Eukaryotes Genomes - TETRAODON NIGROVIRIDIS

Tetraodon nigroviridis is a freshwater pufferfish of the order Tetraodontiformes and lives in the rivers and estuaries of Indonesia, Malaysia and India. This species is 20-30 million years distant from Fugu rubripes, a marine pufferfish from the same family and so far the only other pufferfish to have its genome sequenced.

It has a very thick set body which is shaped like a blunt club. They have protruding eyes and a very broad forehead. The caudal fin is fan shaped and there are no ventral fins. The body is covered with small spines and the skin has a leathery texture. The colour is variable depending on the age and the origin of the fish. In mature specimens the top and head area is marked with large brown or black spots.

The gene repertoire of T. nigroviridis is very similar to that of other vertebrates. However, its relatively small genome of 385 Mb is eight times more compact than that of human, mostly because intergenic and intronic sequences are reduced in size compared to other vertebrate genomes. These genome characteristics along with the large evolutionary distance between bony fish and mammals make Tetraodon a compact vertebrate reference genome - a powerful tool for comparative genetics and for quick and reliable identification of human genes.

References:

Nature 431(7011) 946-57 (2004)
http://www.genoscope.cns.fr/externe/English/Projets/Projet_C/C.html
http://www.broad.mit.edu/annotation/tetraodon/background.html
http://badmanstropicalfish.com/profiles/profile31.html
http://www.fishbase.org/Summary/SpeciesSummary.cfm?id=7763