Deep-sea origin and in-situ diversification of chrysogorgiid octocorals

The diversity, ubiquity and prevalence in deep waters of the octocoral family Chrysogorgiidae Verrill, 1883 make it noteworthy as a model system to study radiation and diversification in the deep sea. Here we provide the first comprehensive phylogenetic analysis of the Chrysogorgiidae, and compare phylogeny and depth distribution. Phylogenetic relationships among 10 of 14 currently-described Chrysogorgiidae genera were inferred based on mitochondrial (mtMutS, cox1) and nuclear (18S) markers. Bathymetric distribution was estimated from multiple sources, including museum records, a literature review, and our own sampling records (985 stations, 2345 specimens). Genetic analyses suggest that the Chrysogorgiidae as currently described is a polyphyletic family. Shallow-water genera, and two of eight deep-water genera, appear more closely related to other octocoral families than to the remainder of the monophyletic, deep-water chrysogorgiid genera. Monophyletic chrysogorgiids are composed of strictly (Iridogorgia Verrill, 1883, Metallogorgia Versluys, 1902, Radicipes Stearns, 1883, Pseudochrysogorgia Pante & France, 2010) and predominantly (Chrysogorgia Duchassaing & Michelotti, 1864) deep-sea genera that diversified in situ. This group is sister to gold corals (Primnoidae Milne Edwards, 1857) and deep-sea bamboo corals (Keratoisidinae Gray, 1870), whose diversity also peaks in the deep sea. Nine species of Chrysogorgia that were described from depths shallower than 200 m, and mtMutS haplotypes sequenced from specimens sampled as shallow as 101 m, suggest a shallow-water emergence of some Chrysogorgia species.     

Additional rDNA ITS sequences and its phylogenetic consequences for the genus Leveillula with emphasis on conidium morphology

Taxonomy of the genus Leveillula has long been considered as a challenge in powdery mildew systematics. The rDNA diversity has recently been used for phylogenetic analysis of several specimens of the genus Leveillula. In the present study, additional rDNA ITS sequences are provided and a new phylogenetic analysis is carried out aiming at a better understanding of the genetic diversity in the genus Leveillula. New analyses confirmed that L. taurica is unique in the genus, as it exhibits an intraspecific gene sequence diversity considerably higher than in other species. In several cases L. taurica s. lat. on a certain host plant species has a sequence different from L. taurica on other host plants. Moreover, DNA data indicated different lineages among L. taurica specimens which were hardly distinguishable by morphology. More than one genotype occurring on a single host is sometimes possible. According to these results, several races such as Leveillula on Artemisia, Acroptilon, Onobrychis, are molecularly well characterized. While there is enough molecular evidence to delimit such races as independent taxa, clear morphological delimitations between these new and already published taxa are very difficult or even impossible. However, ecological features, and above all, host specificity for biotrophic fungi such as powdery mildew, would be a good criterion to discriminate cryptic taxa along with rDNA sequences. In fact, many collections of Leveillula strains on different hosts show their own type of conidial morphology, which is usually consistent for a strain on a single host species. Hence, we have proposed to describe new species for Leveillula on some host plants such as Artemisia, Acroptilon, Echinops and Onobrychis.     

Genetic variation in a network of natural and reintroduced populations of Griffon vulture (Gyps fulvus) in Europe

It is generally considered that limiting the loss of genetic diversity in reintroduced populations is essential to optimize the chances of success of population restoration. Indeed, to counter founder effect in a reintroduced population we should maximize the genetic variability within the founding group but also take into account networks of natural populations in the choice of the reintroduction area. However, assessment of relevant reintroduction strategies requires long-term post-release genetic monitoring. In this study, we analyzed genetic data from a network of native and reintroduced Griffon vulture (Gyps fulvus) populations successfully restored in Southern Europe. Using microsatellite markers, we characterized the level of genetic diversity and degree of genetic structure within and among three native colonies, four captive founding groups and one long-term monitored reintroduced population. We also used Bayesian assignment analysis to examine recent genetic connections between the reintroduced population and the other populations. We aimed to assess the level of fragmentation among native populations, the effectiveness of random choice of founders to retain genetic variability of the species, the loss of genetic diversity in the reintroduced population and the effect of gene flow on this founder effect. Our results indicate that genetic diversity was similar in all populations but we detected signs of recent isolation for one native population. The reintroduced population showed a high immigration rate that limited loss of genetic diversity. Genetic investigations performed in native populations and post-released genetic monitoring have direct implications for founder choice and release design.     

Is it worth eradicating the invasive pest Rattus norvegicus from Molène archipelago? Genetic structure as a decision-making tool

Genetic variability and structure were estimated by microsatellite analysis at 7 loci in brown rat populations (Rattus norvegicus) from the Iroise insular complex and neighbouring mainland (Brittany, France). Island genetic diversity is lower than on the mainland and a highly significant positive correlation was found between mean heterozygosity and the logarithm of island area, which is consistent with theoretical expectations. Rattus norvegicus populations are substructured at a kilometric scale, both on the islands and on the mainland. Intra-island structuration is extremely high, suggesting that no effective migration occurs between islands or with the mainland. Historical and genetical evidence suggest that R. norvegicus was introduced independently on Ouessant and Molène archipelago, with a low and a high founder effect respectively. These results are discussed in terms of recolonization probability of islands that have been cleared of R. norvegicus, which illustrates the usefulness of genetic markers in determining parameters of interest to the conservation biologist.     

