RESUMO
Symbiotic systems are intimately integrated at multiple levels. Host-endosymbiont metabolic complementarity in amino acid biosynthesis is especially important for sap-feeding insects and their symbionts. In weevil-Nardonella endosymbiosis, the final step reaction of the endosymbiont tyrosine synthesis pathway is complemented by host-encoded aminotransferases. Based on previous results from other insects, we suspected that these aminotransferases were likely transported into the Nardonella cytoplasm to produce tyrosine. Here, we identified five aminotransferase genes in the genome of the red palm weevil. Using quantitative real-time RT-PCR, we confirmed that RfGOT1 and RfGOT2A were specifically expressed in the bacteriome. RNA interference targeting these two aminotransferase genes reduced the tyrosine level in the bacteriome. The immunofluorescence-FISH double labeling localization analysis revealed that RfGOT1 and RfGOT2A were present within the bacteriocyte, where they colocalized with Nardonella cells. Immunogold transmission electron microscopy demonstrated the localization of RfGOT1 and RfGOT2A in the cytosol of Nardonella and the bacteriocyte. Our data revealed that RfGOT1 and RfGOT2A are transported into the Nardonella cytoplasm to collaborate with genes retained in the Nardonella genome in order to synthesize tyrosine. The results of our study will enhance the understanding of the integration of host and endosymbiont metabolism in amino acid biosynthesis.
RESUMO
Objective@#To construct a model of professional competency standard for school health education teachers in China, then to provide a framework for the professional development of health education teachers at primary and secondary schools.@*Methods@#Seventy-five indicators of professional competency of school health education teacher were identified through job task analysis, qualitative interview, expert consultation. A total of 282 school health administrators/researchers, school principals, health education teachers in Shanghai, and the first undergraduate students of health education progame in China were surveyed. Items analysis verified appropriateness, and exploratory factor analysis determined construct validity of the competency standards.@*Results@#The framework of competency standards consists of four major areas (general literacy, school health services, school health education, school health management), nine categories, and 70 competence standards. Nine categories include professional ethics, general literacy as teacher, assist to deal with emergency/accident health events and common diseases situation in school, assist vaccination and mental health assessment, monitoring/communication the health situation of students, knowledge of health education and teaching skills, implement health education activities effectively and continuously, deal with infectious diseases and environment/ water/food safety in school, monitor conditions of the school health and optimize health strategy continuously. Cronbach’s Alpha coefficient of total competence standards was 0.98, and those of the sub-dimensions ranged from 0.86 to 0.96 ; the split-half reliability of total system was 0.93 with sub-dimensions coefficient ranging from 0.83 to 0.95.@*Conclusion@#The model of competency standard developed in this study show good validity and reliability, which can provide theoretical framework for the training, using and evaluation of school health education teachers with the characteristics of combinating medicine and teaching.
