Biochemistry of trehalose accumulation in the spring field cricket, Gryllus veletis
Abstract
The freeze tolerant spring field cricket, Gryllus veletis, accumulates trehalose in the blood and tissues during cold acclimation. Trehalose is the main blood sugar in insects, thus its blood concentration is tightly regulated, and trehalose is readily metabolized. How do crickets modify their metabolism to accumulate trehalose in their hemolymph and tissues? I hypothesized that trehalose production, transport, and consumption were modified during the cold acclimation to facilitate trehalose accumulation. Trehalose and the trehalose-specific transporter, TRET-1, are distributed among all tissues, and trehalose accumulates in the hemolymph, fat body, Malpighian tubules, and gut. Trehalose production increases during cold acclimation via increased glycogen phosphorylase activity, facilitating trehalose accumulation. However, trehalose transport and consumption are not modified during acclimation, indicating that they are not critical for trehalose accumulation. My study furthers the understanding of trehalose distribution and the mechanism of trehalose accumulation in a freeze tolerant insect.