Wolbachia plays no role in the one-way reproductive incompatibility between the hybridizing field crickets Gryllus firmus and G. pennsylvanicus.
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.
Maroja
L S
LS
Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, NY 14853, USA.
Clark
M E
ME
Harrison
R G
RG
D000818:Animals; D003433:Crosses, Genetic; D005260:Female; D006135:Gryllidae / Q000235:genetics / Q000382:microbiology* / Q000502:physiology*; D006824:Hybridization, Genetic; D008297:Male; D010063:Ovum / Q000166:cytology / Q000382:microbiology; D012150:Polymorphism, Restriction Fragment Length; D012098:Reproduction; D012726:Sexual Behavior, Animal; D013045:Species Specificity; D013094:Spermatozoa / Q000166:cytology / Q000382:microbiology; D020577:Wolbachia / Q000235:genetics / Q000502:physiology*