Characterization of the genomic region containing the Shadow of Prion Protein (SPRN) gene in sheep.
BACKGROUND
TSEs are a group of fatal neurodegenerative diseases occurring in man and animals. They are caused by prions, alternatively folded forms of the endogenous prion protein, encoded by PRNP. Since differences in the sequence of PRNP can not explain all variation in TSE susceptibility, there is growing interest in other genes that might have an influence on this susceptibility. One of these genes is SPRN, a gene coding for a protein showing remarkable similarities with the prion protein. Until now, SPRN has not been described in sheep, a highly relevant species in prion matters.


RESULTS
In order to characterize the genomic region containing SPRN in sheep, a BAC mini-contig was built, covering approximately 200,000 bp and containing the genes ECHS1, PAOX, MTG1, SPRN, LOC619207, CYP2E1 and at least partially SYCE1. FISH mapping of the two most exterior BAC clones of the contig positioned this contig on Oari22q24. A fragment of 4,544 bp was also sequenced, covering the entire SPRN gene and 1206 bp of the promoter region. In addition, the transcription profile of SPRN in 21 tissues was determined by RT-PCR, showing high levels in cerebrum and cerebellum, and low levels in testis, lymph node, jejunum, ileum, colon and rectum.


CONCLUSIONS
Annotation of a mini-contig including SPRN suggests conserved linkage between Oari22q24 and Hsap10q26. The ovine SPRN sequence, described for the first time, shows a high level of homology with the bovine, and to a lesser extent with the human SPRN sequence. In addition, transcription profiling in sheep reveals main expression of SPRN in brain tissue, as in rat, cow, man and mouse.
Lampo
Evelyne
E
Department of Nutrition, Genetics and Ethology, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium. Evelyne.Lampo@UGent.be <Evelyne.Lampo@UGent.be>
Van Poucke
Mario
M
Hugot
Karine
K
Hayes
Hélène
H
Van Zeveren
Alex
A
Peelman
Luc J
LJ
D000818:Animals; D001483:Base Sequence; D002874:Chromosome Mapping; D022202:Chromosomes, Artificial, Bacterial / Q000235:genetics; D017931:DNA Primers; D058851:GPI-Linked Proteins; D020869:Gene Expression Profiling; D017404:In Situ Hybridization, Fluorescence; D008969:Molecular Sequence Data; D009419:Nerve Tissue Proteins / Q000235:genetics* / Q000378:metabolism; D017096:Prion Diseases / Q000235:genetics*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017422:Sequence Analysis, DNA; D012756:Sheep / Q000235:genetics*; D013045:Species Specificity
D017931:DNA Primers; D058851:GPI-Linked Proteins; D009419:Nerve Tissue Proteins; C478971:SPRN protein, human