Brush border membrane vesicles （BBMV） isolated from insect midguts have been widely used to study CrylA binding proteins. Sample preparation is important in two- dimensional electrophoresis （2-DE）, so to determine...Brush border membrane vesicles （BBMV） isolated from insect midguts have been widely used to study CrylA binding proteins. Sample preparation is important in two- dimensional electrophoresis （2-DE）, so to determine a suitable BBMV preparation method in Helicoverpa armigera for 2-DE, we compared three published BBMV preparation methods mostly used in sodium dodecyl sulfate-polyacrylamide gel electrophoresis （SDS- PAGE）. All methods yielded similar types and numbers of binding proteins, but in different quantities. The Abdul-Rauf and Ellar protocol was the best of the three, but had limitations. Sufficient protein quantity is important for research involving limited numbers of insects, such as studies of insect resistance to Bacillus thuringiensis in the field. Consequently, we integrated the three BBMV isolation methods into a single protocol that yielded high quantities of BBMV proteins from H. armigera larval midguts, which proved suitable for 2- DE analysis.展开更多
The relatively low susceptibility ofHelicoverpa armigera to CrylAc, its history of resistance to chemical insecticides and the seasonal decline in expression of CrylAc in transgenic cotton necessitated the development...The relatively low susceptibility ofHelicoverpa armigera to CrylAc, its history of resistance to chemical insecticides and the seasonal decline in expression of CrylAc in transgenic cotton necessitated the development of cotton expressing two insecticidal proteins to provide sustainable control of this multinational pest. To manage the resistance issue, it was essential that the second insecticidal protein have a significantly different mode of action to CrylAc. A common feature of resistance to CrylA proteins in several species as well as H. armigera has been a change in the binding site. A study of binding sites for some Cry proteins in the brush border membrane vesicles （BBMV） ofH. armigera and Helicoverpa punctigera was undertaken. The binding affinity for CrylAc was higher than for CrylAb, matching their relative toxicities, and CrylAc and CrylAb were found to share at least one binding site in both I-1. armigera and I-1. punctigera. However Cry2Aa did not compete with CrylAc for binding and so could be used in transgenic cotton in combination with CrylAc to control H. armigera and manage resistance. Variation in the susceptibilities of three different H. armigera strains to CrylAc correlated with the parameter Bmax/Kcom.展开更多
AIM： To analyze the effects on the kidney of hypoxia-reoxygenation in an experimental model of normocapnic asphyxia.METHODS： To this end, 40 newborn Landrace/Large-White piglets aged 1-4 d were studied in this work....AIM： To analyze the effects on the kidney of hypoxia-reoxygenation in an experimental model of normocapnic asphyxia.METHODS： To this end, 40 newborn Landrace/Large-White piglets aged 1-4 d were studied in this work. Hypoxia was induced by decreasing the inspired fiO2 to 0.06-0.08. Animals were resuscitated with different fO2 and subdivided into 4 groups： group 1, 2, 3 and 4 received 18%, 21%, 40% and 100% O2 respectively. Macroscopic examination was carried out to evidence possible pathological features. Tissue sample were obtained from both kidneys. Four or fve micron paraffn sections were stained with H-E and PAS stain and examined under an optical microscope.RESULTS： Pathological changes, mainly affecting tubular cells, were observed in the vast majority of kidneys of asphyxiated piglets. The most frequent tubular changes were： tubular casts （95%）, tubulardilatation （87.5%）, tubular vacuolization （70%）, tubular eosinophilia （52.5%）, sloughing （50%）, fragmentation of the brush border （50%）, oedema （32.5%）, apoptosis （15%） and glomerular changes （meningeal cell pro-liferation, capsular adhesion between the flocculus and Bowman’s capsule, glomerulosclerosis and fbrous or cellular crescents associated with collapse of the glomerular tuft）. Statistical analysis was carried out on changes observed when the animals were allocated in the 4 groups （χ2-test 0.05）. The statistical analysis showed no evidence of differences regarding kidney lesions among the animals groups.CONCLUSION： Our data show that renal pathology in newborn piglets is characterized by interindividual variability to hypoxia and is not associated with oxygenGerosa C et al . Individual susceptibility in renal asphyxiaconcentration.展开更多
基金This paper was contributed to the International Symposium on Insect Midgut Biology, April 7-11, 2008, Guangzhou, China.Acknowledgments This research was supported by the National Natural Science Foundation of China （30771424） and National Basic Research Program of China （973-2007CB 109204）. We thank Dr. Jun Zhao （University of West Virginia, USA） for reviewing this manuscript.
