James Cook University

About: James Cook University is a education organization based out in Townsville, Queensland, Australia. It is known for research contribution in the topics: Population & Coral reef. The organization has 9101 authors who have published 27750 publications receiving 1032608 citations. The organization is also known as: JCU.

Ocean Acidification Affects Prey Detection by a Predatory Reef Fish

Abstract: Changes in olfactory-mediated behaviour caused by elevated CO2 levels in the ocean could affect recruitment to reef fish populations because larval fish become more vulnerable to predation. However, it is currently unclear how elevated CO2 will impact the other key part of the predator-prey interaction – the predators. We investigated the effects of elevated CO2 and reduced pH on olfactory preferences, activity levels and feeding behaviour of a common coral reef meso-predator, the brown dottyback (Pseudochromis fuscus). Predators were exposed to either current-day CO2 levels or one of two elevated CO2 levels (∼600 µatm or ∼950 µatm) that may occur by 2100 according to climate change predictions. Exposure to elevated CO2 and reduced pH caused a shift from preference to avoidance of the smell of injured prey, with CO2 treated predators spending approximately 20% less time in a water stream containing prey odour compared with controls. Furthermore, activity levels of fish was higher in the high CO2 treatment and feeding activity was lower for fish in the mid CO2 treatment; indicating that future conditions may potentially reduce the ability of the fish to respond rapidly to fluctuations in food availability. Elevated activity levels of predators in the high CO2 treatment, however, may compensate for reduced olfactory ability, as greater movement facilitated visual detection of food. Our findings show that, at least for the species tested to date, both parties in the predator-prey relationship may be affected by ocean acidification. Although impairment of olfactory-mediated behaviour of predators might reduce the risk of predation for larval fishes, the magnitude of the observed effects of elevated CO2 acidification appear to be more dramatic for prey compared to predators. Thus, it is unlikely that the altered behaviour of predators is sufficient to fully compensate for the effects of ocean acidification on prey mortality.

Transcription of the FMR1 gene in individuals with fragile X syndrome

Abstract: Fragile X syndrome generally arises as a consequence of a large expansion of a CGG trinucleotide repeat element that is located in the GC-rich promoter region of the fragile X mental retardation gene (FMR1). In the conventional model for fragile X, clinical involvement arises as a consequence of silencing of the FMR1 gene, with the attendant loss of FMR1 protein (FMRP). However, it has recently been demonstrated that most males with large premutation alleles (100-200 repeats), or with unmethylated full mutation alleles, have FMR1 mRNA levels that are higher than normal, despite reduced levels of FMRP. In the current work, we extend and confirm these observations using quantitative (fluorescent) reverse transcription polymerase chain reaction on larger sample populations, establishing that even for smaller premutation alleles (55-100 repeats) the mRNA levels are significantly elevated (mean 2.1-fold elevation; P = 3.9 x 10(-3)), relative to normal controls. Thus, an abnormal molecular phenotype is established close to the upper end of the normal range. We also demonstrate that the levels of FMR1 mRNA are elevated in females with premutation alleles; however, the mRNA levels are more varied than in the males, and are attenuated in a manner that is consistent with the fraction of normal alleles that are active in any given individual. Finally, we demonstrate that in lymphoblastoid cells derived from a patient with a severe form of fragile X caused by a point mutation in the second KH domain of the gene, but with a normal CGG element (25 repeats), the FMR1 mRNA level is normal. Thus, although models in which FMRP level (or level of function) modulates transcriptional activity remain viable, other explanations for the elevated message levels, including direct (cis) effects of the CGG element on transcription, must also be considered.

Scaled deployment of Wolbachia to protect the community from dengue and other Aedes transmitted arboviruses.

Abstract: Background : A number of new technologies are under development for the control of mosquito transmitted viruses, such as dengue, chikungunya and Zika that all require the release of modified mosquitoes into the environment. None of these technologies has been able to demonstrate evidence that they can be implemented at a scale beyond small pilots. Here we report the first successful citywide scaled deployment of Wolbachia in the northern Australian city of Townsville. Methods : The w Mel strain of Wolbachia was backcrossed into a local Aedes aegypti genotype and mass reared mosquitoes were deployed as eggs using mosquito release containers (MRCs). In initial stages these releases were undertaken by program staff but in later stages this was replaced by direct community release including the development of a school program that saw children undertake releases. Mosquito monitoring was undertaken with Biogents Sentinel (BGS) traps and individual mosquitoes were screened for the presence of Wolbachia with a Taqman qPCR or LAMP diagnostic assay. Dengue case notifications from Queensland Health Communicable Disease Branch were used to track dengue cases in the city before and after release. Results : Wolbachia was successfully established into local Ae. aegypti mosquitoes across 66 km 2 in four stages over 28 months with full community support. A feature of the program was the development of a scaled approach to community engagement. Wolbachia frequencies have remained stable since deployment and to date no local dengue transmission has been confirmed in any area of Townsville after Wolbachia has established, despite local transmission events every year for the prior 13 years and an epidemiological context of increasing imported cases. Conclusion : Deployment of Wolbachia into Ae. aegypti populations can be readily scaled to areas of ~60km 2 quickly and cost effectively and appears in this context to be effective at stopping local dengue transmission

Possible modes of dissemination of the amphibian chytrid Batrachochytrium dendrobatidis in the environment

Abstract: Amphibian chytridiomycosis caused by Batrachochytrium dendrobatidis has spread at an alarming rate over large distances throughout sensitive frog populations in eastern Australia, Central America and New Zealand. Infected amphibians and contaminated water are implicated in translocation, but other vectors are unknown. Through in vitro studies we show that potential means of translocation may be moist soil and bird feathers. B. dendrobatidis survived for up to 3 mo in sterile, moist river sand with no other nutrients added. B. dendrobatidis attached to and grew on sterile feathers and were able to be transported by feathers to establish new cultures in media, surviving between 1 and 3 h of drying between transfers. If these in vitro results are valid in the natural environment, the findings raise the possibilities that B. dendrobatidis may be translocated by movement of moist river sand and that birds may carry the amphibian chytrid between frog habitats. However, further studies using sand and feathers containing normal microflora are essential.

Projecting Global Biodiversity Indicators under Future Development Scenarios

Abstract: To address the ongoing global biodiversity crisis, governments have set strategic objectives and have adopted indicators to monitor progress toward their achievement. Projecting the likely impacts on biodiversity of different policy decisions allows decision makers to understand if and how these targets can be met. We projected trends in two widely used indicators of population abundance Geometric Mean Abundance, equivalent to the Living Planet Index and extinction risk (the Red List Index) under different climate and land-use change scenarios. Testing these on terrestrial carnivore and ungulate species, we found that both indicators decline steadily, and by 2050, under a Business-as-usual (BAU) scenario, geometric mean population abundance declines by 18–35% while extinction risk increases for 8–23% of the species, depending on assumptions about species responses to climate change. BAU will therefore fail Convention on Biological Diversity target 12 of improving the conservation status of known threatened species. An alternative sustainable development scenario reduces both extinction risk and population losses compared with BAU and could lead to population increases. Our approach to model species responses to global changes brings the focus of scenarios directly to the species level, thus taking into account an additional dimension of biodiversity and paving the way for including stronger ecological foundations into future biodiversity scenario assessments.