Cryobanking of viable biomaterials: implementation of new strategies for conservation purposes

Cryobanking, the freezing of biological specimens to maintain their integrity for a variety of anticipated and unanticipated uses, offers unique opportunities to advance the basic knowledge of biological systems and their evolution. Notably, cryobanking provides a crucial opportunity to support conservation efforts for endangered species. Historically, cryobanking has been developed mostly in response to human economic and medical needs — these needs must now be extended to biodiversity conservation. Reproduction technologies utilizing cryobanked gametes, embryos and somatic cells are already vital components of endangered species recovery efforts. Advances in modern biological research (e.g. stem cell research, genomics and proteomics) are already drawing heavily on cryobanked specimens, and future needs are anticipated to be immense. The challenges of developing and applying cryobanking for a broader diversity of species were addressed at an international conference held at Trier University (Germany) in June 2008. However, the magnitude of the potential benefits of cryobanking stood in stark contrast to the lack of substantial resources available for this area of strategic interest for biological science — and society at large. The meeting at Trier established a foundation for a strong global incentive to cryobank threatened species. The establishment of an Amphibian Ark cryobanking programme offers the first opportunity for global cooperation to achieve the cryobanking of the threatened species from an entire vertebrate class.     

Grapevine fanleaf virus (GFLV)-specific antibodies confer GFLV and Arabis mosaic virus (ArMV) resistance in Nicotiana benthamiana

Grapevine fanleaf virus (GFLV) is one of the most destructive pathogens of grapevine. In this study, we generated monoclonal antibodies binding specifically to the coat protein of GFLV. Antibody FL₃, which bound most strongly to GFLV and showed cross-reactivity to Arabis mosaic virus (ArMV), was used to construct the single-chain antibody fragment scFvGFLVcp-55. To evaluate the potential of this single-chain variable fragment (scFv) to confer antibody-mediated virus resistance, transgenic Nicotiana benthamiana plants were generated in which the scFv accumulated in the cytosol. Recombinant protein levels of up to 0.1% total soluble protein were achieved. The T₁ and T₂ progenies conferred partial or complete protection against GFLV on challenge with the viral pathogen. The resistance to GFLV in transgenic plants was strictly related to scFvGFLVcp-55 accumulation levels, confirming that the antibody fragment was functional in planta and responsible for the GFLV resistance. In addition, transgenic plants conferring complete protection to GFLV showed substantially enhanced tolerance to ArMV. We demonstrate the first step towards the control of grapevine fanleaf degeneration, as scFvGFLVcp-55 could be an ideal candidate for mediating nepovirus resistance.     

Early needle senescence and thinning of the crown structure of Picea abies as induced by chronic SO2pollution. I. Model deduction and analysis

Regarding time ranges of years, a rationale has been developed which is capable of explaining observed ‘spruce decline’ symptoms observed when spruce is exposed to air containing ambient levels of SO₂. It integrates and interrelates (i) ecophysiological data (tree morphology, assimilate partitioning, canopy turnover, senescence physiology, stomatal conductance, canopy throughfall, sulphur metabolism, tonoplast symport), (ii) pedological data (soil leaching, cation recycling, litter decomposition, forest nutrition), and (iii) meteorological data (site elevation, length of the annual trunk growth period, SO₂-pollution). Furthermore, it can explain field observations at numerous sites of spruce decline in central Europe where SO₂ is implicated as a factor of forest decline: (i) thinning of the canopy structure; (ii) early needle senescence; (iii) cation deficiency; (iv) low SO₂ tolerance at sites with depleted soils in the mountains; (v) synergism of SO₂pollution and acidic precipitation; (vi) recovery after liming, fertilization and after decreasing SO₂ pollution; and (vii) higher SO₂ tolerances of deciduous angiosperms. Different SO₂tolerance strategies are identified that are employed by more SO₂-tolerant tree species. Ecophysiological SO₂tolerance factors interact in a complex synergistic or antagonistic manner. It is concluded that chronic SO₂ pollution at ambient concentrations predisposes mainly evergreen gymnosperms to suffer under synergistic environmental stresses (frost, drought, pathogens, etc.). Thinning of the crown structure is massive at extreme sites, where several stresses act simultaneously on the trees (depleted soils, high SO₂ pollution, acidic rain, etc.). Mathematical formulations allow precise definitions of terms such as cooperativity, synergism, antagonism, vitality, predisposition, latency, etc. This universal rationale, which is applicable to all tree species, is exemplified here for Norway spruce (Picea abies [L.] Karst.). Integration of parameters yields an ordinary differential equation, which can be solved analytically. It predicts reversible dynamics of crown structures and gives an ecophysiological background to‘damage’.     