文摘Brush border membrane vesicles （BBMV） isolated from insect midguts have been widely used to study CrylA binding proteins. Sample preparation is important in two- dimensional electrophoresis （2-DE）, so to determine a suitable BBMV preparation method in Helicoverpa armigera for 2-DE, we compared three published BBMV preparation methods mostly used in sodium dodecyl sulfate-polyacrylamide gel electrophoresis （SDS- PAGE）. All methods yielded similar types and numbers of binding proteins, but in different quantities. The Abdul-Rauf and Ellar protocol was the best of the three, but had limitations. Sufficient protein quantity is important for research involving limited numbers of insects, such as studies of insect resistance to Bacillus thuringiensis in the field. Consequently, we integrated the three BBMV isolation methods into a single protocol that yielded high quantities of BBMV proteins from H. armigera larval midguts, which proved suitable for 2- DE analysis.
文摘The relatively low susceptibility ofHelicoverpa armigera to CrylAc, its history of resistance to chemical insecticides and the seasonal decline in expression of CrylAc in transgenic cotton necessitated the development of cotton expressing two insecticidal proteins to provide sustainable control of this multinational pest. To manage the resistance issue, it was essential that the second insecticidal protein have a significantly different mode of action to CrylAc. A common feature of resistance to CrylA proteins in several species as well as H. armigera has been a change in the binding site. A study of binding sites for some Cry proteins in the brush border membrane vesicles （BBMV） ofH. armigera and Helicoverpa punctigera was undertaken. The binding affinity for CrylAc was higher than for CrylAb, matching their relative toxicities, and CrylAc and CrylAb were found to share at least one binding site in both I-1. armigera and I-1. punctigera. However Cry2Aa did not compete with CrylAc for binding and so could be used in transgenic cotton in combination with CrylAc to control H. armigera and manage resistance. Variation in the susceptibilities of three different H. armigera strains to CrylAc correlated with the parameter Bmax/Kcom.
文摘AIM： To analyze the effects on the kidney of hypoxia-reoxygenation in an experimental model of normocapnic asphyxia.METHODS： To this end, 40 newborn Landrace/Large-White piglets aged 1-4 d were studied in this work. Hypoxia was induced by decreasing the inspired fiO2 to 0.06-0.08. Animals were resuscitated with different fO2 and subdivided into 4 groups： group 1, 2, 3 and 4 received 18%, 21%, 40% and 100% O2 respectively. Macroscopic examination was carried out to evidence possible pathological features. Tissue sample were obtained from both kidneys. Four or fve micron paraffn sections were stained with H-E and PAS stain and examined under an optical microscope.RESULTS： Pathological changes, mainly affecting tubular cells, were observed in the vast majority of kidneys of asphyxiated piglets. The most frequent tubular changes were： tubular casts （95%）, tubulardilatation （87.5%）, tubular vacuolization （70%）, tubular eosinophilia （52.5%）, sloughing （50%）, fragmentation of the brush border （50%）, oedema （32.5%）, apoptosis （15%） and glomerular changes （meningeal cell pro-liferation, capsular adhesion between the flocculus and Bowman’s capsule, glomerulosclerosis and fbrous or cellular crescents associated with collapse of the glomerular tuft）. Statistical analysis was carried out on changes observed when the animals were allocated in the 4 groups （χ2-test 0.05）. The statistical analysis showed no evidence of differences regarding kidney lesions among the animals groups.CONCLUSION： Our data show that renal pathology in newborn piglets is characterized by interindividual variability to hypoxia and is not associated with oxygenGerosa C et al . Individual susceptibility in renal asphyxiaconcentration.
