Curious bivalves: Systematic utility and unusual properties of anomalodesmatan mitochondrial genomes.

Mitogenomic trees for Bivalvia have proved problematic in the past, but several highly divergent lineages were missing from these analyses and increased representation of these groups may yet improve resolution. Here, we add seven new sequences from the Anomalodesmata and one unidentified semelid species (Bryopa lata, Euciroa cf. queenslandica, Laternula elliptica, Laternula truncata, Lyonsia norwegica, Myadora brevis, Tropidomya abbreviata, "Abra" sp.). We show that relationships in a mitogenomic tree for the Class are improved by the addition of seven anomalodesmatans from this highly divergent clade, but are still not completely consistent with relationships recovered in studies of nuclear genes. We suggest that some anomalous relationships (for instance the non-monophyly of Bivalvia) may be partially explained by compositional heterogeneity in the mitogenome and suggest that the addition of more taxa may help resolve both this effect and possible instances of long branch attraction. We also identify several curious features about anomalodesmatan mitogenomes. For example, many protein-coding gene boundaries are poorly defined in marine bivalves, but particularly so in anomalodesmatans, primarily due to non-conserved boundary sequences. The use of transcriptomic and genomic data together enabled better definition of gene boundaries, the identification of possible pseudogenes and suggests that most genes are translated monocistronically, which contrasts with many other studies. We also identified a possible case of gene duplication of ND5 in Myadora brevis (Myochamidae). Mitogenome size in the Anomalodesmata ranges from very small compact molecules, with the smallest for Laternula elliptica (Laternulidae) only 14,622bp, to Bryopa lata (Clavagellidae) which is at least 31,969bp long and may be >40,000bp. Finally, sampled species show a high degree of sequence divergence and variable gene order, although intraspecific variation in Laternula elliptica is very low.

Toxoplasmosis epidemic in a population of urbanised allied rock-wallabies (Petrogale assimilis) on Magnetic Island (Yunbenun), North Queensland.

A mortality event involving 23 allied rock-wallabies (Petrogale assimilis) displaying neurological signs and sudden death occurred in late April to May 2021 in a suburban residential area directly adjacent to Magnetic Island National Park, on Magnetic Island (Yunbenun), North Queensland, Australia. Three allied rock-wallabies were submitted for necropsy, and in all three cases, the cause of death was disseminated toxoplasmosis. This mortality event was unusual because only a small, localised population of native wallabies inhabiting a periurban area on a tropical island in the Great Barrier Reef World Heritage Area were affected. A disease investigation determined the outbreak was likely linked to the presence of free-ranging feral and domesticated cats inhabiting the area. There were no significant deaths of other wallabies or wildlife in the same or other parts of Magnetic Island (Yunbenun) at the time of the outbreak. This is the first reported case of toxoplasmosis in allied rock-wallabies (Petrogale assimilis), and this investigation highlights the importance of protecting native wildlife species from an infectious and potentially fatal parasitic disease.

A novel alphaherpesvirus and concurrent respiratory cryptococcosis in a captive koala (Phascolarctos cinereus).

A novel alphaherpesvirus was detected in a captive adult, lactating, female koala (Phascolarctos cinereus) admitted to James Cook University Veterinary Emergency Teaching & Clinical Hospital in March 2019, showing signs of anorexia and severe respiratory disease. Postmortem examination revealed gross pathology indicative of pneumonia. Histopathology demonstrated a chronic interstitial pneumonia, multifocal necrotising adrenalitis and hepatitis. Intranuclear inclusion bodies were detected by light microscopy in the respiratory epithelium of the bronchi, bronchioles, alveoli, and hepatocytes, biliary epithelium and adrenal gland associated with foci of necrosis. Cryptococcus gattii was isolated from fresh lung on necropsy, positively identified by PCR, and detected histologically by light microscopy, only in the lung tissue. A universal viral family-level PCR indicated that the virus was a member of the Herpesviruses. Sequence analysis in comparison to other known and published herpesviruses, indicated the virus was a novel alphaherpesvirus, with 97% nucleotide identity to macropodid alphaherpesvirus 1. We provisionally name the novel virus phascolarctid alphaherpesvirus 3 (PhaHV-3). Further research is needed to determine the distribution of this novel alphaherpesvirus in koala populations and establish associations with disease in this host species.

