Lon phenotype resulting from mutations in lon-8. (A) N2 wild-type hermaphrodite grown at 20°C for 120 hours. Bar is 200 μm. (B) lon-8(hu187) hermaphrodite grown at 20°C for 120 hours. (C) Structure of lon-8 gene. SL1 is the SL1 trans-splice leader sequence. The region which encodes the signal peptide is shaded. The lon-8(hu187) and (hu188) deletions are indicated. (D) Northern blot analysis; RNA was isolated from mixed-stage populations of animals. Blots were probed with the amplified full-length sequence of the lon-8 cDNA. eft-2 was used as a control for loading . Animals containing hu187 express a transcript which is recognized by the lon-8 probe, but is shorter than the wild-type transcript. hu188 animals do not express any transcript recognized by the lon-8 probe. (E) LON-8 amino acid sequence. The signal sequence is indicated in grey and the predicted site of cleavage is shown. The asterisk indicates the initiator methionine of the predicted LON-8 truncation present in hu187.