Use of dolphins and caimans as bait for Calophysus macropterus (Lichtenstein, 1819) (Siluriforme: Pimelodidae) in the Amazon

A new fishery has been developing in the Amazon that uses dolphin and caiman species as bait to catch piracatinga (Calophysus macropterus), having thus the potential to cause adverse food‐web impacts; however a lack of basic understanding of this fishery is a limitation to the necessary management action. Interviews with fishers and analyses of fishing records in Brazil were used for the study, including harvest methods, types of baits used, commercialization chains, and the rate of increase of piracatinga yields in recent years. Piracatinga fishers are subsistence fishers who harvest piracatinga as a means to alleviate economic constraints when the catch of other species is not profitable or banned due to (reproductive) closed seasons. Harvesting is done with wooden and nylon crates and cages in which whole or pieces of caimans and dolphins are placed to attract the piracatinga, entrapping them. The piracatinga are then sold to intermediate sellers for resale to a few large fish freezing and processing plants for export to Colombia. Annual piracatinga yields in the study area increased at an average rate of 446.5% per year, from 865 kg in 2003 to 23 176 kg in 2009. Because dolphins and caimans comprise various endangered species, the Brazilian government has recently implemented a ban on this fishery, which can be enforced at fish freezing and processing plants. However, there is a danger that such enforcement will lead to the development of a geographically dispersed chain of commercialization and export, such as currently exists for other species including caimans, which would be impossible to control.     

Persistent nuclear ribosomal DNA sequence polymorphism in the Amelanchier agamic complex (Rosaceae)

Individual plants of several Amelanchier taxa contain many polymorphic nucleotide sites in the internal transcribed spacers (ITS) of nuclear ribosomal DNA (nrDNA). This polymorphism is unusual because it is not recent in origin and thus has resisted homogenization by concerted evolution. Amelanchier ITS sequence polymorphism is hypothesized to be the result of gene flow between two major North American clades resolved by phylogenetic analysis of ITS sequences. Western North American species plus A. humilis and A. sanguinea of eastern North America form one clade (A), and the remaining eastern North American Amelanchier make up clade B. Five eastern North American taxa are polymorphic at many of the nucleotide sites where clades A and B have diverged and are thought to be of hybrid origin, with A. humilis or A. sanguinea as one parent and various members of clade B as the other parent. Morphological evidence suggests that A. humilis is one of the parents of one of the polymorphic taxa, a microspecies that we refer to informally as A. "erecta." Sequences of 21 cloned copies of the ITS1- 5.8S gene-ITS2 region from one A. "erecta" individual are identical to A. humilis sequence or to the clade B consensus sequence, or they are apparent recombinants of A. humilis and clade B ITS repeats. Amelanchier "erecta" and another polymorphic taxon are suspected to be relatively old because both grow several hundred kilometers beyond the range of one of their parents. ITS sequence polymorphisms have apparently persisted in these two taxa perhaps because of polyploidy and/or agamospermy (asexual seed production), which are prevalent in the genus.      

Trophic role of demersal mesopredators on rocky reefs in an equatorial Atlantic Ocean island

The decrease in the number of sharks around Saint Peter and Saint Paul Archipelago (SPSPA) may impact food web structure. We investigated trophic relationships in the shallow rocky reefs of the SPSPA using stable isotopes and stomach contents with a particular focus on three abundant mesopredators: Caranx lugubris, Enchelycore nigricans and Muraena pavonina. Food web structure was described using samples of the most abundant basal resources, fishes and invertebrates, which were collected in April and October 2012. Individuals of the three focal species (n = 138: C. lugubris, n = 56; E. nigricans, n = 18; M. pavonina, n = 64) were collected during four expeditions to SPSPA (April and October of 2011 and 2012). Results suggest that this shallow water food web is supported by trophic pathways originating from benthic resources. Stable isotope data suggest potential competitive interactions between the whitespot moray and the other two mesopredators. Conversely, stomach content data suggest little niche overlap in the three focal species, but these data must be interpreted carefully because of the small sample sizes and restricted temporal sampling windows. All three mesopredators have a significant, albeit weak, relationship between body size and δ¹⁵N, suggesting ontogenetic diet shifts. These data contribute baseline information to assess shifts in food web structure that may stem from top predator decline in this unique ecosystem.     

