Coordinated ultrastructural and phylogenomic analyses shed light on the hidden phycobiont diversity of Trebouxia microalgae in Ramalina fraxinea

[EN] The precise boundary delineations between taxa in symbiotic associations are very important for evolutionary and ecophysiological studies. Growing evidence indicates that in many cases, the use of either morphological characters or molecular markers results in diversity underestimation. In lichen symbioses. Trebouxia is the most common genus of lichen phycobionts, however, the diversity within this genus has been poorly studied and as such there is no clear species concept. This study constitutes a multifaceted approach incorporating aspects of ultrastructural characterization by TEM and phylogenomics to evaluate the morphological and genetic diversity of phycobionts within the sexually reproducing lichen Ramalina fraxinea in the context of Mediterranean and temperate populations. Results reveal an association with at least seven different Trebouxia lineages belonging to at least two species. T. decolorans and T. jamesii, and diverse combinations of such lineages coexisting within the same thallus depending on the analysed sample. Some of these lineages are shared by several other non-related lichen taxa. Our findings indicate the existence of a highly diverse assemblage of Trebouxia algae associating with R. fraxinea and suggest a possible incipient speciation within T. decolorans rendering a number of lineages or even actual species. This study stresses the importance of coordinated ultrastructural and molecular analyses to improve estimates of diversity and reveal the coexistence of more than one Trebouxia species within the same thallus. lt is also necessary to have clearer species delimitation criteria within the genus Trebouxia and microalgae in general.This study was funded by the Ministerio de Economia y Competitividad (MINECO CGL2012-40058-0O2-01/02), FEDER, the Generalitat Valenciana (PROMETEOII2013/021, GVA) and the Direccion General de Universidades e Investigacion de la Consejeria de Educacion de la Comunidad de Madrid - Universidad de Alcala (CCG10-UAH/GEN-5904). Drs. Arantxa Matins and Patricia Moya (Universitat de Valencia) made helpful comments on the manuscript.Català, S.; Campo, ED.; Barreno, E.; García-Breijo, F.; Reig Armiñana, J.; Casano, L. (2016). Coordinated ultrastructural and phylogenomic analyses shed light on the hidden phycobiont diversity of Trebouxia microalgae in Ramalina fraxinea. Molecular Phylogenetics and Evolution. 94:765-777. https://doi.org/10.1016/j.ympev.2015.10.021S7657779

Estimating retention benchmarks for salvage logging to protect biodiversity

S.T. was supported by the Humboldt-Foundation and by the MOST (Ministry of Science and Technology) Taiwan Research Fellowship to work with A.C. at National Tsing Hua University, Taiwan. S.T. received funds from the Gregor Louisoder Environmental Foundation. A.B.L. received funds from the Humboldt-Foundation.Forests are increasingly affected by natural disturbances. Subsequent salvage logging, a widespread management practice conducted predominantly to recover economic capital, produces further disturbance and impacts biodiversity worldwide. Hence, naturally disturbed forests are among the most threatened habitats in the world, with consequences for their associated biodiversity. However, there are no evidence-based benchmarks for the proportion of area of naturally disturbed forests to be excluded from salvage logging to conserve biodiversity. We apply a mixed rarefaction/extrapolation approach to a global multi-taxa dataset from disturbed forests, including birds, plants, insects and fungi, to close this gap. We find that 75 ± 7% (mean ± SD) of a naturally disturbed area of a forest needs to be left unlogged to maintain 90% richness of its unique species, whereas retaining 50% of a naturally disturbed forest unlogged maintains 73 ± 12% of its unique species richness. These values do not change with the time elapsed since disturbance but vary considerably among taxonomic groups.Open Access funding enabled and organized by Projekt DEA

MATRIX DEGRADING PROTEINASES FROM HUMAN-GRANULOCYTES - TYPE-I, TYPE-II, TYPE-III COLLAGENASE, GELATINASE AND TYPE-IV, TYPE-V-COLLAGENASE - A SURVEY OF RECENT FINDINGS AND INHIBITION BY GAMMA-ANTICOLLAGENASE

Tschesche H, FEDROWITZ J, KOHNERT U, MICHAELIS J, MACARTNEY HW. MATRIX DEGRADING PROTEINASES FROM HUMAN-GRANULOCYTES - TYPE-I, TYPE-II, TYPE-III COLLAGENASE, GELATINASE AND TYPE-IV, TYPE-V-COLLAGENASE - A SURVEY OF RECENT FINDINGS AND INHIBITION BY GAMMA-ANTICOLLAGENASE. FOLIA HISTOCHEMICA ET CYTOBIOLOGICA. 1986;24(2):125-131

Tissue kallikrein effectively activates latent matrix degrading metalloenzymes

Tschesche H, Michaelis J, Kohnert U, Fedrowitz J, Oberhoff R. Tissue kallikrein effectively activates latent matrix degrading metalloenzymes. Adv Exp Med Biol. 1989;247A(3):280-284

The degradation of collagen by a metalloproteinase from human leucocytes

Kohnert U, Oberhoff R, Fedrowitz J, Bergmann U, Rauterberg J, Tschesche H. The degradation of collagen by a metalloproteinase from human leucocytes. Adv Exp Med Biol. 1988;240

Melatonin Levels and Low-Frequency Magnetic Fields in Humans and Rats: Reconciling Opposite Results with a Bayesian Regression

International audienceBackground: The present analysis revisit the impact of extremely low-frequency magnetic fields (ELF MF) on melatonin (MLT) levels in human and rat subjects using both a parametric and non-parametric approach. Method: In this analysis, we use 62 studies from review articles. The parametric approach consists in a Bayesian Logistic Regression (LR) analysis and the non-parametric approach consists of a Support Vector analysis which are designed to be robust against spurious/false results. Results: Both approach reveal a unique well ordered pattern, and show that humans and rat studies are consistent with each other once the MF strength is restricted to cover the same range (with B 50µT). In addition, the data reveal that chronic exposure (longer than ∼ 22 days) to ELF MF appears to decrease MLT levels only when the MF strength is below a threshold of 30µT (log B thr /µT= 1.4 +0.7 −0.5), i.e. when the man-made ELF MF intensity is below that of the static geomagnetic field. Conclusions: Studies reporting an association between ELF MF and changes to MLT levels and some the opposite (no association with ELF MF) can be reconciled under a single framework