Wolbachia pipientis
A Microbial Biorealm page on the genus Wolbachia pipientis
Classification
Higher Order Taxa
Bacteria; Proteobacteria; Alphaproteobacteria; Rickettsiales; Rickettsiaceae; Wolbachieae; Wolbachia
Species
Wolbachia pipientis
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NCBI: Taxonomy Genome: - Wolbachia pipientis wMel |
Genus species
Description and Significance
Wolbachia pipientis are bacteria that infect a wide range of invertebrate, mainly arthropods and numerous insects. Wolbachia is one of the most common pathogens on Earth that infect the reproductive system of insects; it is estimated with more than 18% of insects are infected by it including spider, mosquito, and flies. These gram-negative bacteria give various physical characteristics of its infection. The infection causes a variety of result including deterring chromosomal sex determination from gamete fertilization. Also, it may initiate parthenogenesis that causes growth and development without fertilization by sperm because it can selectively kill males; thus, it creates a detrimental competition against sperm and causes cytoplasmic incompatibility in fertilized eggs. Although the types of hosts that Wolbachia infect are insignificant, their uniqueness in altering reproduction has caught many scientist to research the biology of infection and their potential use for controlling pest and pathosis.
Genome Structure
Analysis of the genome, in particular phylogenomic comparisons with other intracellular bacteria, has revealed many insights into the biology and evolution of Wolbachia. For example, the 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 inefficient, most likely owing to the occurrence of repeated population bottlenecks.
Cell Structure and Metabolism
Genome analysis predicts many metabolic differences with the closely related Rickettsia species, including the presence of intact glycolysis and purine synthesis, which may compensate for an inability to obtain ATP directly from its host, as Rickettsia can. Other discoveries include the apparent inability of Wolbachia to synthesize lipopolysaccharide.
Ecology
Despite the ability of Wolbachia to infect the germline of its host, no evidence has yet been found for either recent lateral gene transfer between Wolbachia and D. melanogaster or older transfers between Wolbachia and any host. Evolutionary analysis further supports the hypothesis that mitochondria share a common ancestor with the alpha-Proteobacteria, but shows little support for the grouping of mitochondria with species in the order Rickettsiales.
Pathology
Wolbachia, a bacterial endosymbiont of diverse arthropods, affects its host's reproduction and so is consequential for its host's fitness. In the fruit fly. Host interactions are complex and range from mutualistic to pathogenic, depending on the combination of host and Wolbachia involved. Most striking are the various forms of “reproductive parasitism” that serve to alter host reproduction in order to enhance the transmission of this maternally inherited agent. These include parthenogenesis (infected females reproducing in the absence of mating to produce infected female offspring), feminization (infected males being converted into functional phenotypic females), male-killing (infected male embryos being selectively killed), and cytoplasmic incompatibility (in its simplest form, the developmental arrest of offspring of uninfected females when mated to infected males).
Application to Biotechnology
Does this organism produce any useful compounds or enzymes? What are they and how are they used?
Current Research
- The bacteria were first identified in 1924 by Hertig and Wolbach in Culex pipiens, a species of mosquito
- Research by Sullivan uncovers modus operandi of parasitic bacterium in insects
- Interaction of Drosophila and its endosymbiont Wolbachia: natural heat shock and the overcoming of sexual incompatibility
- Using Wolbachia to reduce virus transmission: Toward the genetic manipulation of crop pests
