Blattabacterium is a genus of obligate mutualistic endosymbiont bacteria that are believed to inhabit all species of cockroach studied to date, with the exception of the genus Nocticola.[3] The genus' presence in the termite Mastotermes darwiniensis led to speculation, later confirmed, that termites and cockroaches are evolutionarily linked.[4][5]

Blattabacterium
Scientific classification
Domain:
Phylum:
Class:
Order:
Family:
Blattabacteriaceae

Kambhampati 2012[1]
Genus:
Blattabacterium

Hollande and Favre 1931 (Approved Lists 1980)[2]
Species
  • "B. clevelandi" Clark and Kambhampati 2003
  • B. cuenoti (Mercier 1906) Hollande and Favre 1931 (Approved Lists 1980)
  • "B. Blattabacterium punctulatus" Clark and Kambhampati 2003
  • "B. Blattabacterium relictus" Clark and Kambhampati 2003

Diversity edit

B. cuenoti was traditionally considered the only species in the genus Blattabacterium,[6] which is in turn the only genus in the family Blattabacteriaceae.[7] However, three new species have been described hosted by different species of cockroaches in the genus Cryptocercus:

The ancient (~150 My) genus retains throughout a core set of metabolic genes.[8] According to the GTDB, the many strains of the genus have nevertheless diverged enough at the sequence level to define around 40 "species" out of B. cuenoti alone.[9]

In addition, newer genera have been found sufficiently closely related to the genus to warrant assignment to the same family by GTDB: Ca. "Karelsulcia", Ca. "Uzinura", Ca. "Walczuchella", all symbionts of insects.[9]

Function edit

Blattabacterium lives inside the fat cells of the fat bodies (tissues in the abdominal cavity that store fat) of its insect hosts. It serves a vital role in nitrogen recycling, which is important in insects that mainly live on plant material such as wood, which are poor in nitrogen. In insects, uric acid is a waste product of protein metabolism. After breakdown of uric acid by the host (and its other microbial flora, such as gut bacteria and fungi) into urea and/or ammonia, Blattabacterium recycles nitrogen by converting these products into glutamate, and using other raw materials from the host, is able to synthesize all of the essential amino acids and several vitamins.[10][11] It appears to be transmitted to succeeding generations of the host by infection of the mother's eggs prior to their fertilization.[12] When Blattabacterium was depleted within the host's fat bodies, there was an accumulation of urate showing Blattabacterium may be playing a role in regulating purine metabolism.[13]

Transmission edit

Generally, insect endosymbionts are transmitted vertically, where the mother will pass the endosymbiont to the offspring through the egg germ line.[14] Therefore understanding host reproductive behavior is critical to understand how Blattabacterium is transmitted.

Cockroaches are a hugely diverse order of insects called Blattodea, within this order cockroaches exhibit range of reproductive behavior. Most cockroaches are oviparous, meaning they lay their eggs within their environment. Some roaches are ovoviviparous, where developing eggs remain inside the mother until they hatch.[15] In rare cases cockroaches such as Diploptera punctata, have been observed as viviparous. Embryos develop in an egg sac within the mother and are supplied nutrients during development.[16]

