Cryopreservation and thawing of hematopoietic stem cell CD34-induced apoptosis through caspase pathway activation: Key role of granulocytes

IntroductionCell damage inescapably occurs during both the freezing and the thawing graft processes for autologous hematopoietic stem cell (HSC) transplantation. To estimate HSC injury, a quality control is performed including: (i) CD34⁺ quantification; (ii) percentage of CD34⁺ viability and (iii) evaluation of HSC functional ability to form colony forming unit–granulocyte macrophage (CFU-GM). Apoptosis involves complex pathways such as caspase enzymes. Here, we assess the extent of apoptosis that is caspase-dependent before and after cryoconservation of CD34⁺, using a Fluorescent Labeled Inhibitor of CAspases (FLICA).MethodsCaspase pathway activation status was evaluated in 46 patients (multiple myeloma [n = 24], lymphoma [n = 22]), by flow cytometry, using a 7-aminoactinomycin-D (7AAD)/FLICA staining test, in CD34⁺, CD3⁺, CD14⁺ and CD56⁺ cells. Viable 7AAD^?/FLICA⁺ cells were then correlated with various parameters.ResultsWe showed a significant caspase pathway activation, with 23% CD34⁺/7AAD^?/FLICA⁺ cells after thawing, compared with the 2% described in fresh CD34⁺ cells (P < 0.0001). Moreover, caspase pathway was significantly activated in thawing CD3⁺, CD56⁺ and CD14⁺ cells. We also report a significant correlation between the rate of CD34⁺/7AAD^?/FLICA⁺ cells and post-thawing granulocytes count (P = 0.042) and their potential to be differentiated into CFU-GM (P = 0.004).DiscussionOur results show substantial cell death, induced by the increase of caspase pathway activation, secondary to the thawing process, and across all study cell types. This observation may affect the immune response quality during recipient aplasia, without detecting a clinical impact. Moreover, caspase pathway activation through CD3⁺ and CD56⁺ subpopulations could modify the therapeutic result of donor lymphocytes infusion (DLI).     

Endemic evolutionary radiation of Rhagada land snails (Pulmonata: Camaenidae) in a continental archipelago in northern Western Australia

In the Dampier Archipelago of Western Australia's Pilbara Region, several locally endemic, morphologically distinctive species of Rhagada land snails occur, contrasting with the morphologically conservative species with wider distributions on the adjacent mainland. To test alternative origins of this unusual local diversity in a continental archipelago, we examined sequences of the cytochrome oxidase subunit 1 and 16S mitochondrial genes in 22 described species and eight undescribed forms, including all known morphospecies from the Pilbara Region's Dampier Archipelago and adjacent mainland. Phylogenetic analyses consistently resolved four, deep clades within the Pilbara Region, with a mean sequence divergence of 15–18%. All but one of the species from the Dampier Archipelago formed one of the major clades, indicating that the morphological radiation in the archipelago evolved locally, rather than through multiple, relictual mainland lineages. Morphological divergence spanning almost that of the entire genus was within a subclade with sequence divergence < 4%, highlighting the disconnection between morphological diversification and levels of molecular genetic divergence. This in situ morphological radiation in the Dampier Archipelago, which transcends variation seen over much larger distances on the mainland, is unusual for a continental archipelago, and may relate to local heterogeneity of land forms. © 2012 The Linnean Society of London, Biological Journal of the Linnean Society, 2012, 106 , 316–327.     

Drilling and crushing predation on scaphopods from the Miocene of the Netherlands

Klompmaker, A.A. 2011: Drilling and crushing predation on scaphopods from the Miocene of the Netherlands. Lethaia, Vol. 44, pp. 429–439. Reports on the predators of scaphopods are rare. This study records two types of predation traces on the Miocene dentaliid scaphopod Fissidentalium sp. from Langenboom in the Netherlands. The first type is demonstrated by naticid drillholes, located primarily on the middle (and thickest) part of the shell. Based on the examination of more than 700 specimens, the percentage of completely drilled scaphopods is low, at 1%. This is in line with the first graphical overview of drilling percentages on scaphopods through time. The second type of predation is found as jagged, arcuate margins at the functionally anterior end of a significant part of the scaphopod population. These breakages were not caused by pressure due to overburden, as experimental results indicate that such breakages form at right angles to the longitudinal axis of the shell. Reworking was also ruled out, mainly because the breakages were formed at the anterior end of the shell only. Rather, the damage is attributed to carnivorous decapods chipping/peeling with their claws or mandibles. The predation traces suggest that Fissidentalium sp. was a shallow burrower. □Scaphopoda, drillholes, predators, Miocene, the Netherlands, Langenboom     

