Wolbachia plays no role in the one-way reproductive incompatibility between the hybridizing field crickets Gryllus firmus and G. pennsylvanicus

Heredity (Edinb). 2008 Nov;101(5):435-44. doi: 10.1038/hdy.2008.75. Epub 2008 Aug 6.


Wolbachia are cytoplasmically inherited alpha-proteobacteria that can cause cytoplasmic incompatibility (CI) in insects. This incompatibility between sperm and egg is evident when uninfected females mate with infected males. Wolbachia-driven reproductive incompatibilities are of special interest because they may play a role in speciation. However, the presence of Wolbachia does not always imply incompatibility. The field crickets Gryllus firmus and G. pennsylvanicus exhibit a very clear unidirectional incompatibility and have been cited as a possible example of Wolbachia-induced CI. Here, we conduct curing experiments, intra- and interspecific crosses, cytological examination of Wolbachia in testes and Wolbachia quantifications through real-time PCR. All of our data strongly suggest that Wolbachia are not involved in the reproductive incompatibility between G. firmus and G. pennsylvanicus.

Publication types

  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Animals
  • Crosses, Genetic
  • Female
  • Gryllidae / genetics
  • Gryllidae / microbiology*
  • Gryllidae / physiology*
  • Hybridization, Genetic*
  • Male
  • Ovum / cytology
  • Ovum / microbiology
  • Polymorphism, Restriction Fragment Length
  • Reproduction
  • Sexual Behavior, Animal
  • Species Specificity
  • Spermatozoa / cytology
  • Spermatozoa / microbiology
  • Wolbachia / genetics
  • Wolbachia / physiology*