Early life events carry over to influence pre-migratory condition in a free-living songbird

Conditions experienced during development can have long-term consequences for individual success. In migratory songbirds, the proximate mechanisms linking early life events and survival are not well understood because tracking individuals across stages of the annual cycle can be extremely challenging. In this paper, we first use a 13 year dataset to demonstrate a positive relationship between 1(st) year survival and nestling mass in migratory Savannah sparrows (Passerculus sandwichensis). We also use a brood manipulation experiment to show that nestlings from smaller broods have higher mass in the nest relative to individuals from larger broods. Having established these relationships, we then use three years of field data involving multiple captures of individuals throughout the pre-migratory period and a multi-level path model to examine the hypothesis that conditions during development limit survival during migration by affecting an individual's ability to accumulate sufficient lean tissue and fat mass prior to migration. We found a positive relationship between fat mass during the pre-migratory period (Sept-Oct) and nestling mass and a negative indirect relationship between pre-migratory fat mass and fledging date. Our results provide the first evidence that conditions during development limit survival during migration through their effect on fat stores. These results are particularly important given recent evidence showing that body condition of songbirds at fledging is affected by climate change and anthropogenic changes to landscape structure.     

Doxorubicin-antioxidant co-drugs

Doxorubicin-antioxidant multitarget compounds 6 and 7 were obtained by combining doxorubicin (DOX) with caffeic and ferulic acids through an ester linkage at C-14. The products were studied in in vitro models of cardiomyocytes and breast cancer cells, characterized by different degrees of resistance to DOX, due to different expressions of ATP binding cassette (ABC) transporters. Compound 7 was found to be less toxic than DOX in cardiomyocytes and to display the same possibly higher toxicity against the resistant breast cancer cells. This result shows that appropriate DOX-antioxidant co-drugs can limit the onset of cardiac damage, a significant side-effect of DOX, without impairing the antitumor activity of the parent antibiotic.     

Short-term changes in zooplankton community in Paso Ancho basin (Strait of Magellan): functional trophic structure and diel vertical migration

Knowledge on community structure oriented to describe energy flow during late summer season in Paso Ancho basin (Strait of Magellan) is scarce and particularly affected by vertical diel migration (VDM). The main aim of this work is to identify the VDM patterns of selected species and functional feeding groups of mesozooplankton, collected by the electronic multinet BIONESS in 1995. Detailed studies were carried out on keystone components of the community: 7 species of copepods (Ctenocalanus citer, Drepanopus forcipatus, Metridia lucens, Clausocalanus brevipes, Scolecithricella minor, Paraeuchaeta antarctica, Calanus simillimus), one ostracod (Discoconchoecia elegans), one chaetognath (Sagitta tasmanica), one euphausiid (Euphausia vallentini), and two polychaetes (Pelagobia longicirrata, Tomopteris planktonis). Unexpected deviations from the classic pattern reported in literature were uncovered. The shallow layer mesozooplankton at night, although dominated by exclusively or preferentially herbivores, particularly by E. vallentini, was not represented by several species known as herbivores that remained in the deep layer throughout the day cycle. The deep-layer zooplankton throughout the day cycle was well represented by carnivores, detritivores, and omnivores. It is suggested that during low-chlorophyll summer conditions, the composition of functional groups and diet, and VDM patterns changed to take advantage of sinking phytoplankton and picoplankton in deep layers. Pelagic-benthic coupling would be strengthened due to animals that suppressed their vertical daily rise to the shallow layer at nights but remained in the deep layers to feed on a rain of particulate organic matter and other non-migrant zooplankton.     

Searching for new NO-donor aspirin-like molecules: Furoxanylacyl derivatives of salicylic acid and related furazans

A new group of derivatives of salicylic acid containing NO-donor furoxans, and the related des-NO-furazans, were synthesized and evaluated as new aspirin-like molecules. Their stability was assessed in acid (pH 1) and physiological solutions (pH 7.4), and in human serum. No compound exhibited COX-inhibitory activity against COX-1 and COX-2 isoforms, when tested up to 100μM, respectively, on isolated platelets and on monocytes. Phenylsulfonyl- and cyano-substituted furoxans inhibited platelet aggregation induced by collagen in human platelet-rich plasma, through a cGMP dependent mechanism. Furoxan derivatives displayed cGMP-dependent vasodilator activities, tested on rat aorta strips precontracted with phenylephrine. All products showed anti-inflammatory activity similar to that of ASA, tested on rats by the carrageenan-induced paw edema assay. Unlike ASA, all products showed markedly reduced gastrotoxicity in a rat lesion model.     

CD25+CD4+ regulatory T cell migration requires L-selectin expression: L-selectin transcriptional regulation balances constitutive receptor turnover

