1. Facultative Intracellular world Facultative Extracellular Free-living world Obligate (Vertically -transmitted) Obligate (Horizontally- Transmitted) Exposure to novel gene pools HighLow Three Bacterial Lifestyles Obligate (Horizontally- Transmitted)

2. Obligate Intracellular Bacteria That Host-Switch

3. Maternal transmission of obligate intracellular bacteria Bacterial symbionts Insect ovariole Bacterial symbionts Insect nuclei

4. Mom knows best: Aphid maternal transmission of Buchnera

6. Does transmission of obligate intracellular bacteria affect mobile DNA content?

7. Horizontally-transmitted symbionts have more species with mobile DNA than vertically-transmitted species Fisher’s exact test, P = 0.0005 Newton & Bordenstein 2011 Horizontally-transmitted Vertically-transmitted

8. How are Mobile DNAs Transmitted in Obligate Intracellular Bacteria ?

9. Phylum Nematoda (mutualistic) 90% of filarial nematode species Wolbachia = One of the great pandemics in the history of life Phylum Arthropoda (parasitic) Up to 66% of arthropod species (which comprise 85% of all animal spp.) Homo sapiens (pathogenic) River Blindness Lymphatic filariasis The cause is Wolbachia, not the nematode

10. Wolbachia: Mutualist and Parasite Parthenogenesis in wasps Male-killing in insects Feminization in isopods Cytoplasmic incompatibility in arthropods Reproductive parasitism Mutualism Required for nematode fertility and larval development Required for insect oogenesis (Dedeine et al. 2001)

11. x x x x = = = = Wolbachia- infected offspring Uninfected offspring Wolbachia- infected offspring X CI Late prophasePrometaphase MetaphaseTelophase Courtesy of U. Tram Testes Embryo Wolbachia Host Cytoplasmic Incompatibility (CI)