Soil sampling for <Emphasis Type="Italic">Metarhizium anisopliae</Emphasis> spores in Queensland sugarcane fields

Three sugarcane fields in Bundaberg and four fields in each of the Burdekin, Tully and Innisfail (Queensland, Australia) were sampled for spores of Metarhizium anisopliae (Metchnikoff) (Deuteromycotina: Hyphomycetes). This entomopathogenic fungus is the active ingredient in the biocide “BioCane^TM”, which was developed for the management of the greyback canegrub Dermolepida albohirtum (Waterhosue) (Coleoptera: Scarabaeidae) and other scarabs in cane fields. Fields sampled were of different crop ages and all had a history of BioCane^TM treatment in Plant Cane in past years. Soil samples were taken in each field from four depths (0–10, 10–20, 20–30 and 30–40 cm below soil level) with the use of an auger. Spore levels were highest at the depths of 10–20 and 20–30 cm. Spore levels differed between locations with Innisfail and Tully recording the highest spore counts. Spores were also found in the inter-row space in plots sampled in Tully. Sampling statistics were determined for M. anisopliae spores at the four soil depths with 0.1 and 0.25 precision levels. Three sampling methods were compared (use of marker beads; use of 100 mm auger and 150 mm auger). Samples that relied on marker beads resulted in higher spore counts, however, an auger can still be used since BioCane^TM does not normally contain coloured markers. Results obtained demonstrate the ability of the pathogen to translocate in soil profile and across rows, most likely due to grub movements and other soil fauna. Sampling for M. anisopliae spores provides good monitoring of their levels in soil. The implications of this on grub management decisions are discussed.     

Mate Familiarity Affects Pairing Behaviour in a Long‐Term Monogamous Lizard: Evidence from Detailed Bio‐Logging and a 31‐Year Field Study

Long‐term monogamy is most prevalent in birds but is also found in lizards. We combined a 31‐year field study of the long‐lived, monogamous Australian sleepy lizard, Tiliqua rugosa, with continuous behavioural observations through GPS data logging, in 1 yr, to investigate the duration of pair bonds, rates of partner change and whether either the reproductive performance hypothesis or the mate familiarity hypothesis could explain this remarkable long‐term monogamy. The reproductive performance hypothesis predicts higher reproductive success in more experienced parents, whereas the mate familiarity hypothesis suggests that effects of partner familiarity select for partner retention and long‐term monogamy. Rates of partner change were below 34% over a 5‐yr period and most sleepy lizards formed long‐term pair bonds: 31 partnerships lasted for more than 15 yr, 110 for more than 10 yr, and the recorded maximum was 27 yr (ongoing). In the year when we conducted detailed observations, familiar pairs mated significantly earlier than unfamiliar pairs. Previous pairing experience (total number of years paired with previous partners) had no significant effect. Early mating often equates to higher reproductive success, and we infer that is the case in sleepy lizards. Early mating of familiar pairs was not due to better body condition. We propose two suggestions about the proximate mechanisms that may allow familiar pair partners to mate earlier than unfamiliar partners. First, they may have improved coordination of their reproductive sexual cycles to reach receptivity earlier and thereby maximise fertilisation success. Second, they may forage more efficiently, benefiting from effective information transfer and/or cooperative predator detection. Those ideas need empirical testing in the future. Regardless of the mechanism, our observations of sleepy lizard pairing behaviour support the mate familiarity hypothesis, but not the reproductive performance hypothesis, as an explanation for its long‐term monogamous mating system.     

Contemplating the future: Acting now on long‐term monitoring to answer 2050's questions

