PrP GENES IN SALMON AND ZEBRAFISH

¹ Norwegian School of Veterinary Science, Post Box 8146 Dep, 0033 Oslo, Norway

² Inserm E343 - Universite Montpellier II, place E. Battaillon, 34095 Montpellier, France

³ Veterinary faculty, Ludvig Maximilians Universitet Munchen, Kaulbach str.37, D-80539, Munich, Germany

⁴ Robert Koch - Institute, Nordufer 20, 13353 Berlin, Germany.

Investigations of prion proteins (PrP) and their genes in teleostei species are important to elucidate the susceptibility of fish to prion infections. The possibility of studying PrP in species never studied before opens the possibility of deducing PrP function, yet to be determined for mammalian species. A PCR fragment amplified using primers based on the A.salmon PrP sequence (Oidtmann et al 2003) was used as probe to screen a salmon BAC library. Several positive clones have been identified and are now being studied for PrP and PrP-like genes. The promoter region will be cloned from one of the BACs and compared with those of other teleosts and mammals. The complete genomic organization of the zebrafish PrP gene has been completed based on sequence information from the genome project .The zebrafish protein contains the necessary motifs to be classified as a prion protein as such. Despite the very distant relationship to higher vertebrates, a modeled 3D structure displays a high degree of similarity. Bioinformatics analysis of PrP promoters from teleost and mammalian species have conserved motifs, which may be involved in tissue specificity and level of expression. A number of zebrafish PrP promoter constructs are currently beein created and tested for transient reporter gene expression, to confirm the predicted motifs. Endogenous zebrafish PrP expression show onset earlier than 2 days post fertilization (d.p.f).Preliminary data suggests that prion proteins are vital for survival of zebrafish larvae, as morpholino inhibition of translation causes 96% mortality at 1 d.p.f.