Impact of eutrophication on the life cycle, population dynamics and production of Ampithoe valida (Amphipoda) along an estuarine spatial gradient (Mondego estuary, Portugal)

The life cycle, population dynamics and production of Ampithoe valida was studied from an intertidal mudflat in central Portugal, close to the northern limit of the species¹ distributional range in the eastern Atlantic Ocean. Sampling was carried out in eutrophicated areas, where macroalgae blooms of Enteromorpha spp. occur usually from January to early summer, and also in non-eutrophicated areas, with Zostera noltii meadows. A. valida showed a contagious distribution and the population density clearly changed during the study period along the eutrophication gradient. No migratory patterns were detected between the estuary and the sea, but migrations inside the estuary might have occurred. Females were morphologically recognisable at smaller sizes than males. Females reached sexual maturity before males, but males may live slightly longer than females. Females are iteroparous, producing 2, perhaps 3, broods. A 2-generation life cycle involving a short-lived (7 mo), fast-growing summer generation and a longer-lived (9 mo), slower-growing generation that overwinters is hypothesised. Ovigerous females were present year-round. Eggs, depending on the season, increase differently in volume during marsupial development. No correlations were found between fecundity (number of eggs) and the size of females. Along the eutrophication gradient no differences were found regarding the biology of the species. Besides these features, differences were observed between eutrophicated and non-eutrophicated areas with regard to productivity. Growth production (P) of A. valida in the most eutrophicated area was 0.098 g m-2 18 mo-1 and 0.64 g m-2 18 mo-1 in the Z. noltii meadows. P/B- and E/B- ratios (where E is the elimination production and B- is the average population biomass) ranged from 1.42 and 3.06 in the most eutrophicated area to 5.98 and 12.41 in the Z. noltii beds. To a certain extent, the increase of macroalgae biomass may favour A. valida populations, but extensive blooms affecting the whole area of distribution of this species will determine its disappearanc

Efeito da estrutura ovárica e da idade de bovinos da raça Holstein Friesian na quantidade e qualidade de ovócitos e de embriões produzidos in vitro

The aim of the present study was the evaluation of whether the age or the estrous cycle phase would influence the quantity and/or quality of oocytes and in vitro embryo production. Oocytes from ovaries of 63 Holstein- Friesian slaughtered cows, aging between 1 and 15 years old, were divided into 5 groups considering their age and then subdivided according to their phase of estrous cycle. The groups were: ;8 years old. The estrous cycle phase (lutheal or follicular) was evaluated by the presence or absence of a functional corpus luteum. The cumulus-oocyte-complex (COC's) was divided in classes A, B, C and D according to their morphological aspect. The COC's classed as C and D were excluded, being the COC's classed as A and B matured in vitro and fertilized. As result of the study, it was observed that the number of total produced COC's was directly proportional to the age of the cow (R=0,99 - P<0,001). It has also noticed that cows in the lutheal phase produced more COC's than cows in the follicular phase (P<0,001), respectively 7,05 ± 0,11 and 10,87 ± 1,01. The COC's quality augmented from the group of cows aging less than 2 years to cows aging between [7, 8] years old, with a positive correlation (R = 0.94 p<0.01) starting then to decrease. It was also realized that cows in the lutheal phase produced better COC's quality than cows in the follicular phase (6,77 ± 0,64 e 3,84± 0,64; respectively). In what cleavage rate is concerned, better results were achieve with cows in lutheal phase (59,03%) then in follicular phase (45,52%). It was also possible to notice a better embryo production in cows in the lutheal phase (44,23%) then cows in the follicular phase. The results of the present study allow to conclude that there is a relation between the age and the estrous cycle stage in the quality and quantity of COC's and in vitro produced bovine embryos.O objetivo do presente trabalho, foi o estudo dos efeitos da idade e da fase do ciclo estral dos bovinos na quantidade e qualidade de ovócitos e de embriões produzidos in vitro. Para isso, foram utilizados ovócitos de 63 vacas da raça Holstein-Friesian abatidas em matadouro, com idades compreendidas entre 1 e 15 anos, as quais foram divididas em 5 lotes de acordo com a idade. Cada lote foi subdividido de acordo com a fase do ciclo estral em que o animal se encontrava no dia do abate, pela presença ou não de corpo lúteo funcional na superfície do ovário. Os lotes referentes à idade foram: ;8 anos. Após punção dos folículos, os ovócitos foram divididos nas classes A, B, C e D, tendo em conta o seu aspecto morfológico, em que apenas os de classe A e B foram usados para a FIV. Observou-se que o número de ovócitos produzidos foi diretamente proporcional à idade das vacas (R=0,99 - P<0,001). Quanto à fase do ciclo estral, as vacas em fase luteínica, produziram maior número de ovócitos que as vacas em fase folicular (P<0,001), respetivamente 7,05 ± 0,11 e 10,87 ± 1,01. Relativamente à qualidade dos ovócitos em função da idade das vacas, observou-se uma correlação positiva (R = 0,94 p<0,01) até aos [7, 8] anos, começando a baixar a partir desta idade. As vacas em fase luteínica produziram ovócitos de melhor qualidade relativamente às vacas em fase folicular (6,77 ± 0,64 e 3,84± 0,64; respetivamente). Quanto à quantidade de zigotos que clivaram, esta foi superior para os lotes de vacas em fase luteínica em comparação com os de vacas em fase folicular (59,03% e 45,52%; respetivamente), observando-se ainda que as vacas em fase luteínica produziram igualmente, em geral, maior número de embriões aos 7 dias após FIV que as vacas em fase folicular(44,23% e 31,48%; respetivamente). Os resultados do presente trabalho permitem concluir que existe uma estreita relação entre a idade e a fase do ciclo estral das vacas e a quantidade e qualidade dos ovócitos e de embriões produzidos in vitro

