A new species of Pareledone (Cephalopoda : Octopodidae) from Antarctic Peninsula Waters

During recent cruises aboard RV Polarstern in the Antarctic Peninsula region, a new species of benthic octopodid was discovered whose generic affinities based on morphological characteristics were uncertain. Molecular sequence analysis of six mitochondrial and nuclear genes allows this species to be placed with confidence within the genus Pareledone. The species is described herein and morphological diagnostic characters are provided for its identification.

Formation of Novel Di-Nuclear Lanthanide Luminescent Sm(III), Eu(III) and Tb(III) Triple Stranded Helicates from a C2 Symmetrically 2,6-Dicarboxylic Amide based 1,3-Xylene Ligand in CH3CN

The synthesis of the C2-symmetrical ligand 1 consisting of two naphthalene units connected to two pyridine-2,6-dicarboxamide moieties linked by a xylene spacer and the formation of LnIII-based (Ln1/4 Sm, Eu, Tb, and Lu) dimetallic helicates [Ln2 · 13] in MeCN by means of a metal-directed synthesis is described. By analyzing the metal-induced changes in the absorption and the fluorescence of 1, the formation of the helicates, and the presence of a second species [Ln2 · 12] was confirmed by nonlinear- regression analysis. While significant changes were observed in the photophysical properties of 1, the most dramatic changes were observed in the metal-centred lanthanide emissions, upon excitation of the naphthalene antennae. From the changes in the lanthanide emission, we were able to demonstrate that these helicates were formed in high yields (ca. 90% after the addition of 0.6 equiv. of LnIII), with high binding constants, which matched well with that determined from the changes in the absorption spectra. The formation of the LuIII helicate, [ Lu2 · 13 ] , was also investigated for comparison purposes, as we were unable to obtain accurate binding constants from the changes in the fluorescence emission upon formation of [Sm2 · 13], [Eu2 · 13], and [Tb2 · 13].

Unidirectional hybridization at a species' range boundary: implications for habitat tracking

Aim Introgressive hybridization between a locally rare species and a more abundant congener can drive population extinction via genetic assimilation, or the replacement of the rare species gene pool with that of the common species. To date, however, few studies have assessed the effects of such processes at the limits of species' distribution ranges. In this study, we have examined the potential for hybridization between range-edge populations of the wintergreen Pyrola minor and sympatric populations of Pyrola grandiflora. Location Qeqertarsuaq, Greenland and Churchill, Manitoba, Canada. Methods Genetic analysis of samples from Greenland and Canada was carried out using a combination of nuclear and chloroplast single nucleotide polymorphisms (SNPs). Results Analysis of nuclear SNPs confirmed hybridization in populations of morphologically intermediate individuals, as well as revealing the existence of cryptic hybrids in ostensibly morphologically pure P. minor populations. Analysis of chloroplast SNPs revealed that this hybridization is unidirectional and suggests that hybrids originate via pollen swamping of P. minor by the more common P. grandiflora. Main conclusions Extensive unidirectional hybridization may lead to the extinction of peripheral populations of P. minor where the two species grow sympatrically. Extinction could occur as a result of genetic assimilation where F1s are fertile, or via the removal of unidirectionally pollinated sterile F1s, or by a combination of these processes. This could compromise the ability of species to respond to climate change via habitat tracking, although the final outcome of these processes may ultimately depend on the rate of global climate change and its effect on the species' distributions. © 2009 Blackwell Publishing Ltd.

Four independent gene phylogenies confirm the ancient relationships of Madagascar endemic species in the Papilio demoleus group (Lepidoptera, Papilionidae).

Madagascar is home to numerous endemic species and lineages, but the processes that have contributed to its endangered diversity are still poorly understood. Evidence is accumulating to demonstrate the importance of Tertiary dispersal across varying distances of oceanic barriers, supplementing vicariance relationships dating back to the Cretaceous, but these hypotheses remain tentative in the absence of well-supported phylogenies. In the Papilio demoleus group of swallowtail butterflies, three of the five recognized species are restricted to Madagascar, whereas the remaining two species range across the Afrotropical zone and southern Asia plus Australia. We reconstructed phylogenetic relationships for all species in the P. demoleus group, as well as 11 outgroup Papilio species, using 60 morphological characters and about 4 kb of nucleotide sequences from two mitochondrial (cytochrome oxidase I and II) and two nuclear (wg and EF-1a) genes. Of the three endemic Malagasy species, the two that are formally listed as endangered or at risk represented the most basal divergences in the group, while the more common third endemic was clearly related to African P. demodocus. The fifth species, P. demoleus, showed little differentiation across southern Asia, but showed divergence from its subspecies sthenelus in Australia. Dispersal-vicariance analysis using cladograms derived from morphology and three independent genes indicated a Malagasy diversification of lime swallowtails in the middle Miocene. Thus, diversification processes on the island of Madagascar may have contributed to the origin of common butterflies that now occur throughout much of the Old World tropical and subtemperate regions. An alternative hypothesis, that Madagascar is a refuge for ancient lineages resulting from successive colonizations from Africa, is less parsimonious and does not explain the relatively low continental diversity of the group.

