Phylogenomics of the reproductive parasite Wolbachia pipientis
wMel: a streamlined genome overrun by mobile genetic elements.
The complete sequence of the 1,267,782 bp genome of Wolbachia
pipientis wMel, an obligate intracellular bacteria of Drosophila
melanogaster, has been determined. Wolbachia, which are found in
a variety of invertebrate species, are of great interest due to
their diverse interactions with different hosts, which range
from many forms of reproductive parasitism to mutualistic
symbioses. Analysis of the wMel genome, in particular
phylogenomic comparisons with other intracellular bacteria, has
revealed many insights into the biology and evolution of wMel
and Wolbachia in general. For example, the wMel genome is unique
among sequenced obligate intracellular species in both being
highly streamlined and containing very high levels of repetitive
DNA and mobile DNA elements. This observation, coupled with
multiple evolutionary reconstructions, suggests that natural
selection is somewhat inefficie