Archive of Journal
Volume 72, Issue 1, Jan. 2016

Virus isolation and species-dependant selection pressure

Volume 72, Jan 2016

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Abstract: Standard procedure for isolation of influenza A viruses is inoculation of embryonated chicken eggs. However, this procedure is known to introduce mutations in the hemagluttinin gene when applied to human adapted influenza viruses. As an increase in mutation frequency has been shown after low pathogenic viruses have been transferred from their natural host to domesticated poultry, we designed a procedure to investigate isolation on an embryonated egg from the sampled species. The HA gene of two viruses, one H4 and one H6 was sequenced from the raw sample. Subsequently, the viruses were then passaged 6 times in the amniotic and allatoic compartments of embryonated mallard eggs. The same virus was then passaged in the same manner in embryonated chicken eggs. Material from each passaged virus will be sequenced targeting the HA gene, and results regarding selection will be presented at the conference.

Author(s): Wahlgren John, Falk K.I., Olsson G., Olsen B., Lundkvist A

Human and avian influenza A viruses strongly modify ultrastructure and molecular composition of the host human cell nucleolus

Volume 72, Jan 2016

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Abstract: Influenza viruses are responsible for recurrent annual epidemics causing acute febrile respiratory illness. Moreover, they constitute a major threat to public health since they could lead to the emergence of potentially pandemic new variants. These enveloped viruses contain eight single strand negative RNA segments and most of their infectious cycle occurs within the host cellular nucleus. Both viral transcription and replication are associated with host nuclear machinery and many interactions between viral proteins and nuclear components occur during the time course of infection. However, due to the fact that influenza has never constituted tools for studying fundamental molecular mechanisms of the cell, not much data are available concerning ultrastructural and molecular relationships between influenza viruses and human host nuclear domains. Recent publications have mentioned a dynamic nucleolar localization of viral nucleoprotein (NP), early in infection. Moreover, mutations suppressing the nucleolar addressing of NP, result in an abortive viral cycle (Ozawa M. et al., J. of Virology. 2007. Vol. 80, p. 30-41).Although NP is considered as a key adapter molecule between viral genome and host cell machinery, the biological significance of these events needs to be elucidated. Furthermore, the Non Structural protein NS1 was characterized as an interacting partner of nucleolin, a major nucleolar component (Murayama R. et al., Biochem. Biophys. Res. Communications. 2007. Vol. 362 p. 880- 5). Altogether, these results suggest a likely interplay between influenza and the host nucleolus. Nucleoli are known to be the site of ribosomal RNA (rRNA) transcription, processing, and assembly into the ribosomal subunits. In addition, nucleoli are dynamic structures involved in additional non-conventional roles including cell cycle regulation and cellular stress responses (Boisvert et al. Nat. Rev. Mol. Cell Biol. 2007. Vol. 8 p. 574-85). Furthermore, it is now well established that many other viruses, with nuclear replication, induce important remodeling of the ultrastructure, composition and dynamic of nucleoli, and that these modifications are required for optimal infection (Hiscox J.A.,Nature Rev. Microbiol. 2007. Vol. 5, p. 119-127). In this context, we hypothesized that host nucleolus could play a crucial role in determining the outcome of influenza infections. We then explored the potential impact of influenza viruses on the ultrastructure and molecular composition of nucleolus. For this purpose, human epithelium A549 cells were infected with relevant human (A/New Caledonia/20/99, H1N1 and A/Moscow/10/99, H3N2) and avian (A/Turkey/582/2006, H5N1; A/Finch/England/2051/94, H5N2 and A/chicken/Belgium/2003, H7N7) viruses and analysed at several times post-infection by electron microscopy and confocal laser scanning. Our results show that all these influenza type A viruses induce a strong remodelling of nucleolar morphology and a dynamic delocalization of several major constitutive nucleolar markers. These events probably imply interaction between viral nucleoprotein and host endogenous nucleolin which we characterized by a GST pull down assay. Finally, a complementary approach using reverse genetics confirmed that influenza type A viruses have a ?nucleolar experience? for performing effective and optimal viral replication.