Cryptic population structure and insecticide resistance in Anopheles gambiae from the southern Democratic Republic of Congo

The Democratic Republic of Congo (DRC) suffers from one of the highest malaria burdens worldwide, but information on its Anopheles vector populations is relatively limited. Preventative malaria control in DRC is reliant on pyrethroid-treated nets, raising concerns over the potential impacts of insecticide resistance. We sampled Anopheles gambiae from three geographically distinct populations (Kimpese, Kapolowe and Mikalayi) in southern DRC, collecting from three sub-sites per population and characterising mosquito collections from each for resistance to pyrethroids using WHO tube bioassays. Resistance to each of three different pyrethroids was generally high in An. gambiae with < 92% mortality in all tests, but varied between collections, with mosquitoes from Kimpese being the most resistant. Whole genome sequencing of 165 An. gambiae revealed evidence for genetic differentiation between Kimpese and Kapolowe/Mikalayi, but not between the latter two sample sites despite separation of approximately 800 km. Surprisingly, there was evidence of population structure at a small spatial scale between collection subsites in Kimpese, despite separation of just tens of kilometres. Intra-population (H12) and inter-population (FST) genome scans identified multiple peaks corresponding to genes associated with insecticide resistance such as the voltage gated sodium channel (Vgsc) target site on chromosome 2L, a Cyp6 cytochrome P450 cluster on chromosome arm 2R, and the Cyp9k1 P450 gene on chromosome X. In addition, in the Kimpese subsites, the P450 redox partner gene Cpr showed evidence for contemporary selection (H12) and population differentiation (FST) meriting further exploration as a potential resistance associated marker

Impact of eutrophication on the life cycle, population dynamics and production of Ampithoe valida (Amphipoda) along an estuarine spatial gradient (Mondego estuary, Portugal)

The life cycle, population dynamics and production of Ampithoe valida was studied from an intertidal mudflat in central Portugal, close to the northern limit of the species¹ distributional range in the eastern Atlantic Ocean. Sampling was carried out in eutrophicated areas, where macroalgae blooms of Enteromorpha spp. occur usually from January to early summer, and also in non-eutrophicated areas, with Zostera noltii meadows. A. valida showed a contagious distribution and the population density clearly changed during the study period along the eutrophication gradient. No migratory patterns were detected between the estuary and the sea, but migrations inside the estuary might have occurred. Females were morphologically recognisable at smaller sizes than males. Females reached sexual maturity before males, but males may live slightly longer than females. Females are iteroparous, producing 2, perhaps 3, broods. A 2-generation life cycle involving a short-lived (7 mo), fast-growing summer generation and a longer-lived (9 mo), slower-growing generation that overwinters is hypothesised. Ovigerous females were present year-round. Eggs, depending on the season, increase differently in volume during marsupial development. No correlations were found between fecundity (number of eggs) and the size of females. Along the eutrophication gradient no differences were found regarding the biology of the species. Besides these features, differences were observed between eutrophicated and non-eutrophicated areas with regard to productivity. Growth production (P) of A. valida in the most eutrophicated area was 0.098 g m-2 18 mo-1 and 0.64 g m-2 18 mo-1 in the Z. noltii meadows. P/B- and E/B- ratios (where E is the elimination production and B- is the average population biomass) ranged from 1.42 and 3.06 in the most eutrophicated area to 5.98 and 12.41 in the Z. noltii beds. To a certain extent, the increase of macroalgae biomass may favour A. valida populations, but extensive blooms affecting the whole area of distribution of this species will determine its disappearanc

Determination of pregnancy-associated glycoproteins (bPAG) in cow’s milk

peer reviewe

Loss of vhl in the zebrafish pronephros recapitulates early stages of human clear cell renal cell carcinoma

