Phagocytic function in cyclists: correlation with catecholamines and cortisol.

Flow cytometer measurements were made of the basal variations in peripheral blood functional monocytes and granulocytes over the course of a training season (January to November) of a cycling team. Parallel determinations were made of plasma concentration of catecholamines (chromatography) and cortisol (RIA) in a search for neuroendocrine markers. The results showed the greatest phagocytic capacity to occur in the central months (March, May, and July), coinciding with the greatest number and highest level of competitive events with good correlation with a peak in epinephrine during these months (r(2) = 0.998 for monocytes and r(2) = 0.674 for granulocytes). No good correlations were found between phagocytosis and norepinephrine or cortisol. The highest values for phagocytosis and epinephrine concentration were found in May. These results suggest that blood epinephrine concentration could be a good neuroendocrine marker of sportspeople's phagocytic response.     

Evolution of green lacewings (Neuroptera: Chrysopidae): a molecular supermatrix approach

We present a time‐calibrated phylogeny of the charismatic green lacewings (Neuroptera: Chrysopidae). Previous phylogenetic studies on the family using DNA sequences have suffered from sparse taxon sampling and/or limited amounts of data. Here we combine all available previously published DNA sequence data and add to it new DNA sequences generated for this study. We analysed these data in a supermatrix using Bayesian and maximum likelihood methods and provide a phylogenetic hypothesis for the family that recovers strong support for the monophyly of all subfamilies and resolves relationships among a large proportion of chrysopine genera. Chrysopinae tribes Leucochrysini and Belonopterygini were recovered as monophyletic sister clades, while the species‐rich tribe Chrysopini was rendered paraphyletic by Ankylopterygini. Relationships among the subfamilies were resolved, although with relatively low statistical support, and the topology varied based on the method of analysis. Greatest support was found for Apochrysinae as sister to Nothochrysinae and Chrysopinae, which is in contrast to traditional concepts that place Nothochrysinae as sister to the rest of the family. Divergence estimates suggest that the stem groups to the various subfamilies diverged during the Triassic‐Jurassic, and that stem groups of the chrysopine tribes diverged during the Cretaceous.     

A predictive model for freshwater bioassessment (Mondego River,Portugal)

We sampled macroinvertebrates at 75 locations in the Mondego river catchment, Central Portugal, and developed a predictive model for water quality assessment of this basin, based on the Reference Condition Approach. Sampling was done from June to September 2001. Fifty-five sites were identified as “Reference sites” and 20 sites were used as “Test sites” to test the model. At each site we also measured 40 habitat variables to characterize water physics and chemistry, habitat type, land use, stream hydrology and geographic location. Macroinvertebrates were generally identified to species or genus level; a total of 207 taxa were found. By Unweighted Pair Group Method with Arithmetic mean (UPGMA) clustering and analysis of species contribution to similarities percentage (SIMPER), two groups of reference sites were established. Using Discriminant Analysis (stepwise forward), four variables correctly predicted 78% of the reference sites to the appropriate group: stream order, pool quality, substrate quality and current velocity. Test sites’ environmental quality was established from their relative distance to reference sites, in MDS ordination space, using a series of bands (BEAST methodology). The model performed well at upstream sites, but at downstream sites it was compromised by the lack of reference sites. As with the English RIVPACS predictive model, the Mondego model should be continually improved with the addition of new reference sites. The adaptation of the Mondego model methodology to the Water Framework Directive is possible and would consist mainly of the integration of the WFD typology and increasing the number of ellipses that define quality bands. Handling editor: K. Martens     

Ionotropic Receptors as a Driving Force behind Human Synapse Establishment

The origin of nervous systems is a main theme in biology and its mechanisms are largely underlied by synaptic neurotransmission. One problem to explain synapse establishment is that synaptic orthologs are present in multiple aneural organisms. We questioned how the interactions among these elements evolved and to what extent it relates to our understanding of the nervous systems complexity. We identified the human neurotransmission gene network based on genes present in GABAergic, glutamatergic, serotonergic, dopaminergic, and cholinergic systems. The network comprises 321 human genes, 83 of which act exclusively in the nervous system. We reconstructed the evolutionary scenario of synapse emergence by looking for synaptic orthologs in 476 eukaryotes. The Human–Cnidaria common ancestor displayed a massive emergence of neuroexclusive genes, mainly ionotropic receptors, which might have been crucial to the evolution of synapses. Very few synaptic genes had their origin after the Human–Cnidaria common ancestor. We also identified a higher abundance of synaptic proteins in vertebrates, which suggests an increase in the synaptic network complexity of those organisms.     