The contraceptive efficacy of a self-assembling intra-uterine device in domestic mares.

OBJECTIVE: The primary aim of this study was to investigate the contraceptive efficacy of a self-assembling uterine device (iUPOD™) in the mare. In addition, the effects of iUPODs on oestrous cyclicity, uterine health and circulating concentrations of cortisol were evaluated. METHODS: Domestic mares underwent oestrous monitoring and artificial insemination. After subsequent ovulation, mares underwent either placement (n = 7) or sham placement (n = 7; controls) of an iUPOD device. Devices were left in place for at least 3 months. Pregnancy diagnoses were carried out 14 days post-ovulation, with any pregnancies terminated at 28 days post-ovulation. All mares underwent weekly blood sampling with or without reproductive examinations throughout the study. Towards the end of the study, multiple serum samples collected over three consecutive days were analysed for concentrations of cortisol. Endometrial biopsies were collected before artificial insemination and during the subsequent breeding season. Endometrial cytology and bacterial cultures were performed before device removal (iUPOD mares) or at the end of the study (control mares). RESULTS: Pregnancies were diagnosed in 0 of 7 iUPOD mares versus 7 of 7 control mares. Placement of iUPODs was associated with extended luteal phases and variable accumulations of intra-uterine fluid. Bacterial culture results suggested that the mild endometritis associated with iUPODs was sterile in six of seven mares. Short-term placement of iUPODs had no detrimental effects on endometrial architecture. Mean serum cortisol concentrations were significantly lower in iUPOD mares than control mares. CONCLUSION: iUPODs represent a promising means of fertility control in the mare.

Comparison of effects of four weaning methods on health and performance of beef calves.

Weaning of beef calves is a stressful event that negatively impacts health and performance. A variety of interventions have been proposed to reduce stress and improve gains following weaning. This study used 288 7- to 8-month-old calves from two separate locations, to examine four different weaning strategies, as well as the impact of shipment. Calves were blocked by weight and sex, and then randomly assigned to one of four treatments: abrupt weaning (AW), where calves were separated from the dam on day 0 (D0) and allowed no further contact with the dam; fence line (FL), where calves were weaned on D0 but had fence line contact with dams for 7 days; nose flap (NF), where on day -6 calves received a nose flap that interferes with suckling, then had the flap removed and were weaned from the dam on D0; and intermittent separation (SEP), where calves were removed from dams for 24-h intervals on day -13 and day -6, then weaned on D0, but allowed fence line contact with the dam for 7 days. Each treatment group was further divided into two subgroups, one of which was shipped early (D0 for AW, day 7 for others) or shipped later (day 28). Body weight and sickness were recorded for all groups. Results showed a negative impact on gain for early shipping compared to later shipping, and poorer gain in AW calves than most other treatments. Results of the analyses of morbidity were inconclusive. This study found that delayed shipment following FL weaning improves performance under common management conditions for the US cow-calf industry.

The dermal chromatophore unit.

Rapid color changes of amphibians are mediated by three types of dermal chromatophores, xanthophores, iridophores, and melanophores, which comprise a morphologically and physiologically distinct structure, the dermal chromatophore unit. Xanthophores, the outermost element, are located immediately below the basal lamella. Iridophores, containing light-reflecting organelles, are found just beneath the xanthophores. Under each iridophore is found a melanophore from which processes extend upward around the iridophore. Finger-like structures project from these processes and occupy fixed spaces between the xanthophores and iridophores. When a frog darkens, melanosomes move upward from the body of the melanophore to fill the fingers which then obscure the overlying iridophore. Rapid blanching is accomplished by the evacuation of melanosomes from these fingers. Pale coloration ranging from tan to green is provided by the overlying xanthophores and iridophores. Details of chromatophore structure are presented, and the nature of the intimate contact between the chromatophore types is discussed.

