''Phaeodactylum tricornutum'' is a

diatom A diatom (Neo-Latin ''diatoma''), "a cutting through, a severance", from el, διάτομος, diátomos, "cut in half, divided equally" from el, διατέμνω, diatémno, "to cut in twain". is any member of a large group comprising sev ...

. It is the only species in the genus ''Phaeodactylum''. Unlike other diatoms, ''P. tricornutum'' can exist in different morphotypes (

fusiform Fusiform means having a spindle-like shape that is wide in the middle and tapers at both ends. It is similar to the lemon-shape, but often implies a focal broadening of a structure that continues from one or both ends, such as an aneurysm on a b ...

, triradiate, and oval) and changes in cell shape can be stimulated by environmental conditions. This feature can be used to explore the molecular basis of cell shape control and morphogenesis. Unlike most diatoms, ''P. tricornutum'' can grow in the absence of silicon and can survive without making silicified frustules. This provides opportunities for experimental exploration of silicon-based nanofabrication in diatoms. Another peculiarity is that during asexual reproduction the frustules do not appear to become smaller. This allows continuous culture without need for sexual reproduction. It is not known if ''P. tricornutum'' can reproduce sexually. To date no substantial evidence has been found to support sexual reproduction in a laboratory or other setting. Although ''P. tricornutum'' can be considered to be an atypical

pennate diatom The order Pennales is a traditional subdivision of the heterokont algae known as diatoms. The order is named for the shape of the cell walls (or valves or frustules) of pennate diatoms, which are elongated in valve view. The valves may be linear ...

, it is one of the main diatom model species. A transformation protocol has been established and RNAi vectors are available. This makes molecular genetic studies much easier.

History

''Phaeodactylum tricornutum'' was first described in the triradiate morphotype by Bohlin in 1897. Recordings of the first cultures of ''P. tricornutum'' were published by Allen and Nelson in 1910, although it was misidentified as ''Nitzschia colsterium,W. Sm., forma miuntissima''. The isolate was later correctly revised as ''P. tricorntum'' by J.C. Lewin in 1958. This strain among other later isolates are still maintained in culture collections around the world.

Genome sequencing

''Phaeodactylum tricornutum'' is one of three diatoms whose genome has been sequenced (the others being '' Thalassiosira pseudonana'' and ''

Fragilariopsis cylindrus ''Fragilariopsis cylindrus'' is a Pennales, pennate sea-ice diatom that is found native in the Argentine Sea and Antarctic waters, with a pH of 8.1-8.4. It is regarded as an Bioindicator, indicator species for polar water. Description ''Fragil ...

''). The genome contains approximately 10% prokaryote-like genes, an unusually large proportion. Over 30000 expressed sequence tags (ESTs) have been organized into the

Diatom EST Database A diatom (New Latin, Neo-Latin ''diatoma''), "a cutting through, a severance", from el, διάτομος, diátomos, "cut in half, divided equally" from el, διατέμνω, diatémno, "to cut in twain". is any member of a large group com ...

. ''Phaeodactylum tricornutum'' has emerged as a potential microalgal energy source. It grows rapidly and storage lipids constitute about 20-30% of its dry cell weight under standard culture conditions. Nitrogen limitation can induce neutral lipid accumulation in ''P. tricornutum'', indicating possible strategies for improving microalgal biodiesel production .

References

External links

*
journals.tubitak.gov.tr
The Growth of Continuous Cultures of the Phytoplankton Phaeodactylum Tricornutum (pdf)

picture of phaeodactylum tricornutum {{DEFAULTSORT:Phaeodactylum Tricornutum High lipid content microalgae Naviculales

History

Genome sequencing

See also

References

External links