Patterns of RAPD markers and heavy metal concentrations in <Emphasis Type=Italic>Perna viridis</Emphasis> (L.), collected from metal-contaminated and uncontaminated coastal waters: Are they correlated with each other?

Genetic variation due to heavy metal contamination has always been an interesting topic of study. Because of the numerous contaminants being found in coastal and intertidal waters, there is always much discussion and argument as to which contaminant(s) caused the variations in the genetic structures of biomonitors. This study used a Single Primer Amplification Reaction (SPAR) technique, namely Random Amplified Polymorphic DNA (RAPD), to determine the genetic diversity of the populations of the green-lipped mussel Perna viridis collected from a metal-contaminated site at Kg. Pasir Puteh and those from four relatively uncontaminated sites (reference sites). Heavy metal levels (Cd, Cu, Pb, and Zn) were also measured in the soft tissues and byssus of the mussels from all the sites. Cluster analyses employing UPGMA based on the RAPD markers grouped the populations into two major clusters; the Bagan Tiang, Pantai Lido, Pontian, and Kg. Pasir Puteh populations were in one cluster, while the Sg. Belungkor population clustered by itself. This indicated that the genetic diversity based on bands resulting from the use of all four RAPD primers on P. viridis did not indicate its potential use as a biomarker of heavy metal pollution in coastal waters. However, based on a correlation analysis between a particular metal and a band resulting from a specific RAPD primer revealed some significant (P < 0.01) correlations between the primers and the heavy metal concentrations in the byssus and soft tissues. Thus, the correlation between a particular metal and the bands resulting from the use of a specific RAPD primer on P. viridis could be used as biomonitoring tool of heavy metal pollution. The text was submitted by the authors in English.     

British Isles coastal waters: The concentrations of selected heavy metals in sea water,suspended matter and biological indicators — A pilot survey

Data, from British Isles coastal waters, on the concentrations of selected metals in sea water and biological indicators, have been obtained by analytical techniques based on atomic absorption spectrophotometry. The results show that there are some areas where significant contamination exists, and the east Irish Sea appears to have the highest concentrations of most metals. However, data in most regions indicate that the concentrations of the metals examined are not significantly higher than those in the open Atlantic Ocean adjacent to the British Isles. The sampling of seaweeds strongly suggests that concentrations of most metals, including those in polluted areas, have changed little over the ten years up to 1970; the concentrations of cadmium may well, on average, have fallen over this period. In the Irish Sea, where the most detailed examination has been made, there is a rapid decrease in sea water concentrations from the shoreline to offshore, and, in general, the proportions of a metal associated with suspended matter remain fairly constant with respect to variations of total concentrations in either time or space.     

Occurrence of symmetrical diacylguanidines triophamine and limaciamine in three polyceridae species from Canary Islands: are they chemical markers of these nudibranchs?

Two symmetrical diacylguanidines, triophamine (1) and limaciamine (2), have been found to occur in three Polyceridae nudibranchs from Canary Islands. These compounds were previously reported from taxonomically related species collected from distinct geographical areas. Due to the peculiar occurrence of 1 and 2 in Polyceridae nudibranchs and, in particular, exclusively in members of Polycerinae and Triophinae subfamilies, it should be suggested that these diacylguanidines are distinctive chemical markers of this group of nudibranchs.     

The evolution of creationists in the United States: Where are they now,and where are they going?

The history of anti-evolutionism in the United States begins only in the early decades of the 20th century but has evolved considerably since then. Various versions of the movement (“equal time” for creationism, “creation science”, “intelligent design”) have developed over time, but they have made few positive contributions to serious discourse about science and religion. Their main goal has been to try to stop the teaching of evolution. The most recent version of creationism, “intelligent design” (ID), has little in common with William Paley's 18th-century version: ID posits an interventionist Deity who regularly interferes in natural processes to produce complex biological structures and functions. The 2005 “intelligent design” trial in Dover, Pennsylvania, destroyed any pretensions that the movement had to scientific integrity. However, anti-evolutionists continue to foment discord at local levels, where opposition to the teaching of evolution can be presented without strong resistance. Scientists can best demonstrate their concern by becoming involved in federal, state, and local administrative processes that determine curricula and develop and adopt textbooks and other instructional materials. To cite this article: K. Padian, C. R. Biologies 332 (2009).     

Hollow spheroids in ascites of ovarian clear cell carcinoma: how are they formed and how do they behave?