Color changes, unusual melanosomes, and a new pigment from leaf frogs.

Melanosomes of phyllomedusid frogs are unusually large and are composed of an amorphous matrix of thick fibers. Their hitherto undescribed dark red pigment is neither phaeomelanin nor eumelanin, but seems to be related to melanins. Melanophores of at least one of these species, Agalychnis dacnicolor, exhibit color change in direct response to illumination, and it is suggested that these chromatophores are innervated.

Reef coral from aldabra: new mode of reproduction.

A unique mode of asexual reproduction in recently collected specimens of Goniopora (Scleractinia) is reported. Skeleton is absent from new polyps; the skelton develops independently of the parent colony as the new polyps themselves increase. The young colonies eventually become detached. The cycle seems to be a response to a sandy habitat, a conclusion reached by analogy With Fungia and Manicina.

Induction of neural differentiation in cultures of amphibian undetermined presumptive epidermis by cyclic AMP derivatives.

Induction of neural differentiation in cultures of undetermined presumptive epidermis from three amphibian species was achieved by the addition of 1 millimolar dibutyryl adenosine 3',5'-monophosphate, 8-bromadenosine 3',5'-monophosphate, or adenosine C',E'-monophosphate together with theophylline. Adenosine 5'-monophosphate, adenosine 2',3'-monophosphate, dibutyryl guanosine 3',5'-monophosphate, and butyrate at 1 millimolar are ineffective. These results suggest that the action of the primary inductor or inductors may be mediated via adenosine 3',5'-monophosphate.

Induction of melanized cells from a goldfish erythrophoroma: isolation of pigment translocation variants.

Melanization was induced in some cells of a goldfish tumor cell line (GEM-81) by cultivating the cells in autologous serum. The melanized cells continued to proliferate in vitro and several clones were isolated that differed with respect to cell morphology and intracellular distribution of pigment. Some of the clones consisted of cells able to translocate their melanosomes in response to epinephrine, melatonin, or adenosine 3', 5'-monophosphate.

Tumor cell-platelet aggregation: induced by cathepsin B-like proteinase and inhibited by prostacyclin.

The ability of tumor cells to metastasize may be related to their ability to promote aggregation of host platelets. The use of inhibitors of cysteine proteinases resulted in parallel inhibition of B16 amelanotic melanoma-induced platelet aggregation and of a cathepsin B activity. The antimetastatic agent prostacyclin inhibited platelet aggregation induced by the tumor cells and by papain, a cathepsin B-mimicking agent.

Common origin of pigment cells.

The fundamentally diverse vertebrate pigment cells, melanophores, xanthophores, and iridophores, contain pigmentary organelles known, respectively, as melanosomes, pterinosomes, and reflecting platelets. Their pigments are mealanins pteridines, and purines. Mosaic pigment cells containing more than one type of organelle have been observed and mosaic organelles containing more than one type of pigment have been discovered. It is proposed that the various pigment cells are derived from a stem cell that contains a primordial organelle of endoplasmic reticular origin. This primordial organelle can differentiate into any of the known pigmentary organelles.

Sulfur-associated polioencephalomalacia in cattle grazing plants in the Family Brassicaceae.

Polioencephalomalacia was diagnosed histologically in cattle from two herds on the Darling Downs, Queensland, during July-August 2007. In the first incident, 8 of 20 18-month-old Aberdeen Angus steers died while grazing pastures comprising 60%Sisymbrium irio (London rocket) and 40%Capsella bursapastoris (shepherd's purse). In the second incident, 2 of 150 mixed-breed adult cattle died, and another was successfully treated with thiamine, while grazing a pasture comprising almost 100%Raphanus raphanistrum (wild radish). Affected cattle were either found dead or comatose or were seen apparently blind and head-pressing in some cases. For both incidents, plant and water assays were used to calculate the total dietary sulfur content in dry matter as 0.62% and 1.01% respectively, both exceeding the recommended 0.5% for cattle eating more than 40% forage. Blood and tissue assays for lead were negative in both cases. No access to thiaminase, concentrated sodium ion or extrinsic hydrogen sulfide sources were identified in either incident. Below-median late summer and autumn rainfall followed by above-median unseasonal winter rainfall promoted weed growth at the expense of wholesome pasture species before these incidents.

