Ciona Intestinalis. Disclosure 4
Its appearance is very different to vertebrates. However its genome is inked to them. Ciona intestinalis is a marine animal tunicated and urochordated from the class Ascidiacea which during its embryonic phase present a structure very similar to the spine and primitive nervous system.
The study of its genome, composed by 16.000 genes, shows that about 12.000 of them are in vertebrates, included the human specie which are linked to the evolutionary origin of the intestine and heart (both of them are formed during the embryonic phase of the gastrula) as well as with the immune system, nervous system, thyroids gland, eyes and brain (it has a ganglion which can be the primitive anatomic representation of these future organs).
Anatomically, they also have a mouth and a cloaca where come out into the intestine and the reproductive system (hermaphrodite).
There are known over 500 million year old fossils of animals related with the chordated tunicated and for this reason its genetic material is reduced because of the appearance of the vertebrates was related to the duplication of the genetic material while Ciona only has unique copies in most of genes.
This specie can contain relevant information about the connexion between the nervous system and the immune system (we will talk in depth about that during coming weblogs of scientific disclosure) and the relation of necessary balance between brain and intestine (we will also talk in depth about that in coming weblogs).