Elastic fiber assembly in the adult mouse pubic symphysis during pregnancy and postpartum

Impairment of pelvic organ support has been described in mice with genetic modifications of the proteins involved in elastogenesis, such as lysyl oxidase-like 1 (LOXL1) and fibulin 5. During pregnancy, elastic fiber-enriched pelvic tissues are modified to allow safe delivery. In addition, the mouse pubic symphysis is remodeled in a hormone-controlled process that entails the modification of the fibrocartilage into an interpubic ligament (IpL) and the relaxation of this ligament. After first parturition, recovery occurs to ensure pelvic tissue homeostasis. Because ligaments are the main supports of the pelvic organs, this study aimed to evaluate elastogenesis in the IpL during mouse pregnancy and postpartum. Accordingly, virgin, pregnant, and postpartum C57BL/6 mice were studied using light, confocal, and transmission electron microscopy as well as Western blots and real-time PCR. Female mice exhibited the separation of the pubic bones and the formation, relaxation, and postpartum recovery of the IpL. By the time the IpL was formed, the elastic fibers had increased in profile length and diameter, and they consisted of small conglomerates of amorphous material distributed among the bundles of microfibrils. Our analyses also indicated that elastin/tropoelastin, fibrillin 1, LOXL1/Loxl1, and fibulin 5 were spatially and temporally regulated, suggesting that these molecules may contribute to the synthesis of new elastic fibers during IpL development. Overall, this work revealed that adult elastogenesis may be important to assure the elasticity of the pelvic girdle during preparation for parturition and postpartum recovery. This finding may contribute to our understanding of pathological processes involving elastogenesis in the reproductive tract.     

Floristic diversity patterns in the White Carpathians biosphere reserve,Czech Republic

The flora of the White Carpathians, a mountain range in the south-east of the Czech Republic, is documented by about 485,000 records of vascular plant occurrences collected since the mid-19^th century. A total of 1299 species recorded in 93 grid cells of 2.8 × 3.1 km were used for an analysis of spatial patterns of floristic diversity in the White Carpathians. Multivariate statistical techniques such as ordination and classification were used to reveal the main gradients in floristic composition and species richness, and measured environmental data and Ellenberg indicator values were used to assess underlying environmental factors. There is a striking floristic contrast between the western and eastern part of the study area, which is associated with differences in climate, mean altitude, topographic heterogeneity measured as altitudinal range, and land use. The western part is characterised by thermophilous, continental and calcicolous species of open habitats. In contrast, the more forested eastern part along the state border with Slovakia and the north-eastern part of the area are characterised by acidophilous species with higher moisture requirements. This pattern is consistent with the established phytogeographical division of the Czech Republic into the phytogeographical regions of Thermophyticum and Mesophyticum. The further division of the area into four regions, based on classified grid data, is also similar to the current division into phytogeographical districts, except for the Javorníky district. There are two distinct hot spots of species richness, in the western and the extreme north-eastern part. A poorer flora was found in landscapes with intensive agriculture. Species richness is associated with different environmental factors than species composition, namely with soil types and land-use categories. Alien species are more common in areas with a higher incidence of arable land and built-up areas, and less common in areas dominated by grasslands and forests.     

Hymenopteran parasitoids of the ant-eating spider Zodarion styliferum (Simon) (Araneae,Zodariidae)

Calymmochilus dispar Bouček & Andriescu (Hymenoptera, Eupelmidae) and Gelis apterus (Pontoppidan) (Hymenoptera, Ichneumonidae) are newly recorded as parasitoids of the ant-eating spider Zodarion styliferum (Simon) (Araneae, Zodariidae). The larvae of both parasitoid species fed on juvenile spiders. The final instar larva and pupa of Calymmochilus dispar and the male of Gelis apterus are described for the first time. Both species represent new distribution records for Portugal. The biology and host associations of the parasitoids are discussed.     

Digestive activity and stomach temperature in farmed bluefin tuna Thunnus thynnus measured by acoustic tag

Eight farmed Atlantic bluefin tuna Thunnus thynnus were tagged with temperature and depth transmitters inserted in chub mackerels Scomber colias to characterize their digestive activity, feeding physiology and behaviour in captivity. Results obtained in the experiment can be used to optimize daily T. thynnus feeding strategy in farms, reducing the early regurgitation of food and thus the environmental effects of inappropriate feeding practices.     