Responses to genotoxicity in mouse testicular germ cells and epididymal spermatozoa are affected by increased age.

The increased number of cell divisions undergone by spermatogonia of older fathers cannot fully account for the observed increase in germline genetic damage. Studies have shown that the mechanisms induced in germ cells in response to oxidative damage varies with age, that DNA repair efficiency declines, and both sperm DNA damage and spontaneous mutations increase. However, it is not known whether the altered response with age is a cause, or consequence, of an age-associated change in cell susceptibility to genetic damage. Following a single 150 mg/kg dose of cyclophosphamide (CP), young (8-weeks old) and aged (17-month old) male mice were examined 24 h later for induced genetic damage in epididymal spermatozoa using the alkaline comet and sperm chromatin stability assays. Apoptosis among testicular cells was examined on tissue cross-sections using the TUNEL assay. Sperm showed no significant increase in DNA strand breaks with age (detected by the comet assay) and no change in sperm chromatin stability (detected by the SCSA assay). Following CP treatment, there was no effect on DNA-strand breakage but sperm chromatin instability was significantly higher. Furthermore, it was also significantly elevated in old treated, compared with young treated, animals suggesting that increased age affects the sensitivity of epididymal sperm to chromatin damage. There was no difference in apoptosis in testicular germ cells from either young or old control animals, while CP administration resulted in a significant increase in apoptosis among young animals but not old animals. Following genotoxin exposure, an increase in chromatin instability in the spermatozoa of old animals and a decrease in the ability of their testicular germ cells undergo apoptosis suggests an age-related decrease in genome protection mechanisms. Since those germ cells are only transiently present in the testis, it is likely that this age-related deterioration originates in the spermatogonial stem cells. The findings are also evidence that the safety evaluation of reproductive genotoxins should consider young and old individuals separately.

A CRE/ATF-like site in the upstream regulatory sequence of the human interleukin 1 beta gene is necessary for induction in U937 and THP-1 monocytic cell lines.

Transfection of U937 and THP-1 cells with a recombinant plasmid, pIL1(4.0kb)-CAT, containing 4 kb of the interleukin 1 beta (IL-1 beta) gene upstream regulatory sequence resulted in inducer-dependent expression of chloramphenicol acetyltransferase activity. Treatment of the transfected cells with various combinations of the inducers lipopolysaccharide, phorbol myristate acetate, and dibutyryl cyclic AMP upregulated the IL-1 beta promoter. In U937 and THP-1 cells, maximum stimulation of both the endogenous IL-1 beta gene and pIL1(4.0kb)-CAT transfectants was observed following treatment with the combination of inducing agents lipopolysaccharide-phorbol myristate acetate-dibutyryl cyclic AMP. This combination of inducing agents was used to identify and study, at the molecular level, some of the regulatory elements necessary for induction of the IL-1 beta gene. A series of 5' deletion derivatives of the upstream regulatory sequence were used in transient transfection assays to identify an 80-bp fragment located between -2720 and -2800 bp upstream of the mRNA start site that was required for induction. Exonuclease III mapping, electrophoretic mobility shift assays (EMSA), and DNA sequence analysis of this region were used to identify a transcription factor binding sequence which contained a potential cyclic AMP response element (CRE/ATF)- and NF-kappa B-like binding site. Site-directed mutagenesis of the CRE/ATF-like site resulted in the loss of binding of a specific factor or factors as determined by EMSA. The loss of binding activity directly correlated with a loss of approximately 75% of promoter activity as determined in transient transfection assays. As determined by EMSA, the factor binding to the CRE/ATF-like site was present in nuclear extracts prepared from both uninduced and induced THP-1 and U937 cells. However, the intensity of the band appeared to be increased when nuclear extracts from induced cells were used. In contrast to the CRE/ATF mutation, which resulted in the loss of promoter activity, mutation of the NF-kappa B-like site resulted in a moderate increase in activity in U937 cells. A similar increase in promoter activity was not observed in THP-1 cells. From these studies, we conclude that a CRE/ATF-like site and a factor or factors interacting with this site are essential for the maximum induction of the IL-1 beta gene in stimulated U937 and THP-1 cells.

