Dataset documenting prevalence and counts of pine processionary moth tents on local host trees in 3 regions of France with different climatic environments

The pine processionary moth Thaumetopoea pityocampa is a defoliating lepidopter that develops during winter. The larvae are gregarious and bear urticating setae that are harmful to humans and vertebrates. They shelter in conspicuous silk tents that are easy to detect. We here present a dataset comprising tree characterization and tent counts from 3 agglomerations in France located in regions with different climatic environments. The studied trees belong to various conifer species that are potential hosts for the caterpillars. In each site, we defined clusters as one target tree and its 10-62 nearest neighbors, and surveyed each tree within the clusters by informing: tree species, coordinates, size, number of tents. We characterized a total of 3690 trees, including 2009 trees in Orléans (grouped in 68 clusters), 359 trees in La Baule (18 clusters) and 1322 trees in Montpellier (52 clusters). We provide the raw data characterizing each individual tree, graphs showing the prevalence and mean number of tents for the tree species included in the survey, and maps allowing to locate each tree. This dataset brings information about host preference of the pine processionary moth and will be useful as a baseline to study spatio-temporal variability of host-insect relationships. It can also be informative for decision-makers and managers of urban greenings to avoid trees that are likely to be heavily infested for plantation in proximity to vulnerable people.

Incursion Preparedness, Citizen Science and Early Detection of Invasive Insects: The Case of Aleurocanthus spiniferus (Hemiptera, Aleyrodidae) in France

We describe the process by which the quarantine whitefly, Aleurocanthus spiniferus (Hemiptera, Aleyrodidae), was detected in France. The initial observation was made by a volunteer who reported a picture of an adult in the Inventaire National du Patrimoine Naturel (INPN Espèces), a citizen science resource developed by l'Office Français de la Biodiversité and the French Muséum National d'Histoire Naturelle. The specimen was suspected to be A. spiniferus from this picture by one of the expert entomologists in charge of the Hemiptera group validation. Once the species was identified, it was mounted on a slide and the information was officially passed on to the ministry in charge of agriculture via a communication channel set up in advance for this type of situation. The ministry then triggered the regulatory actions planned in the event of the suspected detection of quarantine organisms. Sampling was quickly carried out and the specimens collected on this occasion were formally identified as belonging to the species A. spiniferus. This led to the formalization of an outbreak in France. This sequence of decisions took just two months from the first observation to the implementation of a management plan. This case presents how incursion preparedness contributes to a rapid response. Furthermore, this case exemplifies how citizen science can contribute to the early detection of invasive species and highlights the importance of informing both the general public and professionals about major environmental issues.

Climate change and the potential distribution of the glassy-winged sharpshooter (Homalodisca vitripennis), an insect vector of Xylella fastidiosa

Biological invasions represent a major threat for biodiversity and agriculture. Despite efforts to restrict the spread of alien species, preventing their introduction remains the best strategy for an efficient control. In that context preparedness of phytosanitary authorities is very important and estimating the geographical range of alien species becomes a key information. The present study investigates the potential geographical range of the glassy-winged sharpshooter (Homalodisca vitripennis), a very efficient insect vector of Xylella fastidiosa, one of the most dangerous plant-pathogenic bacteria worldwide. We use species distribution modeling (SDM) to analyse the climate factors driving the insect distribution and we evaluate its potential distribution in its native range (USA) and in Europe according to current climate and different scenarios of climate change: 6 General Circulation Models (GCM), 4 shared socioeconomic pathways of gas emission and 4 time periods (2030, 2050, 2070, 2090). The first result is that the climate conditions of the European continent are suitable to the glassy-winged sharpshooter, in particular around the Mediterranean basin where X. fastidiosa is present. Projections according to future climate conditions indicate displacement of climatically suitable areas towards the north in both North America and Europe. Globally, suitable areas will decrease in North America and increase in Europe in the coming decades. SDM outputs vary according to the GCM considered and this variability indicated areas of uncertainty in the species potential range. Both potential distribution and its uncertainty associated to future climate projections are important information for improved preparedness of phytosanitary authorities.

Environmental factors driving the abundance of Philaenus spumarius in mesomediterranean habitats of Corsica (France)

Philaenus spumarius (Ps) is considered the main insect vector of the bacterium Xylella fastidiosa (Xf) in Europe. As such, it is a key actor of the Xf pathosystem on which surveillance and management strategies could be implemented. Although research effort has increased in the past years, the ecological factors shaping Ps abundance and distribution across landscapes are still poorly known in most regions of Europe. We selected 64 plots of 500m² in Corsican semi-natural habitats in which we sampled nymphs and adults of Ps during three years. While local or surrounding vegetation structure (low or high scrubland) had little effect on Ps abundance, we highlighted a positive relationship between Ps abundance and the density of Cistus monspeliensis in the plots. We also found larger populations of Ps in cooler and moister plots. The pattern of host association highlighted here is unique, which calls for more studies on the ecology of Ps in Europe, to help designing surveillance and management strategy for Xf.

Ultra-Conserved Elements and morphology reciprocally illuminate conflicting phylogenetic hypotheses in Chalcididae (Hymenoptera, Chalcidoidea)

Recent technical advances combined with novel computational approaches have promised the acceleration of our understanding of the tree of life. However, when it comes to hyperdiverse and poorly known groups of invertebrates, studies are still scarce. As published phylogenies will be rarely challenged by future taxonomists, careful attention must be paid to potential analytical bias. We present the first molecular phylogenetic hypothesis for the family Chalcididae, a group of parasitoid wasps, with a representative sampling (144 ingroups and seven outgroups) that covers all described subfamilies and tribes, and 82% of the known genera. Analyses of 538 Ultra-Conserved Elements (UCEs) with supermatrix (RAxML and IQTREE) and gene tree reconciliation approaches (ASTRAL, ASTRID) resulted in highly supported topologies in overall agreement with morphology but reveal conflicting topologies for some of the deepest nodes. To resolve these conflicts, we explored the phylogenetic tree space with clustering and gene genealogy interrogation methods, analyzed marker and taxon properties that could bias inferences and performed a thorough morphological analysis (130 characters encoded for 40 taxa representative of the diversity). This joint analysis reveals that UCEs enable attainment of resolution between ancestry and convergent/divergent evolution when morphology is not informative enough, but also shows that a systematic exploration of bias with different analytical methods and a careful analysis of morphological features is required to prevent publication of artifactual results. We highlight a GC content bias for maximum-likelihood approaches, an artifactual mid-point rooting of the ASTRAL tree and a deleterious effect of high percentage of missing data (>85% missing UCEs) on gene tree reconciliation methods. Based on the results we propose a new classification of the family into eight subfamilies and ten tribes that lay the foundation for future studies on the evolutionary history of Chalcididae.

