The goal of the Insect Cryobiology and Ecophysiology (ICE) Network is to understand how bees overcome harsh winter conditions to successfully emerge and reproduce in spring. North American bees spend most of their lives overwintering in a physiological state that protects them from the damage caused by low temperatures and conserves resources necessary for reproduction during the growing season. Regulation of this overwintering state determines key elements of bee lifecycles, including when these critical pollinators are available in natural and agricultural ecosystems. Many aspects of overwintering physiology have been studied in diverse insects, however a deeper understanding of overwintering has been hindered by complex interactions among gene expression, physiology, and environmental context. Bees are an excellent group in which to study overwintering because we already know much about their overwintering physiology, and we have genomic resources in multiple closely related species. Furthermore, using bees facilitates modeling of population responses to changing environments. The ICE Network brings together experts in genomics, gene regulation, physiology, and ecological modeling. The ultimate goal of the model will be to predict how each of the three species will respond to changes in temperature. Faculty from land-grant universities will collaborate with scientist from the USDA Agricultural Research Service establishing close connections in three states, North Dakota, Wyoming, and New Mexico. The results will make it possible to predict and manipulate overwintering phenotypes in three agriculturally-relevant bee species, setting the stage for improved management of those species and more accurate forecasting of wild and agricultural bee populations. The proposed work will support the development of early-career faculty members, and will involve students from diverse backgrounds, including students from Hispanic Serving Institutions and Tribal colleges.

Technical Abstract

Complex phenotypes frequently have shared physiological mechanisms, but determining the underlying genetic regulation continues to be a challenge. The long-term research goal of the Insect Cryobiology and Ecophysiology (ICE) Network is to understand the genetic and physiological regulation of the overwintering phenotype in solitary and social bees. Overwintering, also called diapause, is hypothesized to be regulated by a shared genetic ?tool kit.? Identifying this tool kit has been hindered because insects have diverse overwintering strategies and there are few opportunities for close comparisons between species with sequenced genomes. Using three species of bee that use different ecological approaches to overwintering and combining expertise from genetic to ecological levels, the ICE Network is uniquely poised to successfully investigate the genome to phenome trajectory of overwintering. The goal of this proposal is to determine the relative contributions to overwintering phenotypes of standing genetic variation, organismal physiology, and maternal effects. In Aim 1, the genomic contributions to overwintering phenotypes will be examined, including maternal effects through methylation. Obligate overwintering species are predicted to have SNPs associated with geographical variation in the timing of overwintering. In contrast, facultative overwintering species are expected to have maternally-regulated epigenetic signatures. In Aim 2, metabolomics and oxidative stress assays will be used to characterize the physiological effects of low temperature stress during overwintering. The balance between oxidative damage and antioxidant production, and increased lipid metabolism are expected to be significant predictors of overwintering success. In Aim 3, a model will be developed using the findings of Aim 1 and 2 to predict success of overwintering bees in response to changing environmental conditions. The proposal will support the development of two early-career faculty, three postdoctoral fellows, eight graduate students, and 24 undergraduates. The ICE Network will recruit students from NMSU, a Hispanic-serving university, and tribal college students affiliated with existing EPSCoR Programs in North Dakota and Wyoming. Infrastructure improvements include core facility equipment for metabolomics and respiration and improvements to an organismal rearing facility. The proposed research will improve management practices for three bee species that are used in agricultural production.

This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

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North Dakota State University Fargo
United States
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