Wolbachia pipientis: Difference between revisions

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[[Image:Wolbachia pipientis.jpg |thumb|450px|right|In a stained egg of the small parasitic wasp, ''Trichogramma kaykai'', are brightly staining ''Wolbachia''. The bacteria accumulate at the end of the egg that is destined to develop into the reproductive organs. Wolbachia induce the eggs of this wasp to develop into female offspring without fertilization. Photo Credit: Merijn Salverda and Richard Stouthamer.]]
[[Image:Wolbachia pipientis_Photo.jpg |thumb|450px|right|In a stained egg of the small parasitic wasp, ''Trichogramma kaykai'', are brightly staining ''Wolbachia''. The bacteria accumulate at the end of the egg that is destined to develop into the reproductive organs. Wolbachia induce the eggs of this wasp to develop into female offspring without fertilization. Photo Credit: Merijn Salverda and Richard Stouthamer.]]


==Classification==
==Classification==


===Higher order taxa===
===Higher Order Taxa===
Scientific classification
Domain: Bacteria
Phylum: Proteobacteria
Class: Alphaproteobacteria
Subclass:Rickettsidae
Order: Rickettsiales
Family: Rickettsiaceae
Genus: Wolbachia
Species of Wolbachia
Wolbachia melophagi (Nöller 1917) Philip 1956[1] Wolbachia persica Suitor and Weiss 1961[2] Wolbachia pipientis Hertig 1936


Bacteria; Proteobacteria; Alphaproteobacteria; Rickettsiales; Rickettsiaceae; Wolbachieae; Wolbachia
===Genus and Species===
 
===Species===


''Wolbachia pipientis''
''Wolbachia pipientis''
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{|
{|
| height="10" bgcolor="#FFDF95" |
| height="10" bgcolor="#FFDF95" |
'''NCBI: [http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Tree&id=2&lvl=3&lin=f&keep=1&srchmode=1&unlock Taxonomy]'''
'''NCBI: [http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Tree&id=2&lvl=3&lin=f&keep=1&srchmode=1&unlock Taxonomy] Genome: - ''<font size="2">[http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?id=163164 Wolbachia pipientis wMel] '''
|}
|}


''Genus species''


==Description and significance==
Wolbachia are gram-negative bacteria that form intracellular inherited infections in many invertebrates. They are extremely common with 20-75% of all insects being infected. Moreover they infect numerous non-insect invertebrates including nematodes, mites and spiders. The limits of the host range of Wolbachia are not fully appreciated at this time. Much of the success of Wolbachia can be attributed to the diverse phenotypes that result from infection. These range from classical mutualism to reproductive parasitism as characterized by the ability of Wolbachia to override chromosomal sex determination, induce parthenogenesis, selectively kill males, influence sperm competition and generate cytoplasmic incompatibility in early embryos. The unique biology of Wolbachia has attracted a growing number of researchers interested in questions ranging from the evolutionary implications of infection through to the use of this agent for pest and disease control


==Genome structure==
==Description and Significance==
''Wolbachia pipientis'' are bacteria that infect a wide range of invertebrate, mainly arthropods and nematodes.  Wolbachia is one of the most common natural pathogens on Earth that alter the reproductive system of insects; it is estimated that more than 18-76% of insects are infected by it including spider, termites, mosquito, flies and nematoades. The bacteria give various physical characteristics of its infection that cause 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 (parthenogenesis) because it can selectively kill males; thus, it creates a detrimental competition against sperm and causes cytoplasmic incompatibility in fertilized eggs.  Wolbachia's uniqueness in altering reproduction has caused many scientists to research the biology of infection and their potential use for controlling pest and pathogens.
 
==Genome Structure==
 
[[Image:Table.JPG|thumb|500px|left|Statistics for Wolbachia pipientis.]]


[[Image:Table.JPG|thumb|500px|right|Statistics for Wolbachia pipientis.]]
From further observation of the genomic structure has unfolded the many mysteries of biology and evolution of the bacteria. For instance, orthologous genes that are unique from bacteria of the same genus show a similar pattern among the bacteria that originate from the same ancestor. Different species of the same genus have closely related DNA sequences with the same repetitiveness and mobile elements. According to a research, this observation, in conjunction with evolutionary dogma, gives an impression that natural selection may somehow ineffective because of population bottleneck.


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.
Furthermore, the chromosome of ''Wolbachia'' appears to be circular just like many other bacteria with about 1.3mbp. Of the sequence, about 1mbp are the primary coding region. The number of genes are estimated to be around 800 with 34 tRNA genes and 3 rRNA genes. The number of A+T nucleotides base pairing is estimated 65% while the number of G+C nucleotides base pairing is 35%.


