Trichoplax
Classification
Domain - Eukarya; Phylum - Placozoa; Family - Trichoplacidae;
Species
Genus species: Trichoplax Adhaerens
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NCBI: Taxonomy [1] |
Description and Significance
Describe the appearance, habitat, etc. of the organism, and why you think it is important.
Trichoplax are the smallest multicellular animal known in science. Their diameter is only 1-2mm and they appear as flat, disc-shaped, and have no body symmetry. They are found in tropical and sub-tropical environments. Trichoplax Adhaerens, the only concretely defined species within the genus, has the smallest DNA sequence discovered within an animal. Trichoplax Adhaerens is viewed as a potential biological model organism as it moves via locomotion and coordinates without full-fledged muscle and nerve tissue. Scientists often think that Trichoplax allows us to imagine how the earliest animals were organized and compartmentalized before complex structures like mouths and nerves.
Genome Structure
Describe the size and content of the genome. How many chromosomes? Circular or linear? Other interesting features? What is known about its sequence?
Trichoplax's genome is the smallest genome of any animal measured. it consists of six haploid chromosomes. Morphology of the chromosome is unclear. Inside the chromosomes there are 11,584 genes which are encoded by ~98,000,0000 base pairs.
Cell Structure, Metabolism and Life Cycle
Interesting features of cell structure; how it gains energy; what important molecules it produces.
Trichoplax only has 6 cell types. Only 2 of the 6 are incorporated into the epithelium that encloses it. The epithelium divides into two parts: the upper and lower epithelium. The upper epithelium is thin and the lower is thicker. As cells transition closer to the lower epithelium, cells become progressively more dense. This creates a pseudostratified arrangement. The most common type of cell within the epithelium are columnar cells and they contain a single cilium and multiple microvilli.
Ecology and Pathogenesis
Habitat; symbiosis; biogeochemical significance; contributions to environment.
If relevant, how does this organism cause disease? Human, animal, plant hosts? Virulence factors, as well as patient symptoms.
Trichoplax live in aquatic environments that are rich in seawater. It has rarely been observed in the wild, leaving many questions regarding its benefit to the environment.
References
Author
Page authored by Mark Peck II, student of Dr. Bradley Tolar at UNC Wilmington.