Author(s): Rosa Calatrava Manuel, Moules V., Josset L., Bouscambert M. Ferraris, O.1; Frobert, E.1; De Chassey, B.3; Hay, A.4; Morfin, F.1; Diaz, J.J.5; Lina, B.1

Does agriculture intensification spare land for nature? A new methodology to overcome scale limitations.

Volume 72, Jan 2016

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Abstract: The impact of Land Use and Land Cover Change (LULCC) is a major issue in conservation biology. In the last 30 years, 85% of undisturbed Chaquean xerophytic forests has been converted to pastures and agricultural lands or is undergoing secondary succession. Land sparing, or the intensification of an export-oriented agriculture to respond to increasing world food demands while sparing land for nature conservation, supports the dominant current land use strategy for the Argentinean Chaco, which is suffering high rates of land use change mainly from forests to soybean plantation fields and shrub lands. This hypothesis predicts recovery of degraded forests due to rural-urban migration, a process that accompanies agricultural intensification. However, there are mixed evidences that either support or reject Land sparing actually taking place. One possible source of divergence is the scale of analysis. Using the Province of Santiago del Estero in the Argentinean dry chaco as an example, we test a methodology to determine if and at which scale land sparing occurs. In a three-step analysis we consider the crucial variables playing a role in the process (forest recovery, protected areas, rural-urban migration) and plot their slope of change in time against the increment in land surface of intensive crops. We use time series of NDVI from MODIS and census data from 2001 and 2010. Preliminary results validate the present methodology as useful to determine the critical scale at which Land sparing occurs.

Author(s): Herrero, Cristina. Smart, Simon.

INTRACRANIAL EVIDENCE OF AUDITORY-MOTOR RESONANCE MECHANISMS

Volume 72, Jan 2016

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Abstract: It is now well established that the human brain is endowed with a mechanism that pairs action perception with its execution. This system has been extensively studied using visual depictions of actions, however, there have been comparatively few attempts using auditory stimuli. In this study, we used a multideviant-mismatch negativity paradigm (MMN) incorporating action sounds (finger and tongue clicks) and acoustically-matched control counterparts to investigate action-related sound processing in a 12 year-old child with two 4-contact depth electrodes located in the anterior and posterior insular region and with an extensive gridcoverage of the frontal, temporal and parietal lobes of right hemisphere. Out of the 23 electrodes that presented an auditory response, 4 electrodes in the temporal and insular regions displayed significantly larger MMN responses for both action-related sounds. In addition, wavelet analysis carried out on electrodes located over the hand region revealed recruitment of the motor cortex for natural finger-click sound compared to control as indexed by a decrease in mu rhythms (12 and 20 Hz) power. These results constitute the first demonstration of the presence of an action-execution paring system sensitive to auditory stimuli in a child and bring further support to the hypothesis of motor resonance mechanism in the human developing brain.

Author(s): Jean-Francois Lepage, Sara Tremblay, Hugo Theoret

From static population models to individual behavior: Combining species distribution models with agent based models using Tawny owls as a case study.

Volume 72, Jan 2016

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Abstract: Understanding causes and effects of ecosystem dynamics is much like finding needles in a haystack. Most often we try to simplify the processes, looking for predictors that affect mean values of a population, e.g. mean mortality risk as a function of the distance to a road. Such approaches, however, do not consider individual behavior and interactions with the environment from which the dynamics arise. Agent Based Models (ABMs) allow individuals to interact with each other and with the environment, giving new insight into population dynamics and ecosystem functioning. In a previously developed SDM we have predicted the distribution of the Tawny owl (Strix aluco) throughout Denmark at the scale of individual breeding territories. We speculated that some of the areas predicted to be occuued by the SDM were out of reach for the species due to behavioral traits and population dynamics and that our SDM predictions could be fine tuned by incorporating it into an ABM. We therefore built an ABM to simulate the distribution of the Tawny owl in Denmark, using the model predictions from the SDM to form a spatially explicit map of more or less suitable areas. The landscape consisted of patches (square grid cells) of 600 by 600 meters covering all parts of Denmark. Each patch was assigned a quality defined as the likelihood of a patch being a breeding territory for the tawny owl as predicted by the SDM. We allowed the individuals to perceive the landscape as a mosaic of more or less suitable territories, and disperse, settle and die according to their immediate surroundings (environment and presence of other individuals). Combining predictions from a SDM may simplify complex behavioral rules that would otherwise have to be incorporated in the dispersal functions in the ABM . We simply created a landscpe of more or less suitable patches and let the individuals be most likely to move to better patches. Our most conservative AGM predicted local extinctions of the Tawny owl in parts of Denmark where it is supposed to be present according to our SDM. Less conservative estimates of adult mortality allowed the population to persist at higher numbers and throughout a larger range, and only unrealistically high mortality and reproductive rates allowed the population to persist in all the areas the SDM had predicted to be occupied. Our results suggest that ABMs can be used to fine tune predictions of SDMs.

