Deltamethrin Resistance Mechanisms in Aedes aegypti Populations from Three French Overseas Territories Worldwide

BACKGROUND:Aedes aegypti is a cosmopolite mosquito, vector of arboviruses. The worldwide studies of its insecticide resistance have demonstrated a strong loss of susceptibility to pyrethroids, the major class of insecticide used for vector control. French overseas territories such as French Guiana (South America), Guadeloupe islands (Lesser Antilles) as well as New Caledonia (Pacific Ocean), have encountered such resistance. METHODOLOGY/PRINCIPAL FINDINGS:We initiated a research program on the pyrethroid resistance in French Guiana, Guadeloupe and New Caledonia. Aedes aegypti populations were tested for their deltamethrin resistance level then screened by an improved microarray developed to specifically study metabolic resistance mechanisms. Cytochrome P450 genes were implicated in conferring resistance. CYP6BB2, CYP6M11, CYP6N12, CYP9J9, CYP9J10 and CCE3 genes were upregulated in the resistant populations and were common to other populations at a regional scale. The implication of these genes in resistance phenomenon is therefore strongly suggested. Other genes from detoxification pathways were also differentially regulated. Screening for target site mutations on the voltage-gated sodium channel gene demonstrated the presence of I1016 and C1534. CONCLUSION /SIGNIFICANCE:This study highlighted the presence of a common set of differentially up-regulated detoxifying genes, mainly cytochrome P450 genes in all three populations. GUA and GUY populations shared a higher number of those genes compared to CAL. Two kdr mutations well known to be associated to pyrethroid resistance were also detected in those two populations but not in CAL. Different selective pressures and genetic backgrounds can explain such differences. These results are also compared with those obtained from other parts of the world and are discussed in the context of integrative research on vector competence

Effect of native and exotic visitors of germination in Lepechinia floribunda (Lamiaceae)

