SMITH, K.J.*; LEE, R.E.; Miami University: Entry into diapause enhances the cold tolerance of specific tissues in the flesh fly Sarcophaga crassipalpis (Diptera: Sarcophagidae)

A primary adaptation for winter survival in insects is a programmed entry into an arrested developmental state known as diapause. Depending on the species, diapause occurs at different times, in different life stages, and is activated by various environmental cues. Upon entry into diapause, organismal cold tolerance is typically enhanced. All larvae tested from both non-diapause-destined and diapause-destined treatment groups survived a cold shock of -8°C for 2 h, but only diapause-destined larvae exhibited vigorous motility. Using a SYBR-14 / propidium iodide fluorescence-reactive stain to assess viability following cold shock, rates of cell survival in tissues isolated from diapause-destined larvae were significantly higher compared to non-diapause-destined controls. Malpighian tubule, fat body, and gut tissues from diapause-destined larvae displayed an average survival rate of 95�2%, compared to 22�2% in non-diapause-destined groups. These results are the foundation for our future research examining the protective effects of diapause and underlying cellular mechanisms of cold tolerance. Supported by NSF grant # IOB-0416720.