Exploring systematic biases, rooting methods and morphological evidence to unravel the evolutionary history of the genus Ficus (Moraceae)

Despite many attempts in the Sanger sequencing era, the phylogeny of fig trees remains unresolved, which limits our ability to analyze the evolution of key traits that may have contributed to their evolutionary and ecological success. We used restriction-site-associated DNA sequencing (c. 420 kb) and 102 morphological characters to elucidate the relationships between 70 species of Ficus. To increase phylogenetic information for higher-level relationships, we targeted conserved regions and assembled paired reads into long loci to enable the retrieval of homologous loci in outgroup genomes. We compared morphological and molecular results to highlight discrepancies and reveal possible inference bias. For the first time, we recovered a monophyletic subgenus Urostigma (stranglers) and a clade with all gynodioecious Ficus. However, we show, with a new approach based on iterative principal component analysis, that it is not (and will probably never be) possible to homogenize evolutionary rates and GC content for all taxa before phylogenetic inference. Four competing positions for the root of the molecular tree are possible. The placement of section Pharmacosycea as sister to other fig trees is not supported by morphological data and considered a result of a long-branch attraction artefact to the outgroups. Regarding morphological features and indirect evidence from the pollinator tree of life, the topology that divides Ficus into monoecious versus gynodioecious species appears most plausible. It seems most likely that the ancestor of fig trees was a freestanding tree and active pollination is inferred as the ancestral state, contrary to previous hypotheses. However, ambiguity remains on the ancestral breeding system. Despite morphological plasticity, we advocate restoring a central role to morphology in our understanding of the evolution of Ficus, as it can help detect systematic errors that appear more pronounced with larger molecular datasets.

A crowdsourcing approach to track the expansion of the brown marmorated stinkbug Halyomorpha halys (Stål, 1855) in France

Background

Halyomorpha halys (Stål, 1855), the brown marmorated stinkbug (BMSB) is a highly successful invasive species, native to eastern Asia. It has managed to spread into North America and Europe in recent decades, causing severe damage to various crops. BMSB has been detected in Europe in 2004 and has since expanded in more than 20 countries from Sweden to Greece and Spain to Turkey, the South European Territory of Russia (Krasnodar region) and Abkhazia. In 2012, we set up a citizen science survey to monitor BMSB expansion in France.

New information

The present crowdsourcing survey was initiated in 2012 and provided a large number of occurrence points of BMSB. These data allowed to track the expansion of the species in France from 2012 to 2019 and brought information about its phenology and distribution in various habitats. The dataset comprises both valid and invalid sightings, thereby allowing us to examine changes in the quality of citizen reports during the course of the survey. Despite a large proportion of misidentifications, the survey provided a large number of valid occurrences. Furthermore, valuable information on hemipterans of Pentatomidae and Coreidae families entering habitations were also gathered. The dataset also illustrates that, although designed for a large public, the Agiir application was mostly used by urban dwellers with very few sightings stemming from professionals of agricultural sectors.

Citizen science and niche modeling to track and forecast the expansion of the brown marmorated stinkbug Halyomorpha halys (Stål, 1855)

Halyomorpha halys (Stål, 1855), the Brown Marmorated StinkBug (BMSB) is a highly successful invasive species native to eastern Asia that managed to spread into North America and Europe in recent decades. We set up a citizen science survey to monitor BMSB expansion in France in 2012 and analyzed the data it yielded between 2012 and 2019 to examine the local expansion of the insect. These data were gathered with occurrences form various sources (GBIF, literature) to calibrate a species niche model and assess potential current BMSB range. We evaluated the potential changes to the BMSB range due to climate change by projecting the model according to 6 global circulation models (GCM) and the shared socio-economic pathways SSP245 in two time periods 2021-2040 and 2041-2060. Citizen science allowed to track BMSB expansion in France and provided information about its phenology and its habitat preferences. The model highlighted the potential for further range expansion in Europe and illustrated the impact of climate change. These results could help managing the current BMSB invasion and the framework of this survey could contribute to a better preparedness of phytosanitary authorities either for the BMSB or other invasive pests.

Monitoring of adult emergence in the pine processionary moth between 1970 and 1984 in Mont Ventoux, France

Background

The current climate change has marked impacts on the phenology of species, i.e. the timing of the various stages of their life cycle. Yet, to fully understand how phenological patterns can be modified according to changes in temperature regimes, it is of prime importance to rely on high quality historical data. Here, we propose a very valuable dataset including individual monitoring from pupation to adult emergence of 46 479 individuals of pine processionary moth (Thaumetopoea pityocampa) surveyed between 1970 and 1984 in southern France along an altitudinal gradient. As optional prolonged diapause occurs in this species, i.e. some individuals experience one or more years of diapause before emerging, the caterpillars sampled in any given year were monitored during up to 5 years. The goal was to give precise information about phenology in this species to further analyse its temporal patterns of variation.

New information

This dataset is unique by its richness and the type of data it contains. Phenology in the pine processionary moth is often monitored by the use of pheromone traps in the field, which does not provide all the necessary information, because it is then not possible to trace back the exact origin of the moth trapped, nor to characterise other steps of the life cycle. Moreover, as it corresponds to historical data dating back to the 70s and the 80s, the dataset provides a historical baseline of trends in the pre-warming period.

Climate change impact on the potential geographical distribution of two invading Xylosandrus ambrosia beetles

Xylosandrus compactus and X. crassiusculus are two polyphagous ambrosia beetles originating from Asia and invasive in circumtropical regions worldwide. Both species were recently reported in Italy and further invaded several other European countries in the following years. We used the MaxEnt algorithm to estimate the suitable areas worldwide for both species under the current climate. We also made future projections for years 2050 and 2070 using 11 different General Circulation Models, for 4 Representative Concentration Pathways (2.6, 4.5, 6.0 and 8.5). Our analyses showed that X. compactus has not been reported in all potentially suitable areas yet. Its current distribution in Europe is localised, whereas our results predicted that most of the periphery of the Mediterranean Sea and most of the Atlantic coast of France could be suitable. Outside Europe, our results also predicted Central America, all islands in Southeast Asia and some Oceanian coasts as suitable. Even though our results when modelling its potential distribution under future climates were more variable, the models predicted an increase in suitability poleward and more uncertainty in the circumtropical regions. For X. crassiusculus, the same method only yielded poor results, and the models thus could not be used for predictions. We discuss here these results and propose advice about risk prevention and invasion management of both species.

