Biology Reference
In-Depth Information
16
Insights into
Wolbachia
Obligatory Symbiosis
Franck Dedeine, Claudio Bandi, Michel Boulétreau,
and Laura H. Kramer
CONTENTS
in Filarial Nematodes ................................................................................268
BeneÝcial and Obligatory
Wolbachia
Wolbachia
in Insects ...........................................................................271
Facultative
Wolbachia
Infections That Enhance Insect Fecundity ........................................271
Obligatory
Wolbachia
in Insects.............................................................................................272
Obligatory
Wolbachia
-Induced Parthenogenesis ..........................................................272
Wolbachia
Dependence for Oogenesis .........................................................................273
Wolbachia
Specializations and Evolutionary Transitions .............................................................276
Reasons for Specialization in
Symbiosis .............................................................276
Why Has the Association Filarial Nematode/
Wolbachia
Led to Obligatory Symbiosis
Why Has the Association Arthropod/
Wolbachia
Not Led More Frequently
Wolbachia
Obligatory Symbiosis: Mutualism or Trickery?...................................................279
Wolbachia
INTRODUCTION
It is now widely accepted that maternal transmission of symbiotic microorganisms (from host
mother to offspring) can lead to the establishment of two different types of hostÏsymbiont rela-
tionships: (1) mutualism, where the symbiont increases its own Ýtness by increasing the Ýtness of
host females, and (2) reproductive parasitism, which regroups the associations where the symbiont
manipulates the reproduction of its host in ways that enhance its spread in the population (Werren
and OÔNeill, 1997; Bandi et al., 2001a). In mutualism, although males are not involved in the
transmission of the symbiont, they often also beneÝt from the infection. The main difference
between mutualism and reproductive parasitism is the consequences on host evolution. In mutual-
ism, selective pressures acting on the host and the symbiont are convergent and can lead to stable
