Chaos of Wolbachia sequences inside the compact fig syconia of Ficus benjamina (Ficus: moraceae)

PLoS One. 2012;7(11):e48882. doi: 10.1371/journal.pone.0048882. Epub 2012 Nov 8.

Abstract

Figs and fig wasps form a peculiar closed community in which the Ficus tree provides a compact syconium (inflorescence) habitat for the lives of a complex assemblage of Chalcidoid insects. These diverse fig wasp species have intimate ecological relationships within the closed world of the fig syconia. Previous surveys of Wolbachia, maternally inherited endosymbiotic bacteria that infect vast numbers of arthropod hosts, showed that fig wasps have some of the highest known incidences of Wolbachia amongst all insects. We ask whether the evolutionary patterns of Wolbachia sequences in this closed syconium community are different from those in the outside world. In the present study, we sampled all 17 fig wasp species living on Ficus benjamina, covering 4 families, 6 subfamilies, and 8 genera of wasps. We made a thorough survey of Wolbachia infection patterns and studied evolutionary patterns in wsp (Wolbachia Surface Protein) sequences. We find evidence for high infection incidences, frequent recombination between Wolbachia strains, and considerable horizontal transfer, suggesting rapid evolution of Wolbachia sequences within the syconium community. Though the fig wasps have relatively limited contact with outside world, Wolbachia may be introduced to the syconium community via horizontal transmission by fig wasps species that have winged males and visit the syconia earlier.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Bacterial Outer Membrane Proteins / chemistry
  • Bacterial Outer Membrane Proteins / genetics
  • Female
  • Ficus
  • Genotype
  • Male
  • Phylogeny
  • Population Dynamics
  • Sequence Analysis, DNA
  • Symbiosis
  • Wasps / microbiology*
  • Wolbachia / genetics*

Substances

  • Bacterial Outer Membrane Proteins
  • Wsp protein, Wolbachia

Grants and funding

This project was supported by the National Natural Science Foundation of China (NSFC grant no. 31090253, 31172072), partially by Major Innovation Program of Chinese Academy of Sciences (KSCX2-EW-Z-2), a grant (No. O529YX5105) from the Key Laboratory of the Zoological Systematics and Evolution of the Chinese Academy of Sciences and National Science Fund for Fostering Talents in Basic Research (Special subjects in animal taxonomy, NSFC- J0930004). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.