N. Kato, K. Narutomi, M. Fukase and T. Motoyama Hollow spheroids in ascites of ovarian clear cell carcinoma: how are they formed and how do they behave? Objective: Although the multicellular aggregates (spheroids) in malignant ascites are usually solid throughout, they sometimes have acellular hollow spaces, especially in ascites of ovarian clear cell carcinoma. The purpose of this study is to analyse the origin and behaviour of hollow spheroids. Methods: Archival cytological and histological specimens of 32 ovarian carcinomas, including 12 clear cell carcinomas, were reviewed. HAC‐2, a clear cell carcinoma cell line, was injected into the abdominal cavity of nude mice for direct comparison of ascitic cytology and tumour histology. Spheroids that were collected from nude mice ascites were cultured in vitro to observe their behaviour. Results: Five of six clear cell carcinomas with hollow spheroids showed spherule‐like hyaluronan‐rich stroma in their tumour tissue, whereas those without hollow spheroids did not. After heterotransplantation, both ascites and tumour imprints showed small or large hollow spheroids. Hyaluronan was detected in the former but not in the latter. The abdominal tumours showed compact spherule‐like hyaluronan‐rich stroma, enlarged oedematous stroma or intermediate stroma. In both size and hyaluronan status, small and large hollow spheroids were approximately comparable to spherule‐like hyaluronan‐rich stroma and oedematous stroma, respectively. During culture in vitro, hollow spheroids were maintained as hollow spheroids in suspension, and produced daughter hollow spheroids. Conclusions: The hollow space in the spheroids originates from spherule‐like hyaluronan‐rich stroma, where water trapping by hyaluronan causes enlargement of the space. The matrix within the hollow space serves as a scaffold that regulates cell polarity and matrix production.     

Genetic and karyotypic structure in the shrews of the Sorex araneus group: are they independent?

The species of the common shrew (Sorex araneus) group are morphologically very similar but exhibit high levels of karyotypic variation. Here we used genetic variation at 10 microsatellite markers in a data set of 212 individuals mostly sampled in the western Alps and composed of five karyotypic taxa (Sorex coronatus, Sorex antinorii and the S. araneus chromosome races Cordon, Bretolet and Vaud) to investigate the concordance between genetic and karyotypic structure. Bayesian analysis confirmed the taxonomic status of the three sampled species since individuals consistently grouped according to their taxonomical status. However, introgression can still be detected between S. antinorii and the race Cordon of S. araneus. This observation is consistent with the expected low karyotypic complexity of hybrids between these two taxa. Geographically based cryptic substructure was discovered within S. antinorii, a pattern consistent with the different postglaciation recolonization routes of this species. Additionally, we detected two genetic groups within S. araneus notwithstanding the presence of three chromosome races. This pattern can be explained by the probable hybrid status of the Bretolet race but also suggests a relatively low impact of chromosomal differences on genetic structure compared to historical factors. Finally, we propose that the current data set (available at http://www.unil.ch/dee/page7010_en.html#1) could be used as a reference by those wanting to identify Sorex individuals sampled in the western Alps.     

Expression of the neural stem cell markers NG2 and L1 in human angiomyolipoma: are angiomyolipomas neoplasms of stem cells?

Angiomyolipomas are benign tumors of the kidney which express phenotypes of smooth muscle, fat, and melanocytes. These tumors appear with increased frequency in the autosomal dominant disorder tuberous sclerosis and are the leading cause of morbidity in adults with tuberous sclerosis. While benign, these tumors are capable of provoking life threatening hemorrhage and replacement of the kidney parenchyma, resulting in renal failure. The histogenesis of these tumors is currently unclear, although currently, we believe these tumors arise from "perivascular epithelioid cells" of which no normal counterpart has been convincingly demonstrated. Recently, stem cell precursors have been recognized that can give rise to smooth muscle and melanocytes. These precursors have been shown to express the neural stem cell marker NG2 and L1. In order to determine whether angiomyolipomas, which exhibit smooth muscle and melanocytic phenotypes, express NG2 and L1, we performed immunocytochemistry on a cell line derived from a human angiomyolipoma, and found that these cells are uniformly positive. Immunohistochemistry of human angiomyolipoma specimens revealed uniform staining of tumor cells, while renal cell carcinomas revealed positivity only of angiogenic vessels. These results support a novel histogenesis of angiomyolipoma as a defect in differentiation of stem cell precursors.     

Does atypical 15N and 13C enrichment in parasites result from isotope ratio variation of host tissues they are infected?

Limnology - Contrary to a general rule of stable isotope trophic discrimination, parasites show great variation in isotope discrimination from their host muscle tissues. One of the possible...     

