ABSTRACT
Contents Introduction........................................................................................................................ 377 Biology of facultative symbionts ..................................................................................... 378
Identication .................................................................................................................. 378 Distribution and transmission .................................................................................... 379 Localization ................................................................................................................... 381 Role of facultative symbionts ...................................................................................... 382
Culturing facultative symbionts......................................................................................383 Reduced metabolic plasticity ......................................................................................383 Symbiont isolation ........................................................................................................384 Growth conditions ........................................................................................................384 Maintenance of cultures ..............................................................................................386
Genetic modication of facultative symbionts .............................................................. 387 Goals and basic approaches ........................................................................................ 387 Plasmid transformation ............................................................................................... 387 Transposon mutagenesis .............................................................................................388 Chemical mutagenesis and “TILLING” ....................................................................388 Allelic exchange and recombineering ....................................................................... 389
Conclusions ........................................................................................................................ 391 Acknowledgments ............................................................................................................. 391 References ........................................................................................................................... 392
