Analysis of cytosolic isocitrate dehydrogenase and glutathione reductase 1 in photoperiod‐influenced responses to ozone using Arabidopsis knockout mutants

Oxidative stress caused by ozone (O₃) affects plant development, but the roles of specific redox‐homeostatic enzymes in O₃ responses are still unclear. While growth day length may affect oxidative stress outcomes, the potential influence of day length context on equal‐time exposures to O₃ is not known. In Arabidopsis Col‐0, day length affected the outcome of O₃ exposure. In short‐days (SD), few lesions were elicited by treatments that caused extensive lesions in long days (LD). Lesion formation was not associated with significant perturbation of glutathione, ascorbate, NADP(H) or NAD(H). To investigate roles of two genes potentially underpinning this redox stability, O₃ responses of mutants for cytosolic NADP‐isocitrate dehydrogenase (icdh) and glutathione reductase 1 (gr1) were analysed. Loss of ICDH function did not affect O₃‐induced lesions, but slightly increased glutathione oxidation, induction of other cytosolic NADPH‐producing enzymes and pathogenesis‐related gene 1 (PR1). In gr1, O₃‐triggered lesions, salicylic acid accumulation, and induction of PR1 were all decreased relative to Col‐0 despite enhanced accumulation of glutathione. Thus, even at identical irradiance and equal‐time exposures, day length strongly influences phenotypes triggered by oxidants of atmospheric origin, while in addition to its antioxidant function, the GR‐glutathione system seems to play novel signalling roles during O₃ exposure.     

Phylogenetic signal in bone histology of amniotes revisited

Legendre, L, Le Roy, N, Martinez‐Maza, C, Montes, L, Laurin, M & Cubo, J. (2012). Phylogenetic signal in bone histology of amniotes revisited. —Zoologica Scripta, 42, 44–53. There is currently a debate about the presence of a phylogenetic signal in bone histological data, but very few rigorous tests have fuelled the discussions on this topic. Here, we performed new analyses using a larger set of seven histological traits and including 25 taxa (nine extinct and 16 extant taxa), using three methods: the phylogenetic eigenvector regression, the tree length distribution and the regressions on distance matrices. Our results clearly show that the phylogenetic signal in our sample of bone histological characters is strong, even after correcting for multiple testing. Most characters exhibit a significant phylogenetic signal according to at least one of our three tests, with the phylogeny often explaining 20–60% of the variation in the histological characters. Thus, we conclude that the phylogenetic comparative method should be systematically used in interspecific analyses of bone histodiversity to avoid problems of non‐independence among observations.     

Decidualisation in the Prepuberal Rat Uterus

Decidualisation has been experimentally induced in the prepuberal rat. It is morphologically similar to that obtained in the adult. The cytodifferentiation includes the formation of binucleated cells and extensive specialised cellular junctions.
Furthermore, blastocysts from adults transferred into uterine horns of immature specimens implant and develop, indicating that the decidual response they induce is functionally comparable to the uterine response at the time of nidation in the fertilised adult.
The model of the experimental decidual induction in the immature is used to study the ontogenic processes of uterine maturation. Preliminary observations indicate that the 7–10-days period might be of significance in the maturation of the rat uterus.     

Monitoring the impact of climate change on biodiversity: The challenge of megadiverse Mediterranean climate ecosystems

The Mediterranean climate regions of Western Australia and South Africa are recognized as global hot spots of diversity. Both are threatened by climate changes that are projected to have significant impacts on the quantity and variability of rainfall and affect key ecosystem drivers (e.g. fire regimes). This poses significant challenges to monitoring programs designed to detect these impacts. Effective monitoring of the impact of climate change on biodiversity (rather than individual species) requires a cross‐disciplinary, coordinated, focused and integrated approach. Ideally, this should involve a multidisciplinary team of specialists working to a common plan on the same set of plots. The contributions of ‘citizen scientists’ are potentially useful if well managed. Biodiversity per se (across all kingdoms of life, and including the levels of the gene, population and community) should be monitored, especially key species interactions and processes. Forestcheck is an example of such a program which has been applied in forests in south‐west Western Australia since 2001. In concert with measuring the direct impact of climate change on biodiversity and the indirect impact of factors that affect biodiversity (such as disease, invasive species, fire regime and habitat removal), there is a need for a proactive focus on creating, maintaining and monitoring resilience to climate change impacts in ecosystems. It is also necessary to monitor the effectiveness of management actions such as vegetation thinning, changes in fire regimes, species translocations and revegetation of farmland to link isolated protected areas in agricultural landscapes, remnant native vegetation in rangelands and extensive protected areas. A pluralist approach is recommended. This should include natural experiments, matched photographs where available, passive adaptive management, active adaptive management and traditional reductionist scientific investigation. The resultant synthesis of information from this range of sources is likely to be a predictive, robust and credible record of historical change.     

Revision of the lygaeid genera Porta and Primierus (Hemiptera: Heteroptera), with the description of a new genus of Ozophorini from Papua New Guinea (Hemiptera)

Abstract. The lygaeid genera Porta Distant and Primierus Distant are revised and placed in the tribe Ozophorini. A key to all species is included. Phylogenetic relationships are discussed and a cladogram constructed. The following new species are described: Porta illustris (Philippines); P.longipes (Sabah), Primierus quadrispinosus (Sarawak, Sabah, Malaya), P.venustus (Sabah), and P.longirostris (Thailand). Gressittocoris intimidator is described as a new genus and species of Ozophorini from Papua New Guinea. Porta gracilis Distant is reported from Sabah, Sumatra and Thailand for the first time and records of P.gracilis from the Philippines are referred to Porta illustris sp.n. Illustrations include details of the genitalia and dorsal views of Primierus quadrispinosus, P.longirostris and Gressittocoris intimidator.