Structural isomers of the S2 state in photosystem II: do they exist at room temperature and are they important for function?

In nature, an oxo‐bridged Mn₄CaO₅ cluster embedded in photosystem II (PSII), a membrane‐bound multi‐subunit pigment protein complex, catalyzes the water oxidation reaction that is driven by light‐induced charge separations in the reaction center of PSII. The Mn₄CaO₅ cluster accumulates four oxidizing equivalents to enable the four‐electron four‐proton catalysis of two water molecules to one dioxygen molecule and cycles through five intermediate S‐states, S₀ – S₄ in the Kok cycle. One important question related to the catalytic mechanism of the oxygen‐evolving complex (OEC) that remains is, whether structural isomers are present in some of the intermediate S‐states and if such equilibria are essential for the mechanism of the O‐O bond formation. Here we compare results from electron paramagnetic resonance (EPR) and X‐ray absorption spectroscopy (XAS) obtained at cryogenic temperatures for the S₂ state of PSII with structural data collected of the S₁, S₂ and S₃ states by serial crystallography at neutral pH (～6.5) using an X‐ray free electron laser at room temperature. While the cryogenic data show the presence of at least two structural forms of the S₂ state, the room temperature crystallography data can be well‐described by just one S₂ structure. We discuss the deviating results and outline experimental strategies for clarifying this mechanistically important question.     

Species richness, taxonomy and peculiarities of the neotropical rust fungi: are they more diverse in the Neotropics?

The species richness of rust fungi (Pucciniales or Uredinales) in the neotropics is reviewed. Species numbers are presented for all neotropical countries and rust-plant-ratios calculated. It is discussed whether the ratio for a given region can be explained by the species richness of vascular plants alone or whether it is caused by additional factors. In the first case, ratios should apply globally and vary only slightly; in the second case, more diverging ratios are expected. Observed ratios ranged between 1:16 and 1:124 in the neotropics. The large differences are certainly influenced by unequal levels of investigation, rendering interpretation difficult. Differences seem also to be influenced by the taxonomic composition of floras regarding the percentage of host families or genera bearing different numbers of rust species. This indicates that rust species richness is not driven solely by plant species richness. Ratios calculated for Switzerland, Austria and Japan are distinctly higher than for the neotropics indicating that certain temperate regions are proportionally richer in rust fungi than the neotropics. Uredinial states and short-cycled rust species prevail in the neotropics. The preponderance of uredinial states may be due to the heterogeneous spatial composition of certain vegetation types in the wet tropics. Short-cycled rusts may be adapted to a pronounced seasonality that can be encountered in many drier neotropical biomes. Future research needs to fill our knowledge gaps on the taxonomy and ecology of neotropical rust fungi are discussed.     

Circulating levels of isoflavones and markers of 5alpha-reductase activity are higher in Japanese compared with New Zealand males: what is the role of circulating steroids in prostate disease?

Epidemiological evidence implicates dietary isoflavone intake as protective against prostate disease. A putative mechanism is attenuated circulating androgen levels in male populations consuming an isoflavone rich diet. We investigated this hypothesis by collecting plasma from 60 Japanese and 60 New Zealand males aged between 21 and 31 years each consuming their traditional diets. We measured plasma testosterone, dihydrotestosterone (DHT), androstenedione, dehydroepiandrosterone sulfate (DHEAS), the combined levels of androsterone sulfate and epiandrosterone sulfate (AoS/epiAoS), sex hormone-binding globulin, and cortisol and corticosteroid-binding globulin as well as the isoflavones genistein and equol. Plasma genistein and equol levels were several times higher in Japanese males as would be expected from an isoflavone rich diet. However, androstenedione, DHEAS, calculated free testosterone and paradoxically markers of 5alpha-reductase, DHT and AoS/epiAoS were all also significantly higher in Japanese rather than the New Zealand male counterparts. All other comparisons were not significant. Plasma DHT and DHEAS correlated positively with plasma equol and plasma AoS/epiAoS correlated positively with genistein levels. Taken together the results suggest that, rather than reduced levels of steroidogenesis, Japanese males may have increased 5alpha-reductase activity and possibly altered 17beta OH steroid dehydrogenase activity. Significantly the positive association between isoflavones levels and 5alpha-steroids is counter-intuitive to isoflavone intake offering prostate protection, unless this is postulated to occur through other mechanisms.     

Induction of heat shock proteins, changes in liver ultrastructure, and alterations of fish behavior: are these biomarkers related and are they useful to reflect the state of pollution in the field?

