Allergen Diversity and Abundance in Different Tissues of the Redclaw Crayfish (Cherax quadricarinatus).

Shellfish allergy affects ~2.5% of the global population and is a type I immune response resulting from exposure to crustacean and/or molluscan proteins. The Australian Redclaw crayfish (Cherax quadricarinatus) is a freshwater species endemic to and farmed in northern Australia and is becoming an aquaculture species of interest globally. Despite being consumed as food, allergenic proteins from redclaw have not been identified or characterised. In addition, as different body parts are often consumed, it is conceivable that redclaw tissues vary in allergenicity depending on tissue type and function. To better understand food-derived allergenicity, this study characterised allergenic proteins in various redclaw body tissues (the tail, claw, and cephalothorax) and how the stability of allergenic proteins was affected through cooking (raw vs. cooked tissues). The potential of redclaw allergens to cross-react and cause IgE-binding in patients allergic to other shellfish (i.e., shrimp) was also investigated. Raw and cooked extracts were prepared from each body part. SDS-PAGE followed by immunoblotting was performed to determine allergen-specific antibody reactivity to sarcoplasmic calcium-binding protein and hemocyanin, as well as to identify redclaw proteins binding to IgE antibodies from individual and pooled sera of shrimp-allergic patients. Liquid chromatography-mass spectrometry (LC/MS) was utilised to identify proteins and to determine the proportion within extracts. Known crustacean allergens were found in all tissues, with a variation in tissue distribution (e.g., higher levels of hemocyanin in the claw and cephalothorax than in the tail). The proportion of some allergens as a percentage of remaining heat-stable proteins increased in cooked tissues. Previously described heat-stable allergens (i.e., hemocyanin and sarcoplasmic calcium-binding protein) were found to be partially heat-labile. Immunoblotting indicated that shrimp-allergic patients cross-react to redclaw allergens. IgE-binding bands, analysed by LC/MS, identified up to 11 known shellfish allergens. The findings of this study provide fundamental knowledge into the diagnostic and therapeutic field of shellfish allergy.

Complete Genome Sequences of Betanodavirus from Australian Barramundi (Lates calcarifer).

The complete RNA-1 and RNA-2 genome sequences of Betanodavirus were obtained from Australian barramundi (Lates calcarifer). Phylogenetic analyses revealed that the sequences have closest homology to the red spotted grouper nervous necrosis virus (RGNNV) species and share between 91 and 98% homology with the other two published complete/near-complete sequences of isolates from Australian fish.

De novo assembly, characterization, functional annotation and expression patterns of the black tiger shrimp (Penaeus monodon) transcriptome.

The black tiger shrimp (Penaeus monodon) remains the second most widely cultured shrimp species globally; however, issues with disease and domestication have seen production levels stagnate over the past two decades. To help identify innovative solutions needed to resolve bottlenecks hampering the culture of this species, it is important to generate genetic and genomic resources. Towards this aim, we have produced the most complete publicly available P. monodon transcriptome database to date based on nine adult tissues and eight early life-history stages (BUSCO - Complete: 98.2% [Duplicated: 51.3%], Fragmented: 0.8%, Missing: 1.0%). The assembly resulted in 236,388 contigs, which were then further segregated into 99,203 adult tissue specific and 58,678 early life-history stage specific clusters. While annotation rates were low (approximately 30%), as is typical for a non-model organisms, annotated transcript clusters were successfully mapped to several hundred functional KEGG pathways. Transcripts were clustered into groups within tissues and early life-history stages, providing initial evidence for their roles in specific tissue functions, or developmental transitions. We expect the transcriptome to provide an essential resource to investigate the molecular basis of commercially relevant-significant traits in P. monodon and other shrimp species.

First complete genome of an Ambidensovirus; Cherax quadricarinatus densovirus, from freshwater crayfish Cherax quadricarinatus.

