Effects of thermal acclimation on seasonal accumulation of an apolipoprotein A-I-like molecule in a cold-adapted lizard

Abstract

Using two-dimensional electrophoresis on total extracts of ovary, liver, and muscle of a cold-adapted lizard, Lacerta vivipara, we investigated the effects of cold at the protein level during autumn and winter. The major phenomenon observed was an accumulation in tissue of an apolipoprotein A-I-like molecule which displayed the same electrophoretic pattern as that previously described in human serum and peripheral tissues (isoform number, charge, apparent molecular mass). However, we detected the isoforms I4, I5, and I6 in all the lizard tissues examined, and two additional more acidic forms (I7, I8), which might come from proteolysis of the basic components. In this study, we report that the accumulation and distribution of the apolipoprotein A-I-like isoforms differ according to thermal acclimation, season, and the particular organ. These findings strongly suggest that significant movements of lipids are involved in the ectothermic hibernation process.