Dietary Exposure of Pacific Oyster (Crassostrea gigas) Larvae to Compromised Microalgae Results in Impaired Fitness and Microbiome Shift.

The Pacific oyster Crassostrea gigas is the world's most cultivated oyster and seed supply is heavily reliant on hatchery production where recurring mass mortality events are a major constraint. Outbreaks of bacterial infection via microalgal feed are frequently implicated in these mortalities. This study assessed the effects of feeding compromised microalgae to developing oyster larvae. Intentionally 'stressed' (high pH) or non-stressed microalgae were fed to 11 day-old oyster larvae at two feeding rations for 96 h, followed by a recovery period. Biological endpoints of larval performance were measured following the 96 h exposure and subsequent recovery. Bacterial communities associated with the microalgae feed, rearing seawater, and the oyster larvae, were characterized and correlated with effects on oyster fitness parameters. Feeding stressed algae to oyster larvae for 96 h increased the occurrence of deformities (>70% vs. 20% in control), reduced feeding and swimming ability, and slowed development. Following the recovery period, fewer larvae reached pediveliger stage (2.7% vs. 36% in control) and became spat (1.5% vs. 6.6% in control). The quantity of stressed algae supplied to oyster larvae also influenced overall larval performance, with high feeding rations generally causing greater impairment than low rations. Bacterial profiling using 16S rRNA showed that most bacterial families characterized in larval tissue were also present in larval rearing seawater and in the microalgae feed (98%). The rearing seawater showed the highest bacterial richness compared to the larval and the microalgal compartments, regardless of feeding regime. In larval tissue, bacterial richness was highest in stressed and high-feed treatments, and negatively correlated with larval fitness parameters. These results suggest significant dysbiosis induced by compromised feed and/or increased feed ration. Several bacterial genera (e.g., Halomonas, Marinomonas) were strongly associated with impaired larval performance while the presence of genera in larvae including Vibrio was closely associated with overfeeding. Our research demonstrated that metabarcoding can be effectively used to identify microbiota features associated with larval fitness.

Developing Successful Breeding Programs for New Zealand Aquaculture: A Perspective on Progress and Future Genomic Opportunities.

Over the past 40 years New Zealand (NZ) aquaculture has grown into a significant primary industry. Tonnage is small on a global scale, but the industry has built an international reputation for the supply of high quality seafood to many overseas markets. Since the early 1990s the industry has recognized the potential gains from selective breeding and the challenge has been to develop programs that can overcome biological obstacles (such as larval rearing and mortality) and operate cost-effectively on a relatively small scale while still providing significant gains in multiple traits of economic value. This paper provides an overview of the current status, and a perspective on genomic technology implementation, for the family based genetic improvement programs established for the two main species farmed in NZ: Chinook (king) salmon (Oncorhynchus tshawytscha) and GreenshellTM mussel (Perna canaliculus). These programs have provided significant benefit to the industry in which we are now developing genomic resources based on genotyping-by-sequencing to complement the breeding programs, enable evaluation of the genetic diversity and identify the potential benefits of genomic selection. This represents an opportunity to increase genetic gain and more effectively utilize the potential for within family selection.

Greenshell™ Mussels: A Review of Veterinary Trials and Future Research Directions.

The therapeutic benefits of Greenshell™ mussel (GSM; Perna canaliculus) preparations have been studied using in vitro test systems, animal models, and human clinical trials focusing mainly on anti-inflammatory and anti-arthritic effects. Activity is thought to be linked to key active ingredients that include omega-3 polyunsaturated fatty acids, a variety of carotenoids and other bioactive compounds. In this paper, we review the studies that have been undertaken in dogs, cats, and horses, and outline new research directions in shellfish breeding and high-value nutrition research programmes targeted at enhancing the efficacy of mussel and algal extracts. The addition of GSM to animal diets has alleviated feline degenerative joint disease and arthritis symptoms, and chronic orthopaedic pain in dogs. In horses, GSM extracts decreased the severity of lameness and joint pain and provided improved joint flexion in limbs with lameness attributed to osteoarthritis. Future research in this area should focus on elucidating the key active ingredients in order to link concentrations of these active ingredients with their pharmacokinetics and therapeutic effects. This would enable consistent and improved efficacy from GSM-based products for the purpose of improved animal health.

Establishing the thermal window for aerobic scope in New Zealand geoduck clams (Panopea zelandica).