Blood Biochemistry of Sea Turtles Captured in Gillnets in the Lower Cape Fear River,North Carolina,USA

ABSTRACT Mortality due to fisheries interactions has been implicated as a contributor to population decline for several species of sea turtle. The incidental capture of sea turtles in the coastal gillnet fisheries of North Carolina, USA, has received much attention in recent years, and mitigation measures to reduce sea turtle mortality due to gillnet entanglement are a high priority for managers and conservationists. Efforts to evaluate effects of gillnet entanglement on sea turtle populations are complicated by the lack of information on health status of turtles released alive from nets and postrelease mortality. We obtained blood samples from green (Chelonia mydas) and Kemp's ridley (Lepidochelys kempii) sea turtles captured in gillnets for 20–240 minutes to assess the impacts of gillnet entanglement on blood biochemistry and physiological status. We measured concentrations of lactate, corticosterone, ions (Na⁺, K⁺, Cl^-, P, Ca²⁺), enzymes (lactate dehydrogenase [LDH], creatine phosphokinase [CPK], aspartate aminotransferase [AST]), protein, and glucose in the blood and also performed physical examinations of turtles to document external indicators of health status (injuries, lethargy, muted reflexes). We evaluated the effects of entanglement time on blood biochemistry and to look for correlations between blood biochemistry and results of the physical examinations. We observed a significant increase in blood lactate, LDH, CPK, phosphorus, and glucose with increased entanglement time. Alterations in blood biochemistry were generally associated with a decline in health status as indicated by results of the physical examination. Although entanglement time plays an important role in determining the health status of sea turtles upon release from a gillnet, our results suggest that factors such as the depth and severity of entanglement may also have an effect on health status of turtles and the probability of postrelease survival. We were unable to set a maximum unattended gillnet soak time to minimize impacts on captured sea turtles, and therefore recommend that fisheries managers continue to enforce the net attendance regulations currently in place in the lower Cape Fear River, North Carolina, during the summer months.     

Effects of fine‐scale genetic structure on male mating success in gynodioecious Beta vulgaris ssp. maritima

Plant mating systems are known to influence population genetic structure because pollen and seed dispersal are often spatially restricted. However, the reciprocal outcomes of population structure on the dynamics of polymorphic mating systems have received little attention. In gynodioecious sea beet (Beta vulgaris ssp. maritima), three sexual types co‐occur: females carrying a cytoplasmic male sterility (CMS) gene, hermaphrodites carrying a non‐CMS cytoplasm and restored hermaphrodites that carry CMS genes and nuclear restorer alleles. This study investigated the effects of fine‐scale genetic structure on male reproductive success of the two hermaphroditic forms. Our study population was strongly structured and characterized by contrasting local sex‐ratios. Pollen flow was constrained over short distances and depended on local plant density. Interestingly, restored hermaphrodites sired significantly more seedlings than non‐CMS hermaphrodites, despite the previous observation that the former produce pollen of lower quality than the latter. This result was explained by the higher frequency of females in the local vicinity of restored (CMS) hermaphrodites as compared to non‐CMS hermaphrodites. Population structure thus strongly influences individual fitness and may locally counteract the expected effects of selection, suggesting that understanding fine scale population processes is central to predicting the evolution of gender polymorphism in angiosperms.     

