Isolation and characterization of nine microsatellite loci in Podarcis bocagei (Squamata: Lacertidae)

Nine dinucleotide microsatellite loci were developed through an enrichment protocol for Bocage's wall lizard, Podarcis bocagei Seoane 1884, a lacertid endemic to the Iberian Peninsula. Nineteen primer pairs were designed and tested. From these, nine loci yielded satisfactory results and were screened on 15–19 individuals. These loci revealed a high level of polymorphism (8–15 alleles) and heterozygosity (0.611–0.947) and will certainly be useful in the study of population structure and evolutionary history of this species.     

Variable levels of introgression between the endangered Podarcis carbonelli and highly divergent congeneric species

Recent empirical studies have demonstrated that speciation with gene flow is more common than previously thought. From a conservation perspective, the potential negative effects of hybridization raise concerns on the genetic integrity of endangered species. However, introgressive hybridization has also been growingly recognized as a source of diversity and new advantageous alleles. Carbonell’s wall lizard (Podarcis carbonelli) is an endangered species whose distribution overlaps with four other congeneric species. Our goal here was to determine whether P. carbonelli is completely reproductively isolated from its congeners and to evaluate the relevance of hybridization and interspecific gene flow for developing a conservation plan. We used restriction site associated DNA (RAD) sequencing to discover SNPs in samples from four contact zones between P. carbonelli and four other species. Principal component analysis, multilocus genotype assignment and interspecific heterozygosity suggest incomplete reproductive isolation and ongoing gene flow between species. However, hybridization dynamics vary across all pairs, suggesting complex interactions between multiple intrinsic and extrinsic barriers. Despite seemingly ubiquitous interspecific gene flow, we found evidence of strong reproductive isolation across most contact zones. Instead, indirect effects of hybridization like waste of reproductive effort in small isolated populations may be more problematic. Our results highlight the need to further evaluate the consequences of introgression for P. carbonelli, both on a geographic and genomic level and included in a comprehensive and urgently needed conservation plan. Besides, those findings will add important insights on the potential effects of hybridization and introgression for endangered species.Subject terms: Population genetics, Speciation     

Chemical constituents of the plants of the genus <Emphasis Type="Italic">Cleistanthus</Emphasis> and their biological activity

Chemical examinations of Cleistanthus collinus Roxb., a poisonous tree from India, and Cleistanthus patulus Muell. Arg. have resulted in isolation of a number of arylnaphthalide lignans and their glycosides as well as some furofuranoid lignans. While Cleistanthus gracilis Hook. f. from Thailand afforded an unusual glucoside of 2-β-hydroxy-8-azabicyclo-(5,0,2)-4β, 9β-epoxynona-5,7-diene, C. schlechteri from South Africa was the first reported source of the pimarane diterpenes. Cleistanthin A and cleistanthin B, diphyllin glycosides isolated from C. collinus were reported to exhibit cytotoxicity on several cancer cell lines. Cleistanthin A was found to cause DNA strand breaks and induce apoptosis in cultured cells while cleistanthin B caused G1 arrest and induced apoptosis in mammalian cells.     

Quantitative comparisons ofin situ microbial biodiversity by signature biomarker analysis

Microscopic examinations have convinced microbial ecologists that the culturable microbes recovered from environmental samples represent a tiny proportion of the extant microbiota. Methods for recovery and enzymatic amplification of nucleic acids from environmental samples have shown that a huge diversity existsin situ, far exceeding any expectations which were based on direct microscopy. It is now theoretically possible to extract, amplify and sequence all the nucleic acids from a community and thereby gain a comprehensive measure of the diversity as well as some insights into the phylogeny of the various elements within this community. Unfortunately, this analysis becomes economically prohibitive if applied to the multitude of niches in a single biome let alone to a diverse set of environments. It is also difficult to utilize PCR amplification on nucleic acids from some biomes because of coextracting enzymatic inhibitors. Signature biomarker analysis which potentially combines gene probe and lipid analysis on the same sample, can serve as a complement to massive environmental genome analysis in providing quantitative comparisons between microniches in the biome under study. This analysis can also give indications of the magnitude of differences in biodiversity in the blome as well as provide insight into the phenotypic activities of each community in a rapid and cost-effective manner. Applications of signature lipid biomarker analysis to define quantitatively the microbial viable biomass of portions of an Eastern USA deciduous forest, are presented.     

Expression of the 18kDa protein of Mycobacterium leprae in Saccharomyces cerevisiae

Summary Mycobacterium leprae, the etiologic agent of leprosy, until now has not been grown in vitro, resulting in exceedingly obstacles for the production of purified antigens. It is therefore of interest to clone the relevant M.leprae antigens in other easy to handle microbial hosts. Here, we describe two different systems for expressing the 18kDa antigen of M.leprae in S. cerevisiae. Each system was shown to be effective in antigen expression, but the secretion system provided easier purification. Working with different host strains under different growth conditions, large quantities of biologically active proteins were obtained.     

Elasmobranch species richness,fisheries, abundance and size composition in the Azores archipelago (NE Atlantic)

ABSTRACT

Elasmobranchs are a vulnerable resource, more susceptible to overfishing than most teleosts, and their assessment is complicated due to a general lack of information about their fisheries, biology and ecology. This study aimed to analyse all fishery and survey data available for elasmobranchs caught over the past c. 25 years around the Azores (NE Atlantic) to provide a baseline information, which can be used to inform stock assessment and management strategies. Elasmobranch species covered pelagic, benthopelagic and demersal habitats, from shallow to deep-water strata in areas around the islands and seamounts. These species are taken accidentally as by-catch of three main fisheries: swordfish fishery, black scabbardfish fishery and demersal bottom longline fishery. The latter represents one of the most important fishing activities in the Azores, and frequent elasmobranch by-catches include Raja clavata, Galeorhinus galeus, Deania calcea, D. profundorum, Etmopterus pusillus and E. spinax. A slight reduction in the abundance indices of these species was observed, despite the implemented technical measures (e.g. minimum size, zero catch). Little is known about resource dynamics for the Azorean region and no analytical assessments have been conducted. This study highlights the vulnerability to overfishing of these resources and the urgent need to develop management strategies.