In 1999, the causative agent of an epizootic in Cherax quadricarinatus was described, and given the provisional name Cherax quadricarinatus parvovirus-like. Sequencing of the 6334 nt genome identified three open-reading frames on the top strand coding NS3 (35.55 kDa), NS1 (67.36 kDa) and NS2 (35.18 kDa) and on the bottom strand a single open reading frame which most likely encodes 4 structural proteins. Motifs characteristic of the Densovirinae were found in the ORFs. Phylogenetic analysis of the amino acids in NS1 places the genome in the genus Ambidensovirus, most closely related to the marine sea star densovirus (75%, E=0.0) and distantly related to Acheta domestica densovirus (44.1%). The virus name is proposed as species Decapod ambidensovirus, variant Cherax quadricarinatus densovirus. This is the first Ambidensovirus to be found in decapod crustaceans and the first of the subfamily Densovirinae to be sequenced from a freshwater crayfish. Cherax quadricarinatus densovirus and sea star densovirus are the first highly related Densovirinae to infect phylogenetically disparate hosts and are thus far, unique among the Densovirinae.

Confirmed case of encephalitis caused by Murray Valley encephalitis virus infection in a horse.

A 5-year-old Australian stock horse in Monto, Queensland, Australia, developed neurological signs and was euthanized after a 6-day course of illness. Histological examination of the brain and spinal cord revealed moderate to severe subacute, nonsuppurative encephalomyelitis. Sections of spinal cord stained positively in immunohistochemistry with a flavivirus-specific monoclonal antibody. Reverse transcription polymerase chain reaction assay targeting the envelope gene of flavivirus yielded positive results from brain, spinal cord, cerebrospinal fluid, and facial nerve. A flavivirus was isolated from the cerebrum and spinal cord. Nucleotide sequences obtained from amplicons from both tissues and virus isolated in cell culture were compared with those in GenBank and had 96-98% identity with Murray Valley encephalitis virus. The partial envelope gene sequence of the viral isolate clustered into genotype 1 and was most closely related to a previous Queensland isolate.

The ratio of square wave jerk rates to blink rates distinguishes progressive supranuclear palsy from Parkinson disease.

BACKGROUND: Distinguishing progressive supranuclear palsy (PSP) from Parkinson disease (PD) may be difficult, particularly in the early stages, because the characteristic vertical supranuclear eye movement abnormalities of PSP may be absent or delayed until late in the course of the disease. In this study we investigated the usefulness of comparing the square wave jerk rate (SWJR) and blink rate (BR) in the differentiation of these two disorders. METHODS: We studied 10 patients with PD (PD group) and 5 patients with PSP (PSP group) who met published diagnostic criteria. The SWJR and BR were measured from video recordings and were used to calculate a ratio (SWJR:BR). RESULTS: The PSP group exhibited a significantly higher SWJR, higher SWJR:BR, and lower BR than did the PD group. No patient with PSP exhibited a SWJR:BR of < 3; however, one patient with PD had a SWJR:BR of 5.3, creating overlap between the two groups. CONCLUSIONS: The SWJR:BR is a simple and reasonably useful clinical measure to distinguish established PSP from PD. Determining the value of this measure in differentiating early PSP from PD requires a prospective study.

A parvo-like virus in cultured redclaw crayfish Cherax quadricarinatus from Queensland, Australia.

In the summer of 1999/2000, an epizootic occurred in cultured juvenile redclaw crayfish Cherax quadricarinatus on one commercial crayfish farm in northern Queensland, Australia. Mortalities occurred over 4 wk, with up to 96% cumulative mortalities in 2 earthen ponds stocked with juveniles. The crayfish were weak, anorexic and lethargic. A transmission trial was conducted, using filtered, cell-free extract prepared from infected crayfish as inoculum. The disease was reproduced, with on-going mortalities occurring in inoculated crayfish over 55 d. Experimentally inoculated crayfish showed gross signs of malaise, anorexia and disorientation before dying. Two types of intranuclear inclusion bodies (INIBs) were seen in tissues of endodermal, ectodermal and mesodermal origin by light microscopy with haematoxylin and eosin (H&E) stained sections. 'Early'-stage INIBs were eosinophilic, rounded and located centrally within slightly enlarged nuclei while 'late'-stage INIBs were well-rounded and deeply basophilic. The gills, cuticular epithelium and epithelial cells of the foregut, midgut and hindgut were the most heavily infected tissues. By transmission electron microscopy, virions with an average diameter of 19.5 nm were seen within electron-dense granular inclusion bodies within enlarged nuclei of both naturally and experimentally infected crayfish. The size of the virions and cytopathology are consistent with characteristics of viruses in the Family Parvoviridae. This is the first reported case of mass mortality caused by a parvo-like virus infection in C. quadricarinatus.