Heat shock protein (hsp70) expression, changes inliver ultrastructure, and alterations of swimmingbehavior were simultaneously investigated in browntrout (Salmo trutta f. fario) exposed towater from test streams in southern Germany undersemi-field conditions during 1995 and 1996. Chemicalanalyses revealed different levels of contamination ofthe two streams by pesticides, PAHs, PCBs, and heavymetals, whereas stream pollution was only partlyreflected by body burdens of contaminants in fish.Biomarker responses were compared after differenttimes of exposure and with respect to differenttemperature conditions. Differences in pollutionstates of the streams were reflected by differentbiomarker responses of the trout. In the highlycontaminated stream, the biomarker responses were morecoincident with one another than in the moderatelypolluted stream in which the biomarkers showed littlerelation to one another. This is primarily due to thedifferential capacities of the biomarkers to integratestress responses over time. Understanding the dynamicsof the stress response curves and the effects oftemperature on biomarker responses is essential forevaluating the effects of environmental stressors suchas contaminants on the health of organisms.     

Studies on UV reflection in feathers of some 1000 bird species: are UV peaks in feathers correlated with violet‐sensitive and ultraviolet‐sensitive cones?

Nine hundred and sixty-eight bird species, covering all orders, were studied in search of distinctive ultraviolet reflections. All species in the following orders were completely surveyed: Struthioniformes, Tinamiformes, Craciformes, Turniciformes, Galbuliformes, Upupiformes, Coliiformes, Apodiformes and Musophagiformes. The coloured plumage regions in particular exhibited high proportions of UV-reflecting feathers. Bird orders with species which are believed to possess VS (violet-sensitive) cone types mostly had their UV maxima between 380 and 399 nm while orders with species which are assumed to have UVS (ultraviolet-sensitive) cone types contained significantly species which had their UV maxima between 300 and 379 nm. With an emphasis on non-passerine birds the present study provides evidence that birds of many more groups may see UV light than have been studied to date. Ecological aspects related to UV reflection and perception, as well as sexual dimorphism visible only in the UV, are discussed.     

Decay kinetics and quantum yields of fluorescence in photosystem I from Synechococcus elongatus with P700 in the reduced and oxidized state: are the kinetics of excited state decay trap-limited or transfer-limited?

Transfer and trapping of excitation energy in photosystem I (PS I) trimers isolated from Synechococcus elongatus have been studied by an approach combining fluorescence induction experiments with picosecond time-resolved fluorescence measurements, both at room temperature (RT) and at low temperature (5 K). Special attention was paid to the influence of the oxidation state of the primary electron donor P700. A fluorescence induction effect has been observed, showing a approximately 12% increase in fluorescence quantum yield upon P700 oxidation at RT, whereas at temperatures below 160 K oxidation of P700 leads to a decrease in fluorescence quantum yield ( approximately 50% at 5 K). The fluorescence quantum yield for open PS I (with P700 reduced) at 5 K is increased by approximately 20-fold and that for closed PS I (with P700 oxidized) is increased by approximately 10-fold, as compared to RT. Picosecond fluorescence decay kinetics at RT reveal a difference in lifetime of the main decay component: 34 +/- 1 ps for open PS I and 37 +/- 1 ps for closed PS I. At 5 K the fluorescence yield is mainly associated with long-lived components (lifetimes of 401 ps and 1.5 ns in closed PS I and of 377 ps, 1.3 ns, and 4.1 ns in samples containing approximately 50% open and 50% closed PS I). The spectra associated with energy transfer and the steady-state emission spectra suggest that the excitation energy is not completely thermally equilibrated over the core-antenna-RC complex before being trapped. Structure-based modeling indicates that the so-called red antenna pigments (A708 and A720, i.e., those with absorption maxima at 708 nm and 720 nm, respectively) play a decisive role in the observed fluorescence kinetics. The A720 are preferentially located at the periphery of the PS I core-antenna-RC complex; the A708 must essentially connect the A720 to the reaction center. The excited-state decay kinetics turn out to be neither purely trap limited nor purely transfer (to the trap) limited, but seem to be rather balanced.     

Trace elements in otoliths of the two‐banded bream from a coastal region in the south‐west Mediterranean: are there differences among locations?

