Sarcodontia pachyodon: a Canker and White‐rot Agent of Plane‐trees

Some lignivorous hymenomycete fungi are capable of causing both cankers and decay in stemwood of adult trees. Recently in Tuscany (Italy), Platanus x acerifolia trees were found colonized by Sarcodontia pachydon (Polyporales, Meruliaceae), a fungus associated with white rot and stem cankers on different host tree species. Because the relationship S. pachyodon‐plane‐tree was only preliminary studied, we decided to investigate whether isolates obtained from this host are distinct from those commonly collected from oaks. For this purpose, isolates obtained from plane‐tree and from holm oak (Quercus ilex) were compared by in vitro test and molecular markers. Results showed that fungal isolates did not differ in growth nor in wood degradation, also molecular tests revealed relative similarity among fungal samples.     

A novel numerical modelling approach for keratoplasty eye procedure

Biomechanics and Modeling in Mechanobiology - Objective of the work is to investigate stress and deformation that conrneal tissue and donor graft undergo during endothelial keratoplasty. In order...     

Immune response and survival

Immune responses have evolved to defend hosts efficiently against the debilitating effects of parasites on host fitness. However, there are relatively few studies of the efficiency of the immune system in terms of providing hosts with an ability to defend themselves against parasitism. A meta-analysis of the literature on survival of birds in relation to non-specific immune response to challenge with an antigen or other measures of immune function demonstrated a mean effect adjusted for sample size of 0.43 across 12 studies. This observation shows that relatively simple estimates of non-specific immune responses often reliably predict a large and significant amount of variation in survivorship.     

Aryl sulphonyl amides as potent agonists of the growth hormone secretagogue (ghrelin) receptor

As part of an on-going lead optimisation effort, a cross screening exercise identified an aryl sulphonyl amide hit that was optimised to afford a highly potent series of ghrelin receptor agonists.     

Detection of insect prey by wild common marmosets: The effect of color vision

Most species of New World primates have an unusual color vision pattern that can affect an individual's ability to detect food. Whereas males can only be dichromatic, females can be either dichromatic or trichromatic. Trichromats are expected to have an advantage in detecting conspicuous food whereas dichromats should be better at locating cryptic resources. Here we aimed to understand how color vision phenotype influences insect foraging by five groups of common marmosets living in a semiarid environment. We recorded insect predation events, noting morphotype and color of the captured insect, and the substrate from which it was captured. Color modeling suggested that, for all values of chromatic contrast resulting from comparing the measured insect–substrate pairs, trichromats outperformed dichromats. Females showed an overall higher insect capture rate than males. Females also showed a higher capture rate of conspicuous insects but there was no sex difference for the capture of cryptic insects. When we compared only dichromatic individuals there was no difference between sexes. These findings suggest that differences found in capture rate related not only to sex but also to visual polymorphism and that the latter is a crucial factor determining insect capture rate in common marmosets. Nevertheless, these results should be interpreted with caution because of the small number (three) of dichromat females and the unknown phenotype of the remaining females. Our results support the balancing selection hypothesis, suggesting that the advantage of one phenotype over the other may depend on environmental circumstances. This hypothesis has recently been considered as the most plausible for the maintenance of visual polymorphism in New World primates.     

Human 4E-T represses translation of bound mRNAs and enhances microRNA-mediated silencing

A key player in translation initiation is eIF4E, the mRNA 5′ cap-binding protein. 4E-Transporter (4E-T) is a recently characterized eIF4E-binding protein, which regulates specific mRNAs in several developmental model systems. Here, we first investigated the role of its enrichment in P-bodies and eIF4E-binding in translational regulation in mammalian cells. Identification of the conserved C-terminal sequences that target 4E-T to P-bodies was enabled by comparison of vertebrate proteins with homologues in Drosophila (Cup and CG32016) and Caenorhabditis elegans by sequence and cellular distribution. In tether function assays, 4E-T represses bound mRNA translation, in a manner independent of these localization sequences, or of endogenous P-bodies. Quantitative polymerase chain reaction and northern blot analysis verified that bound mRNA remained intact and polyadenylated. Ectopic 4E-T reduces translation globally in a manner dependent on eIF4E binding its consensus Y³⁰X₄Lϕ site. In contrast, tethered 4E-T continued to repress translation when eIF4E-binding was prevented by mutagenesis of YX₄Lϕ, and modestly enhanced the decay of bound mRNA, compared with wild-type 4E-T, mediated by increased binding of CNOT1/7 deadenylase subunits. As depleting 4E-T from HeLa cells increased steady-state translation, in part due to relief of microRNA-mediated silencing, this work demonstrates the conserved yet unconventional mechanism of 4E-T silencing of particular subsets of mRNAs.     

Phylogeography and palaeodistribution modelling in the Patagonian steppe: the case of Mulinum spinosum (Apiaceae)

Aim An integrative study of the endemic, yet ubiquitous, Patagonian shrub Mulinum spinosum (Apiaceae) was performed: (1) to assess the historical processes that influenced its geographical pattern of genetic variation; (2) to test hypotheses of its survival in situ or in glacial refugia during glacial cycles; and (3) to model its extant and palaeoclimatic distributions to assess support for the phylogeographical patterns recovered. Location Chilean and Argentinian Andean region and Patagonian steppe. Methods Chloroplast DNA sequences, trnH–psbA, trnS–trnG and 3′trnV–ndhC, were obtained for 314 individuals of M. spinosum from 71 populations. The haplotype data matrix was analysed using nested clade analysis (NCA) to construct a network. Analysis of molecular variance (AMOVA), spatial analysis of molecular variance (SAMOVA) and neutrality tests were also used to test for genetic structure and range expansion in the species. The present potential geographical distribution of M. spinosum was modelled and projected onto a Last Glacial Maximum (LGM) model. Results Amongst the 29 haplotypes observed, one was widely distributed, but most were restricted to either northern or southern regions. The populations with highest haplotype diversity were found in southern Patagonia, the high Andean region, and northern Patagonia. AMOVA and SAMOVA showed latitudinal structure for Argentinian populations. NCA implied patterns of restricted gene flow or dispersal but with some long‐distance dispersal and also long‐distance colonization and/or past fragmentation. Neutrality tests did not support range expansions. The current distribution model was a fairly good representation of the extant geographical distribution of the species, and the distribution model for the LGM did not show important shifts of the extant range to lower latitudes, except for a shift towards the palaeoseashore. Main conclusions Based on agreement amongst phylogeographical patterns, distribution of genetic variability, equivocal evidence of putative refugia and palaeodistribution modelling, it is probable that glaciations did not greatly affect the distribution of Mulinum spinosum. Our results are consistent with the in situ survival hypothesis, and not with the latitudinal migration of plant communities to avoid adverse climate conditions during Pleistocene glaciations. It is possible that populations of northern Patagonia may have been isolated from the southern ones by the Chubut and Deseado basins.