Home / Charophyceae / Conjugate_Non-Desmids / Spirogyra
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Name derivation:
Classification:
Spirogyra Link 1820; 509 of 651 species descriptions are currently accepted taxonomically (Guiry and Guiry 2013). Class Conjugatophyceae; Order Zygnematales Moved from the less-advanced green Chlorophyceae.
Molecular sequence:
Based on 26 strains of Spirogyra and 7 strains of Sirogonium, large subunit of RUBISCO (rbcL) sequence strongly supports monophyly of both genera. All species descriptions of Spirogyra are in a single clade except S. maxima that falls within the Sirogonium clade (Drummond et al. 2005).
Morphology:
The spiral chloroplast is the defining characteristic of this species. It grows to form slimy filamentous masses of algae. It is capable of reproducing both sexually and asexually. A filament may fragment into smaller pieces, each one capable of forming new cells. During sexual reproduction two cells align with each other and form conjugation tubes which connect the two cells and allow for the exchange of genetic material.
Similar genera:
Two related non-desmid conjugating characeans are Zygnema that has two stellate chloroplasts, and Mougeotia with flat rectangular chloroplasts.
Conjugation:
The most easily recognizable genus in the class Zygnemaceae with its spirally coiled chloroplasts is known for its unique sexual reproduction. Stresses from the environment, including pH change, temperature change, or desiccation can induce Spirogyra to undergo conjugation by forming conjugation tubes between male and female gametes. This process allows for the exchange of genetic information within a population, contributing to the individual species fitness and adaptability to change. The structure and formation of this conjugation tube can also be utilized in identification between the more that 400 various species within this genus (Wongsawad and Peerapornpisal 2014).
Human Uses:
In many Asian countries, Spirogyra spp. is valued for human consumption, and is known as an important source of natural bioactive compounds for antibiotic, antiviral, antioxidant, anti-inflammatory, and cytotoxic purposes. A specific trans-Himalayan species, S. porticalis, has thirteen known bioactive chemotypes with phyto-pharmaceutical importance including fatty acid esters, sterols, unsaturated alcohols, and alkynes. These dominant components contribute to the high antioxidant capacities in a methanol media as well as high phenolic content, diverse bioactive phyto-chemotypes, anti-carcinogenic properties, anti-hypoxic, and anti-stress attributes. This species could potentially be utilized as a sustainable source of drugs for human consumption (Kumar et al. 2015).
Cancer Chemopreventative:
Spirogyra neglecta possesses cancer chemopreventitive compounds and activity when examining diethylnitrosamine-initiated preneoplasic lesions (having a high risk of becoming malignant) in rat livers. As humans in Asian countries including Thailand commonly consume this species, various doses ranging from daily consumption to 4x overdose were not toxic in the rats. These doses reduced the number of glutathione-S-transferase placental (GST-P) positive foci in the treated rat livers. These GST-P foci are directly correlated to the development of hepatocellular carcinoma in rats, so treating the rats during the early stages of GST-P development helps in preventing the proliferation of these cancerous cells (Thumvijit et al. 2014). This could have major implications toward cancer study and treatment for similar liver cancers found in humans.
Habitat:
Freshwater . Widespread in freshwater habitats worldwide. Filaments usually found as free-floating masses or ‘clouds’ resting on sediment.
References:
Drummond, C.S., J. Hall, K.G. Karol, and C.F. Delwiche 2005. Phylogeny of Spirogyra and Sirogonium (Zygnematophyceae) based on rbcL sequence data. Journal of Phycology 41:1055-1064. Guiry, M.D. and G.M. Guiry 2013. AlgaeBase. World-wide electronic publication, National University of Ireland, Galway. http://www.algaebase.org; searched on 22 May 2013. Kumar J., P. Dhar, A.B. Tayade, D. Gupta, O.P. Chaurasia et al. 2015. Chemical Composition and Biological Activities of Trans-Himalayan Alga Spirogyra porticalis (Muell.) Cleve. PLoS ONE 10(2): e0118255. Nees, C.G. 1820. Horae physicae Berolinenses collectae ex symbolis virorum doctorum H. Linkii...; edicuravit Christianus Godof. Nees ab Esenbeck. pp. [i-xii], 1-123, [4], 27 pls. Bonnae [Bonn]: Sumtibus Adolphi Marcus. Thumvijit T., S. Taya, C. Punvittayagul, Y. Peerapornpisal and R. Wongpoomchai 2014. Cancer Chemopreventive Effect of Spirogyra neglecta (Hassall) Kutzing on diethylnitrosamine-induced hepatocarcinogenesis in Rats. Asian Pacific Journal of Cancer Prevention 15: 1611-1616. Wongsawad P., and Y. Peerapornpisal 2014. Morphological and molecular profiling of Spirogyra from northeastern and northern Thailand using inter simple sequence repeat (ISSR) markers. Saudi Journal of Biological Sciences 21: 391-510.