TABLE 1.
Mutational inactivation of unc-51 or bec-1 reduces body length in C. elegans
| Genotype | Body length (mm) | N | Phenotype |
|---|---|---|---|
| Wild type | 1.28 ± 0.07 | 241 | Wild-type |
| unc-51(e369) | 0.87 ± 0.09 | 266 | Sma |
| unc-51(e1189) | 0.9 ± 0.08 | 304 | Sma |
| bec-1(ok691); Ex[bec-1(+)] | 0.99 ± 0.08 | 157 | Sma |
| bec-1(ok700); Ex[bec-1(+)] | 1.04 ± 0.14 | 154 | Sma |
| lon-1(e185) [TGF-β]a | 1.72 ± 0.08 | 228 | Lon |
| lon-2(e678) [TGF-β]a | 1.51 ± 0.09 | 243 | Lon |
| dbl-1(+++) [TGF-β]a | 1.38 ± 0.09 | 252 | Lon |
| daf-2(e1370) [insulin/IGF-1]a | 1.36 ± 0.08 | 185 | Lon |
| unc-51(e1189); lon-1(e185) | 1.12 ± 0.1 | 288 | Sma |
| unc-51(e1189); dbl-1(+++) | 1.05 ± 0.06 | 279 | Sma |
| unc-51(e1189); daf-2(e1370) | 0.98 ± 0.06 | 250 | Sma |
| unc-51(e369); lon-1(e185) | 1.07 ± 0.06 | 225 | Sma |
| unc-51(e369); lon-2(e678) | 1.16 ± 0.11 | 253 | Non-Lon |
| unc-51(e369); dbl-1(+++) | 1.05 ± 0.09 | 265 | Sma |
| bec-1(ok691); Ex[bec-1(+)]; lon-2(e678) | 1.1 ± 0.22 | 47 | Sma |
| bec-1(ok691); Ex[bec-1(+)]; dbl-1(+++) | 1.04 ± 0.17 | 58 | Sma |
| bec-1(ok700); Ex[bec-1(+)]; lon-2(e678) | 1.08 ± 0.2 | 47 | Sma |
| bec-1(ok700); Ex[bec-1(+)]; dbl-1(+++) | 1.12 ± 0.13 | 42 | Sma |
| bec-1(ok700); Ex[bec-1(+)]; lon-1(e185) | 1.08 ± 0.1 | 65 | Sma |
| bec-1(ok700); Ex[bec-1(+)]; daf-2(e1370) | 1.02 ± 0.09 | 89 | Sma |
Loss-of-functions mutations in unc-51 or bec-1 reduce body length and suppress, at least partially, the Lon phenotype of insulin/IGF-1 and TGF-β mutants. dbl-1(+++) indicates the DBL-1-overexpressing strain. Body-length measurements were performed as follows. Well-fed, young adult nematodes, which on the day when they become gravid, i.e., start to produce embryos, were anesthetized with 10 mm sodium-azide solution for 5 min. This treatment allows for coiled unc-51 mutants to be relaxed. Body length of anesthetized worms was measured with a dissecting microscope and micrometer. Note that unc-51 mutant animals are defective in movement, therefore, only those individuals were selected for body-length measurement that had remained in the bacterium layer and thus appeared well fed. This criterion may help to avoid the potential effect of restricted food intake on cell growth. Data are given as mean ± standard deviation. For single mutant animals, P < 0.0001 (unpaired t-test, body length of single mutants were compared with that of wild type). For double mutant genotypes, P < 0.0001 (unpaired t-test, body length of double mutants were compared with that of the corresponding “Lon” single mutants). Sma, small body size; Lon, long body length.
daf-2 encodes the IGF-1 receptor, whereas dbl-1, lon-1, and lon-2 encode components of the TGF-β signaling axis.