Nature and Inheritance of Nematode Resistance in Cereals

Resistance to a number of nematodes is present in varieties of temperate and tropical cereals. The occurrence, nature, and inheritance of varietal resistance in cereals is reviewed. Evaluation of the practical significance of nematode resistance in a particular host-nematode combination is discussed in relation to host efficiency, host sensitivity, genetic control of resistance, and presence of virulence in the nematode population.     

Use of plastics for suspension culture vessels

Summary Plastic containers were found to facilitate the adaptation of a number of mammalian cell lines derived from normal tissues to growth in continuous suspension culture. Several different types of plastic materials were studied and a variety of culture vessels were designed.     

Tissue Matching and Early Rejection of Cadaveric-Donor Renal Allografts: The Importance of Unidentified Donor Antigens

Tissue typing has been reviewed in a series of 100 technically successful cadaveric-donor kidney grafts. The criterion of transplant failure was immunological rejection causing total loss of function within three months of operation.No significant correlation was observed between matching grade and graft failure due to early acute rejection. This is attributed to the failure to detect at least one “LA” or “4” antigen (as defined in our laboratory), representing a potential incompatibility, in 89% of the grafts, and in the remaining 11% to the lack of an available recipient with identical “LA” and “4” typing. Undetected antigens on the donor are usually incompatible, and probably these incompatibilities unfavourably influence early graft survival.If the results of cadaveric-donor renal transplantation are to equal those of transplantation from well-matched living related donors it will be necessary to type with sera which can recognize individually all HL-A antigens, including those not yet identified, and to create an international pool of over 1,000 potential recipients.     

Evaluating automated infrared thermography and vulva exposure tracking as components of an estrus detection platform in a commercial dairy herd

The primary objective of this study was to develop an automated infrared thermography platform (Estrus BenchMark) capable of measuring skin temperature and tail movements as a means of identifying cows in estrus. The secondary objective was to evaluate the accuracy of Estrus BenchMark to detect estrus compared to in-line milk progesterone (P₄) analysis (Herd Navigator System) in a commercial dairy herd managed under a robotic milking system. Data were collected on forty-six cows from 45 to 120 d after calving. Cows were flagged in estrus when milk P₄ fell below 5 ng/mL. The Estrus BenchMark true positive estrus alerts (Sensitivity; Se%) were compared to Herd Navigator System estrus alerts at different time-windows (±12 h, ±24 h, ±48 h, and ±72 h) relative to the Estrus BenchMark estrus alerts for all the estrus alerts (AE) and confidence-quality estrus (CQE; >80% quality) alerts identified by Herd Navigator System. The Estrus BenchMark captured skin temperature and tail movements resulting in vulva exposure (left tail movements, LTail; right tail movements, RTail; and pooled tail movements, PTail) for each milking event. Skin temperature tended to increase when the milk P₄ concentration (Least-Squares Means ± SE) dropped for AE (estrus day [d 0]; P₄; 3.51 ± 0.05 ng/mL, Skin temperature; 33.31 ± 2.38 °C) compared with d ?7 (P₄; 20.22 ± 0.73 ng/mL; Skin temperature: 32.05 ± 3.77 °C). The increase in skin temperature, however, was significant in cows with CQE > 80% at d 0 (32.75 ± 0.29 °C) compared to d ?7 (31.80 ± 0.28 °C). The prevalence of tail movements to expose vulva was greater (P = 0.01) in AE at d 0 (LTail: 62.50%; PTail; 68.75%; and RTail: 56.25%) compared with d ?7 (LTail: 18.75%; PTail: 9.37%: and RTail: 9.37%), and d +4 (LTail: 9.37%; PTail: 9.37%; and RTail: 12.5%). Moreover, the higher prevalence of tail movements at d 0 was observed in cows with CQE > 80% (LTail; 65%, PTail; 80%, and RTail; 70%) compared to those with CQE < 80%. The highest Estrus BenchMark Youden index (YJ; 0.45), diagnostic odds ratio (DOR; 9.04), and Efficiency (0.77) were achieved for AE in a ±48 h window and at ±72 h window for CQE (YJ; 0.66, DOR; 25.29, and Efficiency 0.76) relative to Herd Navigator System estrus alerts. The highest Estrus BenchMark resulted in 58% estrus detection rates for AE and 80% for cows with CQE compared to the Herd Navigator System.     