Ooctonus vulgatus (Hymenoptera, Mymaridae), a potential biocontrol agent to reduce populations of Philaenus spumarius (Hemiptera, Aphrophoridae) the main vector of Xylella fastidiosa in Europe

As a vector of Xylella fastidiosa (Wells, 1987) in Europe, the meadow spittlebug Philaenus spumarius (Linnaeus, 1758) (Hemiptera, Aphrophoridae) is a species of major concern. Therefore, tools and agents to control this ubiquitous insect that develops and feeds on hundreds of plant species are wanted. We conducted a field survey of P. spumarius eggs in Corsica and provide a first report of Ooctonus vulgatus Haliday, 1833 (Hymenoptera, Mymaridae) as a potential biocontrol agent of P. spumarius in Europe. To allow species identification, we summarized the main characters distinguishing O. vulgatus from other European species of Ooctonus and generated COI DNA barcodes. Parasitism rates were variable in the four localities included in the survey but could reach 69% (for an average number of eggs that hatched per locality of 109). Based on the geographic occurrences of O. vulgatus obtained from the literature, we calibrated an ecological niche model to assess its potential distribution in the Holarctic. Obviously, several questions need to be addressed to determine whether O. vulgatus could become an effective biocontrol agent of P. spumarius in Europe. So far, O. vulgatus has been reared only from P. spumarius eggs, but its exact host-range should be evaluated to ensure efficiency and avoid non-target effect. The top-down impact of the parasitoid on vector populations should also be assessed on large data sets. Finally, the feasibility of mass rearing should be tested. We hope this report serves as a starting point to initiate research on this parasitoid wasp to assess whether it could contribute to reduce the spread and impact of X. fastidiosa in Europe.

Restriction-site associated DNA markers provide new insights into the evolutionary history of the bark beetle genus Dendroctonus

The bark beetle genus Dendroctonus contains some of the most economically important pests of conifers worldwide. Despite many attempts, there is no agreement today on the phylogenetic relationships within the genus, which limits our understanding of its evolutionary history. Here, using restriction-site associated DNA (RAD) markers from 70 specimens representing 17 species (85% of the known diversity) we inferred the phylogeny of the genus, its time of origin and biogeographic history, as well as the evolution of key ecological traits (host plants, larval behavior and adults' attack strategies). For all combinations of tested parameters (from 6444 to 23,570 RAD tags analyzed), the same, fully resolved topology was inferred. Our analyses suggest that the most recent common ancestor (mrca) of all extant Dendroctonus species was widely distributed across eastern Palearctic and western Nearctic during the early Miocene, from where species dispersed to other Holarctic regions. A first main inter-continental vicariance event occurred during early Miocene isolating the ancestors of D. armandi in the Palearctic, which was followed by the radiation of the main Dendroctonus lineages in North America. During the Late Miocene, the ancestor of the 'rufipennis' species group colonized north-east Palearctic regions from western North America, which was followed by a second main inter-continental vicariance event isolating Pleistocene populations in Asia (D. micans) and western North America (D. murrayanae and D. punctatus). The present study supports previous hypotheses explaining intercontinental range disjunctions across the Northern Hemisphere by the fragmentation of a continuous distribution due to climatic cooling, host range fragmentation and geological changes during the late Cenozoic. The reconstruction of ancestral ecological traits indicates that the mrca bored individual galleries and mass attacked the boles of pines. The gregarious feeding behavior of the larvae as well as the individual attack of the base of trees have apparently independently evolved twice in North America (in the 'rufipennis' and the 'valens' species groups), which suggests a higher adaptive potential than previously thought and may be of interest for plant protection and biodiversity conservation in a rapidly changing world.

Natural flavonoids inhibit the plasma membrane Ca2+-ATPase

Research on flavonoids from plant sources has recently sparked increasing interest because of their beneficial health properties. Different studies have shown that flavonoids change the intracellular Ca²⁺ homeostasis linked to alterations in the function of mitochondria, Ca²⁺ channels and Ca²⁺ pumps. These findings hint at plasma membrane Ca²⁺-ATPase (PMCA) involvement, as it transports Ca²⁺ actively to the extracellular medium coupled to ATP hydrolysis, thus maintaining ion cellular homeostasis. The present study aims to investigate the effect of several natural flavonoids on PMCA both in isolated protein systems and in living cells, and to establish the relationship between flavonoid structure and inhibitory activity on PMCA. Our results show that natural flavonoids inhibited purified and membranous PMCA with different effectiveness: quercetin and gossypin were the most potent and their inhibition mechanisms seem to be different, as quercetin does not prevent ATP binding whereas gossypin does. Moreover, PMCA activity was inhibited in human embryonic kidney cells which transiently overexpress PMCA, suggesting that the effects observed on isolated systems could occur in a complex structure like a living cell. In conclusion, this work reveals a novel molecular mechanism through which flavonoids inhibit PMCA, which leads to Ca²⁺ homeostasis and signaling alterations in the cell.

Using insects to detect, monitor and predict the distribution of Xylella fastidiosa: a case study in Corsica

We sampled ca 2500 specimens of Philaenus spumarius (Hemiptera: Aphrophoridae) throughout Corsica without a priori knowledge on the presence of symptoms on plants. We screened 448 specimens for the presence of Xylella fastidiosa (Xf) using qPCR and a custom nested PCR. qPCR appeared versatile and under-estimated the prevalence of Xf. Nested PCR showed that Xf was present in all populations. Molecular results were validated by prediction on the distribution of Xf made from tests conducted on plants, which shows the pertinence of using vectors in risk assessment studies. Xf was detected in tenerals and adults. Thus, P. spumarius could acquire Xf from its host plant, mostly Cistus monspeliensis in Corsica, which may act as reservoir for the next season. This contrasts with other observations and suggests that management strategies may have to be adapted on a case-by-case basis. At least two genetic entities and several variants of Xf not yet identified on plants were present in the insects, which suggests ancient introductions of Xf and a probable underestimation of the current diversity of the strains present in Corsica. Interestingly 6% of the specimens carried two subspecies of Xf. Studies are required to better characterize the strains present in Corsica and to determine how the disease was introduced, spread and why no sign of a potential epidemic was detected earlier. This study shows that, when sensitive enough methods are implemented, spittlebugs (and more specifically P. spumarius for which species distribution modelling shows it could be a good sentinel for Europe) can be used to predict and better assess the exact distribution of Xf. Furthermore, Xf multiply only in their foregut and does not become circulative, which facilitates its detection.

