Heavy Metals and Trace Element Concentrations in Intertidal Soils of Four Estuaries of SW Iberian Peninsula

Soils from four estuaries of SW Iberian Peninsula, affected by anthropogenic influence (urban, industrial and agricultural activities), were analyzed for the occurrence of a variety of metals and trace elements including Al, As, B, Ba, Ca, Cd, Co, Cr, Cu, Fe, K, Mg, Mn, Na, Ni, P, Pb, S and Zn. The soils presented very high levels of salinity (high concentrations of Na, K and Mg), organic matter and, consequently, of C and N concentrations. In contrast, very low values of CaCO₃, Ca and P were found. In addition, it should be highlighted that in certain localities (Piedras 1 and 2 and Guadiana in Huelva, Spain, and Ria Formosa, Faro, Portugal) the concentrations of Pb, S and Zn were extremely high, reaching levels of pollution.     

CD2v Interacts with Adaptor Protein AP-1 during African Swine Fever Infection

African swine fever virus (ASFV) CD2v protein is believed to be involved in virulence enhancement, viral hemadsorption, and pathogenesis, although the molecular mechanisms of the function of this viral protein are still not fully understood. Here we describe that CD2v localized around viral factories during ASFV infection, suggesting a role in the generation and/or dynamics of these viral structures and hence in disturbing cellular traffic. We show that CD2v targeted the regulatory trans-Golgi network (TGN) protein complex AP-1, a key element in cellular traffic. This interaction was disrupted by brefeldin A even though the location of CD2v around the viral factory remained unchanged. CD2v-AP-1 binding was independent of CD2v glycosylation and occurred on the carboxy-terminal part of CD2v, where a canonical di-Leu motif previously reported to mediate AP-1 binding in eukaryotic cells, was identified. This motif was shown to be functionally interchangeable with the di-Leu motif present in HIV-Nef protein in an AP-1 binding assay. However, we demonstrated that it was not involved either in CD2v cellular distribution or in CD2v-AP-1 binding. Taken together, these findings shed light on CD2v function during ASFV infection by identifying AP-1 as a cellular factor targeted by CD2v and hence elucidate the cellular pathways used by the virus to enhance infectivity.     

Nitric oxide decreases superoxide anion generation by microsomes from soybean embryonic axes

Experiments were carried out to evaluate the effects of exposure to nitric oxide on the ability by NADPH‐dependent microsomal electron transfer to generate oxygen radicals. Such interactions could play a role in the potential antioxidant action of nitric oxide (NO). Isolated microsomes from soybean ( Glycine max [L.] Merr. cv. Hood) embryonic axes were exposed to an exogenously added source of nitric oxide (NO) (S‐nitrosoglutathione + dithiothreitol). The O₂⁻ generation rate by microsomes exposed to NO decreased significantly as compared to the rate measured in microsomes incubated in the absence of NO. The exposure of the microsomes to the NO donor did not alter the microsomal rate of hydroxyl radical generation. Preincubation of the microsomes with the NO donor affected neither iron reduction rate nor activity of cytochrome c reductase. However, cytochrome P₄₅₀ activity was significantly inhibited after exposure to NO. This inhibition was completely prevented by hemoglobin. The data are consistent with the hypothesis that NO exhibits a potential antioxidant role in the plant cell by decreasing the rate of generation of superoxide anion. Since endogenous NO was detected in homogenates of soybean embryonic axes by EPR studies, this interaction between NO and cytochrome P₄₅₀ in soybean embryonic axes could be a factor of relevance for the control of oxidative stress in vivo.     

The Expanded mtDNA Phylogeny of the Franco-Cantabrian Region Upholds the Pre-Neolithic Genetic Substrate of Basques

The European genetic landscape has been shaped by several human migrations occurred since Paleolithic times. The accumulation of archaeological records and the concordance of different lines of genetic evidence during the last two decades have triggered an interesting debate concerning the role of ancient settlers from the Franco-Cantabrian region in the postglacial resettlement of Europe. Among the Franco-Cantabrian populations, Basques are regarded as one of the oldest and more intriguing human groups of Europe. Recent data on complete mitochondrial DNA genomes focused on macrohaplogroup R0 revealed that Basques harbor some autochthonous lineages, suggesting a genetic continuity since pre-Neolithic times. However, excluding haplogroup H, the most representative lineage of macrohaplogroup R0, the majority of maternal lineages of this area remains virtually unexplored, so that further refinement of the mtDNA phylogeny based on analyses at the highest level of resolution is crucial for a better understanding of the European prehistory. We thus explored the maternal ancestry of 548 autochthonous individuals from various Franco-Cantabrian populations and sequenced 76 mitogenomes of the most representative lineages. Interestingly, we identified three mtDNA haplogroups, U5b1f, J1c5c1 and V22, that proved to be representative of Franco-Cantabria, notably of the Basque population. The seclusion and diversity of these female genetic lineages support a local origin in the Franco-Cantabrian area during the Mesolithic of southwestern Europe, ∼10,000 years before present (YBP), with signals of expansions at ∼3,500 YBP. These findings provide robust evidence of a partial genetic continuity between contemporary autochthonous populations from the Franco-Cantabrian region, specifically the Basques, and Paleolithic/Mesolithic hunter-gatherer groups. Furthermore, our results raise the current proportion (≈15%) of the Franco-Cantabrian maternal gene pool with a putative pre-Neolithic origin to ≈35%, further supporting the notion of a predominant Paleolithic genetic substrate in extant European populations.     