When close neighbours become good friends: plasticity of behavioural traits in sympatric fishes that form mono- and mixed-species groups

Like mono-species fish groups, formation of mixed-species assemblages is likely driven by trophic influences and interspecific behavioural traits. Our aim was to identify how sympatric estuarine species of differing phenotypes form mixed-species group associations, and to identify changes to group structure of fish that migrate between mono- and mixed-species groups. We used sympatric yellow-eyed mullet (Aldrichetta forsteri), kahawai (Arripis trutta), and Australian snapper (Chrysophrys auratus), representing different phenotypes for the mixed-species group, and yellow-eyed mullet for the mono- and mixed-species comparison. Group formation and structure was quantified in predator and foraging treatment groups. We used previous research in mono-species yellow-eyed mullet to compare behavioural plasticity with the current study. Our novel results suggest similar behavioural traits in mono- and mixed-species fish groups have beneficially co-evolved and importantly, behavioural plasticity is necessary for migration between groups. Overall, our observations highlight key behavioural responses associated with mixed-species fish formations in estuarine ecosystems.     

Wolbachia infection and dramatic intraspecific mitochondrial DNA divergence in a fig wasp

Mitochondria and Wolbachia are maternally inherited genomes that exhibit strong linkage disequilibrium in many organisms. We surveyed Wolbachia infections in 187 specimens of the fig wasp species, Ceratosolen solmsi, and found an infection prevalence of 89.3%. DNA sequencing of 20 individuals each from Wolbachia-infected and -uninfected subpopulations revealed extreme mtDNA divergence (up to 9.2% and 15.3% in CO1 and cytochrome b, respectively) between infected and uninfected wasps. Further, mtDNA diversity was significantly reduced within the infected group. Our sequencing of a large part of the mitochondrial genome from both Wolbachia-infected and -uninfected individuals revealed that high sequence divergence is common throughout the mitochondrial genome. These patterns suggest a partial selective sweep of mitochondria subsequent to the introduction of Wolbachia into C. solsmi, by hybrid introgression from a related species.     

Elevated carbon dioxide blunts mammalian cAMP signaling dependent on inositol 1,4,5-triphosphate receptor-mediated Ca2+ release

Elevated CO(2) is generally detrimental to animal cells, suggesting an interaction with core processes in cell biology. We demonstrate that elevated CO(2) blunts G protein-activated cAMP signaling. The effect of CO(2) is independent of changes in intracellular and extracellular pH, independent of the mechanism used to activate the cAMP signaling pathway, and is independent of cell context. A combination of pharmacological and genetic tools demonstrated that the effect of elevated CO(2) on cAMP levels required the activity of the IP(3) receptor. Consistent with these findings, CO(2) caused an increase in steady state cytoplasmic Ca(2+) concentrations not observed in the absence of the IP(3) receptor or under nonspecific acidotic conditions. We examined the well characterized cAMP-dependent inhibition of the isoform 3 Na(+)/H(+) antiporter (NHE3) to demonstrate a functional relevance for CO(2)-mediated reductions in cellular cAMP. Consistent with the cellular biochemistry, elevated CO(2) abrogated the inhibitory effect of cAMP on NHE3 function via an IP(3) receptor-dependent mechanism.     

Long term nutrient loads and chlorophyll dynamics in a large temperate Australian lagoon system affected by recurring blooms of cyanobacteria

While rare globally, blooms of the toxic cyanobacteria Nodularia spumigena are a recurring problem in a few estuaries, such as the Baltic Sea and several southern Australian estuaries. Here, we document recurring Nodularia spumigena Mertens blooms in the Gippsland Lakes, S.E. Australia; a temperate lagoon system with episodic, winter-spring dominated catchment inflows. Physico-chemical conditions exerted a strong influence over bloom development, with blooms consistently occurring at surface water salinities between 9 and 20 (average?=?15), inorganic nitrogen concentrations <0.4?μM, and inorganic nitrogen to reactive phosphorus ratios <5. There was a positive correlation between average annual chlorophyll a and total phosphorus (TP) load in years when there was no Nodularia bloom, but this relationship broke down in Nodularia bloom years, even though there was a strong correlation between in-lake TP and chlorophyll a during these years; this highlights the importance of internal sources of phosphorus to bloom development. Large catchment derived nitrate and nitrite (NO_x) inputs following wildfires and floods in 2007, led to high concentrations of NO_x within the surface waters of the Gippsland Lakes through the second half of 2007 and the start of 2008. We hypothesise that these high NO_x concentrations were a key factor leading to an unprecedented Synechococcus sp. bloom that developed in the austral summer of 2007–2008, despite conditions that would otherwise favour a Nodularia bloom.