Multi-scale and multi-site resampling of a study area in spatial genetics: implications for flying insect species

The use of multiple sampling areas in landscape genetic analysis has been recognized as a useful way of generalizing the patterns of environmental effects on organism gene flow. It reduces the variability in inference which can be substantially affected by the scale of the study area and its geographic location. However, empirical landscape genetic studies rarely consider multiple sampling areas due to the sampling effort required. In this study, we explored the effects of environmental features on the gene flow of a flying long-horned beetle (Monochamus galloprovincialis) using a landscape genetics approach. To account for the unknown scale of gene flow and the multiple local confounding effects of evolutionary history and landscape changes on inference, we developed a way of resampling study areas on multiple scales and in multiple locations (sliding windows) in a single large-scale sampling design. Landscape analyses were conducted in 3*104 study areas ranging in scale from 220 to 1,000 km and spread over 132 locations on the Iberian Peninsula. The resampling approach made it possible to identify the features affecting the gene flow of this species but also showed high variability in inference among the scales and the locations tested, independent of the variation in environmental features. This method provides an opportunity to explore the effects of environmental features on organism gene flow on the whole and reach conclusions about general landscape effects on their dispersal, while limiting the sampling effort to a reasonable level.

Landscape epidemiology in urban environments: The example of rodent-borne Trypanosoma in Niamey, Niger

Trypanosomes are protozoan parasites found worldwide, infecting humans and animals. In the past decade, the number of reports on atypical human cases due to Trypanosoma lewisi or T. lewisi-like has increased urging to investigate the multiple factors driving the disease dynamics, particularly in cities where rodents and humans co-exist at high densities. In the present survey, we used a species distribution model, Maxent, to assess the spatial pattern of Trypanosoma-positive rodents in the city of Niamey. The explanatory variables were landscape metrics describing urban landscape composition and physiognomy computed from 8 land-cover classes. We computed the metrics around each data location using a set of circular buffers of increasing radii (20m, 40m, 60m, 80m and 100m). For each spatial resolution, we determined the optimal combination of feature class and regularization multipliers by fitting Maxent with the full dataset. Since our dataset was small (114 occurrences) we expected an important uncertainty associated to data partitioning into calibration and evaluation datasets. We thus performed 350 independent model runs with a training dataset representing a random subset of 80% of the occurrences and the optimal Maxent parameters. Each model yielded a map of habitat suitability over Niamey, which was transformed into a binary map implementing a threshold maximizing the sensitivity and the specificity. The resulting binary maps were combined to display the proportion of models that indicated a good environmental suitability for Trypanosoma-positive rodents. Maxent performed better with landscape metrics derived from buffers of 80m. Habitat suitability for Trypanosoma-positive rodents exhibited large patches linked to urban features such as patch richness and the proportion of landscape covered by concrete or tarred areas. Such inferences could be helpful in assessing areas at risk, setting of monitoring programs, public and medical staff awareness or even vaccination campaigns.

RADIS: analysis of RAD-seq data for interspecific phylogeny

In an attempt to make the processing of RAD-seq data easier and allow rapid and automated exploration of parameters/data for phylogenetic inference, we introduce the perl pipeline RADIS. Users of RADIS can let their raw Illumina data be processed up to phylogenetic tree inference, or stop (and restart) the process at some point. Different values for key parameters can be explored in a single analysis (e.g. loci building, sample/loci selection), making possible a thorough exploration of data. RADIS relies on Stacks for demultiplexing of data, removing PCR duplicates and building individual and catalog loci. Scripts have been specifically written for trimming of reads and loci/sample selection. Finally, RAxML is used for phylogenetic inferences, though other software may be utilized.

Availability and implementation: RADIS is written in perl, designed to run on Linux and Unix platforms. RADIS and its manual are freely available from http://www1.montpellier.inra.fr/CBGP/software/RADIS/.

Contact:astrid.cruaud@supagro.inra.fr

Supplementary information:Supplementary data are available at Bioinformatics online.

The spatiotemporal pattern of earthworm community in the grass savannas of Lamto (Ivory Coast)

BACKGROUND

The impact of earthworms on both soil physical properties and soil organic matter dynamics has been well documented (Lavelle and Spain 2001). There is a wealth of literature dedicated to the biological mechanisms at work or to empirical approaches based on field data. Assessing the functional role of a species or community implies establishing both time and space scales at which it is effectively the primary determinant of the process(es) at hand. In that context, space-time data analyses are powerful tools to process community data collected on numerous occasions but are, however, not widely disseminated in the community of ecologists. Although computer resources are available, one difficulty is that ad hoc field data are not always easily available which hinders the percolation of the methods.

NEW INFORMATION

We provide the results of a 5 dates survey of earthworm community in a grass savanna of Lamto (Ivory Coast) conducted between 1995 and 1997. At each sampling date, earthworm community was assessed by hand-sorting a set of 100 soil monoliths distributed on a regular grid of 5 m mesh. These data were analyzed in Rossi (2003a) and are published here with the aim that they could be reanalyzed using new statistical tools (e.g. MEM analyses see Jiménez et al. 2014) or serve as example for researchers that train on space-time statistical methods.

Urban Market Gardening and Rodent-Borne Pathogenic Leptospira in Arid Zones: A Case Study in Niamey, Niger

Leptospirosis essentially affects human following contact with rodent urine-contaminated water. As such, it was mainly found associated with rice culture, recreational activities and flooding. This is also the reason why it has mainly been investigated in temperate as well as warm and humid regions, while arid zones have been only very occasionally monitored for this disease. In particular, data for West African countries are extremely scarce. Here, we took advantage of an extensive survey of urban rodents in Niamey, Niger, in order to look for rodent-borne pathogenic Leptospira species presence and distribution across the city. To do so, we used high throughput bacterial 16S-based metabarcoding, lipL32 gene-targeting RT-PCR, rrs gene sequencing and VNTR typing as well as GIS-based multivariate spatial analysis. Our results show that leptospires seem absent from the core city where usual Leptospira reservoir rodent species (namely R. rattus and M. natalensis) are yet abundant. On the contrary, L. kirschneri was detected in Arvicanthis niloticus and Cricetomys gambianus, two rodent species that are restricted to irrigated cultures within the city. Moreover, the VNTR profiles showed that rodent-borne leptospires in Niamey belong to previously undescribed serovars. Altogether, our study points towards the importance of market gardening in maintain and circulation of leptospirosis within Sahelian cities. In Africa, irrigated urban agriculture constitutes a pivotal source of food supply, especially in the context of the ongoing extensive urbanization of the continent. With this in mind, we speculate that leptospirosis may represent a zoonotic disease of concern also in arid regions that would deserve to be more rigorously surveyed, especially in urban agricultural settings.

