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Takagi W.,University of Tokyo | Kajimura M.,Wakayama University | Bell J.D.,Deakin University | Bell J.D.,Primary Industries Research Victoria | And 3 more authors.
Comparative Biochemistry and Physiology - B Biochemistry and Molecular Biology | Year: 2012

Cartilaginous fish comprise two subclasses, the Holocephali (chimaeras) and Elasmobranchii (sharks, skates and rays). Little is known about osmoregulatory mechanisms in holocephalan fishes except that they conduct urea-based osmoregulation, as in elasmobranchs. In the present study, we examined the ornithine urea cycle (OUC) enzymes that play a role in urea biosynthesis in the holocephalan elephant fish, Callorhinchus milii (cm). We obtained a single mRNA encoding carbamoyl phosphate synthetase III (cmCPSIII) and ornithine transcarbamylase (cmOTC), and two mRNAs encoding glutamine synthetases (cmGSs) and two arginases (cmARGs), respectively. The two cmGSs were structurally and functionally separated into two types: brain/liver/kidney-type cmGS1 and muscle-type cmGS2. Furthermore, two alternatively spliced transcripts with different sizes were found for cm. gs1 gene. The longer transcript has a putative mitochondrial targeting signal (MTS) and was predominantly expressed in the liver and kidney. MTS was not found in the short form of cmGS1 and cmGS2. A high mRNA expression and enzyme activities were found in the liver and muscle. Furthermore, in various tissues examined, mRNA levels of all the enzymes except cmCPSIII were significantly increased after hatching. The data show that the liver is the important organ for urea biosynthesis in elephant fish, but, extrahepatic tissues such as the kidney and muscle may also contribute to the urea production. In addition to the role of the extrahepatic tissues and nitrogen metabolism, the molecular and functional characteristics of multiple isoforms of GSs and ARGs are discussed. © 2011 Elsevier Inc. Source


Hernandez S.,Victoria University of Wellington | Hernandez S.,Catolica del Norte University | Daley R.,CSIRO | Walker T.,Primary Industries Research Victoria | And 4 more authors.
Fisheries Research | Year: 2015

We used mitochondrial DNA (mtDNA) control region (CR) sequences and genotypes from eight microsatellite DNA (msatDNA) loci to determine the genetic structure of the school shark (Galeorhinus galeus) in New Zealand, Australia and Chile. The estimates of mtDNA haplotype and nucleotide diversity were very similar in New Zealand (h= 0.735 ± 0.032, π= 0.001 ± 0.001) and Australia (h= 0.729 ± 0.027, π= 0.001 ± 0.001), but in Chile they were higher (h= 0.800 ± 0.089, π= 0.002 ± 0.001). The haplotype genealogy showed evidence of two distinct clades, New Zealand and Australia combined (clade 1), and Chile (clade 2). A power analysis suggested that sample sizes were large enough to detect any significant differences within clade 1. Neutrality test, mismatch distribution, and demographic reconstructions based on a coalescence approach, suggested that the Oceania population (clade 1) went through a period of population expansion, whereas the population size of the Chile population (clade 2) has been relatively stable over the last 20,000 years. Data from microsatellite loci also supported the separation of the Oceania and Chile populations. Principal component analysis suggested that there might also be a separation of groups within clade 1, which was not statistically significant (P= 0.434). The genetic data reported in this study supported the model of a single G. galeus stock in New Zealand and Australia. Our findings were consistent with previous tagging data that showed individual G. galeus migrate across the Tasman Sea between Australia and New Zealand, and at least some of these migration events result in successful reproduction. © 2015 Elsevier B.V. Source


Ridge S.E.,Australian Department of Primary Industries and Fisheries | Andreata S.,Australian Department of Primary Industries and Fisheries | Jones K.,Gribbles Veterinary Pathology | Cantlon K.,Gribbles Veterinary Pathology | And 3 more authors.
Australian Veterinary Journal | Year: 2010

