The Experts below are selected from a list of 17994 Experts worldwide ranked by ideXlab platform
Stefanos Siozios - One of the best experts on this subject based on the ideXlab platform.
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Torix group Rickettsia are widespread in Culicoides biting midges (Diptera: Ceratopogonidae), reach high frequency and carry unique genomic features
Environmental Microbiology, 2017Co-Authors: Jack Pilgrim, Mats Ander, Claire Garros, M. Baylis, Gregory D. D. Hurst, Stefanos SioziosAbstract:There is increasing interest in the heritable bacteria of invertebrate vectors of disease as they present novel targets for control initiatives. Previous studies on biting midges (Culicoides spp.), known to transmit several RNA viruses of veterinary importance, have revealed infections with the endosymbiotic bacteria, Wolbachia and Cardinium. However, rickettsial symbionts in these vectors are underexplored. Here, we present the genome of a previously uncharacterized Rickettsia endosymbiont from Culicoides newsteadi (RiCNE). This genome presents unique features potentially associated with host invasion and adaptation, including genes for the complete non-oxidative phase of the pentose phosphate pathway, and others predicted to mediate lipopolysaccharides and cell wall modification. Screening of 414 Culicoides individuals from 29 Palearctic or Afrotropical species revealed that Rickettsia represent a widespread but previously overlooked association, reaching high frequencies in midge populations and present in 38% of the species tested. Sequence typing clusters the Rickettsia within the Torix group of the genus, a group known to infect several aquatic and hematophagous taxa. FISH analysis indicated the presence of Rickettsia bacteria in Ovary Tissue, indicating their maternal inheritance. Given the importance of biting midges as vectors, a key area of future research is to establish the impact of this endosymbiont on vector competence.
David A Wheeler - One of the best experts on this subject based on the ideXlab platform.
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the venom gland transcriptome of the parasitoid wasp nasonia vitripennis highlights the importance of novel genes in venom function
BMC Genomics, 2016Co-Authors: Andre D Sim, David A WheelerAbstract:Prior to egg laying the parasitoid wasp Nasonia vitripennis envenomates its pupal host with a complex mixture of venom peptides. This venom induces several dramatic changes in the host, including developmental arrest, immunosuppression, and altered metabolism. The diverse and potent bioactivity of N. vitripennis venom provides opportunities for the development of novel acting pharmaceuticals based on these molecules. However, currently very little is known about the specific functions of individual venom peptides or what mechanisms underlie the hosts response to envenomation. Many of the venom peptides also lack bioinformatically derived annotations because no homologs can be identified in the sequences databases. The RNA interference system of N. vitripennis provides a method for functional characterisation of venom protein encoding genes, however working with the current list of 79 candidates represents a daunting task. For this reason we were interested in determining the expression levels of venom encoding genes in the venom gland, as this information could be used to rank candidates for further study. To do this we carried out deep transcriptome sequencing of the venom gland and Ovary Tissue and used RNA-seq to rank the venom protein encoding genes by expression level. The generation of a specific venom gland transcriptome dataset also provides further opportunities to investigate novel features of this specialised organ. RNA-seq revealed that the highest expressed venom encoding gene in the venom gland was ‘Venom protein Y’. The highest expressed annotated gene in this Tissue was serine protease Nasvi2EG007167, which has previously been implicated in the apoptotic activity of N. vitripennis venom. As expected the RNA-seq confirmed that venom encoding genes are almost exclusively expressed in the venom gland relative to the neighbouring Ovary Tissue. Novel genes appear to perform key roles in N. vitripennis venom function, with over half of the 15 highest expressed venom encoding loci lacking bioinformatic annotations. The high throughput sequencing data also provided evidence for the existence of an additional 472 previously undescribed transcribed regions in the N. vitripennis genome. Finally, metatranscriptomic analysis of the venom gland transcriptome finds little evidence for the role of Wolbachia in the venom system. The expression level information provided here for the N. vitripennis venom protein encoding genes represents a valuable dataset that can be used by the research community to rank candidates for further functional characterisation. These candidates represent bioactive peptides valuable in the development of new pharmaceuticals.
Ilker Durak - One of the best experts on this subject based on the ideXlab platform.
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Effects of cyclosporine on oxidant/antioxidant status in rat Ovary Tissues: protective role of black grape extract.
International immunopharmacology, 2005Co-Authors: Imge B Ergüder, Recep Cetin, Erdinç Devrim, Bülent Kiliçoğlu, Aslihan Avci, Ilker DurakAbstract:It has been demonstrated that immunosuppressive drug cyclosporine A (CsA) increases the synthesis of reactive oxygen species (ROS) and lipid peroxidation products in vitro and in vivo studies, but its possible toxic effects in Ovary Tissue have not been defined yet. This study was designed to elucidate possible relation between CsA treatment and oxidant/antioxidant status in rat Ovary Tissue and, to determine if antioxidant supplementation is beneficial. CsA and black grape extracts were given to rats orally for 10 days. In each group (control, CsA, CsA plus black grape and black grape alone), there were 7 animals (28 rats in total). After the animals were sacrificed, their ovaries were removed to be used in the measurement of malondialdehyde (MDA) level and activities of superoxide dismutase (SOD), catalase (CAT) and xanthine oxidase (XO) enzymes. In the control, CsA plus black grape and black grape alone groups, MDA levels were significantly lower than CsA group. Xanthine oxidase activities were significantly higher in CsA and CsA plus black grape groups than control group. In addition, XO activity was significantly lower in black grape alone group than all the other groups including control group. There were no significant differences in the activities of SOD and CAT enzymes between the groups. The results suggest that CsA leads to oxidant stress and peroxidation in rat Ovary Tissues mainly due to increased XO activity. It has been suggested that this oxidant stress and peroxidation reactions can be prevented by antioxidant food supplementation like black grape.
