PSC agrin expression before and after selective PSC ablation
| Lane | PSC | Innervation | B0 (% of total) | B8 (% of total) | B8 + B11 + B19 (% of total) |
|---|---|---|---|---|---|
| 1 | PSC+ | Intact | 63 ± 6 | 0 | 37 ± 5 |
| 3 | PSC− | Intact | 86 ± 2 | 0 | 14 ± 1 |
| 5 | PSC+ | Regeneration | 38 ± 2 | 9 ± 2 | 63 ± 4 |
| 7 | PSC− | Regeneration | 72 ± 4 | 2 ± 1 | 26 ± 3 |
Bands of RT-PCR analysis of NMJ-rich tissues as shown in lanes 1, 3, 5, and 7 of Figure 5C were scanned, and the percentage of B0, B8, and all active isoforms (B8/B11/B19) relative to the total isoforms within the individual lane was calculated (see Materials and Methods: n = 3 experiments). The percentage of active agrin isoforms was reduced from 37 to 14% after PSC ablation in normal muscle, with a proportional increase in B0 (lane 1 vs 3). In reinnervated muscles 2 weeks after axotomy, the relative expression of total active isoforms was increased from 37 to 63% (lane 1 vs 5), but this upregulation was abolished to 26% by PSC ablation (lane 7). The B8 isoform was not detected in normal muscle, but was observed in the reinnervated muscle (lane 5). After PSC ablation in reinnervated muscle, B8 dropped from 9 to 2% (lane 7). All values are mean ± SEM.