Luis Teixeira and colleagues introduced defined, fully sequenced Wolbachia strains into the genetic background of the DrosDel stocks. The evolutionary relationships of these strains are shown below.
These stocks were described in Chrostek et al. (2013) "Wolbachia variants induce differential protection to viruses in Drosophila melanogaster: a phenotypic and phylogenomic analysis" PLoS Genetics 9: e1003896.
In addition, both the original and Bloomington versions of the stock sequenced as the reference genome carry Wolbachia, even though the version of the stock sequenced by the Genome Project had lost Wolbachia.
Characterization of this Wolbachia sequence was reported in Gutzwiller et al. (2015) "Dynamics of Wolbachia pipientis gene expression across the Drosophila melanogaster life cycle" G3 5: 2843-2856.
A cautionary note regarding the wMelPop strain
The "popcorn" strain of Wolbachia causes neurodegenerative phenotypes. Its pathogenicity is associated with the tandem duplication of an eight-gene region and the severity of the pathogenicity is proportional to the number of repeats. Tandem duplications are unstable rearrangements that can revert to a single repeat by intrachromosomal recombination. wMelpop strains with more than two repeats may lose repeats quickly. Strains with only two repeats are more stable, but reversion to a single copy is still possible. Be sure to verify the presence of tandem repeats when using wMelPop experimentally. More information is available in Chrostek & Teixeira (2015) "Mutualism breakdown by amplification of Wolbachia genes" PLoS Biol. 13(2): e1002065.
If you examine this stock for the presence of tandem repeats, please let us know. We would like help monitoring the stability of this stock.