In 2050, which aspects of ecosystem change will we regret not having measured? Long‐term monitoring plays a crucial part in managing Australia's natural environment because time is a key factor underpinning changes in ecosystems. It is critical to start measuring key attributes of ecosystems – and the human and natural process affecting them – now, so that we can track the trajectory of change over time. This will facilitate informed choices about how to manage ecological changes (including interventions where they are required) and promote better understanding by 2050 of how particular ecosystems have been shaped over time. There will be considerable value in building on existing long‐term monitoring programmes because this can add significantly to the temporal depth of information. The economic and social processes driving change in ecosystems are not identical in all ecosystems, so much of what is monitored (and the means by which it is monitored) will most likely target specific ecosystems or groups of ecosystems. To best understand the effects of ecosystem‐specific threats and drivers, monitoring also will need to address the economic and social factors underpinning ecosystem‐specific change. Therefore, robust assessments of the state of Australia's environment will be best achieved by reporting on the ecological performance of a representative sample of ecosystems over time. Political, policy and financial support to implement appropriate ecosystem‐specific monitoring is a perennial problem. We suggest that the value of ecological monitoring will be demonstrable, when plot‐based monitoring data make a unique and crucial contribution to Australia's ability to produce environmental accounts, environmental reports (e.g. the State of the Environment, State of the Forests) and to fulfilling reporting obligations under international agreements, such as the Convention on Biological Diversity. This paper suggests what must be done to meet Australia's ecological information needs by 2050.     

Why replication is important in landscape genetics: American black bear in the Rocky Mountains

We investigated how landscape features influence gene flow of black bears by testing the relative support for 36 alternative landscape resistance hypotheses, including isolation by distance (IBD) in each of 12 study areas in the north central U.S. Rocky Mountains. The study areas all contained the same basic elements, but differed in extent of forest fragmentation, altitude, variation in elevation and road coverage. In all but one of the study areas, isolation by landscape resistance was more supported than IBD suggesting gene flow is likely influenced by elevation, forest cover, and roads. However, the landscape features influencing gene flow varied among study areas. Using subsets of loci usually gave models with the very similar landscape features influencing gene flow as with all loci, suggesting the landscape features influencing gene flow were correctly identified. To test if the cause of the variability of supported landscape features in study areas resulted from landscape differences among study areas, we conducted a limiting factor analysis. We found that features were supported in landscape models only when the features were highly variable. This is perhaps not surprising but suggests an important cautionary note - that if landscape features are not found to influence gene flow, researchers should not automatically conclude that the features are unimportant to the species' movement and gene flow. Failure to investigate multiple study areas that have a range of variability in landscape features could cause misleading inferences about which landscape features generally limit gene flow. This could lead to potentially erroneous identification of corridors and barriers if models are transferred between areas with different landscape characteristics.     

Exploring the zoonotic potential of Mycobacterium avium subspecies paratuberculosis through comparative genomics

A comparative genomics approach was utilised to compare the genomes of Mycobacterium avium subspecies paratuberculosis (MAP) isolated from early onset paediatric Crohn's disease (CD) patients as well as Johne's diseased animals. Draft genome sequences were produced for MAP isolates derived from four CD patients, one ulcerative colitis (UC) patient, and two non-inflammatory bowel disease (IBD) control individuals using Illumina sequencing, complemented by comparative genome hybridisation (CGH). MAP isolates derived from two bovine and one ovine host were also subjected to whole genome sequencing and CGH. All seven human derived MAP isolates were highly genetically similar and clustered together with one bovine type isolate following phylogenetic analysis. Three other sequenced isolates (including the reference bovine derived isolate K10) were genetically distinct. The human isolates contained two large tandem duplications, the organisations of which were confirmed by PCR. Designated vGI-17 and vGI-18 these duplications spanned 63 and 109 open reading frames, respectively. PCR screening of over 30 additional MAP isolates (3 human derived, 27 animal derived and one environmental isolate) confirmed that vGI-17 and vGI-18 are common across many isolates. Quantitative real-time PCR of vGI-17 demonstrated that the proportion of cells containing the vGI-17 duplication varied between 0.01 to 15% amongst isolates with human isolates containing a higher proportion of vGI-17 compared to most animal isolates. These findings suggest these duplications are transient genomic rearrangements. We hypothesise that the over-representation of vGI-17 in human derived MAP strains may enhance their ability to infect or persist within a human host by increasing genome redundancy and conferring crude regulation of protein expression across biologically important regions.     

