Meeting Abstract
Adequate nutritional stores are a prerequisite for the initiation of reproductive behavior, particularly the competitive, energetically demanding behavior exhibited in tephritid fruit fly leks. Absence of protein in the adult diet can delay male lekking behavior. To coordinate reproductive behavior with nutritional stores, animals must have mechanisms to measure their nutritional stores. While hormones have been implicated in signaling stored carbohydrate and fat in both vertebrates and insects, the mechanisms indicating stored protein remain unknown. However, the fat body has been implicated in communicating amino acid feeding in insects. One potential indicator of protein nutritional status is the hexamerins, a family of proteins secreted by the fat body that can act as an amino acid store. We hypothesized that adult male Caribbean fruit flies, Anastrepha suspensa, fed protein will accumulate LSP-2 faster and begin calling behavior earlier than males without protein in the adult diet. Male A. suspensa were raised with and without protein in the adult diet, assayed for calling behavior, and then qRT-PCR and western blotting were used to measure LSP-2 transcript and protein abundance. We found that protein feeding increases LSP-2 transcript and protein abundance in A. suspensa adult males. Protein feeding also advances the onset and increases the frequency of male calling behavior. Post hoc analysis suggests that LSP-2 titers are not elevated directly after calling behavior, but LSP-2 may stimulating the development of reproductive tissues, allowing reproductive behavior to proceed. Overall, my results suggest that circulating LSP-2 coordinates protein stores with reproductive behavior in A. suspensa males, supporting a more general role for LSP-2 in sensing protein status in flies.