Author(s): Anker Jensen, Rikke. Nachman, Gosta.

Effects of changing traditional grazing activities and wild boar rooting on alpine earthworm communities in Central Pyrenees.

Volume 72, Jan 2016

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Abstract: Land use changes are currently one of the major environmental concerns worldwide. In alpine grasslands, these changes mainly involve shifts in traditional grazing activities. Pyrenean alpine grasslands are one of the most valuable habitats in Europe, due to their bio-geographic position that involves high biodiversity rates. These grasslands are currently undergoing a gradual but profound change in pastoral use. Since the 60s, sheep herding has declined and in turn cattle herding has increased. This has led to a widespread abandonment of many grasslands, since cattle graze smaller areas than sheep. These changes in grazing regimes have recently been related to an increase in wild boar rooting affection to Pyrenean alpine grasslands. Temperate grasslands are known to support high density and biomass of earthworms. These earthworms communities are known to be a preferred food of wild boar. Investigating the effects of cattle grazing and trampling on the community of earthworms is thus a key step to determine and predict the future impact of wild boar rooting in their search for underground feeding resources. Our study aims to analyze and quantify the abundance and diversity of earthworms with respect to grazing change and the increased in the occurrence of wild boar rooting in three selected areas of the Central Pyrenees. The results will allow us determine the potential impact of wild boar rooting on vegetation structure and its relation to livestock management, and will therefore provide useful guidelines for the management of sensitive Pyrenean grasslands under soil disturbance regimes.

Author(s): Bueno, C. Guillermo. Jimenez, Juan Jose.

Detection of Mediterranean forest canopy areas vulnerable to droughts by integrating remote sensing and climatic variables.

Volume 72, Jan 2016

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Abstract: Nowadays drought remains a phenomenon that affects a wide variety of natural areas in many parts of the globe. Droughts are considered the abiotic factor with most harmful effects on forest areas, thus it is especially important to identify the locations with highest potential impact. Its temporal and spatial distribution, as well as the different types of drought defined, makes difficult its prediction and the impact degree that their appearance involve. Climatic drought, characterized by a temporal sequence with a higher frequency of atmospheric conditions that are unfavorable to the development of precipitation over a region, is the trigger of the process associated with the risk of biological drought. The methodology used to identify periods of climatic drought is mainly based on the analysis of climatic variables such as precipitation or temperature (in our case from the Digital Climatic Atlas of Catalonia). However, these analyses don?t take into account the physiological state of vegetation, a highly important variable that should be used to monitor the status of forest ecosystems vulnerable to droughts. Our aim is to evaluate the potential of satellite images regarding the identification of Mediterranean forest areas that could potentially have had a maximum affection during drought periods. We have integrated a series of images of TM/ETM+ sensors onboard Landsat 4-7 satellites, for the period 1984-2008 together with climatic data to detect drought in forest canopies. This integration may provide a readily applicable methodology for identifying the most vulnerable areas affected by droughts.

Author(s): Domingo, Cristina. Cristobal, Jordi. Ninyerola, Miquel. Pons, Xavier.

Butterfly elevational distributions are constrained by host plant distributions in a mountain area: implications in the context of climate change.