Development and characterization of 10 polymorphic microsatellite loci for the blue shark, Prionace glauca, and their cross shark-species amplification.

Ten polymorphic nuclear microsatellite loci were developed from a microsatellite enriched genomic library of the blue shark, Prionace glauca. The utility of these markers for genetic studies of this globally distributed, heavily exploited, oceanic predator was assessed by screening 120 specimens sampled from six locations throughout the species’ range. Both moderately and highly polymorphic marker loci were identified. Three to 35 alleles were found to be segregating per locus (mean 10.1) with observed heterozygosities ranging from 24 to 91%. Evaluation of the cross-species amplification of these markers across 18 additional shark species indicates that these microsatellites are potentially useful for genetic studies of other species of conservation concern.

Unique genetic variation at a species' rear edge is under threat from global climate change

Global climate change is having a significant effect on the distributions of a wide variety of species, causing both range shifts and population extinctions. To date, however, no consensus has emerged on how these processes will affect the range-wide genetic diversity of impacted species. It has been suggested that species that recolonized from low-latitude refugia might harbour high levels of genetic variation in rear-edge populations, and that loss of these populations could cause a disproportionately large reduction in overall genetic diversity in such taxa. In the present study, we have examined the distribution of genetic diversity across the range of the seaweed Chondrus crispus, a species that has exhibited a northward shift in its southern limit in Europe over the last 40 years. Analysis of 19 populations from both sides of the North Atlantic using mitochondrial single nucleotide polymorphisms (SNPs), sequence data from two singlecopy nuclear regions and allelic variation at eight microsatellite loci revealed unique genetic variation for all marker classes in the rear-edge populations in Iberia, but not in the rear-edge populations in North America. Palaeodistribution modelling and statistical testing of alternative phylogeographic scenarios indicate that the unique genetic diversity in Iberian populations is a result not only of persistence in the region during the last glacial maximum, but also because this refugium did not contribute substantially to the recolonization of Europe after the retreat of the ice. Consequently, loss of these rear-edge populations as a result of ongoing climate change will have a major effect on the overall genetic diversity of the species, particularly in Europe, and this could compromise the adaptive potential of the species as a whole in the face of future global warming.

Endocrine disrupting effects of zearalenone, alpha- and beta-zearalenol at the level of nuclear receptor binding and steroidogenesis.

The mycotoxin zearalenone (ZEN) is a secondary metabolite of fungi which is produced by certain species of the genus Fusarium and can occur in cereals and other plant products. Reporter gene assays incorporating natural steroid receptors and the H295R steroidogenesis assay have been implemented to assess the endocrine disrupting activity of ZEN and its metabolites -zearalenol (-ZOL) and -zearalenol (-ZOL). -ZOL exhibited the strongest estrogenic potency (EC50 0.022 ± 0.001 nM), slightly less potent than 17- estradiol (EC50 0.015 ± 0.002 nM). ZEN was ~70 times less potent than -ZOL and twice as potent as -ZOL. Binding of progesterone to the progestagen receptor was shown to be synergistically increased in the presence of ZEN, -ZOL or -ZOL. ZEN, -ZOL or -ZOL increased production of progesterone, estradiol, testosterone and cortisol hormones in the H295R steroidogenesis assay, with peak productions at 10 M. At 100 M, cell viability decreased and levels of hormones were significantly reduced except for progesterone. -ZOL increased estradiol concentrations more than -ZOL or ZEN, with a maximum effect at 10 M, with -ZOL (562 ± 59 pg/ml) > -ZOL (494 ± 60 pg/ml) > ZEN (375 ± 43 pg/ml). The results indicate that ZEN and its metabolites can act as potential endocrine disruptors at the level of nuclear receptor signalling and by altering hormone production.

