I mentioned Wolbachia in my parthenogenesis post; here I will
talk about it in more detail, because it’s a really cool
parasite, as well as in the center of much research nowadays.
Wolbachia are Gram-negative ⍺-Proteobacteria (order
Rickettsiales, family Anaplasmataceae; Dumler et al.,2001),
systematically split into 6 supergroups, lettered from A to F
(Lo et al., 2002). Those in supergroups C and D have coevolved
with their nematodan hosts and are mutualistic (Bandi et al.,
1998). Those in supergroups A and B are parasites in arthropods.
Morphologically, they come in two groups: ~1µm large rods, and
~0.5µm diameter coccoids. They can be found in a membrane-bound
vacuole in the host cell’s cytoplasm (Yen & Barr, 1971); in
arthropods, this will be in egg and ovarian cells (see diagram
above, from Weiss et al. (2009)), although it has also been
found in other tissues, including the Malpighian tubules, and
muscle and nervous tissue (Stouthamer et al., 1999). When found
in sperm cell cytoplasm, it disappears duri