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Effects of cyclosporine on oxidant/antioxidant status in rat Ovary Tissues: protective role of black grape extract.
International Immunopharmacology, 2005Co-Authors: Imge B Ergüder, Recep Cetin, Erdinç Devrim, Bülent Kiliçoğlu, Aslihan Avci, Ilker DurakAbstract:Abstract Objectives It has been demonstrated that immunosuppressive drug cyclosporine A (CsA) increases the synthesis of reactive oxygen species (ROS) and lipid peroxidation products in vitro and in vivo studies, but its possible toxic effects in Ovary Tissue have not been defined yet. This study was designed to elucidate possible relation between CsA treatment and oxidant/antioxidant status in rat Ovary Tissue and, to determine if antioxidant supplementation is beneficial. Methods CsA and black grape extracts were given to rats orally for 10 days. In each group (control, CsA, CsA plus black grape and black grape alone), there were 7 animals (28 rats in total). After the animals were sacrificed, their ovaries were removed to be used in the measurement of malondialdehyde (MDA) level and activities of superoxide dismutase (SOD), catalase (CAT) and xanthine oxidase (XO) enzymes. Results In the control, CsA plus black grape and black grape alone groups, MDA levels were significantly lower than CsA group. Xanthine oxidase activities were significantly higher in CsA and CsA plus black grape groups than control group. In addition, XO activity was significantly lower in black grape alone group than all the other groups including control group. There were no significant differences in the activities of SOD and CAT enzymes between the groups Conclusion The results suggest that CsA leads to oxidant stress and peroxidation in rat Ovary Tissues mainly due to increased XO activity. It has been suggested that this oxidant stress and peroxidation reactions can be prevented by antioxidant food supplementation like black grape.
Jack Pilgrim - One of the best experts on this subject based on the ideXlab platform.
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Torix group Rickettsia are widespread in Culicoides biting midges (Diptera: Ceratopogonidae), reach high frequency and carry unique genomic features
Environmental Microbiology, 2017Co-Authors: Jack Pilgrim, Mats Ander, Claire Garros, M. Baylis, Gregory D. D. Hurst, Stefanos SioziosAbstract:There is increasing interest in the heritable bacteria of invertebrate vectors of disease as they present novel targets for control initiatives. Previous studies on biting midges (Culicoides spp.), known to transmit several RNA viruses of veterinary importance, have revealed infections with the endosymbiotic bacteria, Wolbachia and Cardinium. However, rickettsial symbionts in these vectors are underexplored. Here, we present the genome of a previously uncharacterized Rickettsia endosymbiont from Culicoides newsteadi (RiCNE). This genome presents unique features potentially associated with host invasion and adaptation, including genes for the complete non-oxidative phase of the pentose phosphate pathway, and others predicted to mediate lipopolysaccharides and cell wall modification. Screening of 414 Culicoides individuals from 29 Palearctic or Afrotropical species revealed that Rickettsia represent a widespread but previously overlooked association, reaching high frequencies in midge populations and present in 38% of the species tested. Sequence typing clusters the Rickettsia within the Torix group of the genus, a group known to infect several aquatic and hematophagous taxa. FISH analysis indicated the presence of Rickettsia bacteria in Ovary Tissue, indicating their maternal inheritance. Given the importance of biting midges as vectors, a key area of future research is to establish the impact of this endosymbiont on vector competence.
Andre D Sim - One of the best experts on this subject based on the ideXlab platform.
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the venom gland transcriptome of the parasitoid wasp nasonia vitripennis highlights the importance of novel genes in venom function
BMC Genomics, 2016Co-Authors: Andre D Sim, David A WheelerAbstract:Prior to egg laying the parasitoid wasp Nasonia vitripennis envenomates its pupal host with a complex mixture of venom peptides. This venom induces several dramatic changes in the host, including developmental arrest, immunosuppression, and altered metabolism. The diverse and potent bioactivity of N. vitripennis venom provides opportunities for the development of novel acting pharmaceuticals based on these molecules. However, currently very little is known about the specific functions of individual venom peptides or what mechanisms underlie the hosts response to envenomation. Many of the venom peptides also lack bioinformatically derived annotations because no homologs can be identified in the sequences databases. The RNA interference system of N. vitripennis provides a method for functional characterisation of venom protein encoding genes, however working with the current list of 79 candidates represents a daunting task. For this reason we were interested in determining the expression levels of venom encoding genes in the venom gland, as this information could be used to rank candidates for further study. To do this we carried out deep transcriptome sequencing of the venom gland and Ovary Tissue and used RNA-seq to rank the venom protein encoding genes by expression level. The generation of a specific venom gland transcriptome dataset also provides further opportunities to investigate novel features of this specialised organ. RNA-seq revealed that the highest expressed venom encoding gene in the venom gland was ‘Venom protein Y’. The highest expressed annotated gene in this Tissue was serine protease Nasvi2EG007167, which has previously been implicated in the apoptotic activity of N. vitripennis venom. As expected the RNA-seq confirmed that venom encoding genes are almost exclusively expressed in the venom gland relative to the neighbouring Ovary Tissue. Novel genes appear to perform key roles in N. vitripennis venom function, with over half of the 15 highest expressed venom encoding loci lacking bioinformatic annotations. The high throughput sequencing data also provided evidence for the existence of an additional 472 previously undescribed transcribed regions in the N. vitripennis genome. Finally, metatranscriptomic analysis of the venom gland transcriptome finds little evidence for the role of Wolbachia in the venom system. The expression level information provided here for the N. vitripennis venom protein encoding genes represents a valuable dataset that can be used by the research community to rank candidates for further functional characterisation. These candidates represent bioactive peptides valuable in the development of new pharmaceuticals.