Changes in the biochemical composition of fat body stores during adult development of female crickets, Gryllus bimaculatus

Abstract

Age-dependent changes in the fat body composition and aspects of lipogenesis in the free abdominal fat body of female crickets, Gryllus bimaculatus, were studied. Lipid, protein, glycogen, and free carbohydrate content of the fat body, and fat body wet weight increased simultaneously and sharply from day 0 onwards and were doubled/almost doubled by day 2 after adult emergence. Lipogenic activity of the fat body, fat body weight, and the energy stores in the fat body peaked on day 2, except for free carbohydrate, which peaked on day 3. On day 2, the fat body was mainly comprised of lipid (53.8%) and protein (6.6%), while glycogen and free carbohydrate together contributed less than 1% of the fat body wet weight. After peaking, both lipogenesis and energy stores decreased in a synchronous manner. The depletion of the fat body energy stores and the consequent decrease in the fat body weight were concomitant with a fast and massive gain in ovary weight (day 2: 19.5 +/- 1.5 mg; day 4: 332.8 +/- 31.5 mg) due to the vitellogenic oocyte growth that started on day 2. Our data clearly underline the importance of the free abdominal fat body as a source of energy for reproduction in the cricket. Fat body fatty acid synthase activity coincided with lipogenic activity. Adipokinetic hormone inhibits lipid synthesis in the fat body, but treatment of the fat body with adipokinetic hormone in vitro showed no consistent effect on fatty acid synthase activity.

Environmental control of trypsin secretion in the midgut of the two-spotted field cricket, Gryllus bimaculatus

“…The total nutrient value of the chow was 40% carbohydrate, 25% protein, and 6% lipids (Lorenz and Anand, 2004). The optimal growth (maximal weight gain and shortest development time) for G. bimaculatus fed a diet containing from 10% to 50% casein was achieved with a 30% casein diet (Merkel, 1977).…”

Feeding, nutrient flow, and functional gut morphology in the cricket Gryllus bimaculatus

“…Newly emerged females were isolated within 1 h after the last molt and designated 0-day-old. Animals had access to water and a food mixture consisting of ground dry cat food, rat food, and rabbit food (40% carbohydrates, 25% protein, 6% lipids; Lorenz and Anand, 2004).…”

“…8). After day 3, food uptake as well as the weight of the entire gut system decreases, due to space restrictions in the abdomen that are caused by the massively growing ovaries (Lorenz, 2003;Lorenz and Anand, 2004).…”

Insects as Food for Insectivores

“…In general, carbohydrates are present in relatively small amounts in insects (Finke, 2002(Finke, , 2013. In the field cricket (Gryllus bimaculatus De Geer), polysaccharide and carbohydrate content are approximately 0.3% of the fresh weight (Hoffmann, 1973) and free carbohydrate content of the fat body in females of this species is less than 0.5% dry matter (Lorenz and Anand, 2004). In yellow mealworm larvae, the carbohydrate content can vary between 1% and 7% dry matter, depending on the diet provided (Ramos-Elorduy et al, 2002), although some of these differences may be the result of the food remaining in the gastrointestinal tract.…”