Mycobacterium avium subsp. paratuberculosis in the catchment area and water of the River Taff in South Wales, United Kingdom, and its potential relationship to clustering of Crohn's disease cases in the city of Cardiff

In South Wales, United Kingdom, a populated coastal region lies beneath hill pastures grazed by livestock in which Mycobacterium avium subsp. paratuberculosis is endemic. The Taff is a spate river running off the hills and through the principal city of Cardiff. We sampled Taff water above Cardiff twice weekly from November 2001 to November 2002. M. avium subsp. paratuberculosis was detected by IS900 PCR and culture. Thirty-one of 96 daily samples (32.3%) were IS900 PCR positive, and 12 grew M. avium subsp. paratuberculosis bovine strains. Amplicon sequences from colonies were identical to the sequence with GenBank accession no. X16293, whereas 16 of 19 sequences from river water DNA extracts had a single-nucleotide polymorphism at position 214. This is consistent with a different strain of M. avium subsp. paratuberculosis in the river, which is unculturable by the methods we used. Parallel studies showed that M. avium subsp. paratuberculosis remained culturable in lake water microcosms for 632 days and persisted to 841 days. Of four reservoirs controlling the catchment area of the Taff, M. avium subsp. paratuberculosis was present in surface sediments from three and in sediment cores from two, consistent with deposition over at least 50 years. Previous epidemiological research in Cardiff demonstrated a highly significant increase of Crohn's disease in 11 districts. These bordered the river except for a gap on the windward side. A topographical relief map shows that this gap is directly opposite a valley open to the prevailing southwesterly winds. This would influence the distribution of aerosols carrying M. avium subsp. paratuberculosis from the river.     

Sudden loading during a dynamic lifting task: a simulation study

It is believed that nurses risk the development of back pain as a consequence of sudden loadings during tasks in which they are handling patients. Forward dynamics simulations of sudden loads (applied to the arms) during dynamic lifting tasks were performed on a two-dimensional whole-body model. Loads were in the range of -80 kg to 80 kg, with the initial load being 20 kg. Loading the arm downwards with less than that which equals a mass of 20 kg did not change the compressive forces on the spine when compared to a normal lifting motion with a 20 kg mass in the hands. However when larger loads (40 kg to 80 kg extra in the hands) were simulated, the compressive forces exceeded 13,000 N (above 3400 N is generally considered a risk factor). Loading upwards led to a decrease in the compressive forces but to a larger backwards velocity at the end of the movement. In the present study, it was possible to simulate a fast lifting motion. The results showed that when loading the arms downwards with a force that equals 40 kg or more, the spine was severely compressed. When loading in the opposite direction (unloading), the spine was not compressed more than during a normal lifting motion. In practical terms, this indicates that if a nursing aide tries to catch a patient who is falling, large compressive forces are applied to the spine.     

Marine actinobacteria: perspectives, challenges, future directions

In this paper we evaluate the current state of research on the biology biotechnology of marine actinobacteria. The topics covered include the abundance, diversity, novelty and biogeographic distribution of marine actinobacteria, ecosystem function, bioprospecting, and a new approach to the exploration of actinobacterial taxonomic space. An agenda for future marine actinobacterial research is suggested based upon consideration of the above issues.     

MOLECULAR GENETICS OF ADAPTATION IN AN EXPERIMENTAL MODEL OF COOPERATION

The evolution of cooperation was studied in an empirical system utilizing a parasitic bacteriophage (f1) and a bacterial host. Infected cells were propagated by serial passage so that a phage could increase its representation among infected hosts only by enhancing the rate of growth of its host. Loss of infectivity was therefore without selective penalty, and phage benevolence could potentially evolve through a variety of genetic changes. The infected hosts evolved to grow faster over the course of the study, but the genetic bases of this phenotypic change were more difficult to anticipate. Two fundamentally different types of genetic changes in the phage were revealed. One involved the loss of some phage genes, resulting in a noninfectious plasmid that continued to replicate via the parental phage replicon. The second change involved integration of the phage genome into host DNA by a process that, at low frequency, could be reversed to produce infectious phage particles. Integration is a previously unknown property of wild-type f1, and in the system studied, may have resulted from the use of a phage bearing an insert containing nonfunctional DNA. The evolution of this novel function apparently depended only on the presence of a small region in the phage genome that provided some homology to the host DNA, with the host providing all necessary functions. Although f1 is one of the simplest phages known, these observations suggest that host-parasite interactions of the filamentous phages are more complicated than previously thought. More generally, the f1 system offers a useful model for many problems concerning the genetic basis of adaptation.