Introduction :

MHCgenes (Class I, Class II) were discovered, for the first time, in Invertebrates, and particularly en 2 classes of Echinodermata : the ophuirids and the crinoïds out of 5 classes

(1). It was important to research in the 3 other classes (and particularly in asterids) the presence or not of similar MHC genes. We recall this research(1) was concerning HLAE

 gene,HLA B gene from MHC Class I and HLADRB1 gene, HLADQB1 gene from MHC Class II.
Materials and Methods :

Sea stars Asterias rubens were immunized twice to HRP (Horse-radish peroxydase from Sigma Products) :

100µg/injection in sea star coelomic cavity. 5 days after the last injection, digestive coeca

 were removed and treated with Trizol (Invitrogen) to obtain RNA

Secondly, cDNA was normalized using double strand specific nuclease essentially as des cribed by Zhulidov et al (2). cDNA was fragmented using DNA Fragmentase (New England Biolabs), according to the manufacturer's instructions. After ligation of adapters for Illumina's GSII sequencing system, the cDNA was sequenced on the Illumina GSII platform sequencing 100 bp from one side of the approximately 200 bp fragments. Sequences were assembled using Velvet Zerbino et al. (3)

Assembled nodes were used for further assembly including Beta vulgaris EST-Data from NCBI in MIRA.

Results :
The two described MHC Class I genes (1) are present in sea star Asterias rubens genome. Furthermore, A    HLA-A transcriptome was revealed in this last one ; the sequence of which, en 5’-3’ was the following :
Contig 1 -Length : 152

The concern e-value was :3,50e-66 at a significant degree.

Conclusion :

Results show clearly a HLA-A gene exists in Asterias rubens genome.

 It appears as clearly as possible that 3 MHC Class I genes are present in Echinodermata : we recall next to HLA-A gene : the HLA-B, the HLA-E genes we described.

Further studies are necessary to clarify a) the existence or not of new MHC Class II genes in Asterias rubens b) the rôle of Immunization to HRP which can induce the appearance of new MHC genes.