The objective of the current project is to obtain a large sample of embryonic cDNA sequences from the lamprey and the dogfish. Analysis of this data should make it possible to clarify the following :

• the phylogenetic problems which remain in the chordates (monophyletic nature of the cyclostomes; relationship between the vertebrates and other chordates),
• chronology and mechanisms of gene duplications at the origin of the vertebrates,
• the mode of molecular evolution of genetic model systems,
• evolution of regulatory networks implicated in several developmental processes studied by the partners.

With this objective, Genoscope is undertaking systematic reads of cDNA cloned in the pSPORT1 vector and previously ordered (one read per clone).

Seven embryonic cDNA libraries have been constructed: :

• Lamprey L. fluviatilis, 3 libraries: embryo, larva and adult stages (brain, eye, pineal gland)
• Dogfish S. canicula, 4 libraries: gastrulation, beginning of organogenesis, postnatal stage, adult brain.