| Popis: |
We examined thermal acclimation of cuticular lipids in five full-sibling families of the lesser migratory grasshopper, Melanoplus sanguinipes. The use of exuviae for lipid studies enabled us to follow the course of acclimation for each individual Surface lipid biophysical properties were studied by means of Fourier transform infrared spectroscopy, which served as an indicator of the functional physiological consequences of changes in lipid composition. Changes in melting temperatures of cuticular lipids ($T_{m}$) were most dramatic during the first molting cycle after transfer from 27° C to 34° C but continued through two more molts. Melting temperatures increased from 40° -43° C in second-instar juveniles held at 27° C to 44° -46° C by the fifth instar when juveniles were transferred to 34° C Melting points also tended to increase slightly in individuals transferred to 29° C There was significant genetic variation for $T_{m}$, as indicated by differences among families reared under the same conditions. S... |
