Life cycle of the Early Cambrian acritarchs

XV lnternational A.P.L.E. Symposium of Palynolog

A Single-Tube HNB-Based Loop-Mediated Isothermal Amplification for the Robust Detection of the Ostreid Herpesvirus 1

The Ostreid herpesvirus 1 species affects shellfish, contributing significantly to high economic losses during production. To counteract the threat related to mortality, there is a need for the development of novel point-of-care testing (POCT) that can be implemented in aquaculture production to prevent disease outbreaks. In this study, a simple, rapid and specific colorimetric loop-mediated isothermal amplification (LAMP) assay has been developed for the detection of Ostreid herpesvirus1 (OsHV-1) and its variants infecting Crassostrea gigas (C. gigas). The LAMP assay has been optimized to use hydroxynaphthol blue (HNB) for visual colorimetric distinction of positive and negative templates. The effect of an additional Tte UvrD helicase enzyme used in the reaction was also evaluated with an improved reaction time of 10 min. Additionally, this study provides a robust workflow for optimization of primers for uncultured viruses using designed target plasmid when DNA availability is limited.info:eu-repo/semantics/publishedVersio

Early sponges and toxic protists: Possible sources of cryostane, an age diagnostic biomarker antedating Sturtian Snowball Earth

The period 800-717 million years (Ma) ago, in the lead-up to the Sturtian Snowball glaciation, saw an increase in the diversity of eukaryotic microfossils. To afford an independent and complementary view of this evolutionary period, this study presents the distribution of eukaryotic biomarkers from three pre-Sturtian successions across the supercontinent Rodinia: the ca. 780 Ma Kanpa Formation of the Western Australian Officer Basin, the ca. 800-740 Ma Visingsö Group of Sweden, and the 740 Ma Chuar Group in Arizona, USA. The distribution of eukaryotic steranes is remarkably similar in the three successions but distinct from all other known younger and older sterane assemblages. Cholestane was the only conventional structure, while indigenous steranes alkylated in position C-24, such as ergostane, stigmastane, dinosterane and isopropylcholestane, and n-propylcholestane, were not observed. This sterane distribution appears to be age diagnostic for the pre-Sturtian Neoproterozoic. It attests to the distinct evolutionary state of pre-Snowball eukaryotes, pointing to a taxonomic disparity that was still lower than in the Ediacaran (635-541 Ma). All three basins also show the presence of a new C28 sterane that was tentatively identified as 26-methylcholestane, here named cryostane. The only known extant organisms that can methylate sterols in the 26-position are demosponges. This assignment is plausible as molecular clocks place the appearance of the earliest animals into the pre-Sturtian Neoproterozoic. The unusual 26-methylsterol may have protected sponges, but also other eukaryotes, against their own membranolytic toxins. Some protists release lytic toxins to deter predators and kill eukaryotic prey. As conventional membrane sterols can be the site of attack for these toxins, sterols with unusual side-chain modification protect the cell. This interpretation of cryostane supports fossil evidence of predation in the Chuar Group and promotes hypotheses about the proliferation of eukaryophagy in the lead-up to the Cryogenian

HIF-1 α as a Key Factor in Bile Duct Ligation-Induced Liver Fibrosis in Rats

Background: Although several studies suggested hypoxia as an important microenvironmental factor contributing to inflammation and fibrosis in chronic liver diseases, the mechanism of this process is not fully understood. We considered hypoxia inducible factor (HIF-1α) as a key transcription factor in liver fibrosis. The aim of the study was to evaluate the mechanisms of signaling pathway during bile duct ligation (BDL)-induced liver fibrosis in rats. Methods: BDL animal model of liver fibrosis was used in the study. Male Wistar rats were divided randomly into two experimental groups: sham group (n = 15), BDL group (n = 30). Hydroxyproline (Hyp) content as a marker of collagen accumulation in liver of rats subjected to BDL was evaluated according to the method described by Gerling B et al. Expression of signaling proteins [integrin β1 receptor, HIF-1α, nuclear factor kappa B (NF-κB), and transforming growth factor (TGF-β)] was evaluated applying Western-immunoblot analysis. In all experiments, the mean values for six assays ± standard deviations (SD) were calculated. The results were submitted to the statistical analysis using the Student's “t” test, accepting p < 0.05 as significant. Results: Ligation of bile ducts was found to increase Hyp content in rat liver, accompanied by increase of HIF-1α expression during 10 weeks after BDL. The Hyp level was time dependent. There was not such a difference in control group (p < 0.001). Simultaneously expression of NF-κB, TGF-β, β1-integrin receptor was significantly elevated starting from sixth week after ligation. Activity of metalloproteinases 2 and 9 in the livers were increased 1 week after surgery and remained increased until the end of the experiment. Conclusions: The mechanism of development of liver fibrosis involves activation of Matrix metalloproteinase-2 (MMP-2) and Matrix metalloproteinase-9 (MMP-9), upregulation of HIF-1α transcriptional activity and its related factors, NF-κB and TGF-β. It suggests that they may represent targets for the treatment of the disease