Assessing the Risk of Invasion by Tephritid Fruit Flies: Intraspecific Divergence Matters

Widely distributed species often show strong phylogeographic structure, with lineages potentially adapted to different biotic and abiotic conditions. The success of an invasion process may thus depend on the intraspecific identity of the introduced propagules. However, pest risk analyses are usually performed without accounting for intraspecific diversity. In this study, we developed bioclimatic models using MaxEnt and boosted regression trees approaches, to predict the potential distribution in Europe of six economically important Tephritid pests (Ceratitis fasciventris (Bezzi), Bactrocera oleae (Rossi), Anastrepha obliqua (Macquart), Anastrepha fraterculus (Wiedemann), Rhagoletis pomonella (Walsh) and Bactrocera cucurbitae (Coquillet)). We considered intraspecific diversity in our risk analyses by independently modeling the distributions of conspecific lineages. The six species displayed different potential distributions in Europe. A strong signal of intraspecific climate envelope divergence was observed in most species. In some cases, conspecific lineages differed strongly in potential distributions suggesting that taxonomic resolution should be accounted for in pest risk analyses. No models (lineage- and species-based approaches) predicted high climatic suitability in the entire invaded range of B. oleae—the only species whose intraspecific identity of invading populations has been elucidated—in California. Host availability appears to play the most important role in shaping the geographic range of this specialist pest. However, climatic suitability values predicted by species-based models are correlated with population densities of B. oleae globally reported in California. Our study highlights how classical taxonomic boundaries may lead to under- or overestimation of the potential pest distributions and encourages accounting for intraspecific diversity when assessing the risk of biological invasion.

An exhaustive inventory of coniferous trees in an agricultural landscape

BACKGROUND

Various species of forest trees are commonly used for ornamental purposes and are therefore frequently found in non-forest ecosystems. These trees constitute a significant component of the trees outside forests (TOF). Although increasingly recognized as prominent feature of agricultural lands and built-up areas, not much is known, however, about TOF since they are generally absent from forest inventories.

NEW INFORMATION

In the present study, we focus on the coniferous tree species that constitute potential hosts for a forest defoliator, the pine processionary moth Thaumetopoeapityocampa Den. & Schiff. (Lepidoptera, Notodontidae). We carried out an exhaustive inventory of all pines (Pinus spp.), cedars (Cedrus spp.) and Douglas-fir (Pseudotsugamenziesii) in a 22 × 22 km study window located in the open-field region of Beauce in the centre of France. We recorded a total of 3834 individuals or small groups host trees corresponding a density of 7.9 occurrences per 100 ha. We provide the spatial coordinates of the points without differentiation between tree species.

Dissecting the multi-scale spatial relationship of earthworm assemblages with soil environmental variability

Background

Studying the drivers and determinants of species, population and community spatial patterns is central to ecology. The observed structure of community assemblages is the result of deterministic abiotic (environmental constraints) and biotic factors (positive and negative species interactions), as well as stochastic colonization events (historical contingency). We analyzed the role of multi-scale spatial component of soil environmental variability in structuring earthworm assemblages in a gallery forest from the Colombian “Llanos”. We aimed to disentangle the spatial scales at which species assemblages are structured and determine whether these scales matched those expressed by soil environmental variables. We also tested the hypothesis of the “single tree effect” by exploring the spatial relationships between root-related variables and soil nutrient and physical variables in structuring earthworm assemblages. Multivariate ordination techniques and spatially explicit tools were used, namely cross-correlograms, Principal Coordinates of Neighbor Matrices (PCNM) and variation partitioning analyses.

Results

The relationship between the spatial organization of earthworm assemblages and soil environmental parameters revealed explicitly multi-scale responses. The soil environmental variables that explained nested population structures across the multi-spatial scale gradient differed for earthworms and assemblages at the very-fine- (<10 m) to medium-scale (10–20 m). The root traits were correlated with areas of high soil nutrient contents at a depth of 0–5 cm. Information on the scales of PCNM variables was obtained using variogram modeling. Based on the size of the plot, the PCNM variables were arbitrarily allocated to medium (>30 m), fine (10–20 m) and very fine scales (<10 m). Variation partitioning analysis revealed that the soil environmental variability explained from less than 1% to as much as 48% of the observed earthworm spatial variation.

Conclusions

A large proportion of the spatial variation did not depend on the soil environmental variability for certain species. This finding could indicate the influence of contagious biotic interactions, stochastic factors, or unmeasured relevant soil environmental variables.

Electronic supplementary material

The online version of this article (doi:10.1186/s12898-014-0026-4) contains supplementary material, which is available to authorized users.

Spatial segregation between invasive and native commensal rodents in an urban environment: a case study in Niamey, Niger

Invasive rodents have been responsible for the diffusion worldwide of many zoonotic agents, thus representing major threats for public health. Cities are important hubs for people and goods exchange and are thus expected to play a pivotal role in invasive commensal rodent dissemination. Yet, data about urban rodents' ecology, especially invasive vs. native species interactions, are dramatically scarce. Here, we provide results of an extensive survey of urban rodents conducted in Niamey, Niger, depicting the early stages of rodent bioinvasions within a city. We explore the species-specific spatial distributions throughout the city using contrasted approaches, namely field sampling, co-occurrence analysis, occupancy modelling and indicator geostatistics. We show that (i) two species (i.e. rural-like vs. truly commensal) assemblages can be identified, and that (ii) within commensal rodents, invasive (Rattus rattus and Mus musculus) and native (Mastomys natalensis) species are spatially segregated. Moreover, several pieces of arguments tend to suggest that these exclusive distributions reflect an ongoing native-to-invasive species turn over. The underlying processes as well as the possible consequences for humans are discussed.

Dissecting the space-time structure of tree-ring datasets using the partial triadic analysis

Tree-ring datasets are used in a variety of circumstances, including archeology, climatology, forest ecology, and wood technology. These data are based on microdensity profiles and consist of a set of tree-ring descriptors, such as ring width or early/latewood density, measured for a set of individual trees. Because successive rings correspond to successive years, the resulting dataset is a ring variables × trees × time datacube. Multivariate statistical analyses, such as principal component analysis, have been widely used for extracting worthwhile information from ring datasets, but they typically address two-way matrices, such as ring variables × trees or ring variables × time. Here, we explore the potential of the partial triadic analysis (PTA), a multivariate method dedicated to the analysis of three-way datasets, to apprehend the space-time structure of tree-ring datasets. We analyzed a set of 11 tree-ring descriptors measured in 149 georeferenced individuals of European larch (Larix decidua Miller) during the period of 1967–2007. The processing of densitometry profiles led to a set of ring descriptors for each tree and for each year from 1967–2007. The resulting three-way data table was subjected to two distinct analyses in order to explore i) the temporal evolution of spatial structures and ii) the spatial structure of temporal dynamics. We report the presence of a spatial structure common to the different years, highlighting the inter-individual variability of the ring descriptors at the stand scale. We found a temporal trajectory common to the trees that could be separated into a high and low frequency signal, corresponding to inter-annual variations possibly related to defoliation events and a long-term trend possibly related to climate change. We conclude that PTA is a powerful tool to unravel and hierarchize the different sources of variation within tree-ring datasets.

