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Mathieu Vanhove Anne Sicard Jeffery Ezennia Nina Leviten Rodrigo P.P. Almeida 《Environmental microbiology》2020,22(7):2625-2638
Xylella fastidiosa subsp. fastidiosa causes Pierce's disease of grapevine (PD) and has been present in California for over a century. A singly introduced genotype spread across the state causing large outbreaks and damaging the grapevine industry. This study presents 122 X. fastidiosa subsp. fastidiosa genomes from symptomatic grapevines, and explores pathogen genetic diversity associated with PD in California. A total of 5218 single-nucleotide polymorphisms (SNPs) were found in the dataset. Strong population genetic structure was found; isolates split into five genetic clusters divided into two lineages. The core/soft-core genome constituted 41.2% of the total genome, emphasizing the high genetic variability of X. fastidiosa genomes. An ecological niche model was performed to estimate the environmental niche of the pathogen within California and to identify key climatic factors involved in dispersal. A landscape genomic approach was undertaken aiming to link local adaptation to climatic factors. A total of 18 non-synonymous polymorphisms found to be under selective pressures were correlated with at least one environmental variable highlighting the role of temperature, precipitation and elevation on X. fastidiosa adaptation to grapevines in California. Finally, the contribution to virulence of three of the genes under positive selective pressure and of one recombinant gene was studied by reverse genetics. 相似文献
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H L Alexandre 《Journal of reproduction and fertility》1974,36(2):417-420
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Extra-pair paternity, testes size and testosterone level in relation to colour polymorphism in the barn owl Tyto alba 总被引:1,自引:0,他引:1
Alexandre Roulin Wendt Müller Lajos Sasvári Cor Dijkstra Anne-Lyse Ducrest Christian Riols Michael Wink Thomas Lubjuhn 《Journal of avian biology》2004,35(6):492-500
In many bird populations, individuals display one of several genetically inherited colour morphs. Colour polymorphism can be maintained by several mechanisms one of which being frequency-dependent selection with colour morphs signalling alternative mating strategies. One morph may be dominant and territorial, and another one adopt a sneaky behaviour to gain access to fertile females. We tested this hypothesis in the barn owl Tyto alba in which coloration varies from reddish-brown to white. This trait is heritable and neither sensitive to the environment in which individuals live nor to body condition. In Switzerland, reddish-brown males were observed to feed their brood at a higher rate and to produce more offspring than white males. This observation lead us to hypothesize that white males may equalise fitness by investing more effort in extra-pair copulations. This hypothesis predicts that lighter coloured males produce more extra-pair young, have larger testes and higher levels of circulating testosterone. However, our results are not consistent with these three predictions. First, paternity analyses of 54 broods with a total of 211 offspring revealed that only one young was not sired by the male that was feeding it. Second, testes size was not correlated with male plumage coloration suggesting that white males are not sexually more active. Finally, in nestlings at the time of feather growth testosterone level was not related to plumage coloration suggesting that this androgen is not required for the expression of this plumage trait. Our study therefore indicates that in the barn owl colour polymorphism plays no role in the probability of producing extra-pair young. 相似文献
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H. M. C. Kemps R. W. M. Brouwers M. J. Cramer H. T. Jorstad E. P. de Kluiver R. A. Kraaijenhagen P. M. J. C. Kuijpers M. R. van der Linde E. de Melker S. F. Rodrigo R. F. Spee M. Sunamura T. Vromen M. E. Wittekoek 《Netherlands heart journal》2020,28(7):387-390
The ongoing coronavirus disease 2019 (COVID-19) crisis is having a large impact on acute and chronic cardiac care. Due to public health measures and t 相似文献
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Purinergic Signalling - After more than two decades of preclinical and clinical studies, on August 27, 2019, the US Food and Drug Administration (FDA) approved the adenosine A2A receptor antagonist... 相似文献