Geoduck clams (Panopea spp.) are the longest-lived and largest deep burrowing bivalve. Their unique morphology allows them to live buried in the sediment at depths of up to 1 m. The endemic New Zealand geoduck (Panopea zelandica Quoy and Gaimard, 1835) has recently been identified as a potential species for aquaculture. However, very little is known about the biology and physiology of this entirely subtidal geoduck species. Currently, the New Zealand geoduck fishery relies entirely upon wild harvests, but farms are expected to emerge as cultivation protocols are established. A key step in the optimization of cultivation procedures is the identification of optimal temperature and food rations. One method for establishing thermal optima is to identify the temperature window that supports the widest aerobic scope: the degree to which metabolic rate can be increased to support elevated activity demands. Thus, we investigated the aerobic scope for activity at five different temperatures representative of typical environmental conditions (8, 11, 15, 19, and 23 °C) for juvenile and young adult P. zelandica. Clearance rate was also measured at all temperatures. Comparisons of aerobic scope for activity and clearance rates between size classes revealed that juvenile geoducks had a narrower thermal optimum than young adults (15-19 versus 11-19 °C, respectively). Temperatures higher than 19 °C resulted in a reduction of aerobic scope for activity and clearance rate for both juvenile and young adults, which may lead to reduced performance and elevated mortality. These findings provide the first measures of aerobic scope in P. zelandica, a key step towards a meaningful understanding of the ecophysiology of this unusual species.

The Biodiversity Informatics Potential Index.

BACKGROUND: Biodiversity informatics is a relatively new discipline extending computer science in the context of biodiversity data, and its development to date has not been uniform throughout the world. Digitizing effort and capacity building are costly, and ways should be found to prioritize them rationally. The proposed 'Biodiversity Informatics Potential (BIP) Index' seeks to fulfill such a prioritization role. We propose that the potential for biodiversity informatics be assessed through three concepts: (a) the intrinsic biodiversity potential (the biological richness or ecological diversity) of a country; (b) the capacity of the country to generate biodiversity data records; and (c) the availability of technical infrastructure in a country for managing and publishing such records. METHODS: Broadly, the techniques used to construct the BIP Index were rank correlation, multiple regression analysis, principal components analysis and optimization by linear programming. We built the BIP Index by finding a parsimonious set of country-level human, economic and environmental variables that best predicted the availability of primary biodiversity data accessible through the Global Biodiversity Information Facility (GBIF) network, and constructing an optimized model with these variables. The model was then applied to all countries for which sufficient data existed, to obtain a score for each country. Countries were ranked according to that score. RESULTS: Many of the current GBIF participants ranked highly in the BIP Index, although some of them seemed not to have realized their biodiversity informatics potential. The BIP Index attributed low ranking to most nonparticipant countries; however, a few of them scored highly, suggesting that these would be high-return new participants if encouraged to contribute towards the GBIF mission of free and open access to biodiversity data. CONCLUSIONS: The BIP Index could potentially help in (a) identifying countries most likely to contribute to filling gaps in digitized biodiversity data; (b) assisting countries potentially in need (for example mega-diverse) to mobilize resources and collect data that could be used in decision-making; and (c) allowing identification of which biodiversity informatics-resourced countries could afford to assist countries lacking in biodiversity informatics capacity, and which data-rich countries should benefit most from such help.

Limb-girdle muscular dystrophy in the United States.

Limb-girdle muscular dystrophy (LGMD) has been linked to 15 chromosomal loci, 7 autosomal-dominant (LGMD1A to E) and 10 autosomal-recessive (LGMD2A to J). To determine the distribution of subtypes among patients in the United States, 6 medical centers evaluated patients with a referral diagnosis of LGMD. Muscle biopsies provided histopathology and immunodiagnostic testing, and their protein abnormalities along with clinical parameters directed mutation screening. The diagnosis in 23 patients was a disorder other than LGMD. Of the remaining 289 unrelated patients, 266 had muscle biopsies sufficient for complete microscopic evaluation; 121 also underwent Western blotting. From this combined evaluation, the distribution of immunophenotypes is 12% calpainopathy, 18% dysferlinopathy, 15% sarcoglycanopathy, 15% dystroglycanopathy, and 1.5% caveolinopathy. Genotypes distributed among 2 dominant and 7 recessive subtypes have been determined for 83 patients. This study of a large racially and ethnically diverse population of patients with LGMD indicates that establishing a putative subtype is possible more than half the time using available diagnostic testing. An efficient approach to genotypic diagnosis is muscle biopsy immunophenotyping followed by directed mutational analysis. The most common LGMDs in the United States are calpainopathies, dysferlinopathies, sarcoglycanopathies, and dystroglycanopathies.

Proteomic analysis of rat kidney cortex following treatment with gentamicin.

The regionally specific structure and function of the kidney renders it susceptible to toxic exposure. To characterize these changes at the proteome level, we have investigated the effects on protein expression following treatment with gentamicin. The more than 20 proteins identified were involved in the citric acid cycle, gluconeogenesis, fatty acid synthesis, and transport or cellular stress responses. These results strongly support the notion that energy production is impaired and mitochondrial dysfunction is involved in gentamicin-induced nephrotoxicity.