[[Image:Wolbachia genome.jpg|frame|left|A schematic of the circular Wolbachia genome. Credit: Julie Dunning Hotopp and Seth Bordenstein, 2005.]]
==Cell Structure and Metabolism==
Wolbachia is a gram-negative bacteria. In these bacteria, the cell wall contains fewer layer of peptidoglycan than gram-positive bacteria. So, the structure of the outer membrane contains porins that help to transfer molecules, and lipopolysaccharide that contains Lipid A, core polysaccharide, and O-polysaccharide. Furthermore, lipoproteins are attached to the polysaccharide backbone.


==Cell structure and metabolism==
Another analysis to the genomes, shows a pattern of paralogous genes which have similar function, but often times not because the copy of the duplicated gene is less practical; this copy is free to mutate and acquire new functions. Unlike the metabolic activity of a closely related Rickettsia that is able to generate ATP from their hosts, Wolbachia use glycolysis and purine synthesis. Another observation includes the lack of lipopolysaccharide synthesis in Wolbachia.
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==
==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.
Based on many studies, the evidence of vertical gene transfer in their hosts by Wolbachia is apparent. However, there’s no proof that supports any lateral gene transfer between Wolbachia and ''D. melanogaster'' or between Wolbachia and any other hosts. Furthermore, evolutionary evidence shows that mitochondria share a common ancestor with alpha-Proteobacteria, but has no evidence for similarity with mitochondria with species in the order of Rickettsiales.


==Pathology==
==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).
 
[[Image:Confocal2.jpg|frame|right| Cellular examination of the bacteria ''Wolbachia'' on reproductive mechanisms of the fruit fly ''D. melanogaster''. In this image, DNA is labeled green, and Wolbachia are red. Photo credit to UCSC]]
 
''Wolbachia'' is a parasitic bacteria that infects reproductive system of insects which ultimately affects their linage continuation. The symbiosis between the bacteria and host is complex. Depending on the interaction, it ranges from mutualism to parasitism. The bacteria infect different types of organ, but the remarkable characteristic is their ability to alter the way maternal genes are passed on to the next generation by infecting the testes and ovaries of their hosts.  
There are four different phenotypes expressed:
* male killing (death of infected males). This selectively allows females to survive and more likely to reproduce even in the absence of males.
*feminization (infected males grow as either fully fertile females or infertile pseudo-females)  
*parthenogenesis(reproduction of infected females asexually)  
*Cytoplasmic incompatibility (the inability of ''Wolbachia''-infected males to successfully reproduce with uninfected females). This method causes a certain ''Wolbachia'' strain to be more dominant over the others.
Furthermore, ''Wolbachia'' are not found in mature sperms, but are found in mature eggs. So, the infection is carried along to offspring by infected females but not males.


==Application to Biotechnology==
==Application to Biotechnology==
Does this organism produce any useful compounds or enzymes?  What are they and how are they used?
Currently, there's no known compound or enzyme identified for biotechnological use.


==Current Research==
==Current Research==


Enter summaries of the most recent research here--at least three required
*Wolbachia pipientis is a intracelluler gram negative bacteria, firstly identified in 1924 by Hertig and Wolbach in sex cells of ''Culex pipiens'', a species of mosquito, while comprehensive description were published by Hertig in 1936. Last few decades  wolbachia become a noval endosymbiotic natural bio-control agent due to its ubiquitous phenotyptic behavior. Now a days lot of genomic research conduct on this multi-functional bacteria ( Parasitic and Mutualistic behavior).Here some examples of recent published research work related to this bacteria:
*The Intracellular Bacterium Wolbachia Uses Parasitoid Wasps as Phoretic Vectors for Efficient Horizontal Transmission
PLoS Pathog (2015)11(2): e1004672. doi:10.1371/journal.ppat.1004672
*Wolbachia-Based Population Control Strategy Targeting Culex quinquefasciatus Mosquitoes Proves Efficient under Semi-Field Conditions
Research Article | published 13 Mar 2015 | PLOS ONE 10.1371/journal.pone.0119288
*Wolbachia Infection Dynamics in Tribolium confusum (Coleoptera: Tenebrionidae) and Their Effects on Host Mating Behavior and Reproduction
J. Econ. Entomol. 108(3): 1408–1415 (2015); DOI: 10.1093/jee/tov053
*Characterization of Wolbachia cell division protein (ftsz) gene for potential management of Uzifly Exorista sorbillans (Diptera: Tachinidae)
Journal of Entomology and Zoology Studies 2015; 3 (2): 57-61
*Wolbachia infection affects female fecundity in Drosophila suzukii
Bulletin of Insectology 68 (1): 153-157, 2015 ISSN 1721-8861
*How do hosts react to endosymbionts? A new insight into the molecular mechanisms underlying the Wolbachia–host association
Insect Molecular Biology (2015) 24(1), 1–12
*Evidence of natural Wolbachia infections in field populations of Anopheles gambiae
Nature Communications 06 Jun 2014
*Lateral transfers of insertion sequences between Wolbachia, Cardinium and Rickettsia bacterial endosymbionts
Heredity (2013), 1–8: doi:10.1038/hdy.2013.56