NUCLEAR STAINING IN ALGAL HERBARIUM MATERIAL - A REAPPRAISAL OF THE HOLOTYPE OF CALLITHAMNION-DECOMPOSITUM AGARDH,J. (RHODOPHYTA)

The taxonomic importance of uninucleate vs. multinucleate vegetative cells in the Ceramiaceae is emphasized. It has been possible to make visible nuclei in old material, including type specimens, using aceto-carmine and aceto-iron-haematoxylin stains. The holotypes of Ceramium roseum and Callithamnion fasciculatum (currently known as Callithamnion roseum and Pleonosporium borreri var. fasciculatum) have uninucleate cells and belong to Aglaothamnion. In contrast, the holotype of Callithamnion decompositum, a name that has been applied to collections of at least two uninucleate taxa, has multinucleate cells; its morphological and cytological details agree with those of specimens collected in France and Ireland that were previously thought to represent an undescribed species. Female reproductive morphology (described from a thallus with gametangia in addition to tetrasporangia), in conjunction with habit and vegetative features, indicates that this species belongs to Compsothamnion (Compsothamnieae), as a third species, being distinguished from C. thuyoides and C. gracillimum by its sessile, lateral tetrasporangia. The required new combinations under Aglaothamnion and Compsothamnion are made.

Degradation of 4-fluorobiphenyl by mycorrhizal fungi as determined by (19)F nuclear magnetic resonance spectroscopy and (14)C radiolabelling analysis

The pathways of biotransformation of 4-fluorobiphenyl (4FBP) by the ectomycorrhizal fungus Tylospora fibrilosa and several other mycorrhizal fungi were investigated by using (19)F nuclear magnetic resonance (NMR) spectroscopy in combination with (14)C radioisotope-detected high-performance liquid chromatography ((14)C-HPLC). Under the conditions used in this study T. fibrillosa and some other species degraded 4FBP. (14)C-HPLC profiles indicated that there were four major biotransformation products, whereas (19)F NMR showed that there were six major fluorine-containing products. We confirmed that 4-fluorobiphen-4'-ol and 4-fluorobiphen-3'-ol were two of the major products formed, but no other products were conclusively identified. There was no evidence for the expected biotransformation pathway (namely, meta cleavage of the less halogenated ring), as none of the expected products of this route were found. To the best of our knowledge, this is the first report describing intermediates formed during mycorrhizal degradation of halogenated biphenyls.

Postglacial dispersal, rather than in situ glacial survival, best explains the disjunct distribution of the Lusitanian plant species Daboecia cantabrica (Ericaceae)

Aim:

The distribution of the Lusitanian flora and fauna, species which are found only in southern and western Ireland and in northern Spain and Portugal but which are absent from intervening countries, represents one of the classic conundrums of biogeography. The aim of the present study was to determine whether the distribution of the Lusitanian plant species Daboecia cantabrica was due to persistence in separate Irish and Iberian refugia, or has resulted from post-glacial recolonization followed by subsequent extinction of intervening populations.

Location:

Northern Spain and Co. Galway, western Ireland.

Methods:

Palaeodistribution modelling using Maxent was employed to identify putative refugial areas for D. cantabrica at the Last Glacial Maximum (LGM). Phylogeographical analysis of samples from 64 locations in Ireland and Spain were carried out using a chloroplast marker (atpB–rbcL), the nuclear ITS region, and an anonymous nuclear single-copy locus.

Results:

The palaeodistribution model indicated areas with a high probability of survival for D. cantabrica at the LGM off the western coast of Galicia in Spain, and in the Bay of Biscay. Spanish populations exhibited substantially higher genetic diversity than Irish populations at all three loci, as well as geographical structuring of haplotypes within Spain consistent with divergence in separate refugia. Spanish populations also exhibited far more endemic haplotypes. Divergence time between Irish and Spanish populations associated with the putative Biscay refugium was estimated as 3.333–32 ka.

Main conclusions:

Our data indicate persistence by D. cantabrica throughout the LGM in two separate southern refugia: one in western Galicia and one in the area off the coast of western France which now lies in the Bay of Biscay. Spain was recolonized from both refugia, whilst Ireland was most likely recolonized from the Biscay refugium. On the balance of evidence across the three marker types and the palaeodistribution modelling, our findings do not support the idea of in situ survival of D. cantabrica in Ireland, contrary to earlier suggestions. The fact that we cannot conclusively rule out the existence of a small, more northerly refugium, however, highlights the need for further analysis of Lusitanian plant species.

Dietary Restriction Induced Longevity is Mediated by Nuclear Receptor NHR-62 in Caenorhabditis elegans

Dietary restriction (DR) extends lifespan in a wide variety of species, yet the underlying mechanisms are not well understood. Here we show that the C. elegans HNF4a- related nuclear hormone receptor NHR-62 is required for metabolic and physiologic responses associated with DR-induced longevity. nhr-62 mediates the longevity of eat- 2 mutants, a genetic mimetic of dietary restriction, and blunts the longevity response of DR induced by bacterial food dilution at low nutrient levels. Metabolic changes associated with DR, including decreased Oil Red O staining, increased autophagy, and changes in fatty acid composition are partly reversed by mutation of nhr-62. Expression profiles reveal that several hundred genes induced by DR depend on the activity of NHR-62, including a putative lipase required for the DR response. This study provides critical evidence that nuclear hormone receptors regulate the DR response, suggesting hormonal and metabolic control of life span.