References edit

  1. ^ Kambhampati S (2010). "Family II. Blattabacteriaceae fam. nov.". In Krieg NR, Staley JT, Brown DR, Hedlund BP, Paster BJ, Ward NL, Ludwig W, Whitman WB (eds.). Bergey's Manual of Systematic Bacteriology. Vol. 4 (2nd ed.). New York, NY: Springer. p. 315.
  2. ^ Hollande AC, Favre R (1931). "La structure cytologique de Blattabacterium cuenoti (Mercier) N.G., symbiote du tissu adipeux des Blattides". Comptes Rendus des Séances de la Société de Biologie (Paris). 107: 752–754.
  3. ^ Lo N, Beninati T, Stone F, Walker J, Sacchi L (June 2007). "Cockroaches that lack Blattabacterium endosymbionts: the phylogenetically divergent genus Nocticola". Biology Letters. 3 (3): 327–330. doi:10.1098/rsbl.2006.0614. PMC 2464682. PMID 17376757.
  4. ^ Zuckerman W (16 April 2011). "The secret superpower of the cockroach". New Scientist.
  5. ^ Lo N, Eggleton P (2011). "Termite Phylogenetics and Co-cladogenesis with Symbionts". In Bignell D, Roisin Y, Lo N (eds.). Biology of Termites: A Modern Synthesis. pp. 27–50. doi:10.1007/978-90-481-3977-4_2.
  6. ^ Clark JW, Kambhampati S (January 2003). "Phylogenetic analysis of Blattabacterium, endosymbiotic bacteria from the wood roach, Cryptocercus (Blattodea: Cryptocercidae), including a description of three new species". Molecular Phylogenetics and Evolution. 26 (1): 82–88. doi:10.1016/S1055-7903(02)00330-5. PMID 12470940.
  7. ^ Boone DR, Castenholz RW, eds. (2001). Bergey's Manual of Systematic Bacteriology. Volume 1. The Archaea and the deeply branching and phototrophic Bacteria (2nd ed.). New York: Springer-Verlag. pp. 465–466. ISBN 978-0-387-98771-2.
  8. ^ Patiño-Navarrete R, Moya A, Latorre A, Peretó J (2013). "Comparative genomics of Blattabacterium cuenoti: the frozen legacy of an ancient endosymbiont genome". Genome Biology and Evolution. 5 (2): 351–361. doi:10.1093/gbe/evt011. PMC 3590773. PMID 23355305.
  9. ^ a b "Blattabacterium Tree". Genome Taxonomy Database (GTDB). The University of Queensland. Retrieved 20 December 2022.
  10. ^ Sabree ZL, Kambhampati S, Moran NA (November 2009). "Nitrogen recycling and nutritional provisioning by Blattabacterium, the cockroach endosymbiont". Proceedings of the National Academy of Sciences of the United States of America. 106 (46): 19521–19526. Bibcode:2009PNAS..10619521S. doi:10.1073/pnas.0907504106. PMC 2780778. PMID 19880743.
  11. ^ Patiño-Navarrete R, Piulachs MD, Belles X, Moya A, Latorre A, Peretó J (July 2014). "The cockroach Blattella germanica obtains nitrogen from uric acid through a metabolic pathway shared with its bacterial endosymbiont". Biology Letters. 10 (7): 7. doi:10.1098/rsbl.2014.0407. PMC 4126632. PMID 25079497.
  12. ^ Carrasco P, Pérez-Cobas AE, van de Pol C, Baixeras J, Moya A, Latorre A (June 2014). "Succession of the gut microbiota in the cockroach Blattella germanica". International Microbiology. 17 (2): 99–109. doi:10.2436/20.1501.01.212. PMID 26418854.
  13. ^ Jahnes BC, Sabree ZL (June 2020). "Nutritional symbiosis and ecology of host-gut microbe systems in the Blattodea". Current Opinion in Insect Science. Pests and resistance * Behavioural ecology. 39: 35–41. doi:10.1016/j.cois.2020.01.001. PMID 32109859. S2CID 211565307.
  14. ^ Engelstädter J, Hurst GD (December 2009). "The Ecology and Evolution of Microbes that Manipulate Host Reproduction". Annual Review of Ecology, Evolution, and Systematics. 40 (1): 127–149. doi:10.1146/annurev.ecolsys.110308.120206. ISSN 1543-592X.
  15. ^ Hintze-Podufal C, Vetter R (1996-01-01). "Hormonal Control of Courtship Behavior and Reproductive Cycle in the Cockroach Species Blaptica dubia (Blattoidea: Blaberoidea: Blaberidae)". Entomologia Generalis. 20 (3): 169–175. doi:10.1127/entom.gen/20/1996/169. ISSN 0171-8177.
  16. ^ Jennings EC, Korthauer MW, Hamilton TL, Benoit JB (September 2019). "Matrotrophic viviparity constrains microbiome acquisition during gestation in a live-bearing cockroach, Diploptera punctata". Ecology and Evolution. 9 (18): 10601–10614. doi:10.1002/ece3.5580. PMC 6787804. PMID 31624569.

Further reading edit