47 research outputs found

    Molecular cloning and expression studies of two divergent α-tubulin genes in Neurospora crassa

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    Three α-tubulin isoforms were previously detected in Neurospora crassa. We have cloned and analysed two α-tubulin cDNAs, Tub αA and Tub αB that encode polypeptides of 453 and 451 amino acids, respectively. The encoded amino acids exhibit an unusual divergence of 35%. This is the highest divergence ever observed between α-tubulins from the same species. The expression of the two genes is developmentally regulated. We did not detect any transcription of the Tub αA gene in dormant macroconidia and during the first 30 min of development even though the α-tub A protein is already present in the early stage of germination. In contrast, the Tub αB gene is continuously transcribed during the vegetative cycle and the expression profile of the protein follows the ones of its mRN

    Purification of a 47-kDa calmodulin-binding polypeptide as an actin-binding protein from Neurospora crassa

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    We have enriched a 47-kDa polypeptide (p47) from Neurospora crassa on the basis of its affinity to calmodulin. The p47 was purified to homogeneity by chromatography on a Mono S cation exchange column and evidence is presented that the polypeptide co-sediments specifically with F-actin. The intracellular distribution of p47 and actin was also examined using indirect double immunofluorescence staining of cells at different stages of development. Our results suggest that by altering the conformation binding site of actin to p47, calmodulin could play a regulatory role in the polarized hyphal growth of N. crass

    Lecanora lecideopsis Cl. Roux et C. Coste sp. nov.

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    Description of a new species of lichen, Lecanora lecideopsis Cl. Roux et C. Coste sp. nov., known in a single station of France (department of Hérault, municipality of Mons) on non-calcareous rock (gneiss), which differs differs from Lecanora lecideoides (Nyl.) Harm. by its epithecium green to greenish brown, N + (purple), containing cinereorufa green, its thallus with different chemistry (norstictic acid besides atranorine) and its much narrower, oblong or long ellipsoid spores (10)12–14,4-16(18) x (3)3,5-4,0-4,5(5) µm. Comparison with affine species or analogues. Lectotypification of Lecanora lecideoides, species form which L. rubrofusca should be excluded. Key of determination of Lecanora gr. subfusca of Western Europe, saxicolous, with epithecium without crystals and thallus K + (yellow).Peer reviewe

    Looking for a needle in a haystack: inference about individual fitness components in a heterogeneous population

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    Studies of wild vertebrates have provided evidence of substantial differences in lifetime reproduction among individuals and the sequences of life history ‘states’ during life (breeding, nonbreeding, etc.). Such differences may reflect ‘fixed’ differences in fitness components among individuals determined before, or at the onset of reproductive life. Many retrospective life history studies have translated this idea by assuming a ‘latent’ unobserved heterogeneity resulting in a fixed hierarchy among individuals in fitness components. Alternatively, fixed differences among individuals are not necessarily needed to account for observed levels of individual heterogeneity in life histories. Individuals with identical fitness traits may stochastically experience different outcomes for breeding and survival through life that lead to a diversity of ‘state’ sequences with some individuals living longer and being more productive than others, by chance alone. The question is whether individuals differ in their underlying fitness components in ways that cannot be explained by observable ‘states’ such as age, previous breeding success, etc. Here, we compare statistical models that represent these opposing hypotheses, and mixtures of them, using data from kittiwakes. We constructed models that accounted for observed covariates, individual random effects (unobserved heterogeneity), first-order Markovian transitions between observed states, or combinations of these features. We show that individual sequences of states are better accounted for by models incorporating unobserved heterogeneity than by models including first-order Markov processes alone, or a combination of both. If we had not considered individual heterogeneity, models including Markovian transitions would have been the best performing ones. We also show that inference about age-related changes in fitness components is sensitive to incorporation of underlying individual heterogeneity in models. Our approach provides insight into the sources of individual heterogeneity in life histories, and can be applied to other data sets to examine the ubiquity of our results across the tree of life

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    SARS-CoV-2 susceptibility and COVID-19 disease severity are associated with genetic variants affecting gene expression in a variety of tissues

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    Variability in SARS-CoV-2 susceptibility and COVID-19 disease severity between individuals is partly due to genetic factors. Here, we identify 4 genomic loci with suggestive associations for SARS-CoV-2 susceptibility and 19 for COVID-19 disease severity. Four of these 23 loci likely have an ethnicity-specific component. Genome-wide association study (GWAS) signals in 11 loci colocalize with expression quantitative trait loci (eQTLs) associated with the expression of 20 genes in 62 tissues/cell types (range: 1:43 tissues/gene), including lung, brain, heart, muscle, and skin as well as the digestive system and immune system. We perform genetic fine mapping to compute 99% credible SNP sets, which identify 10 GWAS loci that have eight or fewer SNPs in the credible set, including three loci with one single likely causal SNP. Our study suggests that the diverse symptoms and disease severity of COVID-19 observed between individuals is associated with variants across the genome, affecting gene expression levels in a wide variety of tissue types

    A first update on mapping the human genetic architecture of COVID-19

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    Rôle des facteurs comportementaux dans la démographie des espèces à reproduction coloniale ; cas de la Mouette tridactyle (Rissa tridactyla)

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    Danchin Etienne, Monnat Jean-Yves. Rôle des facteurs comportementaux dans la démographie des espèces à reproduction coloniale ; cas de la Mouette tridactyle (Rissa tridactyla). In: Revue d'Écologie. Supplément n°4, 1987. p. 200

    Gestion des ressources et aménagement des îles

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    Singelin Patrick, Monnat Jean-Yves. Gestion des ressources et aménagement des îles. In: Norois, n°145, Janvier-Mars 1990. Iles et sociétés insulaires. pp. 21-23
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