Chiton phylogeny (Mollusca Polyplacophora) and the placement of the enigmatic species Choriplax grayi (H. Adams & Angas)

Shallow marine chitons (Mollusca:Polyplacophora:Chitonida) are widespread and well described from established morphoanatomical characters, yet key aspects of polyplacophoran phylogeny have remained unresolved. Several species, including Hemiarthrum setulosum Carpenter in Dall, 1876, and especially the rare and enigmatic Choriplax grayi (Adams & Angas, 1864), defy systematic placement. Choriplax is known from only a handful of specimens and its morphology is a mosaic of key taxonomic features from two different clades. Here, new molecular evidence provides robust support for its correct association with a third different clade: Choriplax is placed in the superfamily Mopalioidea. Hemiarthrum is included in Cryptoplacoidea, as predicted from morphological evidence. Our multigene analysis of standard nuclear and mitochondrial markers demonstrates that the topology of the order Chitonida is divided into four clades, which have also been recovered in previous studies: Mopalioidea is sister to Cryptoplacoidea, forming a clade Acanthochitonina. The family Callochitonidae is sister to Acanthochitonina. Chitonoidea is resolved as the earliest diverging group within Chitonida. Consideration of this unexpected result for Choriplax and our well-supported phylogeny has revealed differing patterns of shell reduction separating the two superfamilies within Acanthochitonina. As in many molluscs, shell reduction as well as the de novo development of key shell features has occurred using different mechanisms, in multiple lineages of chitons.

Effects of the mycotoxin patulin at the level of nuclear receptor transcriptional activity and steroidogenesis in vitro

Patulin (PAT) is a mycotoxin produced by various species of fungi, with Penicillium expansum being the most commonly occurring. Apples and apple products are the main sources of PAT contamination. This mycotoxin has been shown to induce toxic effects in animals, a few of which include reproductive toxicity and interference with the endocrine system. Here the endocrine disrupting potential of PAT has been investigated in vitro to identify disruption at the level of oestrogen, androgen, progestagen and glucocorticoid nuclear receptor transcriptional activity, and to assess interferences in estradiol, testosterone and progesterone steroid hormone production. At the receptor level, 0.5-5000ng/ml (0.0032-32μM) PAT did not appear to induce any specific (ant) agonistic responses in reporter gene assays (RGAs); however, nuclear transcriptional activity was affected. A >6 fold increase in the glucocorticoid receptor transcriptional activity was observed following treatment with 5000ng/ml PAT in the presence of cortisol. At the hormone production level, despite cytotoxicity being observed after treatment with 5000ng/ml PAT, estradiol levels had increased >2 fold. At 500ng/ml PAT treatment, an increase in progesterone and a decrease in testosterone production were observed. The findings of this study could be considered in assessing the health risks following exposure to PAT.

Characterisation of deuterium spectra from laser driven multi-species sources by employing differentially filtered image plate detectors in Thomson spectrometers

A novel method for characterising the full spectrum of deuteron ions emitted by laser driven multi-species ion sources is discussed. The procedure is based on using differential filtering over the detector of a Thompson parabola ion spectrometer, which enables discrimination of deuterium ions from heavier ion species with the same charge-to-mass ratio (such as C^{6 +}, O^{8 +}, etc.). Commonly used Fuji Image plates were used as detectors in the spectrometer, whose absolute response to deuterium ions over a wide range of energies was calibrated by using slotted CR-39 nuclear track detectors. A typical deuterium ion spectrum diagnosed in a recent experimental campaign is presented, which was produced from a thin deuterated plastic foil target irradiated by a high power laser.

Photosensitized destruction of Chlorella vulgaris by methylene blue or nuclear fast red combined with hydrogen peroxide under visible light irradiation

A considerable number of investigations have started to elucidate the essential roles biological agents play in the biodeterioration of stone. Chemical biocides are becoming increasingly banned because of the environmental and health hazards associated with these toxic substances. The present study reports the photodynamic effect of Methylene Blue (MB) and Nuclear Fast Red (NFR) in the presence of hydrogen peroxide (H₂O₂) on the destruction of the algae Chlorella vulgaris (C. vulgaris) under irradiation with visible light. Illumination of C. vulgaris in the presence of MB or NFR combined with H₂O₂ results in the decomposition of both the algal species and the photosensitizer. The photodynamic effect was investigated under aerobic and anaerobic conditions. Differences in mechanism type are reported and are dependent on both the presence and the absence of oxygen. The behavior of each photosensitizer leads to a Type II mechanism and a Type I/Type II combination for MB and NFR, respectively, being concluded. This novel combination could be effective for the remediation of biofilm-colonized stone surfaces.