Fig. 8

Minimal LEA-1 motifs promote desiccation and osmotic stress survival in vivo. A Endogenous lea-1 sequence was largely deleted and replaced with sequence encoding codon optimized, mNG-tagged, idealized motifs of 44 amino acids (4 × 11-mer) or 97 amino acids. B Expression of 44 and 97 amino acid LEA-1 motifs is sufficient for the formation of dauer larvae (25 °C) that are resistant to 1% SDS. C Desiccation survival of daf-2, daf-2;lea-1Δ, daf-2;44-mer::mNG, and daf-2;97-mer::mNG animals is shown. daf-2;lea-1Δ mutants had significantly lower survival than control animals at both 97.5% RH (p < 0.0001, unpaired T test, n = 4) and 60% RH (p < 0.0001, unpaired T test, n = 4). At 97.5% RH motif-expressing worms had survival that was statistically indistinguishable from control and significantly improved relative to daf-2;lea-1Δ animals (44-mer p = 0.36 , 97-mer p = 0.78 , unpaired T tests, n = 4). When dehydrated at 60% RH, motif-expressing worms each had significantly reduced survival (daf-2;44-mer::mNG p = 0.0003, daf-2;97-mer::mNG p < 0.0001, unpaired T tests relative to daf-2, n = 4). D daf-2;lea-1Δ mutants, but not motif-expressing animals, were sensitive to osmotic stress in 1 M NaCl for 4 h (daf-2;lea-1Δ p < 0.0001, daf-2;44-mer::mNG p = 0.53, daf-2;97-mer::mNG p = 0.87 unpaired T test vs. daf-2, n = 4). Worms expressing LEA motifs had significantly improved survival relative to daf-2;lea-1Δ animals (daf-2;44-mer::mNG p < 0.0001, daf-2;97-mer::mNG p < 0.0001, unpaired T test, n = 4). ***p < 0.001