Volume 72, Jan 2016

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Abstract: Climate change is expected to force species distributions towards higher elevations and latitudes. However, this expectation assumes that all other conditions and resources are suitable and available, respectively, in the potentially colonisable areas under future warmer climate conditions. Based on detailed distributional data for 40 locations over a 560-2250 m elevation range in a mountain area in central Spain, we tested to what extent prevalence (proportion of occupied sites), and upper and lower elevation limits of 45 butterfly species were associated with those of their respective host plants. Butterfly prevalence was positively correlated with host plant prevalence. 33% of species occurred above 2000 m in elevation, suggesting that they were topographically limited by the maximum mountain altitude. For the remaining species, we found a positive correlation between butterfly and host plant upper elevation limits. The ranges of 44% of species stretched below 750 m in elevation, indicating that they have no apparent lower elevation limits in the area. For the remaining species, there was no significant correlation between butterfly and host plant lower elevation limits. Our research revealed that, apart from the obvious topographic limitation of maximum mountain altitude, future range shifts at upper elevation range limits could be limited by host plant availability for many species. This limitation imposed by the availability of biotic resources could exacerbate expected losses in range area due to climatically-driven uphill range shifts for species with lower elevation range limits in mountain regions

Author(s): Gutierrez, David. Gutierrez Illan, Javier. Diez, Sonia B.. Wilson, Robert J.

Characterization of dispersive altitudinal movements of birds mountain.

Volume 72, Jan 2016

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Abstract: In order to study dispersive altitudinal behavior of birds as an adaptation to the mountain, there were conducted biweekly census by the ?Points Method?, between October 2009 and September 2010, in 33 fixed points in ?Serra da Estrela?, Portugal, since 400 to 1993 meters of altitude. The birds community presents a high specific diversity (n=133 species). The resident species present a major representativeness (n=58; 48%), while the remaining are migratory. From the variation of population numbers of resident passerines, it appears that ?time? and ?altitude? presents a significant influence in their relative abundance, evidence of pronounced seasonal altitudinal movements. Of these, 35% perform altitudinal movements (n=14), being possible to distinguish four variation patterns of altitudinal distribution: (1) species distributed mainly by higher areas during reproduction and by the basal areas in winter (n=6 species); (2) species distributed mainly by higher areas during reproduction and uniformly throughout the altitudinal gradient in winter (n=1 species); (3) species distributed uniformly across the altitudinal gradient during reproduction and mainly in the basal areas in winter (n=5 species); (4) species in spite of distributing themselves preferentially by basal areas throughout the hole year, during reproduction they suffer a decrease of the effective in basal floors in detriment of an increase in higher areas (n=2 species). Only 31, 5% of the variation of abundances is related with biophysical factors, while the variables related to habitat and time of the year, present major significance than climatic factors. It is concluded that the altitudinal movements aren?t a direct response to climatic factors but to the changes that they induce in the biotypes. The largest proportion of the variation is justified by biological factors such as availability of resources and competition.

Author(s): Horta, Pedro. Raposeira, Helena. Conde, Jos?. Martins, Filipe. Lu?s, Ant?nio.

Global warming will influence the quality and quantity of food available for tundra herbivores

Volume 72, Jan 2016

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Abstract: Regardless of numerous studies on global warming affecting tundra vegetation, only very recently herbivores have been acknowledged as important factors interacting with or even counteracting warming. The Arctic is encountering remarkable temperature increase, and knowledge on the combined effects of warming and grazing on vegetation is needed for better management plans. Shrubs - the dominant growth form and key food source on tundra - are rapidly responding to warming. This study analyzes the effects of long-term warming (open-top chambers) on abundance and nutritional quality of four dominant shrub species, aiming at better understanding how food resources available for tundra herbivores respond to warming climate. We used a multisite experiment in forest-tundra ecotone along 900 km gradient from central to northern Norway. Warming increased shrub abundance in all locations, only Vaccinium myrtillus decreased in the southernmost location due to heavy competition with Empetrum hermaphroditum. Nitrogen and phosphorus concentrations of Betula nana decreased, but remained unchanged in the other shrub species. Total soluble phenolics did not respond to warming. Tannins varied greatly among species, locations and habitats and showed idiosyncratic responses to warming. Our findings suggest that abundance of palatable shrubs will increase especially in northern tundra habitats, whereas less-palatable Empetrum is highly increasing in nutrient-rich alpine forests. The large changes in shrub abundance will probably be more important for herbivores than the minor, and partly idiosyncratic, effects of warming on plant quality. Future warming is thus expected to be favorable to tundra herbivores, at least if only food availability is considered.

Author(s): Kaarlejarvi, Elina. Khitun, Olga. Olofsson, Johan.