Genome-wide CRISPR Screens Reveal Host Factors Critical for SARS-CoV-2 Infection

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Murine Cytomegalovirus m02 Gene Family Protects against Natural Killer Cell-Mediated Immune Surveillance

The murine cytomegalovirus m02 gene family encodes putative type I membrane glycoproteins named m02 through m16. A subset of these genes were fused to an epitope tag and cloned into an expression vector. In transfected and murine cytomegalovirus-infected cells, m02, m04, m05, m06, m07, m09, m10, and m12 localized to cytoplasmic structures near the nucleus, whereas m08 and m13 localized to a filamentous structure surrounding the nucleus. Substitution mutants lacking the m02 gene (SMsubm02) or the entire m02 gene family (SMsubm02-16) grew like their wild-type parent in cultured cells. However, whereas SMsubm02 was as pathogenic as the wild-type virus, SMsubm02-16 was markedly less virulent. SMsubm02-16 produced less infectious virus in most organs compared to wild-type virus in BALB/c and C57BL/6J mice, but it replicated to wild-type levels in the organs of immunodeficient gamma(c)/Rag2 mice, lacking multiple cell types including natural killer cells, and in C57BL/6J mice depleted of natural killer cells. These results argue that one or more members of the m02 gene family antagonize natural killer cell-mediated immune surveillance.     

Poly(ADP-ribose) polymerase forms loops with DNA

The interaction between highly purified poly(ADP-ribose) polymerase from calf thymus and different topological forms of pBR322 DNA has been studied by gel retardation electrophoresis and electron microscopy. We show that: (i) in the absence of nicks on DNA the enzyme has a marked affinity for supercoiled (form I) DNA, (ii) in the presence of single stranded breaks poly(ADP-ribose) polymerase preferentially binds to form II, (iii) in all cases enzyme molecules are frequently located at DNA intersections, (iv) a cooperative binding of the enzyme on DNA occurs.     

Regulation of ATP synthesis catalyzed by the calcium pump of sarcoplasmic reticulum

The role of pH, KCl, ATP, water activity, and temperature in ATP synthesis from ADP and Pi was investigated in sarcoplasmic reticulum vesicles isolated from rabbit skeletal muscle. In totally aqueous medium, the synthesis of ATP was inhibited by ATP, KCl, and pH values above 6.5. When the water activity of the medium was decreased by the addition of 30% (v/v) dimethyl sulfoxide, the synthesis of ATP was no longer inhibited by ATP; it was activated by KCl and the optimum pH changed from 6.5 to 7.5. In totally aqueous medium, the concentration of MgCl2 needed for half-maximal synthesis of ATP was found to vary with the temperature of the assay medium; at 35 degrees C it was 1 mM and increased to a value higher than 10 mM when the temperature was decreased to 15 degrees C. In the presence of 30% dimethyl sulfoxide, maximal synthesis of ATP was attained in presence of 0.05 mM MgCl2 at both 15 and 35 degrees C. The hypothesis is raised that in the living cell water structure may play a role in regulating the synthesis of ATP observed during the reversal of the Ca2+ pump of the sarcoplasmic reticulum.     

Biology, serology and biochemistry of leucemogenic viruses derived from a radiation-induced tumor of C57BL mice

Two distinct rat propagates of a radiation leukemia virus (RadLV-Rs) from the C57BL mouse respectively induced characteristic leukemogenic effects. These were found to be related with the infection titers of the isolates, but not with either their antigenic specificities or their viral and proviral genome sequences.