There were no significant differences in otolith chemistry (Li, Mn, Sr, Cd, Ba) of Diplodus vulgaris between sites (distances >100 m) and few differences among locations (distance >10 km) along the south-west coast of Spain. Multivariate analysis of otolith chemistry detected a difference among locations, but a posteriori comparisons could not detect which locations differed. This is one of the few studies to show little variation in otolith chemistry among locations. Of the studies reviewed, <10% showed non-significant differences. It is suggested that the region of the Mediterranean where this study was conducted may be relatively homogeneous in comparison to estuarine and coastal regions where many of the other studies have been conducted.     

Photoreducible high spin iron electron paramagnetic resonance signals in dark-adapted Photosystem II: are they oxidised non-haem iron formed from interaction of oxygen with PSII electron acceptors?

An electron paramagnetic resonance (EPR) signal near g=6 in Photosystem II (PSII) membranes has been assigned to a high spin form of cytochrome (Cyt) b(559) (R. Fiege, U. Schreiber, G. Renger, W. Lubitz, V.A. Shuvalov, FEBS Lett. 377 (1995) 325-329). Here we have further investigated the origin of this signal. A slow formation of the signal during storage in the dark is observed in oxygen-evolving PSII membranes, which correlate with the oxidation of Fe(2+) by plastosemiquinone or oxygen. Removal of oxygen inhibits formation of the high spin iron signal. The g=6 EPR signal is photoreduced at cryogenic temperatures and is restored slowly by subsequent dark storage at 77 K. The amplitude of the photoreduced signal increases as the pH is lowered, which shows that the origin is not the hydroxyl ligated Cyt b(559) species proposed previously. Different cryoprotectants also influence the amplitude and lineshape of the high spin iron signal in a manner suggesting that smaller cryoprotectants can penetrate the iron environment. A correlation between the high spin iron and g=1.6 EPR signal assigned to an interaction involving the semiquinones of Qa and Qb is shown. It is concluded that the appearance of the high spin iron signal in oxygen-evolving PSII membranes involves reduced PSII electron acceptors and oxygen and suggests that the signal is from the non-haem iron of PSII.     

Polyploidy and microsatellite variation in the relict tree Prunus lusitanica L.: how effective are refugia in preserving genotypic diversity of clonal taxa?

Refugia are expected to preserve genetic variation of relict taxa, especially in polyploids, because high gene dosages could prevent genetic erosion in small isolated populations. However, other attributes linked to polyploidy, such as asexual reproduction, may strongly limit the levels of genetic variability in relict populations. Here, ploidy levels and patterns of genetic variation at nuclear microsatellite loci were analysed in Prunus lusitanica, a polyploid species with clonal reproduction that is considered a paradigmatic example of a Tertiary relict. Sampling in this study considered a total of 20 populations of three subspecies: mainland lusitanica (Iberian Peninsula and Morocco), and island azorica (Azores) and hixa (Canary Islands and Madeira). Flow cytometry results supported an octoploid genome for lusitanica and hixa, whereas a 16‐ploid level was inferred for azorica. Fixed heterozygosity of a few allele variants at most microsatellite loci resulted in levels of allelic diversity much lower than those expected for a high‐order polyploid. Islands as a whole did not contain higher levels of genetic variation (allelic or genotypic) than mainland refuges, but island populations displayed more private alleles and higher genotypic diversity in old volcanic areas. Patterns of microsatellite variation were compatible with the occurrence of clonal individuals in all but two island populations, and the incidence of clonality within populations negatively correlated with the estimated timing of colonization. Our results also suggest that gene flow has been very rare among populations, and thus population growth following founder events was apparently mediated by clonality rather than seed recruitment, especially in mainland areas. This study extends to clonal taxa the idea of oceanic islands as important refugia for biodiversity, since the conditions for generation and maintenance of clonal diversity (i.e. occasional events of sexual reproduction, mutation and/or seed immigration) appear to have been more frequent in these enclaves than in mainland areas.     

Serum thyrotropin, thyroxine and free thyroxine concentrations as predictors of mortality in critically ill puppies with parvovirus infection: a model for human paediatric critical illness?

This prospective case-controlled study investigated the role of the pituitary-thyroidal axis in the prediction of mortality in dogs. Serum thyrotropin, thyroxine and free thyroxine were measured at admission and daily until death or discharge in dogs ill with parvoviral diarrhoea. Serum thyroxine and free thyroxine in ill dogs were significantly lower than in controls and also significantly lower in nonsurvivors than in survivors on days 1-4. Serum thyrotropin at admission in ill dogs was similar to controls, but was significantly higher in nonsurvivors than in survivors. Thyrotropin concentrations became significantly lower in nonsurvivors vs survivors by day 4.