Deletion of the alpha-synuclein locus in a subpopulation of C57BL/6J inbred mice.
BACKGROUND
The presynaptic protein alpha-synuclein is involved in a range of neurodegenerative diseases. Here we analyze potential compensatory mechanisms in alpha-synuclein null mutant mice. Furthermore, the findings reveal problems that may be associated with inbred mouse strains.


RESULTS
Expression profiling by cDNA array technology in a transgenic mouse model revealed striking differences only in the expression level of alpha-synuclein. This was caused by a chromosomal deletion of the alpha-synuclein locus in the C57BL/6J inbred strain used for backcrossing. However, the deletion is only present in a subpopulation of C57BL/6J mice, namely animals from Harlan. No other genes are known to be affected by the deletion, which is estimated to be smaller than 2 cM. We propose to name this strain C57BL/6S. C57BL/6S animals appear phenotypically normal. They show no upregulation of beta-synuclein or gamma-synuclein, excluding a compensatory mechanism. Also, the expression of synphilin-1 was unaffected.


CONCLUSIONS
The C57BL/6S strain should help in the understanding of the physiological function of alpha-synuclein and its involvement in synucleinopathies. Also, the findings exemplify unexpected complications that may arise during the study of transgenic models or inbred strains, in particular when combined with genome wide screening techniques.
Specht
C G
CG
Laboratory for Molecular Pharmacology, UCL, Gower Street, London WC1E 6BT, UK. c.specht@ucl.ac.uk
Schoepfer
R
R
D000818:Animals; D002352:Carrier Proteins / Q000096:biosynthesis / Q000235:genetics; D003433:Crosses, Genetic; D017353:Gene Deletion; D020869:Gene Expression Profiling; D018507:Gene Expression Regulation, Developmental; D017403:In Situ Hybridization; D047908:Intracellular Signaling Peptides and Proteins; D051379:Mice; D008810:Mice, Inbred C57BL; D008817:Mice, Mutant Strains; D023421:Models, Animal; D009419:Nerve Tissue Proteins / Q000096:biosynthesis / Q000172:deficiency* / Q000235:genetics*; D020411:Oligonucleotide Array Sequence Analysis; D010641:Phenotype; D012333:RNA, Messenger / Q000096:biosynthesis; D051843:Synucleins; D051844:alpha-Synuclein; D051846:beta-Synuclein; D051845:gamma-Synuclein
D002352:Carrier Proteins; D047908:Intracellular Signaling Peptides and Proteins; D009419:Nerve Tissue Proteins; D012333:RNA, Messenger; C497605:Snca protein, mouse; C498464:Sncaip protein, mouse; C497608:Sncb protein, mouse; D051843:Synucleins; D051844:alpha-Synuclein; D051846:beta-Synuclein; D051845:gamma-Synuclein