Patients with von Hippel–Lindau (VHL) disease harbor a germline mutation in the VHL gene leading to the development of several tumor types including clear cell renal cell carcinoma (ccRCC). In addition, the VHL gene is inactivated in over 90% of sporadic ccRCC cases. ‘Clear cell’ tumors contain large, proliferating cells with ‘clear cytoplasm’, and a reduced number of cilia. VHL inactivation leads to the stabilization of hypoxia inducible factors 1a and 2a [HIF1a and HIF2a (HIF2a is also known as EPAS1)] with consequent up-regulation of specific target genes involved in cell proliferation, angiogenesis and erythropoiesis. A zebrafish model with a homozygous inactivation in the VHL gene (vhl−/−) recapitulates several aspects of the human disease, including development of highly vascular lesions in the brain and the retina and erythrocytosis. Here, we characterize for the first time the epithelial abnormalities present in the kidney of the vhl−/− zebrafish larvae as a first step in building a model of ccRCC in zebrafish. Our data show that the vhl−/− zebrafish kidney is characterized by an increased tubule diameter, disorganized cilia, the dramatic formation of cytoplasmic lipid vesicles, glycogen accumulation, aberrant cell proliferation and abnormal apoptosis. This phenotype of the vhl−/− pronephros is reminiscent of clear cell histology, indicating that the vhl−/− mutant zebrafish might serve as a model of early stage RCC. Treatment of vhl−/− zebrafish embryos with a small-molecule HIF2a inhibitor rescued the pronephric abnormalities, underscoring the value of the zebrafish model in drug discovery for treatment of VHL disease and ccRCC

Long-term trends in intertidal and subtidal benthic communities in response to water quality improvement measures.

Long-term monitoring studies are needed to understand changes in ecosystem status when restoration measures are implemented. A long-term data series (1996– 2007) of the Tagus estuary (Portugal) intertidal and subtidal benthic communities was collected in a degraded area where mitigation measures were implemented. Multivariate analysis was used to analyze spatial and temporal patterns in benthic community composition and trends in five benthic community metrics (i.e., taxonomic richness, density, biomass, Shannon–Wiener diversity and the AMBI index) were also examined. The results revealed a clear separation between intertidal and subtidal assemblages, although they had 50% of taxa in common, including the most abundant. Significant positive trends were found for all metrics showing that both intertidal and subtidal communities responded to the restoration measures implemented. Nevertheless, biotic indices need some adaptation before being universally applied to intertidal and subtidal habitats

Preliminary results of biological monitoring using benthic macroinfauna of the discharge areas of Lisbon drainage basins in Tagus estuary after new developments in sanitation infrastructures

The present study focused on the use of benthic macroinfauna to assess the ecological quality status of two specific areas in the Tagus estuary (Portugal), after the improvement in the sanitation infrastructures discharging in those areas. The sampling campaigns were held in summer of 2009, 2010 and 2011 in a set of impact and control stations. Multivariate analysis was used to determine the evolution of spatial and temporal patterns in benthic macroinfauna assemblages' composition. The ecological status of these assemblages was assessed by means of taxa richness, Shannon–Wiener diversity index and AMBI and M-AMBI biotic indices. The results obtained in both study areas seemed to indicate a trend for an improvement in the ecological condition of their benthic macroinfauna assemblages over time, although a consistent pattern was not found in all the analyses performed. When benthic macroinfauna assemblages under analysis are considerably degraded, the multimetric index M-AMBI seems to be more adequate for conducting monitoring studies than the AMBI index. However, the continuation of this work is indispensable to ensure the validity of this conclusion

A congenital activating mutant of WASp causes altered plasma membrane topography and adhesion under flow in lymphocytes

Leukocytes rely on dynamic actin-dependent changes in cell shape to pass through blood vessels, which is fundamental to immune surveillance. Wiskott-Aldrich Syndrome protein (WASp) is a hematopoietic cell–restricted cytoskeletal regulator important for modulating cell shape through Arp2/3-mediated actin polymerization. A recently identified WASpI294T mutation was shown to render WASp constitutively active in vivo, causing increased filamentous (F)–actin polymerization, high podosome turnover in macrophages, and myelodysplasia. The aim of this study was to determine the effect of WASpI294T expression in lymphocytes. Here, we report that lymphocytes isolated from a patient with WASpI294T, and in a cellular model of WASpI294T, displayed abnormal microvillar architecture, associated with an increase in total cellular F-actin. Microvillus function was additionally altered as lymphocytes bearing the WASpI294T mutation failed to roll normally on L-selectin ligand under flow. This was not because of defects in L-selectin expression, shedding, cytoskeletal anchorage, or membranal positioning; however, under static conditions of adhesion, WASpI294T-expressing lymphocytes exhibited altered dynamic interaction with L-selectin ligand, with a significantly reduced rate of adhesion turnover. Together, our results demonstrate that WASpI294T significantly affects lymphocyte membrane topography and L-selectin–dependent adhesion, which may be linked to defective hematopoiesis and leukocyte function in affected patients