Study of Spatial-β expression in the thymus. (A) Expression of Spatial-β mRNA in the mouse thymus by RT-PCR; the amplicons were the short Spatial isoforms: Spatial-α, -β, -γ and the housekeeping gene GAPDH. The size of the amplicons are indicated. m, 100 bp DNA marker; lane 1, positive control, Spatial-α, -γ; lane 2, Spatial-β; lane 3, GAPDH and lane 4, negative control. For the amplification of Spatial-β, we used forward primer specific to the additional 69-bases while the reverse primer was specific to the exon 5. (B) Analysis of Spatial-β protein expression in the thymus; in the nuclear fraction (nf), bands at 38, 34 and 32 kDa are detected corresponding to Spatial-α, Spatial-β and Spatial-γ respectively. In the cytosolic fraction (cf), only one band at 38 kDa is detected which corresponds to Spatial-α that could be under nuclear translocation process.