Effect of growth temperature on complement-mediated killing of mesophilic Aeromonas spp. serotype O:34

Abstract Mesophilic Aeromonas spp. strains (serotype O:34) showed sensitivity to complement-mediated killing when they were cultivated at 37°C (serum-sensitive) but not when they were cultivated at 20°C (serum-resistant). These strains produced smooth lipopolysaccharide when they were grown at 20°C and rough lipolysaccharide when cultivated at 37°C. The reason for the resistance to complement-mediated killing could be that C3b is rapidly degraded (possibly because it is bound far from the cell membrane), consequently the lytic complex (C5b-9) is not formed.     

PHENOTYPIC PLASTICITY INDUCED IN TRANSPLANT EXPERIMENTS IN A MUTUALISTIC ASSOCIATION BETWEEN THE RED ALGA JANIA ADHAERENS (RHODOPHYTA,CORALLINALES) AND THE SPONGE HALICLONA CAERULEA (PORIFERA: HAPLOSCLERIDA): MORPHOLOGICAL RESPONSES OF THE ALGA1

The association between the red macroalga Jania adhaerens J. V. Lamour. and the sponge Haliclona caerulea is the most successful life‐form between 2 and 4 m depth in Mazatlán Bay (Mexican Pacific). J. adhaerens colonizes the rocky intertidal area and penetrates into deeper areas only when it lives in association with H. caerulea. The aposymbiotic form of the sponge has not been reported in the bay. To understand the ecological success of this association, we examined the capacity of J. adhaerens to acclimate in Mazatlán Bay using transplant experiments. The transplanted aposymbiotic J. adhaerens did not survive the first 2 weeks; however, J. adhaerens when living in association with H. caerulea, acclimated easily to depth, showing no sign of mortality during the 103 d of the experiment. We conclude that the ability of J. adhaerens to colonize in deeper areas in this hydrodynamic environment may in part rely on the protection provided by the sponge to the algal canopy. Both species contribute to the shape of the associated form. Nevertheless, the morphological variation in the association appears to be dominated by the variation in J. adhaerens canopy to regulate pigment self‐shading under light‐limited conditions and/or tissue resistance under high hydrodynamics. Consequently, our results are consistent with light as the abiotic controlling factor, which regulates the lower depth distribution of the association in Mazatlán Bay, through limiting the growth rate of J. adhaerens. Hydrodynamics may determine the upper limit of the association by imposing high mass losses.     

On the morphology of spermatozoa of tuco-tucos, Ctenomys (Rodentia: Ctenomyidae): New data and its implications for the evolution of the genus

Sperm morphology was studied in 10 species of the caviomorph rodent Ctenomys. Ctenomys argentinus, C. conoueri, C. dorbigny and C.perrensis had symmetric spermatozoa with paddle-like heads. Ctenomys australis, C. mendocinus, C. porteousi, C. rionegrensis and Ctenomys sp., on the other hand, had spermatozoa with paddle-like heads but with the tail inserted at one side of the central axis and a nuclear caudal extension originating from the base of the head at the opposite side of the insertion of the tail and running parallel to the flagellum; these spermatozoa are referred to as simple-asymmetric. In C. yolandae, a complex-asymmetric morphological type not previously described for the genus was found. This type is characterized by the presence of two nuclear caudal extensions. Symmetric spermatozoa (total length = 52 pm) were shorter than asymmetric (both simple and complex) ones (total length = 87 pm). In spite of these differences, the relative size of heads, midpieces and tails were maintained in the three groups, representing 12%, I I YO and 88% of the average total length, respectively. Within each group of species bearing the same sperm type, a low interspecific variability both in morphological patterns and dimensions of sperm cells was observed. This low interspecific variability associated with the north to south geographical distribution of species having, respectively, symmetric and asymmetric spermatozoa, suggests that these characters appeared at an early stage in evolution of the group, and probably played an important role in the first steps of speciation by promoting reproductive isolation.