No inbreeding depression in an outcrossing alpine species: The breeding system of Campanula thyrsoides

Plants that live in fragmented landscapes, where populations are isolated from each other and in which long-distance dispersal is essential for colonization of empty sites, reproduction should be favoured by self-compatibility (Baker's law). Nevertheless, outcrossing mechanisms, such as self-incompatibility and dichogamy, are common in many species and are often maintained by inbreeding depression in the fitness of selfed progeny. Here, we studied the breeding system and the consequences of selfing and sister mating in Campanula thyrsoides, a short-lived perennial monocarp, which is found in the naturally fragmented landscape of the Alps. An experiment with controlled pollinations was set up in the common garden with plants grown from seeds originating from 14 seed families, collected in the siliceous Central Alps, where this plant is found on isolated carbonate bearing outcrops.Our results indicate that C. thyrsoides has a strong self-incompatibility system (SI) with no or low seed set in selfed flowers compared to outcrossed and sister-crossed flowers. Moreover, the SI system in C. thyrsoides did not break down with flower age as in some other Campanula species. Surprisingly, there was no significant difference in seed set, seed weight, germination percentage, seedling survival and size between outcrossed and sister-crossed offspring, which indicates no inbreeding depression.We suggest that the absence of inbreeding depression in this outcrossing species might be a result of frequent bottlenecks during colonization of the isolated habitats in the alpine landscape.     

Oestradiol and tamoxifen inhibit murine Colon 38 cancer growth and increase the cytotoxic effect of fluorouracil

The poor efficacy of reference chemotherapy (fluorouracil -FU) in colon cancer has resulted in a constant search for agents which could augment the action of FU. Epidemiological data, such as the decreased risk of colorectal cancer among menopausal women receiving hormonal replacement therapy, indicate the role of oestrogen in the pathogenesis of this disease. The differences between normal and neoplastic colon cells in the expression of oestrogen receptor beta (ERbeta) could confirm this association. However, the direct influence of oestrogen or tamoxifen (SERM, selective oestrogen receptor modulator) on colon cancer growth has rarely been studied. The aim of the present study was to examine the direct effects of various concentrations of oestradiol and tamoxifen (10(-4) to 10(-12) M), applied alone or together with FU, on the growth of murine Colon 38 cancer in vitro as assessed by three colorimetric methods: Mosmann's method, incorporation of BrdU into cell nuclei and the TUNEL method. At high concentrations oestradiol and tamoxifen decreased the cancer growth in a dose- and time-dependent manner (the Mosmann and BrdU methods) and at some concentrations augmented the cytotoxic action of FU (Mosmann's method). Tamoxifen exerted a very early and potent inhibitory effect, inducing even total cancer growth inhibition at the concentration of 10(-4) M (the Mosmann and BrdU methods). All the substances studied at different concentrations and at different incubation time points increased the apoptosis of tumour cells (the TUNEL method). The results indicate that oestradiol and tamoxifen inhibit Colon 38 cancer growth and increase the cytotoxic effect of FU, which confirms the role of sex steroids in colon carcinogenesis and even suggests new therapeutic schemes.     

Polar lipid and fatty acid profiles – Re-vitalizing old approaches as a modern tool for the classification of mycoplasmas?

A set of 20 Mollicutes strains representing different lines of descent, including the type species of the genus Mycoplasma, Mycoplasma mycoides, Acholeplasma laidlawii and a strain of Mesoplasma, were subjected to polar lipid and fatty acid analyses in order to evaluate their suitability for classification purposes within members of this group. Complex polar lipid and fatty acid profiles were detected for each examined strain. All strains contained the polar lipids phosphocholine-6'-alpha-glucopyranosyl-(1'-3)-1, 2-diacyl-glycerol (MfGL-I), 1-O-alkyl/alkenyl-2-O-acyl-glycero-3-phosphocholine (MfEL), sphingomyelin (SphM), 1-O-alkyl/alkenyl-glycero-3-phosphocholine (lysoMfEL), the unknown aminophospholipid APL1 and the cholesterol Chol2. A total of 19 strains revealed the presence of phosphatidylethanolamine (PE) and/or phosphatidylglycerol (PG), and the presence of diphosphatidylglycerol (DPG) was detected in 13 strains. The unknown aminolipid AL1 was found in the extracts of 17 strains. Unbranched saturated and unsaturated compounds predominated in the fatty acid profiles. Major fatty acids were usually C16:0, C18:0, C18:1 omega9c and 'Summed feature 5' (C18:2 omega6, 9c/C18:0 anteiso). Our results demonstrated that members of the M. mycoides cluster showed rather homogenous polar lipid and fatty acid profiles. In contrast, each of the other strains was characterized by a unique polar lipid profile and significant quantitative differences in the presence of certain fatty acids. These results indicate that analyses of both polar lipid and fatty acid profiles could be a useful tool for classification of mycoplasmas.     

Lysosomal trafficking functions of mucolipin-1 in murine macrophages

Background  

Mucolipidosis Type IV is currently characterized as a lysosomal storage disorder with defects that include corneal clouding, achlorhydria and psychomotor retardation. MCOLN1, the gene responsible for this disease, encodes the protein mucolipin-1 that belongs to the "Transient Receptor Potential" family of proteins and has been shown to function as a non-selective cation channel whose activity is modulated by pH. Two cell biological defects that have been described in MLIV fibroblasts are a hyperacidification of lysosomes and a delay in the exit of lipids from lysosomes.     

