Meeting Abstract
Diets ideally should match the needs to yield increased reproduction and extended lifespan, a result of attaining thresholds of nutrition and storage faster. A challenge is to design the dietary protein to the species’ needs. Approximating an approach using exome-matching in fruit flies, we designed a diet that matched the amino acid (AA) profile of grasshopper vitellogenin (Vg), the precursor to egg yolk protein. This ‘Vg-balanced’ diet was then fed to female lubber grasshoppers, which have large reproductive responses to adult diet. For example, only 1gm lettuce daily is insufficient for reproduction, whereas ad libitum lettuce feeding is over 4gm daily. Each individual (n=90) in the present study was fed 1gm lettuce and ad libitum artificial diet (0P:35C) daily. Four groups were created by feeding additional foods: 1) a solution of AA matched to the composition of Vg (group ID: Vg-balanced & 1gm), 2) an isonitrogenous solution with AA out of proportion from Vg (Unbalanced & 1gm), 3) buffer and unlimited access to lettuce (Buffer & ad-lib), and 4) buffer only (Buffer & 1gm). Age of oviposition and number of eggs both differed across all groups. Buffer & ad-lib had the highest yield, followed by Vg-balanced & 1gm, Unbalanced & 1gm, and Buffer & 1gm. In contrast, body mass and fat body mass, both after oviposition, did not differ across the three groups fed 1gm lettuce daily. Therefore, the isonitrogenous diets exhibited a difference in reproduction but not somatic growth. With hemolymph samples, we will test for reproductive thresholds of body mass, amino acid ingestion, vitellogenin, and protein storage.