Objective: To compare the results of radiometric culture conducted in three Australian laboratories for Mycobacterium avium subsp. paratuberculosis (Mptb) using bulk vat and individual animal milk samples. Procedure: Milk samples were collected from 15 cows exhibiting clinical signs of Johne's disease, and subsequently confirmed as infected with Mptb, and from the bulk milk vats on 91 farms running herds known to be infected with Mptb. Each milk sample was divided into three equivalent samples and one of each of the replicates was forwarded to the three participating laboratories. The identity and nature of the samples was protected from the study collaborators. The laboratories processed the samples and undertook radiometric culture for Mptb using their standard method. Results of testing were provided to the principal investigator for collation and analysis. Results: In total, 2 (2.2%) of 91 vat-milk samples and 8 (53.3%) of 15 individual cows' milk samples returned positive radiometric milk culture results. Only one sample, from a clinical case of Johne's disease, was identified as positive by more than one laboratory. There were differences in the absolute frequency with which Mptb was identified in the milk samples by the collaborating laboratories. Conclusions: Mptb was cultured from a very small percentage of Australian raw bulk milk samples sourced from known infected herds. By contrast, Mptb was successfully cultured from half of the milk samples collected from clinically affected cows. There was no statistical difference between laboratories in the proportion of vat samples or individual animal milk samples in which Mptb was detected. © 2010 Department of Primary Industries Victoria. Journal compilation © 2010 Australian Veterinary Association. Source


Kuske T.,Cooperative Research Center for Greenhouse Gas Technologies | Kuske T.,Geoscience Australia | Jenkins C.,Cooperative Research Center for Greenhouse Gas Technologies | Jenkins C.,CSIRO | And 5 more authors.
Energy Procedia | Year: 2013

Atmospheric tomography is a monitoring technique that uses an array of sampling sites and a Bayesian inversion technique to simultaneously solve for the location and magnitude of a gaseous emission. Application of the technique to date has relied on air samples being pumped over short distances to a high precision FTIR Spectrometer, which is impractical at larger scales. We have deployed a network of cheaper, less precise sensors during three recent large scale controlled CO2 release experiments; one at the CO 2CRC Ginninderra site, one at the CO2CRC Otway Site and another at the Australian Grains Free Air CO2 Enrichment (AGFACE) facility in Horsham, Victoria. The purpose of these deployments was to assess whether an array of independently powered, less precise, less accurate sensors could collect data of sufficient quality to enable application of the atmospheric tomography technique. With careful data manipulation a signal suitable for an inversion study can be seen. A signal processing workflow based on results obtained from the atmospheric array deployed at the CO2CRC Otway experiment is presented. © 2013 The Author. Source


Robinson N.,South Australian Research And Development Institute | Robinson N.,Flinders University | Li X.,South Australian Research And Development Institute | Hayes B.,Primary Industries Research Victoria
Aquaculture Research | Year: 2010

The genetic response and economic benefit from alternative breeding programme designs for blacklip and greenlip abalone (Haliotis rubra and Haliotis laevigata, respectively) were evaluated using a computer simulation model. Two selection criteria were investigated, one used family breeding values for liability to disease challenge test infection and the other used a direct selection of the best performing individuals across families for growth rate. Five scales of breeding programme were tested and the model predicted that if growth rate is the only selection criterion, breeding programmes of a scale using 150 families of each species each generation would result in 12-13% genetic improvement in initial generations and have the greatest beneficial economic impact on the Australian abalone industry of the options tested. The model predicts an average discounted benefit-cost ratio of 48:1, total added discounted benefit of AU$4.90 for each kilogram of abalone produced and nominal economic effect on operating income of over AU$16 million per year after 10 years. If disease resistance is the only selective breeding criterion, 100 families of each species would result in the highest benefit-cost ratio of the options tested, although some genetic gain would need to be sacrificed to reduce inbreeding to acceptable levels in this scenario. A strategy for a stand-alone abalone selective breeding cooperative was also modelled. For a farm of current tank area yielding 100 t year-1, participation is expected to yield over AU$0.7 million in discounted total added production value and annual discounted returns of over AU$0.4 million per annum by year 10. © 2010 The Authors. Journal Compilation © 2010 Blackwell Publishing Ltd. Source

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