==References==
==References==
Line 53: Line 89:
*[http://wolbachia.sols.uq.edu.au/about.cfm Wolbachia - wolbachia.sols.uq.edu.au]
*[http://wolbachia.sols.uq.edu.au/about.cfm Wolbachia - wolbachia.sols.uq.edu.au]


==Genome structure==
===Genome Structure===
*[http://cmr.tigr.org/tigr-scripts/CMR/GenomePage.cgi?database=dmg Genome data for Wolbachia pipientis (TIGR)]
*[http://cmr.tigr.org/tigr-scripts/CMR/GenomePage.cgi?database=dmg Genome data for Wolbachia pipientis (TIGR)]
===Pathology===
*[http://microbiology.ucsc.edu/confocal.html Sullivan's laboratory confocal microscopy examination.]
===Current Research===
* M. Hertig & S. B. Wolbach (1924). "Studies on ''Rickettsia''-like microorganisms in insects". ''Journal of Medical Research'' 44: 329–374
*[http://www.cbse.ucsc.edu/news/2005/10/28/sullivan/index.shtml Research by Sullivan]
*[http://pondside.uchicago.edu/%7Efeder/MSS/overcome.html Interaction of ''Drosophila'' and its endosymbiont ''Wolbachia'']
*[http://mcknight.ccrp.cornell.edu/projects/wolbachia/china_wolbachia.html Using ''Wolbachia'' to reduce virus transmission]

Latest revision as of 13:49, 15 October 2016

This is a curated page. Report corrections to Microbewiki.

A Microbial Biorealm page on the genus Wolbachia pipientis

In a stained egg of the small parasitic wasp, Trichogramma kaykai, are brightly staining Wolbachia. The bacteria accumulate at the end of the egg that is destined to develop into the reproductive organs. Wolbachia induce the eggs of this wasp to develop into female offspring without fertilization. Photo Credit: Merijn Salverda and Richard Stouthamer.

Classification

Higher Order Taxa

Scientific classification Domain: Bacteria Phylum: Proteobacteria Class: Alphaproteobacteria Subclass:Rickettsidae Order: Rickettsiales Family: Rickettsiaceae Genus: Wolbachia Species of Wolbachia Wolbachia melophagi (Nöller 1917) Philip 1956[1] Wolbachia persica Suitor and Weiss 1961[2] Wolbachia pipientis Hertig 1936

Genus and Species

Wolbachia pipientis

NCBI: Taxonomy Genome: - Wolbachia pipientis wMel


Description and Significance

Wolbachia pipientis are bacteria that infect a wide range of invertebrate, mainly arthropods and nematodes. Wolbachia is one of the most common natural pathogens on Earth that alter the reproductive system of insects; it is estimated that more than 18-76% of insects are infected by it including spider, termites, mosquito, flies and nematoades. The bacteria give various physical characteristics of its infection that cause 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 (parthenogenesis) because it can selectively kill males; thus, it creates a detrimental competition against sperm and causes cytoplasmic incompatibility in fertilized eggs. Wolbachia's uniqueness in altering reproduction has caused many scientists to research the biology of infection and their potential use for controlling pest and pathogens.

Genome Structure

Statistics for Wolbachia pipientis.

From further observation of the genomic structure has unfolded the many mysteries of biology and evolution of the bacteria. For instance, orthologous genes that are unique from bacteria of the same genus show a similar pattern among the bacteria that originate from the same ancestor. Different species of the same genus have closely related DNA sequences with the same repetitiveness and mobile elements. According to a research, this observation, in conjunction with evolutionary dogma, gives an impression that natural selection may somehow ineffective because of population bottleneck.

Furthermore, the chromosome of Wolbachia appears to be circular just like many other bacteria with about 1.3mbp. Of the sequence, about 1mbp are the primary coding region. The number of genes are estimated to be around 800 with 34 tRNA genes and 3 rRNA genes. The number of A+T nucleotides base pairing is estimated 65% while the number of G+C nucleotides base pairing is 35%.