Fil: Baranzelli, Matías C. Universidad Nacional Autónoma de México. Instituto de Ecología; México.Fil: Baranzelli, Matías C. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto Multidisciplinario de Biología Vegetal. Laboratorio de Ecología Evolutiva y Biología Floral; Argentina.Fil: Martínez, Gabriela. Universidad Nacional Autónoma de México. Instituto de Ecología; México.Fil: Juan, Fornoni. Universidad Nacional Autónoma de México. Instituto de Ecología; México.Fil: Camina, Julia. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal. Laboratorio de Interacciones Ecológicas y Conservación; Argentina.Fil: Camina, Julia. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina.Fil: Ashworth, Lorena. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal. Laboratorio de Interacciones Ecológicas y Conservación; Argentina.Fil: Ashworth, Lorena. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina.Fil: Sérsic, Alicia N. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto Multidisciplinario de Biología Vegetal. Laboratorio de Ecología Evolutiva y Biología Floral; Argentina.Fil: Cocucci, Andrea A. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto Multidisciplinario de Biología Vegetal. Laboratorio de Ecología Evolutiva y Biología Floral; Argentina.Fil: Issaly, Andres E. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto Multidisciplinario de Biología Vegetal. Laboratorio de Ecología Evolutiva y Biología Floral; Argentina.Fil: Benitez-Vieyra, Santiago. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto Multidisciplinario de Biología Vegetal. Laboratorio de Ecología Evolutiva y Biología Floral; Argentina.Fil: Rocamundi, Nicolás. Universidad Provincial de Córdoba. Facultad de Turismo y Ambiente; Argentina.La relación entre las plantas con flores y los polinizadores rara vez ocurre de a pares dado que la mayoría de las especies de plantas son visitadas por más de una especie polinizadora. Un aspecto central es la identificación de los visitantes florales que ejercen el mayor efecto positivo sobre el éxito reproductivo de las plantas. En Lepechinia floribunda (Lamiaceae), se ha observado que los polinizadores nativos (Bombus spp) proporcionan un mayor movimiento de polen y formación de semillas en comparación con los polinizadores exóticos (Apis mellifera). Sin embargo, aún se desconoce cómo esta eficiencia se refleja en los niveles de germinación de las semillas (calidad de la progenie) de las flores visitadas por cada grupo de polinizadores. Este estudio evalúa cómo la efectividad en la polinización de los principales grupos de polinizadores afecta el éxito de germinación de las semillas de L. floribunda. Se compararon los niveles acumulados y totales de germinación de 363 semillas provenientes de 256 flores visitadas por Bombus spp o A. mellifera. Se observaron patrones similares a lo largo del tiempo, con una ligera tendencia hacia una mayor germinación de las semillas de las visitas de Bombus spp, aunque esta tendencia no fue estadísticamente significativa. Estos resultados sugieren que la menor eficiencia de A. mellifera polinizando no afectarían significativamente el potencial de supervivencia de la progenie de L. floribunda. Además, destacan la importancia de cuantificar de manera integral la contribución de cada visitante floral al éxito reproductivo de las plantas.Abstract: The relationship between flowering plants and pollinators seldom occurs in pairs as the majority of plant species are visited by more than one pollinator species. Thus, a central aspect is identifying floral visitors that exert the greatest positive effect on the reproductive success of plants. In Lepechinia floribunda, it has been observed that native pollinators (Bombus spp) provide greater pollen movement and seed formation compared to exotic pollinators (Apis mellifera) despite their overabundance. However, it is still unknown how such efficiency translates into the germination levels of seeds from flowers visited by either group of pollinators. That is, how the quality of visits from each pollinator translates into plant progeny. Therefore, this study evaluates how the relative effectiveness in pollination of the two main groups of pollinators is reflected in the germination success of L. floribunda seeds. Based on 33 focal plants, 256 flowers, and 363 seeds visited by Bombus or A. mellifera, accumulated and total germination levels were compared over time. Similar patterns were observed over time, with a slight tendency towards higher germination of seeds from Bombus spp visits, but this trend was not statistically significant. These results suggest that the lower efficiency of A. mellifera in pollinating L. floribunda flowers and its differential behavior during visits would not affect the potential survival of the progeny. They also illustrate the importance of quantifying, beyond pollination, the contribution of each floral visitor to the reproductive success of plants.info:eu-repo/semantics/publishedVersionFil: Baranzelli, Matías C. Universidad Nacional Autónoma de México. Instituto de Ecología; México.Fil: Baranzelli, Matías C. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto Multidisciplinario de Biología Vegetal. Laboratorio de Ecología Evolutiva y Biología Floral; Argentina.Fil: Martínez, Gabriela. Universidad Nacional Autónoma de México. Instituto de Ecología; México.Fil: Juan, Fornoni. Universidad Nacional Autónoma de México. Instituto de Ecología; México.Fil: Camina, Julia. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal. Laboratorio de Interacciones Ecológicas y Conservación; Argentina.Fil: Camina, Julia. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina.Fil: Ashworth, Lorena. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal. Laboratorio de Interacciones Ecológicas y Conservación; Argentina.Fil: Ashworth, Lorena. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina.Fil: Sérsic, Alicia N. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto Multidisciplinario de Biología Vegetal. Laboratorio de Ecología Evolutiva y Biología Floral; Argentina.Fil: Cocucci, Andrea A. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto Multidisciplinario de Biología Vegetal. Laboratorio de Ecología Evolutiva y Biología Floral; Argentina.Fil: Issaly, Andres E. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto Multidisciplinario de Biología Vegetal. Laboratorio de Ecología Evolutiva y Biología Floral; Argentina.Fil: Benitez-Vieyra, Santiago. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto Multidisciplinario de Biología Vegetal. Laboratorio de Ecología Evolutiva y Biología Floral; Argentina.Fil: Rocamundi, Nicolás. Universidad Provincial de Córdoba. Facultad de Turismo y Ambiente; Argentina

Optimization of the wheat puroindoline-a production in Pichia pastoris

25 ref.International audienc

Influence of nutrient, pH and dissolved oxygen on the production of Metarhizium flavoviride Mf189 blastospores in submerged batch culture

Corresponding author. fax: +33-3-8069-3229.E-mail address: [email protected] (A. Durand).International audienceThe influence of different parameters on the sporulation of Metarhizium flavoviride was studied during submerged cultures in shake flasks and in 5 l bioreactors. The screening in shake flasks of several carbon and nitrogen sources allowed the definition of an optimal medium, based on sucrose and brewer’s yeast with a C/N ratio of 1.6. With this medium, a production of 5.4 _ 108 blastospores per ml (Bspores ml_1) was obtained after 169 h of cultivation. The influence of pH and pO2 was independently studied in 5 l working volume bioreactors using the optimal medium. The best production was obtained with pH and pO2 regulated respectively to 7 and 100%. Finally, when the culture was grown under optimized conditions, the blastospores concentration increased 16-fold, with 1.1 109 Bspores ml-1 obtained after 144 h cultivation. This represents a gain of productivity of about 4.8 time

