Fig. 4. Variation in expression of P2X2 splice variants in SGN.
(A) Schematic of the three P2X2 isoforms expressed in SGN,
showing their C-terminal region variation. ECD, extracellular domain; TM,
transmembrane domain. (B) End-point single-cell RT-PCR analysis of a
sample of six SGN showing the expression of P2X2 isoforms in
individual cells (lanes 1-6). Amplicon sizes:
P2X2-1=499 bp;
P2X2-2=292 bp;
P2X2-3=480 bp.
P2X2-3 was the most prominent isoform (4/6
cells). The agarose gel also includes two positive controls of cDNA from whole
spiral ganglion (lane 9) and whole cochlea (lane 10). Lane 7 (-) control for
no template. Lane 8 (-) bath sample processed for RT-PCR. (C) Analysis
of P2X2 splice variant combinations detected in the 31 single-cell
RT-PCR experiments. P2X2-3 was the dominant
isoform either expressed alone or with one or more of the other isoforms
(23/31 neurons).