Cell Structure and Metabolism

Wolbachia is a gram-negative bacteria. In these bacteria, the cell wall contains fewer layer of peptidoglycan than gram-positive bacteria. So, the structure of the outer membrane contains porins that help to transfer molecules, and lipopolysaccharide that contains Lipid A, core polysaccharide, and O-polysaccharide. Furthermore, lipoproteins are attached to the polysaccharide backbone.

Another analysis to the genomes, shows a pattern of paralogous genes which have similar function, but often times not because the copy of the duplicated gene is less practical; this copy is free to mutate and acquire new functions. Unlike the metabolic activity of a closely related Rickettsia that is able to generate ATP from their hosts, Wolbachia use glycolysis and purine synthesis. Another observation includes the lack of lipopolysaccharide synthesis in Wolbachia.

Ecology

Based on many studies, the evidence of vertical gene transfer in their hosts by Wolbachia is apparent. However, there’s no proof that supports any lateral gene transfer between Wolbachia and D. melanogaster or between Wolbachia and any other hosts. Furthermore, evolutionary evidence shows that mitochondria share a common ancestor with alpha-Proteobacteria, but has no evidence for similarity with mitochondria with species in the order of Rickettsiales.

Pathology

Cellular examination of the bacteria Wolbachia on reproductive mechanisms of the fruit fly D. melanogaster. In this image, DNA is labeled green, and Wolbachia are red. Photo credit to UCSC

Wolbachia is a parasitic bacteria that infects reproductive system of insects which ultimately affects their linage continuation. The symbiosis between the bacteria and host is complex. Depending on the interaction, it ranges from mutualism to parasitism. The bacteria infect different types of organ, but the remarkable characteristic is their ability to alter the way maternal genes are passed on to the next generation by infecting the testes and ovaries of their hosts. There are four different phenotypes expressed:

  • male killing (death of infected males). This selectively allows females to survive and more likely to reproduce even in the absence of males.
  • feminization (infected males grow as either fully fertile females or infertile pseudo-females)
  • parthenogenesis(reproduction of infected females asexually)
  • Cytoplasmic incompatibility (the inability of Wolbachia-infected males to successfully reproduce with uninfected females). This method causes a certain Wolbachia strain to be more dominant over the others.

Furthermore, Wolbachia are not found in mature sperms, but are found in mature eggs. So, the infection is carried along to offspring by infected females but not males.

Application to Biotechnology

Currently, there's no known compound or enzyme identified for biotechnological use.

Current Research

  • Wolbachia pipientis is a intracelluler gram negative bacteria, firstly identified in 1924 by Hertig and Wolbach in sex cells of Culex pipiens, a species of mosquito, while comprehensive description were published by Hertig in 1936. Last few decades wolbachia become a noval endosymbiotic natural bio-control agent due to its ubiquitous phenotyptic behavior. Now a days lot of genomic research conduct on this multi-functional bacteria ( Parasitic and Mutualistic behavior).Here some examples of recent published research work related to this bacteria:
  • The Intracellular Bacterium Wolbachia Uses Parasitoid Wasps as Phoretic Vectors for Efficient Horizontal Transmission

PLoS Pathog (2015)11(2): e1004672. doi:10.1371/journal.ppat.1004672

  • Wolbachia-Based Population Control Strategy Targeting Culex quinquefasciatus Mosquitoes Proves Efficient under Semi-Field Conditions

Research Article | published 13 Mar 2015 | PLOS ONE 10.1371/journal.pone.0119288

  • Wolbachia Infection Dynamics in Tribolium confusum (Coleoptera: Tenebrionidae) and Their Effects on Host Mating Behavior and Reproduction

J. Econ. Entomol. 108(3): 1408–1415 (2015); DOI: 10.1093/jee/tov053

  • Characterization of Wolbachia cell division protein (ftsz) gene for potential management of Uzifly Exorista sorbillans (Diptera: Tachinidae)

Journal of Entomology and Zoology Studies 2015; 3 (2): 57-61

  • Wolbachia infection affects female fecundity in Drosophila suzukii

Bulletin of Insectology 68 (1): 153-157, 2015 ISSN 1721-8861

  • How do hosts react to endosymbionts? A new insight into the molecular mechanisms underlying the Wolbachia–host association

Insect Molecular Biology (2015) 24(1), 1–12

  • Evidence of natural Wolbachia infections in field populations of Anopheles gambiae

Nature Communications 06 Jun 2014

  • Lateral transfers of insertion sequences between Wolbachia, Cardinium and Rickettsia bacterial endosymbionts

Heredity (2013), 1–8: doi:10.1038/hdy.2013.56

References

Description and Significance:

Genome Structure

Pathology

Current Research