The molecular mechanisms controlling regulatory CD25(+)Foxp3(+)CD4(+) T cell (T(reg)) migration are central to in vivo immune responses. T(reg) cell subsets differentially express L-selectin, an adhesion molecule mediating lymphocyte migration to peripheral LNs (PLNs) and leukocyte rolling during inflammation. In this study, L-selectin was essential for T(reg) cell migration and normal tissue distribution. Specifically, there was a 90% reduction in PLN T(reg) cells in L-selectin(-/-) mice with a compensatory increase in spleen T(reg) cell numbers. Unexpectedly, however, 40% of the CD4(+) T cells remaining within PLNs of L-selectin(-/-) mice were T(reg) cells. The migratory properties of T(reg) cells were nonetheless markedly different from those of naive CD4(+) T cells, with 3- to 9-fold lower migration of T(reg) cells into PLNs and approximately 2-fold lower migration into the spleen. T(reg) cells also turned over cell surface L-selectin at a faster rate than CD25(-)CD4(+) T cells, but maintained physiologically appropriate L-selectin densities for optimal migration. Specifically, T(reg) cells expressed 30-40% more cell surface L-selectin when its endoproteolytic cleavage was blocked genetically, which resulted in a 2-fold increase in T(reg) cell migration into PLNs. However, increased L-selectin cleavage by T(reg) cells in wild-type mice was accompanied by 2-fold higher L-selectin mRNA levels, which resulted in equivalent cell surface L-selectin densities on T(reg) and naive T cells. Thus, T(reg) cells and CD25(-)CD4(+) T cells share similar requirements for L-selectin expression during migration, although additional molecular mechanisms constrain T(reg) cell migration beyond what is required for naive CD4(+) T cell migration.     

Invasion of European pine stands by a North American forest pathogen and its hybridization with a native interfertile taxon

It was recently reported that North American (NA) individuals of the forest pathogen Heterobasidion annosum were found in a single pine stand near Rome, in association with the movement of US troops during World War II. Here, we report on some aspects of the invasion biology of this pathogen in Italian coastal pinewoods, and on its interaction with native (EU) Heterobasidion populations. Spores of Heterobasidion were sampled using woody traps in pine stands along 280 km of coast around Rome. DNA of single-spore colonies was characterized by two sets of nuclear and one set of mitochondrial taxon-specific polymerase chain reaction primers. NA spores were found not only in a single site, but in many locations over a wide geographic area. Invasion occurred at an estimated rate of 1.3 km/year through invasion corridors provided by single trees, and not necessarily by sizable patches of forests. Within the 100-km long range of expansion, the NA taxon was dominant in all pure pine stands. Because abundance of the EU taxon is low and identical among stands within and outside the area invaded by NA individuals, we infer that the exotic population has invaded habitats mostly unoccupied by the native species. Discrepancy between a mitochondrial and a nuclear marker occurred in 3.8% of spores from one site, a mixed oak-pine forest where both taxa were equally represented. Combined phylogenetic analyses on nuclear and mitochondrial loci confirmed these isolates were recombinant. The finding of hybrids indicates that genetic interaction between NA and EU Heterobasidion taxa is occurring as a result of their current sympatry.     

Spermiophagic activity in the female genital system of some species of terrestrial isopods (Crustacea,Halophilosciidae)

The females of some species of the family Halophilosciidae receive in the course of mating a quantity of sperm considerably redundant with respect to the number of eggs that can be fertilized; this is possible thanks to the peculiar morpho-functional organization that characterizes their genital system and that allows them to store the sperm not only in the great seminal receptacle but also within the ovary. While most of the sperm stay free in the lumen of the seminal receptacle, a part of those present in the ovary undergoes a process of capture by the follicular cells with consequent internalization within endocellular cavities. This process concerns exclusively the immotile tail, that characterizes the peculiar spermatozoon of the isopods and which is essentially of proteic nature. After their capture the sperm tails undergo a gradual process of digestion, which seems to be apparently realized without the intervention of lysosomes. The possible role of this spermiophagic activity might be to represent a significant trophic paternal investment aimed at improving the fitness of the female and of the offsprings.     

Nonoverlapping functions of the Polycomb group Cbx family of proteins in embryonic stem cells

Polycomb group proteins are essential regulators of cell fate decisions during embryogenesis. In mammals, at least five different Cbx proteins (Cbx2, Cbx4, Cbx6, Cbx7, and Cbx8) are known to associate with the core Polycomb repressive complex 1 (PRC1). Here we show that pluripotency and differentiation of mouse embryonic stem cells (ESCs) is regulated by different Cbx-associated PRC1 complexes with unique functions. Maintenance of pluripotency primarily depends on Cbx7, while lineage commitment is orchestrated by Cbx2 and Cbx4. At the molecular level, we have uncovered a Polycomb autoregulatory loop in which Cbx7 represses the expression of prodifferentiation Cbx proteins, thereby maintaining the pluripotent state. We additionally show that the occupancy of Cbx7 on promoters is completely dependent on PRC2 activity but only partially dependent on a functional PRC1 complex. Thus, Cbx proteins confer distinct target selectivity to the PRC1 complex, achieving a balance between the self-renewal and the differentiation of ESCs.     

Population structure analysis provides insights into the infection biology and invasion strategies of Kretzschmaria deusta in trees

Infection biology and invasion strategies of Kretzschmaria deusta were investigated through the analysis of patterns of colonization and population diversity in three case studies, comprising different host species. Molecular analysis and isolation assays performed on stem sections at different heights indicated a prevalent heart rot mode of expansion. Random amplified microsatellites – RAMs and somatic incompatibility assays on isolates allowed detection, in one case, of a genet occupying the entire decay column and, in the other cases, of several different genets in each individual tree. Hypotheses on modes of arrival and entrance of K. deusta in trees are discussed on the basis of the distribution of genets and population genetics analyses. Significant correlation (Spearman ρ = 1.0; p < 0.001) between the number of genets and the number of areas delimited by pseudosclerotial plates (PSPs) on the decayed portions of stem sections suggests PSPs are interaction zone lines between different individuals of K. deusta occupying adjacent decay columns.