Postzygotic isolation between the two European subspecies of the house mouse: estimates from fertility patterns in wild and laboratory-bred hybrids

We assessed the fertility (reproductive success, litter size, testis weight, spermatocyte-to-spermatid ratio) of F₁s and backcrosses between different wild-derived outbred and inbred strains of two mouse subspecies, Mus musculus domesticus and M. m. musculus . A significant proportion of the F₁ females between the outbred crosses did not reproduce, suggesting that female infertility was present. As the spermatocyte-to-spermatid ratio was correlated with testis weight, the latter was used to attribute a sterile vs. fertile phenotype to all males. Segregation proportions in the backcrosses of F₁ females yielded 11 (inbred) to 17% (outbred) sterile males, suggesting the contribution of two to three major genetic factors to hybrid male sterility. Only one direction of cross between the inbred strains produced sterile F₁ males, indicating that one factor was borne by the musculus X-chromosome. No such differences were observed between reciprocal crosses in the outbred strains. The involvement of the X chromosome in male sterility thus could not be assessed, but its contribution appears likely given the limited introgression of X-linked markers through the hybrid zone between the subspecies. However, we observed no sterile phenotypes in wild males from the hybrid zone, although testis weight tended to decrease in the centre of the transect.  © 2005 The Linnean Society of London, Biological Journal of the Linnean Society , 2005, 84 , 379–393.     

Climate‐induced changes in the distribution of freshwater fish: observed and predicted trends

1. Climate change could be one of the main threats faced by aquatic ecosystems and freshwater biodiversity. Improved understanding, monitoring and forecasting of its effects are thus crucial for researchers, policy makers and biodiversity managers. 2. Here, we provide a review and some meta‐analyses of the literature reporting both observed and predicted climate‐induced effects on the distribution of freshwater fish. After reviewing three decades of research, we summarise how methods in assessing the effects of climate change have evolved, and whether current knowledge is geographically or taxonomically biased. We conducted multispecies qualitative and quantitative analyses to find out whether the observed responses of freshwater fish to recent changes in climate are consistent with those predicted under future climate scenarios. 3. We highlight the fact that, in recent years, freshwater fish distributions have already been affected by contemporary climate change in ways consistent with anticipated responses under future climate change scenarios: the range of most cold‐water species could be reduced or shift to higher altitude or latitude, whereas that of cool‐ and warm‐water species could expand or contract. 4. Most evidence about the effects of climate change is underpinned by the large number of studies devoted to cold‐water fish species (mainly salmonids). Our knowledge is still incomplete, however, particularly due to taxonomic and geographic biases. 5. Observed and expected responses are well correlated among families, suggesting that model predictions are supported by empirical evidence. The observed effects are of greater magnitude and show higher variability than the predicted effects, however, indicating that other drivers of changes may be interacting with climate and seriously affecting freshwater fish. 6. Finally, we suggest avenues of research required to address current gaps in what we know about the climate‐induced effects on freshwater fish distribution, including (i) the need for more long‐term data analyses, (ii) the assessment of climate‐induced effects at higher levels of organisation (e.g. assemblages), (iii) methodological improvements (e.g. accounting for uncertainty among projections and species’ dispersal abilities, combining both distributional and empirical approaches and including multiple non‐climatic stressors) and (iv) systematic confrontation of observed versus predicted effects across multi‐species assemblages and at several levels of biological organisation (i.e. populations and assemblages).     

A role for oxalic acid generation in ozone‐induced signallization in Arabidopis cells

Ozone (O₃) is an air pollutant with an impact increasingly important in our industrialized world. It affects human health and productivity in various crops. We provide the evidences that treatment of Arabidopsis thaliana with O₃ results in ascorbate‐derived oxalic acid production. Using cultured cells of A. thaliana as a model, here we further showed that oxalic acid induces activation of anion channels that trigger depolarization of the cell, increase in cytosolic Ca²⁺ concentration, generation of reactive oxygen species and cell death. We confirmed that O₃ reacts with ascorbate in the culture, thus resulting in production of oxalic acid and this could be part of the O₃‐induced signalling pathways that trigger programmed cell death.     

Microsatellite DNA markers for Lysiphlebus testaceipes

Microsatellite loci were isolated from the aphid parasitoid Lysiphlebus testaceipes (Hymenoptera: Braconidae). Ten loci were obtained from an enriched partial genomic library. Genetic diversity was analysed at seven of these loci and two natural populations, one on oleander and one on citrus. The observed number of alleles ranged from one to 17, and the observed heterozygosity ranged from 0.37 to 0.82. In both populations, no departure from Hardy–Weinberg equilibrium was detected except for one locus. The differentiation between the two populations was characterized by an F_ST of 0.09.