CytokineDB: a database collecting biological information

Cytokines are subdivided in 12 sub-families and are described as multi-functional molecules that play an important biological activity in host defense system against pathogens, in homeostasis, tissue repair, cell growth and development. CytokineDB is an annotated database that collects biological information regarding the cytokines family in human and will be periodically updated by including new biological information. This database is freely available online and can be accessed at the URL: http://www.cro-m.eu/CytokineDB/     

The ameliorative effects of vinpocetine on apoptosis and HSP-70 expression in testicular torsion in rats

Vinpocetine is a potent antioxidant and free radical scavenger. We investigated the effects of vinpocetine on torsion/detorsion (T/D) induced testicular damage, HSP-70 expression and germ cell apoptosis in rats. Sixty Wistar albino adult male rats were divided into five groups of 12. The groups comprised a control group, a sham treated group, a T/D group, a vinpocetine treated group, and a T/D plus vinpocetine treated group. The left testis of each rat was subjected to unilateral torsion followed by detorsion after 2 h. Vinpocetine was administered intraperitoneally immediately and for 10 days following detorsion. At the end of the study, the rats were sacrificed and their testes removed and processed. HSP-70 expression, apoptosis and histopathological damage scores were determined for each group. Testicular T/D caused significant increases in apoptosis and HSP-70 expression, and a significant decrease in Johnsen’s testicular biopsy scores and mean seminiferous tubule diameter. Vinpocetine ameliorated testicular histopathology and HSP-70 expression in the T/D + vinpocetine group. Consequently, vinpocetine may prevent testicular injury following testicular torsion owing to its antioxidant effects.     

Morphological and immunohistochemical characterisation of the thymus in juvenile turbot (<Emphasis Type="Italic">Psetta maxima,</Emphasis> L.)

We performed structural and immunohistochemical studies on the thymus of juvenile turbot (Psetta maxima L.) in order to define its cellular composition. The thymic stroma was mainly composed of two subpopulations of reticulo-epithelial cells (RECs). RECs immunoreactive to anti-actin antibody were distributed through the organ, while RECs that were cytokeratin-immunopositive were located in the outer zone of the thymus. The parenchyma of the thymus was composed of several cell types such as lymphocytes/thymocytes, lymphoblasts, melano-macrophages and to a lesser extent of nurse-like cells, immunoglobulin positive (Ig+) cells, mucous cells, rodlet cells and neuroendocrine cells. CD3ε+ lymphocytes were mainly located in the outer zone. On the other hand, Ig+ cells were observed in the transitional region between the inner and outer zones of the thymus. The neuroendocrine cells were large and exhibited immunoreactivity to neuropeptide Y and vasoactive intestinal polypeptide. They were located in the inner zone of the thymus in close association with lymphoblasts and lymphocytes/thymocytes. This work provides useful information on the structure and cellular composition of the thymus of turbot, identifying several immunomarkers that allow the identification of different cell types, providing the basis for further studies on the immune response of turbot against diseases.     

Structure–function relationship and evolutionary history of the human selenoprotein M (SelM) found over-expressed in hepatocellular carcinoma

In humans we know 25 selenoproteins that play important roles in redox regulation, detoxification, immune-system protection and viral suppression. In particular, selenoprotein M (SelM) may function as thiol disulfide oxidoreductase that participates in the formation of disulfide bonds, and can be implicated in calcium responses. However, it presents a redox motif (CXXU), where U is a selenocysteine, and may also function as redox regulator because its decreased or increased expression regulated by dietary selenium alters redox homeostasis. No data are reported in literature about its involvement in cancer but only in neurodegenerative diseases. In this paper we evaluated the SelM expression in two hepatoma cell lines, HepG2 and Huh7, compared to normal hepatocytes. The results suggested its involvement in hepatocellular carcinoma (HCC) as well as its possible use to follow the progression of this cancer as putative marker. The aim of this study has been to analyze the structure–function relationships of SelM. Hence, firstly we studied the evolutionary history of this protein by phylogenetic analysis and GC content of genes from various species. So, we modeled the three-dimensional structure of the human SelM evaluating its energetic stability by molecular dynamics simulations. Moreover, we modeled some of its mutants to obtain structural information helpful for structure-based drug design.