Auranticordis

Auranticordis quadriverberis

Auranticordis quadriverberis is a heterotrophic flagellate from the group of Cercozoa. He is the only species of the genus Auranticordis and is in uncertain position mapped to the root Cercozoa. It differs from the other Cercozoen by their orange color and the probable primary endosymbiosis with a cyanobacterium.

Features

Appearance and movement

The cells can easily change their shape and are lobed, heart-shaped or ovate. The cell size ranges of 35 to 75 microns. The front end is narrower, the wider rear end consists of four major lobes. Here, a lobe is smaller than the other three, on his right side, ventral side, there is a depression, and to his left a pit in which the flagella is. Auranticordis features instead of the usual two Cercozoa four flagella, the rich in the aforementioned pit backwards. The flagella arise from a apical pocket. They run along the pit to the rear and light microscopy are therefore almost unrecognizable. They are arranged in two pairs and are covered with hair or scourge Mastigonemen. Flagella are all approximately the same length and thereby longer than the cell. They suggest the same and provide a sliding movement of the cells on the substrate. Pseudopodia are not known.

The cells are stained orange. This is due to the presence of linearly arranged orange mucus leading bodies which are distributed over the entire cell surface. These are small compartments of approximately 780 nanometers in diameter, which are directly under the cell membrane. Other Extrusomen not occur in Auranticordis.

The surface of the cells is ribbed and consists of about 80 longitudinal ribs. In the furrows between the openings of the body mucus open a. Beneath each rib there is a single row of microtubules, which are probably responsible for the changes in shape of the cell. There is no cell wall or shell on the cell exterior.

The nature of the food intake is not known. In the cell interior captured bacteria were observed.

Internal cell

Auranticordis quadriverberis has a large nucleus 15 to 20 microns in diameter, which is located in the front area of the cell. There are several conspicuous nucleoli in him. Condensed chromosomes as in several Cercozoa exist, do not exist here. In the forward-facing end of the cell nucleus is pointed and connected with a striped band, which is located near the basal body and microtubule roots. On one side of the cell nucleus is significantly dented.

Near the front end are still black material of unknown origin and function, lipid globules, and Golgi apparatus. Mitochondria with tubular cristae are until now not known, a number of elongated bodies near the cell surface, however, remember to acristate mitochondria. This is interpreted as a degenerate form in connection with the low oxygen environment or as any preparation artifact. The structures 135 to 185 nanometers in length, and thus much smaller than the other Cercozoa mitochondria.

Orange body as possible endosymbionts

The cells each contain 2 to 30 orange body of variable shape and about 4 to 5 microns in diameter. Some are long and 14 microns. They are distributed over the entire cell, but concentrated in the front region. Each body is surrounded by two compressed inner membranes, which in turn are surrounded by bag-like vesicles. The innermost membrane invaginates into the interior of the body and forms multiple, unstacked thylakoids in the outer region of the body. In the center of the body, there are no membranes, it contains an electron-dense area in which there are tailed viral particles. The orange color corresponds to the plastids of some dinoflagellates or diatoms, their ultrastructure, however, is substantially different from these plastids. The characteristics of the orange body are compatible with three possible identities:

• The body can be captured prey that are on the first stage of digestion. However, all the objects examined were practically intact and not in an advanced state of digestion.
• The body may be time-limited, photosynthetic active endosymbionts, which are regularly renewed by Kleptoplastie.
• The body can be permanently built-in, photo synthetically active endosymbionts, ie plastids. The presence of viral particles and arrangement of the thylakoids indicates primary endosymbiosis with a cyanobacterium.

Dissemination

The species is known only from the place of first description. She was in the sands of the tidal range of Spanish Banks in Vancouver, British Columbia, collected.

System

Auranticordis quadriverberis part due to the molecular genetic studies of the tribe Cercozoa. Here it forms together with Pseudopirsonia mucosa and some uncultured environmental samples a group that represents the sister group to the large group Cercomonadidae Heteromitidae Euglyphida Thaumatomonadida.

The genus name means Auranticordis orange heart and refers to the shape and color of the cells. The Style epithet quadriverberis means viergeißelig.

Documents

• Chitchai Chantangsi, Heather J. Esson, Brian S. Leander: Morphology and molecular phylogeny of a marine interstitial tetraflagellate with putative endosymbionts: Auranticordis quadriverberis n Gen. et sp. ( Cercozoa ). BMC Microbiology, Volume 8, 2008, Publication 123, (online)

• Cercozoa (Taxon )
• Cercozoa