Isolation of Ixodes ricinus salivary gland mRNA encoding factors induced during blood feeding.

In tick salivary glands, genes induced during blood feeding result in the expression of new proteins secreted into tick saliva. These proteins are potentially involved in modulation of vertebrate host immune and hemostatic responses. In this study, subtractive and full-length cDNA libraries were constructed by use of mRNA extracted from salivary glands of unfed and 5-day engorged Ixodes ricinus. Sequences from these 2 libraries were compared with European Molecular Biology Laboratory (EMBL)/GenBank databases, which led to their classification into 2 major groups. The first group comprises cDNAs that failed to match or showed low homology to genes of known function. The second group includes sequences that showed high homology to genes of known function--for example, anticoagulants, inhibitors of platelet aggregation, and immunomodulatory proteins. Analyses of corresponding proteins suggest that they may be secreted by salivary gland cells. To study the properties of the recombinant proteins, selected cDNAs were expressed in mammalian or bacterial systems.Journal ArticleResearch Support, Non-U.S. Gov'tinfo:eu-repo/semantics/publishe

Impacts of Warm and Cold situations in the Mediterranean Basins on the West African monsoon: observed connection patterns (1979-2006) and climate simulations

International audienceUsing both empirical and numerical ensemble approaches this study focuses on the Mediterranean / West African relationship in northern summer. Statistical analyses utilize skin temperature, sea surface temperature, in situ and satellite rainfall, Outgoing Longwave Radiation (OLR) observations and reanalyzed data winds and specific humidity on isobaric surfaces. Numerical investigations are based on a large set of sensitivity experiments performed on four Atmospheric General Circulation Models (AGCM): ARPEGE-Climat3, ECHAM4, LMDZ4 and UCLA7.3. Model outputs are compared to observations, discussed model by model and with an ensemble (multi-model) approach. As in previous studies the anomalous Mediterranean warm events are associated with specific impacts over the African monsoon region, i.e., a more intense monsoon, enhanced flux convergence and ascendances around the ITCZ, a strengthening of low level moisture advection and a more northward location of ascending motion in West Africa. The results show also new features (i) thermal variability observed in the two Mediterranean basins has unalike impacts, i.e. the western Mediterranean covaries with convection in Gulf of Guinea, while the eastern Mediterranean can be interpreted as Sahelian thermal-forcing; (ii) although observations show symmetry between warming and cooling, modelling evidences only support the eastern warming influence; (iii) anomalous East warm situations are associated with a more northward migration of the monsoon system accompanied by enhanced southwesterly flow and weakened northeasterly climatological wind; (iv) the multi-model response shows that anomalous East warm surface temperatures generate an enhancement of the overturning circulation in low and high levels, an increase in TEJ (Tropical Easterly Jet) and a decrease in AEJ (African Easterly Jet)

Impacts of the Mediterranean basins on the West African monsoon: observed connection patterns (1979

International audienc

Interannual and decadal SST-forced responses of the West African monsoon

International audienceWe review the studies carried out during the African Monsoon Multidisciplinary Analysis (AMMA)-EU on the changes of interannual sea surface temperature (SST)-West African monsoon (WAM) covariability at multidecadal timescales, together with the influence of global warming (GW). The results obtained in the AMMA-EU suggest the importance of the background state, modulated by natural and anthropogenic variability, in the appearance of different interannual modes. The lack of reliability of current coupled models in giving a realistic assessment for WAM in the future is also stated