The susceptibility of the moderate halophile Vibrio costicola to heavy metals

Fifty-eight strains of the moderate halophile Vibrio costicola , including both culture collection strains and freshly isolated strains from solar salterns, were examined for their susceptibility to 10 heavy metal ions by using an agar dilution technique. All strains were sensitive to cadmium, copper, silver, zinc and mercury. This latter ion showed the highest activity even at 0·05 mmol/1 metal concentration. On the other hand, all strains were similarly tolerant to lead, and a great proportion of them were also tolerant to nickel (91%) and chromium (88%). Only 44% and 14% of them showed tolerance to arsenate and cobalt, respectively. The majority of strains (96·4%) were multiply metal-tolerant, with three different metal ion tolerances as the major pattern.     

Nuclear envelope‐associated dynein drives prophase centrosome separation and enables Eg5‐independent bipolar spindle formation

The microtubule motor protein kinesin‐5 (Eg5) provides an outward force on centrosomes, which drives bipolar spindle assembly. Acute inhibition of Eg5 blocks centrosome separation and causes mitotic arrest in human cells, making Eg5 an attractive target for anti‐cancer therapy. Using in vitro directed evolution, we show that human cells treated with Eg5 inhibitors can rapidly acquire the ability to divide in the complete absence of Eg5 activity. We have used these Eg5‐independent cells to study alternative mechanisms of centrosome separation. We uncovered a pathway involving nuclear envelope (NE)‐associated dynein that drives centrosome separation in prophase. This NE‐dynein pathway is essential for bipolar spindle assembly in the absence of Eg5, but also functions in the presence of full Eg5 activity, where it pulls individual centrosomes along the NE and acts in concert with Eg5‐dependent outward pushing forces to coordinate prophase centrosome separation. Together, these results reveal how the forces are produced to drive prophase centrosome separation and identify a novel mechanism of resistance to kinesin‐5 inhibitors.     

Multilocus and morphological analysis of south-eastern Iberian Wall lizards (Squamata,Podarcis)

The phylogenetic relationships among the wall lizards of the Podarcis hispanicus complex that inhabit the south-east (SE) of the Iberian Peninsula and other lineages of the complex remain unclear. In this study, four mitochondrial and two nuclear markers were used to study genetic relationships within this complex. The phylogenetic analyses based on mtDNA gene trees constructed with ML and BI, and a species tree using *BEAST support three divergent clades in this region: the Valencia, Galera and Albacete/Murcia lineages. These three lineages were also corroborated in species delimitation analyses based on mtDNA using bPTP, mPTP, GMYC, ABGD and BAPS. Bayesian inference species delimitation method (BPP) based on both nuclear data and a combined data set (mtDNA + nuclear) showed high posterior probabilities for these three SE lineages (≥0.94) and another Bayesian analysis (STACEY) based on combined data set recovered the same three groups in this region. Divergence time dating of the species tree provided an estimated divergence of the Galera lineage from the other SE group (Podarcis vaucheri, (Albacete/Murcia, Valencia)) at 12.48 Ma. During this period, the Betic–Rifian arc was isolated, which could have caused the isolation of the Galera form distributed to the south of the Betic Corridor. Although lizards from the Albacete/Murcia and Galera lineage are morphologically similar, they clearly represent distinct genetic lineages. The noteworthy separation of the Galera lineage enables us to conclude that this lineage must be considered as a new full species.     

Functional architecture of the ligamentum arteriosum in adults]

The ligamentum arteriosum was studied in eight normal adult human hearts obtained at autopsy. Four of these hearts were treated by the Zemper method and extensively dissected under a steromicroscope (from X 6 up to X 40); two were embedded in celloidin and sectioned at 100mugm; two were embedded in paraffin and sectioned one 50mugm and the other at 75 mugm. Section were stained by the axan and the resorcin-fuchsin methods. Unstained sections were examined under polarized light.The ligamentum arteriosum may be considered as a small smooth muscle, whose origin is in the arteria pulmonalis sinistra and the insertion in the arcus aortae. Therefore, the ligamentum arterisum may be considered as a myoelastic system, included in a collagenous stroma. Muscle, elastic and collagen fibers present a cross-spiral disposition. Being a myoelastic system with a collagen component, the ligamentum arteriosum cannot be considered as a simple arcus aortae support; it must play some functional role in controlling the arcus aortae curvature during the several different steps of the cardiac cycle.     

Construction of Aspergillus nidulans strains producing enzymes of potential use in enology

Two different Aspergillus nidulans recombinant strains producing either the Aspergillus nidulans a-L-arabinofuranosidase A or a Candida molischiana b-glucosidase have been constructed. Depending on the growing conditions, the modified strains produce up to 4 or 18 times more b-glucosidase or a-L-arabinofuranosidase activity levels, respectively, than the wild type strain.     

Elastase in the different primary granules of the human neutrophil

Elastase in the human neutrophil is associated with various subpopulations of primary granules of different density. The proportion of this enzyme that is extracted with acetate pH 4.2 and cetyltrimethylammonium bromide varies in the different subpopulations. Nevertheless, the electrophoretic mobility and relative proportions of elastase isoenzymes is the same in both extracts from the different subpopulations. On stimulation of neutrophils with N-formylmethionylleucylphenylalanine, elastase is not released from the least dense subpopulation, whereas other two subpopulations do undergo degranulation to approximately the same extent. However, the release of elastase from these two denser granules differs after they are isolated and treated with calcium.