Outline of phylogeny and character evolution in Rhizocarpon (Rhizocarpaceae, lichenized Ascomycota) based on nuclear ITS and mitochondrial SSU ribosomal DNA sequences

The phylogeny of the lichen genus Rhizocarpon (Rhizocarpaceae, lichenized Ascomycota) was investigated using nucleotide sequences from the ITS region of the nuclear ribosomal DNA and the SSU region of the mitochondrial ribosomal DNA from 13 species of Rhizocarpon , Catolechia wahlenbergii and Poeltinula cerebrina . Phylogenetic estimations were performed using maximum parsimony and Bayesian MCMC tree sampling. Twelve phylogenetic null hypotheses were tested using MCMC tree sampling. The evolution of five morphological characters was assessed by mapping them onto MCMC tree samples. The results indicate that Rhizocarpon in its current sense is polyphyletic and can only be made monophyletic if R. hochstetteri is excluded or Poeltinula , and possibly also Catolechia , are included. The root placement in the Rhizocarpaceae is ambiguous, either Catolechia or Poeltinula + R. hochstetteri being the sistergroup to the rest of the family. Previously suggested infrageneric arrangements based on presence or absence of the yellow substance rhizocarpic acid in the thallus or the septation of the ascospores are unnatural. Some species with grey or brown thallus may have evolved from a yellow ancestor. Spore septation and colour, amyloidity of the thalline medulla, and the presence of stictic acid complex and rhizocarpic acid are shown to have changed multiple times during the course of evolution.  © 2002 The Linnean Society of London, Biological Journal of the Linnean Society , 2002, 77 , 535–546.     

On the distribution of developmental errors: comparing the normal, gamma, and log-normal distribution

The amount of between‐individual variation in the unobservable developmental instability (DI) has been the subject of intense recent debates. The unexpectedly high estimates of between‐individual variation in DI based on distributional characteristics of observable asymmetry values (of on average bilaterally symmetric traits) rely on statistical models that assume an underlying normal distribution of developmental errors. This prompted doubts on the assumption of the Gaussian nature of developmental errors. However, when applying other candidate distributions [log‐normal and gamma (γ)], recent analyses of empirical datasets have indicated that estimates remain generally high. Yet, all estimates were based on bilaterally symmetric traits, which did not allow for a formal comparison of the alternative distributions. In the present study, we extend a recent statistical model to allow statistical comparison of the different distributions based on traits that developed repeatedly under the same conditions, such as flower traits and regrown feathers. We analyse simulated and empirical data and show that: (1) it is statistically difficult to differentiate among the three alternatives when variances are small relative to the mean, as is often the case with DI; (2) the normal distribution fits the log‐normal or γ relatively well under those circumstances; (3) the deviance information criterion (DIC) is able to pick up differences in model fit among the three alternative distributions, yet more strongly so when levels of DI were high; (4) empirical datasets show a better fit of the normal over the log‐normal and γ‐distributions as judged by the DIC; and (5) estimates of between‐individual variation in DI in the three empirical datasets were relatively high (> 50%) under each distributional assumption. In conclusion, and based on our three datasets, the normal approximation appears to be a reasonable choice for statistical models of DI and the remarkably high estimates of variation in DI cannot be attributed to non‐normal developmental noise. Nevertheless, our method should be applied to a broad range of traits and organisms to evaluate the generality of this result. We argue that there is an urgent need for studies that reveal the underlying mechanisms of developmental noise and stability, as well as the role of developmental selection, in order to be able to determine the biological importance of the highly skewed distributions of developmental instability often observed. © 2007 The Linnean Society of London, Biological Journal of the Linnean Society, 2007, 92 , 197–210.     

Encarsia or Encarsiella? – redefining generic limits based on morphological and molecular evidence (Hymenoptera,Aphelinidae)

Abstract.  The genus Encarsiella ( syn.n. ) (Hymenoptera, Chalcidoidea, Aphelinidae) is synonymized with Encarsia on the basis of molecular and morphological characters. A phylogenetic analysis was conducted of the D2 expansion region of the 28S ribosomal DNA including thirty-eight Encarsia species. Our phylogenetic analysis revealed a polyphyletic origin of Encarsiella and confirmed the results of earlier analyses indicating the paraphyly of Encarsia . Four species are described as new ( Encarsia bifasciata sp.n. , E. caelata sp.n. , E. obliqua sp.n. and E. pilosa sp.n. ). The following species are transferred from Encarsiella to Encarsia : Encarsia aleurodici ( Girault, 1916 ) comb.n. , E. amabilis ( Huang & Polaszek, 1998 ) comb.n. , E. boswelli ( Girault, 1915 ) comb.n. , E. magniclava ( Girault, 1915 ) comb.n. , E. narroi Gómez & García comb.n. , E. nepalensis ( Polaszek & Hayat, 1992 ) comb.n. , E. noyesi ( Hayat, 1983 ) comb.n. , E. pithecura ( Polaszek, 1999 ) comb.n. , E. tachii ( Polaszek & Hayat, 1992 ) comb.n. , E. taiwanensis ( Chou & Chou, 1994 ) comb.n. and E. tamaulipeca ( Myartseva & Coronado-Blanco, 2002 ) comb.n. The generic limits of Encarsia are re-defined based on a re-assessment of morphological characters, and the results are discussed with respect to the current classification of the aphelinid subfamily Coccophaginae.     