Assessing species distribution using Google Street View: a pilot study with the Pine Processionary Moth

Mapping species spatial distribution using spatial inference and prediction requires a lot of data. Occurrence data are generally not easily available from the literature and are very time-consuming to collect in the field. For that reason, we designed a survey to explore to which extent large-scale databases such as Google maps and Google street view could be used to derive valid occurrence data. We worked with the Pine Processionary Moth (PPM) Thaumetopoea pityocampa because the larvae of that moth build silk nests that are easily visible. The presence of the species at one location can therefore be inferred from visual records derived from the panoramic views available from Google street view. We designed a standardized procedure allowing evaluating the presence of the PPM on a sampling grid covering the landscape under study. The outputs were compared to field data. We investigated two landscapes using grids of different extent and mesh size. Data derived from Google street view were highly similar to field data in the large-scale analysis based on a square grid with a mesh of 16 km (96% of matching records). Using a 2 km mesh size led to a strong divergence between field and Google-derived data (46% of matching records). We conclude that Google database might provide useful occurrence data for mapping the distribution of species which presence can be visually evaluated such as the PPM. However, the accuracy of the output strongly depends on the spatial scales considered and on the sampling grid used. Other factors such as the coverage of Google street view network with regards to sampling grid size and the spatial distribution of host trees with regards to road network may also be determinant.

Toxoplasmosis seroprevalence in urban rodents: a survey in Niamey, Niger

A serological survey of Toxoplasma gondii was conducted on 766 domestic and peridomestic rodents from 46 trapping sites throughout the city of Niamey, Niger. A low seroprevalence was found over the whole town with only 1.96% of the rodents found seropositive. However, differences between species were important, ranging from less than 2% in truly commensal Mastomys natalensis, Rattus rattus and Mus musculus, while garden-associated Arvicanthis niloticus displayed 9.1% of seropositive individuals. This is in line with previous studies on tropical rodents--that we reviewed here--which altogether show that Toxoplasma seroprevalence in rodent is highly variable, depending on many factors such as locality and/or species. Moreover, although we were not able to decipher statistically between habitat or species effect, such a contrast between Nile grass rats and the other rodent species points towards a potentially important role of environmental toxoplasmic infection. This would deserve to be further scrutinised since intra-city irrigated cultures are extending in Niamey, thus potentially increasing Toxoplasma circulation in this yet semi-arid region. As far as we are aware of, our study is one of the rare surveys of its kind performed in Sub-Saharan Africa and the first one ever conducted in the Sahel.

Where do adaptive shifts occur during invasion? A multidisciplinary approach to unravelling cold adaptation in a tropical ant species invading the Mediterranean area

Evolution may improve the invasiveness of populations, but it often remains unclear whether key adaptation events occur after introduction into the recipient habitat (i.e. post-introduction adaptation scenario), or before introduction within the native range (i.e. prior-adaptation scenario) or at a primary site of invasion (i.e. bridgehead scenario). We used a multidisciplinary approach to determine which of these three scenarios underlies the invasion of the tropical ant Wasmannia auropunctata in a Mediterranean region (i.e. Israel). Species distribution models (SDM), phylogeographical analyses at a broad geographical scale and laboratory experiments on appropriate native and invasive populations indicated that Israeli populations followed an invasion scenario in which adaptation to cold occurred at the southern limit of the native range before dispersal to Israel. We discuss the usefulness of combining SDM, genetic and experimental approaches for unambiguous determination of eco-evolutionary invasion scenarios.

Soil macroinvertebrates as indicators of pollution by heavy metals

A broad range of soil pollutants were found to decrease with distance from a zinc smelter from 35,000 to 77, 8270 to 40 and from 190 to less than 1 ppm for zinc, lead and cadmium, respectively. Along this gradient, observed species richness of soil macro-organisms seemed to be more affected by the land-use type than by soil pollution--minimum in crops (21), maximum in woody sites (126). IndVal index allowed isolation of 21 indicator species from the 339 morphospecies identified. Most of these indicator species were characteristic of the unpolluted sites: only two diplopods and one gastropod from polluted poplar plantations, and none from the most polluted site. Since soil invertebrates respond to different environmental factors, including direct effect of heavy metals, we suggest there may be some confounding factors generating spurious relationships between the values of species as bioindicators and the pollution status they are supposed to indicate.

Synthesis and human leukocyte elastase inhibitory evaluation of phosphate triesters and acyl phosphates of penam sulfides and sulfones

The synthesis of 6,6-dibromo-3alpha-(diphenylphosphate)oxymethyl-2,2-dimethyl penam sulfone (3a), 6alpha-chloro-3alpha-(diphenylphosphate)oxymethyl-2,2-dimethyl penam sulfone (3b), benzyl 6alpha-(diphenyl-phosphate)oxypenicillanate sulfone (4) and 6,6-dibromo-3alpha-(methylphosphate)carbonyl-2,2-dimethylpenam sulfone (12) are reported. When tested as inhibitors of human leukocyte elastase, the compound 4 proved to be the most active.

Convergence of the Integration Dynamics of the Construction-Integration Model

The connectionist network corresponding to the nonlinear integration dynamical system associated with Kintsch's construction-integration (CI) model is analysed with linear algebra tools. This addresses some theoretical questions raised and left unanswered by Rodenhausen (1992, Psychological Review 99, 547-549). A mathematical characterization for equilibrium points, which allows an a priori enumeration of all possible asymptotic states for the integration dynamical system, given a connectivity matrix, is given. The dynamics of convergence of the integration dynamical system is characterized in some detail as well. This provides a tool for understanding CI simulations and helps in particular to let us know to what extent the outcome will depend on the initial conditions. The criteria also provide a new mathematical analysis which allows for the explicit calculation of asymptotic states of the integration process without requiring computer simulation experiments. The new mathematical analysis should facilitate comparisons of the model's predictions with behavioural data. Copyright 2001 Academic Press.

