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Aspergillus fumigatus is the most common airborne fungal pathogen for humans. In this mold, iron starvation induces production of the siderophore triacetylfusarinine C (TAFC). Here we demonstrate a link between TAFC and ergosterol biosynthetic pathways, which are both critical for virulence and treatment of fungal infections. Consistent with mevalonate being a limiting prerequisite for TAFC biosynthesis, we observed increased expression of 3-hydroxy-3-methyl-glutaryl (HMG)-CoA reductase (Hmg1) under iron starvation, reduced TAFC biosynthesis following lovastatin-mediated Hmg1 inhibition, and increased TAFC biosynthesis following Hmg1 overexpression. We identified enzymes, the acyl-CoA ligase SidI and the enoyl-CoA hydratase SidH, linking biosynthesis of mevalonate and TAFC, deficiency of which under iron starvation impaired TAFC biosynthesis, growth, oxidative stress resistance, and murine virulence. Moreover, inactivation of these enzymes alleviated TAFC-derived biosynthetic demand for mevalonate, as evidenced by increased resistance to lovastatin. Concordant with bilateral demand for mevalonate, iron starvation decreased the ergosterol content and composition, a phenotype that is mitigated in TAFC-lacking mutants.siderophore | isoprenoide | statins

The occurrence of amber in Sierra de Cantabria (álava, Basque Country) has been known for more than two decades but biological inclusions have only recently been found. The existence of crustaceans (amphipods and isopods), chelicerates (acari and arachnids), 12 orders of insects, and several bird feathers are reported in this preliminary study. In addition, there are leaf remains, molluscs, and a fair number of inorganic inclusions.Pollen analysis of the clastic series indicates an age between upper Aptian—middle Albian, which allows an assignment of this stratigraphic unit to the Nograro Formation. Chemical analysis indicates that the amber has high maturity, which reflects its Cretaceous age. Chemical composition analysis also indicates an araucariacean origin, which is corroborated by pollen found within the amber deposit.This new fossil site provides information for the reconstruction of paleocommunities of arthropods and sedimentary environments in the extreme south of the Basque-Cantabrian Basin during the Lower Cretaceous, characterized by coniferous forests with an understory of vascular cryptograms. Some of the identified arthropods add to the fossil record for various groups that are poorly known or unknown for this time period. This Lagerstätte constitutes one of the most important deposits of Mesozoic amber in the world.

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A first case of temperature-dependent distribution of polybromodiphenyl ethers (PBDEs) in remote areas is shown. Analysis of these compounds in fish from Pyrenean lakes distributed along an altitudinal transect shows higher concentrations at lower temperatures, as predicted in the global distillation model. Conversely, no temperature-dependent distribution is observed in a similar transect in the Tatra mountains (Central Europe) nor in fish from high mountain lakes distributed throughout Europe. The fish concentrations of polychlorobiphenyls (PCBs) examined for comparison showed significant temperature correlations in all these studied lakes. Cold trapping of both PCBs and PBDEs concerned the less volatile congeners. In the Pyrenean lake transect the concentrations of PCBs and PBDEs in fish were correlated despite the distinct use of these compounds and their 40 year time lag of emissions to the environment. Thus, temperature effects have overcome these anthropogenic differences constituting at present the main process determining their distributions. These cases of distinct PBDEs and PCBs behavior in high mountains likely reflect early stages in the environmental distribution of the former since they have been under secondary redistribution processes over much shorter time than the latter.

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