BsGCLM, when aligned with the same protein of other deuterostomes
, showed identities ranging from 34.
Until now, the earliest deuterostomes
scientists have discovered were between 510 and 520 million years old, when they had already begun to diversify into vertebrates, sea squirts, echinoderms such as starfish and sea urchins, and hemichordates.
The four new laboratory sequences (Mga lab, Oed lab, Sma lab, and Vpu lab) presented three residues that are characteristic of PG-1 proteins in deuterostomes
and protostomes, Ala29, Asn41, and Thr43 (Fig.
A newly described group of primitive soft-bodied deuterostomes
, called vetulocystids, bears similarities to some of the bizarre early echinoderms.
The central nervous system in deuterostomes
lies on the dorsal side, but on the ventral side in protostomes, such as the lobster.
Of course, eyes are characteristic of the vertebrates in the deuterostome
In protostomes, as well as in deuterostomes
, the first cleavages initially result in the separation of the cells of the presumptive ectodermal and endodermal germ layers.
While it has been variously suggested that deuterostomes
(Nursall, 1962), protostomes (Inglis, 1985), and cnidarians (Hanson, 1977) independently evolved multicellularity, the group most commonly considered to have been derived from a separate protist lineage is the sponges, phylum Porifera (as evidenced by Barnes, 1980, p.
Urochordates are monophyletic within the deuterostomes
The echinoid immune system and the phylogenetic occurrence of immune mechanisms in deuterostomes
marine), lophotrochozoans have been separated from deuterostomes
or ecdysozoans for over 550 million years and the genetic machinery has likely changed substantially.
Glycobiology of sperm-egg interactions in deuterostomes