Endothelins and their receptors in embryo implantation

As a critical stage of pregnancy, the implantation of blastocysts into the endometrium is a progressive, excessively regulated local tissue remodeling step involving a complex sequence of genetic and cellular interplay executed within an optimal time frame. For better understanding the causes of infertility and, more importantly, for developing powerful strategies for successful implantations and combating infertility, an increasing number of recent studies have been focused on the identification and study of newly described substances in the reproductive tree. The endothelins (ET), a 21-aminoacidic family of genes, have been reported to be responsible for the contraction of vascular and nonvascular smooth muscles, including the smooth muscles of the uterus. Therefore, this review aims to comprehensively discuss the physiological role of endothelins and signaling through their receptors, as well as their probable involvement in the implantation process.     

Current advances in aptamer‐assisted technologies for detecting bacterial and fungal toxins

Infectious diseases are among the common leading causes of morbidity and mortality worldwide. Associated with the emergence of new infectious diseases, the increasing number of antimicrobial‐resistant isolates presents a serious threat to public health and hospitalized patients. A microbial pathogen may elicit several host responses and use a variety of mechanisms to evade host defences. These methods and mechanisms include capsule, lipopolysaccharides or cell wall components, adhesions and toxins. Toxins inhibit phagocytosis, cause septic shock and host cell damages by binding to host surface receptors and invasion. Bacterial and fungal pathogens are able to apply many different toxin‐dependent mechanisms to disturb signalling pathways and the structural integrity of host cells for establishing and maintaining infections Initial techniques for analysis of bacterial toxins were based on in vivo or in vitro assessments. There is a permanent demand for appropriate detection methods which are affordable, practical, careful, rapid, sensitive, efficient and economical. Aptamers are DNA or RNA oligonucleotides that are selected by systematic evolution of ligands using exponential enrichment (SELEX) methods and can be applied in diagnostic applications. This review provides an overview of aptamer‐based methods as a novel approach for detecting toxins in bacterial and fungal pathogens.     

Phytogeography of Genu and Homag,two mountains with an Irano–Turanian flora in the Saharo–Sindian regional zone,south Iran

The Saharo–Sindian regional zone encompasses the flat and arid areas of North Africa, the Arabian Peninsula, southern Iran and the deserts of Pakistan and west India. There are some scattered mountains situated within this area, like Hoggar in Sahara, Saint Catherine in Sinai and Genu and Homag in southern Iran. These highlands serve as interglacial refugia for cold adapted plant species. In the present study, phytogeographical patterns and relationships of the flora of Genu and Homag mountains are described and discussed in relation to the phytogeography of the flora of low‐lying Hormoz Island. According to a chorological assesment of the flora, Genu and Homag mountains belong to the Irano–Turanian region with 59% of the species restricted to this area. In contrast, the surrounding lowland plains are part of the Saharo–Sindian area with a rather high proportion of widespread species (17%) and Somalia–Masai‐linking elements (20%). It is noteworthy that several Turanian enclaves also occur in the lowland zone. Furthermore, the distributional patterns imply that the mountainous Irano–Turkestanian region is an integrated area which is supposedly distinct from the Turanian lowland areas in the north and from the Saharo–Sindian lowland areas in the south. On the other hand, the expansive floras of Turanian and Saharo–Sindian regions are linked to each other. Endemic species in lowland areas in south Iran are mostly either frost sensitive vicariants of cold adapted Turanian species or of Saharo–Sindian origin, while the highland endemics in the area trace their origins to the Irano–Turkestanian region.     

Immunohistochemical Localization of Intermediate Filament Proteins of Neuronal and Nonneuronal Origin in the Goldfish Optic Nerve: Specific Molecular Markers for Optic Nerve Structures

The predominant proteins (58K) of the intermediate filament complex in the goldfish visual pathway consist of a series of isoelectric variants. Previous biochemical studies have shown that proteins ON1 and ON2 are of neuronal origin, whereas ON3 and ON4 are of nonneuronal origin. Polyclonal antibodies, purified by affinity chromatography, that are specific for ON1 and ON2 or ON3 and ON4 have been used to localize histologically the ON proteins within the normal and crushed optic nerve. Anti-ON1/ON2 antiserum presented a pattern consistent with intraaxonal staining. A nonneuronal staining pattern was observed with anti-ON3/ON4 antiserum. The two patterns were distinct from and complementary to each other. The data suggest that ON3 and ON4 represent a novel glial fibrillary acidic protein. The results are discussed in terms of the function of these proteins in development, plasticity, and regeneration.