Quantitation of plasma membrane calcium pump phosphorylated intermediates by electrophoresis

P-ATPases are characterized by the formation of acid-stable phosphorylated intermediates (EP) during their reaction cycle. We have developed a microscale method to determine EP that involves the phosphorylation of the enzyme using [gamma-(32)P]ATP and precipitation with TCA; separation of the sample by SDS-PAGE, and measurement of the enzyme protein and (32)P-labeled EP by digital analysis of both the stained gel and its autoradiogram, respectively. The principal advantages of this method over typical procedures (filtration and centrifugation) are the low amount of enzyme required and the substantial decrease in the blank values and data scattering produced by unspecific phosphorylation and nonquantitative recovering of the enzyme. Application of this new method to a purified preparation of the plasma membrane calcium ATPase (PMCA) results in overcoming the difficulties of measuring EP at high ATP concentrations. A biphasic behavior of the substrate curve for EP was observed when the study was extended to ATP levels within the physiological range. Since, in principle, the method does not require the use of highly purified preparations, it could be helpful for the study of phosphorylated intermediates especially under conditions in which small amounts of protein are available, e.g., mutated variants of P-ATPases.

Oligomerization of the plasma membrane calcium pump involves two regions with different thermal stability

Ca(2+) pump dimerization was studied by using a combined approach of thermal denaturation and fluorescence resonance energy transfer. The measurement of calcium pump ability to dimerize after the unfolding of individual functional domains of the enzyme demonstrated the existence of two different regions involved in the self-association process. One of these regions is highly susceptible to thermal unfolding and was identified as the calmodulin (CaM)-binding domain. The other region whose thermal stability is higher than those of the catalytic and CaM-binding domains could be related with the previously found C28W-binding regions.

Export and folding of signal-sequenceless Bacillus licheniformis beta-lactamase in Escherichia coli

Two genetically engineered variants of the Bacillus licheniformis beta-lactamase gene were expressed in Escherichia coli. One variant coded for the exo-small mature enzyme without the signal peptide. The other coded for the exo-large mature enzyme preceded by 10, mostly polar, residues from an incomplete heterologous signal. As observed following the extraction by a lysozyme-EDTA treatment, the signal-less variant was exported to the periplasm with nearly 20% efficiency, whereas the variant with the N-terminal extension was translocated to a lesser degree; interestingly, nearly all of the former and half of the latter were extracted by osmotic shock, which may be of importance for our understanding of cellular compartments. The fact that a signal-less protein is translocated with substantial yields raises questions about the essential role of signal peptides for protein export. As folding and export are related processes, we investigated the folding in vitro of the two variants. No differences were found between them. In the absence of denaturant, they are completely folded, fully active and have a large DeltaG of unfolding. Under partially denaturing conditions they populate several partially folded states. The absence of significant amounts of a non-native state under native conditions makes a thermodynamic partitioning between folding and export less likely. In addition, kinetic measurements indicated that these B. licheniformis lactamases fold much faster than E. coli beta-lactamase. This behavior suggests that they are exported by a kinetically controlled process, mediated by one or more still unidentified interactions that slow folding and allow a folding intermediate to enter the export pathway.

Thermal stability of the plasma membrane calcium pump. Quantitative analysis of its dependence on lipid-protein interactions

Thermal stability of plasma membrane Ca(2+) pump was systematically studied in three micellar systems of different composition, and related with the interactions amphiphile-protein measured by fluorescence resonance energy transfer. Thermal denaturation was characterized as an irreversible process that is well described by a first order kinetic with an activation energy of 222 +/- 12 kJ/mol in the range 33-45 degrees C. Upon increasing the mole fraction of phospholipid in the mixed micelles where the Ca(2+) pump was reconstituted, the kinetic coefficient for the inactivation process diminished until it reached a constant value, different for each phospholipid species. We propose a model in which thermal stability of the pump depends on the composition of the amphiphile monolayer directly in contact with the transmembrane protein surface. Application of this model shows that the maximal pump stability is attained when 80% of this surface is covered by phospholipids. This analysis provides an indirect measure of the relative affinity phospholipid/detergent for the hydrophobic transmembrane surface of the protein (K(LD)) showing that those phospholipids with higher affinity provide greater stability to the Ca(2+) pump. We developed a method for directly measure K(LD) by using fluorescence resonance energy transfer from the membrane protein tryptophan residues to a pyrene-labeled phospholipid. K(LD) values obtained by this procedure agree with those obtained from the model, providing a strong evidence to support its validity.

Molecular characterization of the glycated plasma membrane calcium pump

We have previously demonstrated (Diabetes 39:707-711, 1990) that in vitro glycation of the red cell Ca(2+) pump diminishes the Ca(2+)-ATPase activity of the enzyme up to 50%. Such effect is due to the reaction of glucose with lysine residues of the Ca(2+) pump (Biochem. J. 293:369-375, 1993). The aim of this work was to determine whether the effect of glucose is due to a full inactivation of a fraction of the total population of Ca(2+) pump, or to a partial inactivation of all the molecules. Glycation decreased the V(max) for the ATPase activity leaving unaffected the apparent affinities for Ca(2+), calmodulin or ATP. The apparent turnover was identical in both, the glycated and the native enzyme. Glycation decreased the V(max) for the ATP-dependent but not for the calmodulin-activated phosphatase activities. Concomitantly with the inhibition, up to 6.5% of the lysine residues were randomly glycated. The probabilistic analysis of the relation between the enzyme activity and the fraction of nonmodified residues indicates that only one Lys residue is responsible for the inhibition. We suggest that glucose decreases the Ca(2+)-ATPase activity by reacting with one essential Lys residue probably located in the vicinity of the catalytic site, which results in the full inactivation of the enzyme. Thus, Ca(2+)-ATPase activity measured in erythrocyte membranes or purified enzyme preparations preincubated with glucose depends on the remaining enzyme molecules in which the essential Lys residue stays unglycated.

Identification of Bordetella pertussis virulence-associated outer membrane proteins

Bordetella pertussis virulence-associated 30-, 32-, 90- and 95-kDa outer membrane proteins were purified and their N-terminal amino acid sequences were determined. The 30- and 32-kDa outer membrane proteins showed identity to the C-terminal region of the precursors of the serum resistance protein (BrkA) and the tracheal colonization factor, respectively. We confirmed the cleavage site of these precursors after N731 for BrkA and after N393 for tracheal colonization factor. Associated with the 32-kDa outer membrane protein, we found a new group of 36-kDa virulence-associated peptides. The 95-kDa outer membrane protein showed identity to Vag8. The 90-kDa outer membrane protein did not show homology with the described proteins. We report the N-termini sequence of Vir-90, a novel potential virulence factor.

