Table 1.
Behavior of different proteins in the retinotectal system of the chick embryo
| Protein | kDa | Retention in eye 20 hr after injection (%) | Transport efficiency pg/tectum/ng/eye | Receptor-mediated transport? (%) | Synaptic accumulation(% of whole tectum) | Amount in synaptosomal fraction (cpm) |
|---|---|---|---|---|---|---|
| NT-3 | 28 | 30.3 ± 2.4 | 1.34 ± 0.1 | >80 | 5.94 ± 0.36 | 522 ± 48.5 |
| NGF | 26 | 25.1 ± 3.5 | 2.02 ± 0.4 | ≈501-a | 1.15 ± 0.10 | 69.9 ± 1.4 |
| Tet tox | 47 | 36.5 ± 6.9 | 4.04 ± 0.6 | >80 | 1.72 ± 0.16 | 170 ± 35.5 |
| Cyt. C | 12.3 | 47.1 ± 2.1 | 1.78 ± 0.4 | 01-b | 2.06 ± 0.27 | 162 ± 23.2 |
| SP | 1.3 | 1.8 ± 0.30 | 0.52 ± 0.1 | <10 | 0.58 ± 0.11 | 27 ± 2.6 |
Retention in the eye, efficiencies of anterograde axonal transport, and accumulation in retinotectal synapses. Values are ± SEM. Kilodaltons are indicated for monomers (Tet tox, Cyt. C, and SP) and dimers (NT-3 and NGF). Tet tox, Tetanus toxin C fragment; Cyt. C, cytochrome C; SP, substance p.
F1-a
Data from von Bartheld et al., 1996.
F1-b
Data from Butowt and von Bartheld, 2001.