Single step purification of a wheat 9kDa lipid transfer protein secreted by Pichia pastoris

International audienc

Growth arrest and terminal differentiation of leukemic myelomonocytic cells induced through ligation of surface CD23 antigen

Abstract Acute myelogenous leukemia (AML) cells express CD23 surface antigen after in vitro treatment with various cytokines, including interleukin- 4 (IL-4) and interferon gamma. Subsequent ligation of CD23 by specific monoclonal antibody (MoAb) induces substantial morphologic and functional modifications in these cells. In the present study, we investigated the role of CD23 in the proliferation and the maturation of leukemic cells from AML patients or the U937 cell line. CD23+ cell treatment with CD23 MoAb inhibited the proliferation of leukemic cells. This correlated with their terminal differentiation after 7 to 9 days incubation because they (1) definitively lost their growth capacity; (2) adhered to culture flasks and became monocyte/macrophage-like; and (3) expressed mature monocyte markers including nonspecific esterases. Intracellular mechanism of this antitumoral effect was then analyzed in U937 cells. Induction of high-density surface CD23 expression by IL-4 or granulocyte-macrophage colony-stimulating factor coincided with a transient decrease of U937 cell proliferation. CD23 ligation during this low-proliferative phase induced a rapid activation of L-arginine- dependent pathway and the intracellular accumulation of cyclic guanosine monophosphate and cyclic adenosine monophosphate (cAMP). Induction of these early messengers was followed by the activation of nuclear factor-kB transcription factor and the modulation of proto- oncogene expression by U937 cells. Whereas U937 cell treatment with IL- 4 decreased c-fos/c-jun expression, CD23 MoAb reinduced c-fos/c-jun and promoted the expression of cell maturation-associated proto-oncogenes junB and c-fms, during the first 24 hours. Both IL-4 and CD23 MoAb downregulated the expression of c-myb. CD23 ligation also induced the production of TNF alpha by U937 cells. Inhibitors of cAMP and nitric oxide reversed CD23-mediated modification in U937 cells. These data evidence the ability of CD23 surface antigen to mediate terminal differentiation of early leukemic myelomonocytic cells.</jats:p

Growth Arrest and Terminal Differentiation of Leukemic Myelomonocytic Cells Induced through Ligation of Surface CD23 Antigen.

International audienc

Growth arrest and terminal differentiation of leukemic myelomonocytic cells induced through ligation of surface CD23 antigen

Acute myelogenous leukemia (AML) cells express CD23 surface antigen after in vitro treatment with various cytokines, including interleukin- 4 (IL-4) and interferon gamma. Subsequent ligation of CD23 by specific monoclonal antibody (MoAb) induces substantial morphologic and functional modifications in these cells. In the present study, we investigated the role of CD23 in the proliferation and the maturation of leukemic cells from AML patients or the U937 cell line. CD23+ cell treatment with CD23 MoAb inhibited the proliferation of leukemic cells. This correlated with their terminal differentiation after 7 to 9 days incubation because they (1) definitively lost their growth capacity; (2) adhered to culture flasks and became monocyte/macrophage-like; and (3) expressed mature monocyte markers including nonspecific esterases. Intracellular mechanism of this antitumoral effect was then analyzed in U937 cells. Induction of high-density surface CD23 expression by IL-4 or granulocyte-macrophage colony-stimulating factor coincided with a transient decrease of U937 cell proliferation. CD23 ligation during this low-proliferative phase induced a rapid activation of L-arginine- dependent pathway and the intracellular accumulation of cyclic guanosine monophosphate and cyclic adenosine monophosphate (cAMP). Induction of these early messengers was followed by the activation of nuclear factor-kB transcription factor and the modulation of proto- oncogene expression by U937 cells. Whereas U937 cell treatment with IL- 4 decreased c-fos/c-jun expression, CD23 MoAb reinduced c-fos/c-jun and promoted the expression of cell maturation-associated proto-oncogenes junB and c-fms, during the first 24 hours. Both IL-4 and CD23 MoAb downregulated the expression of c-myb. CD23 ligation also induced the production of TNF alpha by U937 cells. Inhibitors of cAMP and nitric oxide reversed CD23-mediated modification in U937 cells. These data evidence the ability of CD23 surface antigen to mediate terminal differentiation of early leukemic myelomonocytic cells.</jats:p