Pasteurella multocida and bovine respiratory disease.

Pasteurella multocida is a pathogenic Gram-negative bacterium that has been classified into three subspecies, five capsular serogroups and 16 serotypes. P. multocida serogroup A isolates are bovine nasopharyngeal commensals, bovine pathogens and common isolates from bovine respiratory disease (BRD), both enzootic calf pneumonia of young dairy calves and shipping fever of weaned, stressed beef cattle. P. multocida A:3 is the most common serotype isolated from BRD, and these isolates have limited heterogeneity based on outer membrane protein (OMP) profiles and ribotyping. Development of P. multocida-induced pneumonia is associated with environmental and stress factors such as shipping, co-mingling, and overcrowding as well as concurrent or predisposing viral or bacterial infections. Lung lesions consist of an acute to subacute bronchopneumonia that may or may not have an associated pleuritis. Numerous virulence or potential virulence factors have been described for bovine respiratory isolates including adherence and colonization factors, iron-regulated and acquisition proteins, extracellular enzymes such as neuraminidase, lipopolysaccharide, polysaccharide capsule and a variety of OMPs. Immunity of cattle against respiratory pasteurellosis is poorly understood; however, high serum antibodies to OMPs appear to be important for enhancing resistance to the bacterium. Currently available P. multocida vaccines for use in cattle are predominately traditional bacterins and a live streptomycin-dependent mutant. The field efficacy of these vaccines is not well documented in the literature.

Pimelea trichostachya poisoning (St George disease) in horses.

A dense population of Pimelea trichostachya plants (Family Thymelaeaceae) in pasture poisoned a horse herd in southern inland Queensland in October-November 2005. Plant density was 2 to 45 g wet weight/m(2) (mean 16 g/m(2)) from 5 to 69 plants/m(2) (mean 38 plants/m(2)) representing 3 to 20% (mean 9%) of the volume of pasture on offer. Ten of 35 mares, fillies and geldings were affected. Clinical signs were loss of body weight, profound lethargy, serous nasal discharge, severe watery diarrhoea and subcutaneous oedema of the intermandibular space, chest and ventral midline. Pathological findings were anaemia, leucocytopenia, hypoproteinaemia, dilatation of the right ventricle of the heart, dilated hepatic portal veins and periportal hepatic sinusoids (peliosis hepatis), alimentary mucosal hyperaemia and oedema of mesenteric lymph nodes. Cattle grazing the same pasture were affected by Pimelea poisoning simultaneously. Removal of the horses to Pimelea-free pasture initiated recovery. The one other incident of this syndrome, previously only recognised in cattle in Australia, occurred in horses, in South Australia in 2002, with access to a dense Pimelea simplex population.

Inhibition by prostacyclin of the tumor cell-induced platelet release reaction and platelet aggregation.

Prostacyclin was examined for its inhibitory effects on the tumor cell-induced platelet release reaction. Prostacyclin inhibited in a dose-dependent manner tumor cell-induced release of platelet dense granules and alpha-granules concomitant with an inhibition of platelet aggregation. Release was determined by assay of biochemical markers (serotonin for dense granules and beta-thromboglobulin for alpha-granules). A tenfold higher concentration of prostacyclin was required to inhibit completely serotonin release as compared to the concentration required for beta-thromboglobulin release. Correlative ultrastructural studies demonstrated that prostacyclin at doses of over 10 ng/ml inhibited the ultrastructural changes associated with tumor cell-induced platelet shape change and platelet granule release. Platelet aggregates exhibited the retention of granule reservoirs that could potentially be involved in long-term release of biologically active substances.

Platelet enhancement of tumor cell adhesion to subendothelial matrix: role of platelet cytoskeleton and platelet membrane.

