EVIDENCE FOR ESTIVATION SPECIFIC PROTEINS IN OTALA-LACTEA

Changes in [S-35]methionine protein labeling patterns were examined by following incorporation into the acid precipitate protein fraction of land snails, Otala lactea (Muller) (Pulmonata, Helicidae). Labeled pr oteins were analyzed by SDS polyacrylamide gel electrophoresis and iso electric focusing columns. Snails in four different physiological stat es were compared: active controls, short term aestivating snails (inje cted and allowed to enter aestivation), long term aestivating snails ( aestivated for 14 days, injected, and maintained in the aestivating st ate), and snails aroused after aestivation (aestivated, injected, and aroused). Protein associated radioactivity was measured over a 7 day t ime course post injection. Autoradiographic analysis of SDS-polyacryla mide gels showed increases in the radioactivity of four proteins: 91 k Da (hepatopancreas, day 1 in long term aestivating animals), 50 kDa (h epatopancreas, day 2 in short term aestivating snails), 70 kDa and 30 kDa (foot, day 2 in short term aestivating animals). Hepatopancreas an d foot from day 1 long term aestivating and day 2 short term aestivati ng animals were also analyzed by isoelectric focusing columns. Several pH-specific differences were apparent when controls and aestivating a nimals were analyzed. In particular a peak of radioactivity was observ ed at pH 5.05 in 1 d long term aestivating hepatopancreas and at pH 4. 30 in 2d short term aestivating animals. Several differences were note d in foot with no specific pattern emerging. SDS-polyacrylamide gel el ectrophoresis analysis of the hepatopancreas peaks showed the appearan ce of several bands with increased radioactivity, including the 91 kDa and 50 kDa proteins described above. These results suggest that O. la ctea aestivation specific proteins may be involved in the transition t o a depressed metabolic state.