| Chinese Abstract | 第9-11页 |
| Abstract | 第11-12页 |
| 1. General introduction | 第13-18页 |
| 1.1 Gut microbiota and their physiological roles | 第13-14页 |
| 1.2 Gut immune defences and maintenance of gut microbiota | 第14-15页 |
| 1.3 Importance of gut homeostasis study | 第15-17页 |
| 1.4 Research hypothesis and objectives | 第17-18页 |
| 2. Materials and Methods | 第18-25页 |
| 2.1 Insect collection and rearing | 第18页 |
| 2.2 Cloning and sequence analysis of RfPGRP-LB cDNA | 第18-19页 |
| 2.3 Expression analysis of RfPGRP-LB and antimicrobial peptides by reversetranscription (RT)-qPCR | 第19-21页 |
| 2.4 In-vitro functional assays of recombinant RfPGRP-LB | 第21-22页 |
| 2.5 The effects of RfPGRP-LB knockdown on the persistence of nonresidentialbacteria and load of the indigenous gut microbiota | 第22-23页 |
| 2.6 RJPGRP-LB knockdown-mediated changes in the community structure of RPW gut microbiota by 16S rRNA gene-based Illumina high-throughput sequencing | 第23-24页 |
| 2.7 Statistical analysis | 第24-25页 |
| 3. Results | 第25-37页 |
| 3.1 RfPGRP-LB is a secreted catalytic PGRP induced by bacterial infection | 第25-29页 |
| 3.2 In-vitro verification of rRfPGRP-LB immune function by antibacterial assay | 第29-31页 |
| 3.3 Effects of RfPGRP-LB knockdown on the persistence of nonresidential bacteria,load of indigenous gut microbiota and the abundance of antimicrobial peptides ingut | 第31-33页 |
| 3.4 RfPGRP-LB knockdown-mediated alterations in the community structure ofRPW gut microbiota | 第33-37页 |
| 4. Discussion | 第37-40页 |
| 5. Conclusion | 第40-41页 |
| References | 第41-50页 |
| Acknowledgements | 第50-51页 |
| Publication during study period | 第51页 |