Temperature-induced conformational transition of intestinal fatty acid binding protein enhancing ligand binding: a functional, spectroscopic, and molecular modeling study

Intestinal fatty acid binding protein (IFABP) undergoes a reversible thermal transition between 35 and 50 degreesC, as revealed by circular dichroism spectroscopy in the near-UV region. For the apoprotein, the molar ellipticity measured at 254 nm (possibly implicating the environment around F17 and/or F55) decreases significantly in this temperature range, while in the holoprotein (bound to oleic acid), this phenomenon is not observed. Concomitantly, an increase in the activity of binding to [14C]oleic acid occurs. Nevertheless, other spectroscopic evidence indicates that the beta-barrel structure, the major motif of this protein, is highly stable up to 70 degreesC. No changes associated with conformation were detected for both structures by fourth-derivative analysis of the UV absorption spectra, circular dichroism in the far-UV region, and intrinsic fluorescence measurements. Further structural information arises from experiments in which binding to the anionic fluorescent probes 1-anilinonaphthalene-8-sulfonic acid (ANS) and its dimer bisANS was examined. The fluorescence intensity of bound ANS diminishes monotonically, whereas that of bisANS increases slightly in the temperature range of 35-50 degreesC. Given the different size of these probes, model building suggests that ANS would be able to sense regions located deeply inside the cavity, while bisANS could also reach the vicinity of the small helical domain of this protein. In light of these results, we believe that this subtle conformational transition of IFABP, which positively influences the binding activity, would involve fluctuations at the peripheral "entry portal" region for the ligand. This interpretation is compatible with the discrete disorder observed in this place in apo-IFABP, as evidenced by NMR spectroscopy [Hodsdon, M. E., and Cistola, D. P. (1997) Biochemistry 36, 1450-1460].

Effect of 2-hydroxyoestradiol on insulin secretion in normal rat pancreatic islets

The possible action of 2-hydroxyoestradiol (2-OHE2) on glucose-induced insulin secretion was evaluated in pancreatic islets isolated from normal rats by collagenase digestion and incubated in KRB buffer. Insulin output in response to either 3.3 or 16.6 mM glucose was measured by radioimmunoassay in the absence or presence of different concentrations of 2-OHE2, norepinephrine (NE), or oestradiol. Islets were also incubated with 2-OHE2, NE, or oestradiol plus a fixed concentration (1 microM) of the alpha 2-adrenergic-receptor blocking agent yohimbine. The results showed that 2-OHE2, oestradiol and NE within a range of 0.1 to 20 microM inhibited glucose-induced insulin secretion in a dose-dependent manner: Ki (microM): 0.04 +/- 0.0001, 0.04 +/- 0.0002, and 0.01 +/- 9.1 E-6 respectively. This suppression was significantly reversed by yohimbine. Contrary to NE and 2-OHE2, oestradiol at lower concentrations (increasing within a range of 0.001 to 0.05 microM) in incubation medium in the same experimental conditions had a significant stimulatory effect on insulin secretion. Thus, it would appear that catecholoestrogens suppress islet insulin release via alpha 2-adrenergic receptors, which suggests that oestrogens may exert a dual modulatory effect on insulin secretion by enhancing release via direct interaction with the cytosolic-oestrogen receptor and inhibiting release after their local hydroxylation and the interaction of their new catechol moiety with alpha 2-adrenergic receptors. Our results suggest that these compounds may play a complementary role to CAs as negative modulators, and they also provide a broader scope for understanding the effect of oestrogens and/or their metabolites in the control of endocrine functions other than those related to reproduction.

The pitch of short-duration fundamental frequency glissandos

Pitch perception for short-duration fundamental frequency (F0) glissandos was studied. In the first part, new measurements using the method of adjustment are reported. Stimuli were F0 glissandos centered at 220 Hz. The parameters under study were: F0 glissando extents (0, 0.8, 1.5, 3, 6, and 12 semitones, i.e., 0, 10.17, 18.74, 38.17, 76.63, and 155.56 Hz), F0 glissando durations (50, 100, 200, and 300 ms), F0 glissando directions (rising or falling), and the extremity of F0 glissandos matched (beginning or end). In the second part, the main results are discussed: (1) perception seems to correspond to an average of the frequencies present in the vicinity of the extremity matched; (2) the higher extremities of the glissando seem more important; (3) adjustments at the end are closer to the extremities than adjustments at the beginning. In the third part, numerical models accounting for the experimental data are proposed: a time-average model and a weighted time-average model. Optimal parameters for these models are derived. The weighted time-average model achieves a 94% accurate prediction rate for the experimental data. The numerical model is successful in predicting the pitch of short-duration F0 glissandos.

Chemical modification reveals involvement of different sites for nucleotide analogues in the phosphatase activity of the red cell calcium pump

The calcium pump of plasma membranes catalyzes the hydrolysis of ATP and phosphoric esters like p-nitrophenyl phosphate (pNPP). The latter activity requires the presence of ATP and/or calmodulin, and Ca2+ [22, 25]. We have studied the effects of nucleotide-analogues and chemical modifications of nucleotide binding sites on Ca2+-pNPPase activity. Treatment with fluorescein isothiocyanate (FITC), abolished Ca2+-ATPase and ATP-dependent pNPPase, but affected only 45% of the calmodulin-dependent pNPPase activity. The nucleotide analogue eosin-Y had an inhibitory effect on calmodulin-dependent pNPPase (Kieosin-Y = 2 microM). FITC treatment increased Kieosin-Y 15 times. Acetylation of lysine residues with N-hydroxysuccinimidyl acetate inactivates Ca2+-ATPase by modifying the catalytic site, and impairs stimulation by modulators by modifying residues outside this site [9]. Acetylation suppressed the ATP-dependent pNPPase with biphasic kinetics. ATP or pNPP during acetylation cancels the fast component of inactivation. Acetylation inhibited only partially the calmodulin-dependent pNPPase, but neither ATP nor pNPP prevented this inactivation. From these results we conclude: (i) ATP-dependent pNPPase depends on binding of ATP to the catalytic site; (ii) the catalytic site plays no role in calmodulin-dependent pNPPase. The decreased affinity for eosin-Y of the FITC-modified enzyme, suggests that the sites for these two molecules are closely related but not overlapped. Acetimidation of the pump inhibited totally the calmodulin-dependent pNPPase, but only partially the ATP-pNPPase. Since calmodulin binds to E1, the E1 conformation or the E2 if E1 transition would be involved during calmodulin-dependent pNPPase activity.