Evidence for glycosylation on a DNA-binding protein of <Emphasis Type="Italic">Salmonella enterica</Emphasis>

Background  

All organisms living under aerobic atmosphere have powerful mechanisms that confer their macromolecules protection against oxygen reactive species. Microorganisms have developed biomolecule-protecting systems in response to starvation and/or oxidative stress, such as DNA biocrystallization with Dps (DNA-binding protein from starved cells). Dps is a protein that is produced in large amounts when the bacterial cell faces harm, which results in DNA protection. In this work, we evaluated the glycosylation in the Dps extracted from Salmonella enterica serovar Typhimurium. This Dps was purified from the crude extract as an 18-kDa protein, by means of affinity chromatography on an immobilized jacalin column.     

Melatonin and thyroxine response to pollution in white stork nestlings (Ciconia ciconia): aspects of rhythmicity and age

There is growing evidence that ubiquitous environmental contaminants may interfere with vertebrate endocrine systems. The selected endocrine biomarkers are used to indicate the condition of free-ranging populations of wildlife, including avian species. The aim of this study was to determine the impact of environment quality on serum thyroxine (T4) and melatonin (Mel) in white stork nestlings (Ciconia ciconia) living in different locations: small villages in natural areas surrounded by forests and crop fields, near the city and near the copper smelter. We extended our analyses to examine the hormones' day-night changes in conjunction with chicks' age. Total serum T4 and Mel was measured by RIA. T4 level, as a decisive measure of thyroid hormone productivity, was significantly lower in the nestlings exposed to pollutants from the copper smelter. Mel, as a well-known scavenger of free radicals, was elevated in the nestlings in the area near the copper smelter. This study indicates that alteration in T4 and Mel levels could be a useful marker of exposure of nestling wild storks to different toxic substances in field studies. Mel is postulated to be a susceptible defensive molecule as a protective mechanism for organisms.     

Gynoecium structure in Sapindales and a case study of Trichilia pallens (Meliaceae)

Journal of Plant Research - Sapindales is a monophyletic order within the malvid clade of rosids. It represents an interesting group to address questions on floral structure and evolution due to a...     

TFG clusters COPII‐coated transport carriers and promotes early secretory pathway organization

In mammalian cells, cargo‐laden secretory vesicles leave the endoplasmic reticulum (ER) en route to ER‐Golgi intermediate compartments (ERGIC) in a manner dependent on the COPII coat complex. We report here that COPII‐coated transport carriers traverse a submicron, TFG (Trk‐fused gene)‐enriched zone at the ER/ERGIC interface. The architecture of TFG complexes as determined by three‐dimensional electron microscopy reveals the formation of flexible, octameric cup‐like structures, which are able to self‐associate to generate larger polymers in vitro. In cells, loss of TFG function dramatically slows protein export from the ER and results in the accumulation of COPII‐coated carriers throughout the cytoplasm. Additionally, the tight association between ER and ERGIC membranes is lost in the absence of TFG. We propose that TFG functions at the ER/ERGIC interface to locally concentrate COPII‐coated transport carriers and link exit sites on the ER to ERGIC membranes. Our findings provide a new mechanism by which COPII‐coated carriers are retained near their site of formation to facilitate rapid fusion with neighboring ERGIC membranes upon uncoating, thereby promoting interorganellar cargo transport.     

Microbiota in Wheat Roots,Rhizosphere and Soil in Crops Grown in Organic and Other Production Systems

Culturable microbial communities and diseases were compared in organic, integrated and conventional systems of winter wheat production and monoculture. Particular emphasis was placed on the density and diversity of cereal pathogens and their potential antagonists, and on the association of the active microbial populations with the health and productivity of wheat. In roots, rhizoplane and rhizosphere, fungi tended to be most abundant in the integrated system or monoculture, and bacteria in the organic system. The dominant fungal groups (with individual frequency >5%) included root pathogens (Fusarium, Gibberella, Haematonectria and Ilyonectria) and known pathogen antagonists (Acremonium strictum, Clonostachys, Chaetomium, Gliocladium and Trichoderma spp.). The 50 subdominant species (with individual frequency 1–5%) included the pathogens Alternaria, Cladosporium (leaf spot), Gaeumannomyces graminis (take‐all), Glomerella graminicola (anthracnose), Oculimacula yallundae (eyespot), Phoma spp. (leaf spots), and Pythium and Rhizoctonia (root rot). The 40 subrecedent species (with individual frequency <1%) included minor pathogens (Botrytis, Coniothyrium, Leptosphaeria). Antagonists in roots, rhizoplane and rhizosphere were most frequent in the organic system and least frequent in monoculture, suggesting that these systems had the most and least disease‐suppressive habitats, respectively. The other two systems were intermediate, with microbial communities suggesting that the conventional system produced a slightly more suppressive environment than the integrated system. The highest grain yield, in the integrated system, was associated with high abundance of fungi, including fungal pathogens, lowest abundance of Arthrobacter, Pseudomonas and Streptomyces in roots, rhizoplane and soil, and relatively high stem‐base and leaf disease severity. The lowest grain yields, in the organic system and monoculture, were associated with less abundant fungi and more abundant Pseudomonas. There is no clear indication that yields were affected by diseases.