The Kinome of Pacific Oyster Crassostrea gigas, Its Expression during Development and in Response to Environmental Factors

Oysters play an important role in estuarine and coastal marine habitats, where the majority of humans live. In these ecosystems, environmental degradation is substantial, and oysters must cope with highly dynamic and stressful environmental constraints during their lives in the intertidal zone. The availability of the genome sequence of the Pacific oyster Crassostrea gigas represents a unique opportunity for a comprehensive assessment of the signal transduction pathways that the species has developed to deal with this unique habitat. We performed an in silico analysis to identify, annotate and classify protein kinases in C. gigas, according to their kinase domain taxonomy classification, and compared with kinome already described in other animal species. The C. gigas kinome consists of 371 protein kinases, making it closely related to the sea urchin kinome, which has 353 protein kinases. The absence of gene redundancy in some groups of the C. gigas kinome may simplify functional studies of protein kinases. Through data mining of transcriptomes in C. gigas, we identified part of the kinome which may be central during development and may play a role in response to various environmental factors. Overall, this work contributes to a better understanding of key sensing pathways that may be central for adaptation to a highly dynamic marine environment

Zika virus: An updated review of competent or naturally infected mosquitoes

International audienceZika virus (ZIKV) is an arthropod-borne virus (arbovirus) that recently caused outbreaks in the Americas. Over the past 60 years, this virus has been observed circulating among African, Asian, and Pacific Island populations, but little attention has been paid by the scientific community until the discovery that large-scale urban ZIKV outbreaks were associated with neurological complications such as microcephaly and several other neurological malformations in fetuses and newborns. This paper is a systematic review intended to list all mosquito species studied for ZIKV infection or for their vector competence. We discuss whether studies on ZIKV vectors have brought enough evidence to formally exclude other mosquitoes than Aedes species (and particularly Aedes aegypti) to be ZIKV vectors. From 1952 to August 15, 2017, ZIKV has been studied in 53 mosquito species, including 6 Anopheles, 26 Aedes, 11 Culex, 2 Lutzia, 3 Coquillettidia, 2 Mansonia, 2 Eretmapodites, and 1 Uranotaenia. Among those, ZIKV was isolated from 16 different Aedes species. The only species other than Aedes genus for which ZIKV was isolated were Anopheles coustani, Anopheles gambiae, Culex perfuscus, and Mansonia uniformis. Vector competence assays were performed on 22 different mosquito species, including 13 Aedes, 7 Culex, and 2 Anopheles species with, as a result, the discovery that A. aegypti and Aedes albopictus were competent for ZIKV, as well as some other Aedes species, and that there was a controversy surrounding Culex quinquefasciatus competence. Although Culex, Anopheles, and most of Aedes species were generally observed to be refractory to ZIKV infection, other potential vectors transmitting ZIKV should be explored

Vector species naturally infected by ZIKV or studied experimentally for their ZIKV competence.

<p>Vector species naturally infected by ZIKV or studied experimentally for their ZIKV competence.</p

Synthesis of the research related to vector species of ZIKV between 1952 and March 15, 2017.

<p>Evolution of the number of scientific papers related to vector species of ZIKV, the number of field species tested for the presence of Zika, the number of naturally ZIKV-infected species, the number of species studied experimentally for their competence, and the number of species observed once competent for ZIKV between 1952 and March 15, 2017. ZIKV, Zika virus.</p

Flow diagram of search strategies for eligible studies.

<p>Flow diagram of search strategies for eligible studies.</p

Energy and Antioxidant Responses of Pacific Oyster Exposed to Trace Levels of Pesticides

International audienceHere, we assess the physiological effects induced by environmental concentrations of pesticides in Pacific oyster Crassostrea gigas. Oysters were exposed for 14 d to trace levels of metconazole (0.2 and 2 mu g/L), isoproturon (0.1 and 1 mu g/L), or both in a mixture (0.2 and 0.1 mu g/L, respectively). Exposure to trace levels of pesticides had no effect on the filtration rate, growth, and energy reserves of oysters. However, oysters exposed to metconazole and isoproturon showed an overactivation of the sensing-kinase AMP-activated protein kinase alpha (AMPK alpha), a key enzyme involved in energy metabolism and more particularly glycolysis. In the meantime, these exposed oysters showed a decrease in hexokinase and pyruvate kinase activities, whereas 2-DE proteomic revealed that fructose-1,6-bisphosphatase (F-1,6-BP), a key enzyme of gluconeogenesis, was upregulated. Activities of antioxidant enzymes were higher in oysters exposed to the highest pesticide concentrations. Both pesticides enhanced the superoxide dismutase activity of oysters. Isoproturon enhanced catalase activity, and metconazole enhanced peroxiredoxin activity. Overall, our results show that environmental concentrations of metconazole or isoproturon induced subtle changes in the energy and antioxidant metabolisms of oysters

A novel mosquito species identification method based on PCR and capillary electrophoresis

In the Anopheles genus, various mosquito species are able to transmit Plasmodium parasites responsible for malaria, while others are non-vectors. In an effort to better understand the biology of Anopheles species and to quantify transmission risk in an area, the identification of mosquito species collected on the field is an essential but problematic task. Morphological identification requires expertise, well-preserved specimens and high-quality equipment, and it does not allow any subsequent verification when samples are later used in a destructive treatment. Moreover, it involves physical manipulations that are not compatible with experiments requiring fast sampling and processing of specimens, hence species identification is often based on DNA sequencing of reference genes or region such as the Internal Transcribed Spacer 2 (ITS2) region of nuclear ribosomal DNA. Sequencing ITS2 for numerous samples is costly, but the design of species-specific PCR primers is not always possible when local species diversity is high. Here, we introduce a molecular technique of species identification based on precise determination of ITS2 length combined with a simple visual observation, the color of mosquito hindleg tip. DNA extracted from field-collected Anopheles mosquitoes was amplified with universal Anopheles ITS2 primers and analyzed with a capillary electrophoresis device, which precisely determines the size of the fragments. We defined windows of amplicon sizes combined with fifth hind tarsus color, which allow to discriminate the major Anopheles species found in our collections. We validated our parameters via Sanger sequencing of the ITS2 amplicons. This method can be particularly useful in situations with a moderate species diversity, i.e. when the number of local species is too high to define species-specific primers but low enough to avoid individual ITS2 sequencing. This tool will be of interest to evaluate local malaria transmission risk and this approach may further be implemented for other mosquito genera

Successes and failures of sixty years of vector control in French Guiana: what is the next step?

Since the 1940s, French Guiana has implemented vector control to contain or eliminate malaria, yellow fever, and, recently, dengue, chikungunya, and Zika. Over time, strategies have evolved depending on the location, efficacy of the methods, development of insecticide resistance, and advances in vector control techniques. This review summarises the history of vector control in French Guiana by reporting the records found in the private archives of the Institute Pasteur in French Guiana and those accessible in libraries worldwide. This publication highlights successes and failures in vector control and identifies the constraints and expectations for vector control in this French overseas territory in the Americas

Number and percentage of ePK and aPK genes up- and down-regulated under environmental stressors.

<p>Number and percentage of ePK and aPK genes up- and down-regulated under environmental stressors.</p

Taxonomic distribution of protein kinases (ePKs, aPKs) in various species.

<p>Taxonomic distribution of protein kinases (ePKs, aPKs) in various species.</p