportion of animals taken adopts a precautionary principle as conservation of the species remains the foremost consideration. This approach ensures that the harvesting of kangaroos has, and is, managed in an ecologically sustainable way.
Over 99% of the commercial kangaroo harvest occurs in the arid grazing rangelands, some 2 million km2 [3]. As with any natural population, all species of kangaroos undergo natural fluctuations in population abundance, generally in response to rainfall [4,5]. The Wildlife Protection (Regulation of Exports and Imports) Act of 1982 regulates the exports and imports of kangaroo products. In addition, as a signatory to the Convention on International Trade in Endangered Species (CITES), Australia has the responsibility to regulate the exports and imports (and harvest) of all native animals and plants including kangaroos. Like many wildlife products, once the product has been processed (into packing/shipping containers), it is extremely difficult (if not impossible) to identify the species, or origin of the sample simply by inspection of the product. Forensic investigations can offer an important service in the regulation of illegal killing as well as fraudulent mis-description of end food products. This is important because consumers are demanding clear and accurate information for the food they buy (‘truth in labelling’), be those for conservation, religious, social, health or lifestyle reasons [6]. Furthermore, in any wild harvest there is also a conservation concern, as overharvesting may ultimately lead to the decline or even complete collapse of the industry as has been seen in some fisheries. As such, an important function of wildlife protection authorities is to make sure that illegal (over)harvesting does not occur. To do this, authorities need to be equipped with indisputable tools that would allow them to regulate and detect discrepancies within the product that is being regulated. The harvesting of kangaroos is an example of such an industry. Furthermore, given the significant differences between the pricing of premium versus substandard and inferior substitutes, it is also an increasing concern that there is ‘truth in labelling’.
For investigative work with kangaroos, we were unable to identify an existing dataset with sufficient fine-scale resolution to identify the macropods to species level. As such, here we describe a dataset generated from a range of commercial and other species of macropods for the express purpose of forming the basis of a database that can be used to identify a seizure sample to a known species of origin
Characterisation and cross-species utility of 20 microsatellite markers for population and forensic applications in the endangered Carnaby’s Black-cockatoo, Calyptorhynchus latirostris
We characterise 20 microsatellite loci identified from the endangered Carnaby’s Black-cockatoo (Calyptorhynchus latirostris). The primers were tested across 40 individuals from the southwest of Western Australia and displayed between 4 and 11 alleles per locus with expected heterozygosities ranging from 53 to 87% and exclusion probabilities of C0.999. These loci will be useful in population genetic studies to facilitate conservation management decisions in addition to wildlife enforcement applications for the endangered Carnaby’s Black-cockatoo. We also tested the markers in 12 high profile and smuggled species from five genera, Cacatua, Callocephalon, Calyptorhynchus, Nymphicus and Probosciger. These species detected between 2 and 19 alleles per locus with 50–100% amplification success
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