Figure 10.

RT-PCR on single cells revealed widespread expression of KCNQ and erg subunits. A, Agarose gels showing PCR products from P8 rat utricular hair cells for KCNQ3, KCNQ4, and KCNQ5 (top) and erg1, erg2, and erg3 (bottom). Top, Nine type I hair cells from one macula were probed for KCNQ3–KCNQ5. Six cells (3, 4, 5, 6, 8, 9) were positive for KCNQ3 (160 bp). Seven cells (1, 2, 3, 4, 5, 7, 8) were positive for KCNQ5 (106 bp). The band for cell 1 was faint. The identities of products at other molecular weights are not known. None were positive for KCNQ4 (380 bp). Bottom, Six type I hair cells from another macula were probed for erg1, erg2, and erg3. Cell 2 was positive for all three subunits, cell 4 was positive for erg2 and erg3 (the band corresponding to erg2 is faint), and five of six cells (cells 1–5) were positive for erg3. B, Percentages of positive PCR products for the following: left, single type I hair cells tested with erg1, erg2, erg3, KCNQ3, KCNQ4, and KCNQ5 probes at P1 and P8, and with erg1, erg2, erg 3, and KCNQ4 probes at P14; right, single type II cells tested with KCNQ3 and KCNQ5 probes at P8. We did not test type II cells at other ages, nor did we test them for KCNQ4 at any age. The number of cells tested in each condition is given at the top of the histogram bars.