Phylogenetic relationships among the Caribbean members of the Cliona viridis complex (Porifera, Demospongiae, Hadromerida) using nuclear and mitochondrial DNA sequences

Species complexes - groups of closely related species in which intraspecific and interspecific variability overlap - have generated considerable interest and study. Frequently, members of a species complex do not have complete reproductive isolation; therefore, the complex may go through extensive gene flow. In the Caribbean Sea, some encrusting and excavating sponges of the genus Cliona (Porifera, Hadromerida, Clionaidae) are grouped within the great "Cliona viridis" complex because of their morphological similarities. This study examined the evolutionary relationships of the Caribbean members of this complex (C. caribbaea, C. tenuis, C. aprica and C. varians) and related taxa based on nuclear (ITS1 and ITS2) and mitochondrial (3' end of ND6) DNA sequences. The intragenomic ITS variation and its secondary structures were evaluated using a mixed approach of Denaturing Gradient Gel Electrophoresis (DGGE), DNA sequencing and secondary structure prediction. Considerable intragenomic variation was found in all the species, with apparently functional ITS1 and ITS2 secondary structures. Despite the subtle but clear morphological differentiation in these excavating sponges, the intragenomic copies of C. caribbaea, C. tenuis and C. aprica had a polyphyletic placement in the ITS1 and ITS2 genealogies and very low divergence. Therefore, it is clear that these species constitute a species complex (herein called Ct-complex). Genetic distances within the Ct-complex revealed that an important part of the interspecific variation overlapped with intraspecific variation, suggesting either incomplete lineage sorting or extensive gene flow. In contrast, C. varians and an unidentified "Pione" species emerged as monophyletic clades, being the closest sister groups to the Ct-complex. Additionally, our results support that C. laticavicola and C. delitrix conform a monophyletic group, but absence of reciprocal monophyly in these species suggests they may be life stages or ecophenotypes of a single species or they have diverged recently. Our work showed that the 3' end of the ND6 mitochondrial gene was highly conserved and not suitable for phylogenetic analysis at the interspecific level.     

Is inaccurate mimicry ancestral to accurate in myrmecomorphic spiders (Araneae)?

Batesian mimicry, in which a palatable organism resembles an unpalatable model, is widespread among taxa. Batesian mimics can be classified based on their level of accuracy (inaccurate or accurate). Using data on defensive strategies in more than 1000 species of spiders I investigated whether inaccurate myrmecomorphy is ancestral to accurate myrmecomorphy. I classified 233 myrmecomorphic species into four accuracy levels based on morphology, from poor inaccurate mimics to very accurate ones. I found that myrmecomorphy has evolved independently in 16 families and 85 genera. On the family‐level phylogeny, the occurrence of myrmecomorphy is confined mainly to families branching later on the tree, from the RTA clade. On the generic‐level phylogenies in Corinnidae and Salticidae, myrmecomorphy is not only of derived origin. Estimated ancestral state was non‐mimetic in Salticidae and poor inaccurate myrmecomorphy in Corinnidae. Thus, inaccurate myrmecomorphic spider mimics seem rather ancestral to accurate but additional analysis on species‐level phylogenies is needed to support this conclusion. © 2014 The Linnean Society of London, Biological Journal of the Linnean Society, 2014, 113 , 97–111.     

Relationship between abundance of N2-fixing cyanobacteria and environmental features of Spanish rice fields

In order to estimate the potential utilization of N₂-fixing (heterocystous) cyanobacteria as natural biofertilizers in the Valencian rice fields (Spain), the distribution and seasonal variation of these microorganisms in water and sediment samples were evaluated, and the relationships among cyanobacterial abundance and physical and chemical characteristics of soil and water were investigated. N₂-fixing cyanobacteria were present in all the samples analyzed (25 sampling points sampled three times per year during two years). The relative cyanobacterial abundance in soil and water followed contrasting patterns, maximum presence in soil coincided with minimum abundance in water. Correlation analysis showed that cyanobacterial abundance in the two phases (water and sediment) was influenced more by water than by soil properties. Salinity, mineralization variables, and soluble reactive phosphate (SRP) correlated positively with heterocystous cyanobacteria presence. Furthermore, dissolved inorganic nitrogen (DIN) and the ratio DIN: SRP correlated negatively with cyanobacterial abundance. However DIN: SRP ratio better described the cyanobacterial distribution, with a threshold effect: below the Redfield ratio value (7.2 in mass units) cyanobacterial abundance was clearly higher. Correspondence to: A. Quesada.