Volvox carteri

Volvox carteri
Scientific classification
(unranked):Viridiplantae
Class:Chlorophyceae
Order:Chlamydomonadales
Family:Volvocaceae
Genus:Volvox
Species: V. carteri
Binomial name
Volvox carteri
F.Stein 1873

Volvox carteri F. Stein 1873 is a species of colonial green algae in the order Volvocales.[1] V. carteri forms large spherical colonies, or coenobium, of 2000-6000 Chlamydomonas type cells.[2] Colonies contain mostly somatic cells plus a smaller number of gametes in female or male colonies.[2] In addition to female colonies with eggs and male colonies with sperm bundles, purely vegetative colonies exist.[2] All three types of colonies may also have specialized cells called gonidia for asexual reproduction of the colony.[2]

The genome of this species of algae was sequenced in 2010.[3]

Sexual reproduction

V. carteri can reproduce either asexually or sexually. Thus, it is a facultatively sexual organism. In nature, Volvox reproduces asexually in temporary ponds in spring, but becomes sexual and produces dormant over-wintering zygotes before the ponds dry up in the summer heat. V. carteri can be induced to reproduce sexually by heat shock treatment.[4] However, this induction can be inhibited by antioxidants indicating that the induction of sex by heat shock is mediated by oxidative stress.[5] Nedelcu et al.[6] further found that an inhibitor of the mitochondrial electron transport chain that induces oxidative stress also induced sex in V. carteri. Nedelcu and Michod[5] and Nedelcu et al.[6] suggested that oxidative DNA damage caused by oxidative stress may be the underlying cause of the induction of sex in their experiments. Other agents that cause DNA damage (i.e. glutaraldehyde, formaldehyde and UV) also induce sex in V. carteri.[7][8][9] These findings lend support to the general idea that a principal adaptive function of sex is repair of DNA damages.[10][11] [12][13]

References

  1. ↑ Guiry, M.D.; Guiry, G.M. (2008). "'Volvox carteri'". AlgaeBase. World-wide electronic publication, National University of Ireland, Galway.
  2. 1 2 3 4 Lee, Robert Edward (2005) [1999]. Phycology (3rd ed.). Cambridge University Press.
  3. ↑ Prochnik SE, Umen J, Nedelcu AM, Hallmann A, Miller SM, Nishii I, Ferris P, Kuo A, et al. (2010). "Genomic analysis of organismal complexity in the multicellular green alga Volvox carteri". Science. 329 (5988): 223–6. doi:10.1126/science.1188800. PMC 2993248. PMID 20616280.
  4. ↑ Kirk DL, Kirk MM (January 1986). "Heat shock elicits production of sexual inducer in Volvox". Science. 231 (4733): 51–4. doi:10.1126/science.3941891. PMID 3941891.
  5. 1 2 Nedelcu AM, Michod RE; Michod (November 2003). "Sex as a response to oxidative stress: the effect of antioxidants on sexual induction in a facultatively sexual lineage". Proc. Biol. Sci. 270 Suppl 2: S136–9. doi:10.1098/rsbl.2003.0062. PMC 1809951. PMID 14667362.
  6. 1 2 Nedelcu AM, Marcu O, Michod RE (August 2004). "Sex as a response to oxidative stress: a twofold increase in cellular reactive oxygen species activates sex genes". Proc. Biol. Sci. 271 (1548): 1591–6. doi:10.1098/rspb.2004.2747. PMC 1691771. PMID 15306305.
  7. ↑ Starr RC, Jaenicke L (1988). "Sexual induction in Volvox carteri f. nagariensis by aldehydes". Sex Plant Reprod. 1: 28–31. doi:10.1007/bf00227019.
  8. ↑ Loshon CA, Genest PC, Setlow B, Setlow P (July 1999). "Formaldehyde kills spores of Bacillus subtilis by DNA damage and small, acid-soluble spore proteins of the alpha/beta-type protect spores against this DNA damage". J. Appl. Microbiol. 87 (1): 8–14. doi:10.1046/j.1365-2672.1999.00783.x. PMID 10432583.
  9. ↑ Zeiger E, Gollapudi B, Spencer P (March 2005). "Genetic toxicity and carcinogenicity studies of glutaraldehyde--a review". Mutat. Res. 589 (2): 136–51. doi:10.1016/j.mrrev.2005.01.001. PMID 15795166.
  10. ↑ Bernstein H, Byerly HC, Hopf FA, Michod RE (September 1985). "Genetic damage, mutation, and the evolution of sex". Science. 229 (4719): 1277–81. doi:10.1126/science.3898363. PMID 3898363.
  11. ↑ Birdsell JA, Wills C (2003). The evolutionary origin and maintenance of sexual recombination: A review of contemporary models. Evolutionary Biology Series >> Evolutionary Biology, Vol. 33 pp. 27-137. MacIntyre, Ross J.; Clegg, Michael, T (Eds.), Springer. Hardcover ISBN 978-0306472619, ISBN 0306472619 Softcover ISBN 978-1-4419-3385-0.
  12. ↑ Hörandl E (December 2009). "A combinational theory for maintenance of sex". Heredity (Edinb). 103 (6): 445–57. doi:10.1038/hdy.2009.85. PMC 2854797. PMID 19623209.
  13. ↑ Bernstein H, Bernstein C, Michod RE (2012). DNA repair as the primary adaptive function of sex in bacteria and eukaryotes. Chapter 1: pp.1-49 in: DNA Repair: New Research, Sakura Kimura and Sora Shimizu editors. Nova Sci. Publ., Hauppauge, N.Y. ISBN 978-1-62100-808-8 https://www.novapublishers.com/catalog/product_info.php?products_id=31918
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