Larval food stress differentially affects flight morphology in male and female speckled woods (Pararge aegeria)

Abstract 1. Adaptive plasticity in flight morphology can be of great importance for organisms, in order to deal with changing environments. When different demands are imposed to this morphology, different responses to environmental changes can be expected. 2. The aim of this study is to examine whether males and females of Pararge aegeria, which show different flight behaviours, respond differently to larval food stress. 3. In a food‐stress experiment, larvae of 35 families were reared on host plants subjected to a drought‐stress treatment with three groups: a control group, a low‐stress group and a high‐stress group. 4. Individuals from stress treatments significantly differed in wing morphology; they had lower wing loadings, and stressed females tended to have more pointed wings than females of the control group. 5. The difference in phenotypic response to food stress between both sexes may indicate that males and females benefit from different changes in morphology. In females, an increase in dispersal capacity may entail fitness benefits, whereas male morphology is mainly shaped by mate‐location strategy.     

The molecular population structure of the tall forb Cicerbita alpina (Asteraceae) supports the idea of cryptic glacial refugia in central Europe

There is an ongoing debate about the glacial history of non‐arctic species in central and northern Europe. The two main hypotheses are: (1) postglacial colonization from refugia outside this region; (2) glacial survival in microclimatically favourable sites within the periglacial areas. In order to clarify the glacial history of a boreo‐montane tall forb, we analysed AFLPs from populations of Cicerbita alpina through most of its range (Scandinavia, the mountains of central Europe, the Alps, the Pyrenees and the Balkan Peninsula). We found a major differentiation between the Pyrenean population and all others, supported by principal coordinate, neighbour joining and STRUCTURE analyses. Furthermore, three populations from the central and north‐eastern Alps were genetically distinct from the bulk of populations from Scandinavia, central Europe, the Alps and the Balkan Peninsula. Most populations, including those from central and northern Europe, had moderate to high levels of genetic diversity (mean Shannon index H_Sh = 0.292, mean percentage of polymorphic loci P = 54.1%, mean Nei's gene diversity H = 0.195). The results indicate separate glacial refugia in the Pyrenean region and the Italian Alps. Furthermore, they provide evidence of glacial persistence in cryptic refugia north of the Alps, from where Scandinavia and most of the Alps are likely to have been colonized following deglaciation. © 2010 The Linnean Society of London, Botanical Journal of the Linnean Society, 2010, 164 , 142–154.     

The anatomy,taphonomy, taxonomy and systematic affinity of Markuelia: Early Cambrian to Early Ordovician scalidophorans

Abstract: Markuelia is a vermiform, annulated introvertan animal known as embryonic fossils from the Lower Cambrian to Lower Ordovician. Analysis of an expanded and revised dataset for Introverta shows that the precise position of Markuelia within this clade is dependent on the taxa included. As a result, Markuelia is assigned to the scalidophoran total group to reflect uncertainty as to whether it is a stem‐scalidophoran or a stem‐priapulid. The taxonomy of the genus is revised to provide an improved taxonomic framework for material assigned to Markuelia. Five species are recognized: M. secunda Val’kov, M. hunanensis Dong and Donoghue, M. lauriei Haug et al., M. spinulifera sp. nov. and M. waloszeki sp. nov. Finally, the preservation of Markuelia is evaluated in the light of both the taphonomy of the fossil embryos themselves and the experimental taphonomy of the priapulid Priapulus caudatus, which has been proposed as both a close relative and an anatomical analogue of Markuelia.     

Climate–growth relationships of tropical tree species in West Africa and their potential for climate reconstruction

Most tropical regions are facing historical difficulties of generating biologically reconstructed long‐term climate records. Dendrochronology (tree‐ring studies) is a powerful tool to develop high‐resolution and exactly dated proxies for climate reconstruction. Owing to the seasonal variation in rainfall we expected the formation of annual tree rings in the wood of tropical West African tree species. In the central‐western part of Benin (upper Ouémé catchment, UOC) and in northeastern Ivory Coast (Comoé National Park, CNP) we investigated the relationship between climate (precipitation, sea surface temperature (SST)) and tree rings and show their potential for climate reconstruction. Wood samples of almost 200 trees belonging to six species in the UOC and CNP served to develop climate‐sensitive ring‐width chronologies using standard dendrochronological techniques. The relationship between local precipitation, monthly SST anomalies in the Gulf of Guinea, El Niño‐ Southern Oscillation (ENSO) and ring‐width indices was performed by simple regression analyses, two sample tests and cross‐spectral analysis. A low‐pass filter was used to highlight the decadal variability in rainfall of the UOC site. All tree species showed significant relationships with annual precipitation proving the existence of annual tree rings. ENSO signals could not be detected in the ring‐width patterns. For legume tree species at the UOC site significant relationships could be found between SST anomalies in the Gulf of Guinea indicating correlations at periods of 5.1–4.1 and 2.3 years. Our findings accurately show the relationship between tree growth, local precipitation and SST anomalies in the Gulf of Guinea possibly associated with worldwide SST patterns. A master chronology enabled the reconstruction of the annual precipitation in the UOC to the year 1840. Time series analysis suggest increasing arid conditions during the last 160 years which may have large impacts on the hydrological cycles and consequently on the ecosystem dynamics and the development of socio‐economic cultures and sectors in the Guinea‐Congolian/Sudanian region.