Platelet involvement during tumor cell adhesion to subendothelial matrix was examined in vitro. Platelets were subjected to thrombin stimulation and mechanical lysis and examined for their effects on tumor cell adhesion. These treatments altered the platelet ultrastructure and cytoskeletal integrity. Untreated washed rat platelets (WRP) exhibited extensive adhesion to and spreading on substrates and substantially enhanced tumor cell adhesion to the same substrates (i.e., 250% greater than tumor cells without platelets). Thrombin prestimulation of platelets limited platelet adhesion and spreading and platelet facilitation of tumor cell adhesion. Complete mechanical lysis disrupted both the platelet membrane and the cytoskeleton and eliminated the ability of platelets to adhere or to enhance tumor cell adhesion. Partially lysed platelets resembled membrane ghosts and facilitated tumor cell adhesion by a mechanism independent of spreading and cytoskeletal rearrangement. Fractionation studies indicated that platelet cytoskeletal components played a role in the adhesion process. Pretreatment of WRP with cytochalasin A or B dose dependently inhibited microfilament-mediated platelet spreading and platelet-enhanced tumor cell adhesion. Colchicine and vinblastine induced microtubule depolymerization, but they had no observable effect on platelet spreading or platelet-enhanced tumor cell adhesion. It was concluded that platelet-enhanced tumor cell adhesion to subendothelial matrix depends on an intact platelet cytoskeleton and on a platelet membrane component(s) and is mediated by surface contact between platelets and tumor cells. Furthermore, platelet-mediated tumor cell adhesion to subendothelial matrix may involve two mechanisms: one dependent on, and one independent of, platelet spreading and cytoskeletal rearrangement.

In vivo characterization of combination antitumor chemotherapy with calcium channel blockers and cis-diamminedichloroplatinum(II).

We have examined nifedipine, a dihydropyridine class calcium channel blocker, for ability to overcome cis-diamminedichloroplatinum(II) (cisplatin) resistance in a murine tumor line variant, B16a-Pt, which we developed for resistance to cisplatin. Nifedipine significantly enhanced the antitumor actions of cisplatin against primary subcutaneous B16a-Pt tumors and their spontaneous pulmonary metastases. We have characterized, in vivo, the pharmacokinetics and dose-response interactions between nifedipine and cisplatin. We now report our studies designed to compare, in vivo, the efficacy of nifedipine and other calcium active compounds including: (a) structurally similar calcium channel blockers (nimodipine, nicardipine) from the dihydropyridine class, (b) structurally different calcium channel blockers from the benzothiazepine (diltiazem) and the phenylalkylamine (verapamil) classes, and (c) calmodulin antagonists (trifluoperazine and calmidazolium) for ability to enhance the antitumor action of cisplatin. Nifedipine was included as the standard or reference compound. In these studies verapamil and diltiazem failed to enhance the antitumor actions of cisplatin as did both calmodulin antagonists. Our findings suggest that nifedipine has a greater degree of specificity for B16a-Pt cells than structurally different calcium channel blockers from other chemical classes (i.e., diltiazem and verapamil), or the two calmodulin antagonists (i.e., trifluoperazine and calmidazolium). We concluded that nifedipine interacts with specific target site(s) which are not accessible by verapamil, by diltiazem, or by the calmodulin antagonists. Surprisingly, the two dihydropyridine class calcium channel blockers, nimodipine and nicardipine, also failed to enhance cisplatin's antitumor actions despite the fact that their specificity and kinetics for binding to the dihydropyridine receptor component of the calcium channel favors them (nimodipine and nicardipine) over nifedipine. Therefore, we postulate that the synergism between cisplatin and nifedipine is independent of the latter's effect on the voltage sensitive, slow inward calcium channel. We suggest that cisplatin cytotoxicity is enhanced by nifedipine's interaction with an as yet unidentified specific "target site," as opposed to nonspecific interactions with the tumor cell plasma membrane or specific interactions with calmodulin or the P-glycoprotein (which is responsible for pleiotropic resistance).