Location: Insect Genetics and Biochemistry Research
2018 Annual Report
Objectives
Develop means for long-term storage of bee germplasm, including cryopreservation of embryos. [NP 305, Component 2, Problem Statements 2A, 2B, 2C]
Approach
Pollinating insects are important to the U.S. agricultural economy, contributing an estimated $16 billion to annual crop production. This critical component is currently at risk due to a dramatic decrease in managed and native pollinators, and will face additional challenges due to climate change in the future. Despite this importance, there is no organized germplasm biorepository (genebank) for bees. This project will develop protocols that support the establishment of a National Bee Germplasm Repository. Specifically, the project will focus on: 1) the development of an improved protocol for the cryopreservation of bee spermatozoa, 2) the development of a novel protocol for the cryopreservation of bee embryos, and 3) the development of a protocol for the in vitro rearing of embryos after storage into reproductively viable adults. This research will ultimately result in the preservation of elite and genetically diverse pollinator strains, the development of a cryogenically-based system for the safe importation of bee germplasm, and the systematic delivery of high-quality germplasm and insects to end users.
Progress Report
Objective 1: The cryopreservation of insect embryos requires a complex protocol that must be individually adapted to the physiology of each species being stored. Honeybee embryos present unique challenges due to the highly controlled environment in which they develop and the level of care given to them by worker bees. However, after substantial adaptation of the original protocol, a honeybee embryo has successfully been cryopreserved and recovered from storage, resulting in emergence of a viable first instar larva. Methods are also under development for the possible grafting of larvae into an active hive after cryopreservation as well as determining the nutritional requirements of in vitro queen rearing.
Objective 3: Although USDA-ARS researchers in Baton Rouge, Louisiana first developed a protocol for honeybee cryopreservation in the late 1970s, concerns about sperm quality after storage limited widespread use. Beginning in 2016, USDA-ARS scientists in Fargo, North Dakota began developing a new protocol that focused on improving sperm quality. This research resulted in the development of Fargo Honeybee Extender Medium, which not only improves spermatozoa quality after cryopreservation, but allows for the transportation of sperm samples at room temperature. However, all spermatozoa assessments used laboratory assays. To address stakeholder concerns, researchers from the USDA-ARS in Fargo, North Dakota and Baton Rouge, Louisiana are collaborating to use artificial insemination to determine how cryopreserved sperm performs under field conditions.
Accomplishments
1. Successful cryopreservation of a honeybee embryo. Scientists from the USDA-ARS Insect Unit in Fargo, North Dakota, in collaboration with USDA-ARS researchers in Baton Rouge, Louisiana, have created the world’s first cryopreserved honeybee embryo. Although honeybee sperm is currently being stored by the National Animal Germplasm Program in Ft. Collins, Colorado, embryonic cryopreservation has remained elusive. Once optimized, this new technique will substantially improve the biosecurity of honeybee germplasm and the accessibility of the nascent National Honeybee Germplasm Repository.
