2013 Annual Report
1a.Objectives (from AD-416):
Objective 1: Complete development and implementation of a publically available Version 2.0 of the Animal-GRIN database and initiate planning and development of a genomic component for the database: Version 2.1 of the Animal-GRIN.
Objective 2: Quantify genetic diversity in the germplasm collection, and in-situ populations, and compare their similarities via genomic or quantitative approaches and use the results to guide germplasm collection development and provide genetic diversity assessments to breed associations.
Objective 3: Refine cryopreservation, germplasm evaluation and reproductive technologies that facilitate efficient germplasm collection and its utilization by various livestock industries.
1b.Approach (from AD-416):
Globally, 20% of the world’s livestock breeds are “at risk” of extinction -- such a contraction limits the flexibility of livestock producers to respond to future biological or economic challenges. Underlying this contraction of genetic resources are financial pressures faced by the livestock breeder coupled with greater organization of genetic selection programs. Public sector institutions are also faced with mounting pressures to reduce or eliminate research populations. This trend is of particular concern as research moves from genetic sequencing to understanding how genes function and translate into phenotypes. This project plan addresses genetic security by continuing the development of germplasm and tissues collections for all major livestock species in the U.S., so that industry and the research community can access these resources at any time. Three primary objectives address: database development, assessing in-situ and germplasm collection genetic diversity, and improvement in the efficiency and efficacy of cryopreservation protocols. All three of these objectives are highly interdependent and are required for the functionality of the repository. The expected results from this plan are a greater level of genetic security for U.S. livestock populations; information about the collection so researchers and industry can readily access the material; and improved cryopreservation protocols and germplasm evaluation methods. The successful execution of these objectives translates into greater national and global food security and greater economic vitality of the U.S. livestock sector.
Database development is the glue for managing large genetic resource collections. This tool enables gene bank managers and the public to understand the content of the animal collections and stimulates interest in collection use. To this end progress in developing Animal-Genetic Resources Information Network Version 2 by the joint Brazilian, Canadian, and US programming team achieved the milestone for Objective 1 and real time testing of the information system has commenced. Evaluation of genetic diversity and change can provide policy makers with insights for decision making (subobjective 2b and 2d). Using germplasm samples from the repository, we documented large and substantial levels of genetic drift which had occurred among current Meishan pig populations vs samples from the original Chinese importation in 1989. This information has important ramifications about access and benefit sharing arrangements between countries as they consider the adaptation of the Nagoya Protocol. In an analysis comparing plains and wood bison we determined that the genetic distance between these two groups is small and therefore breeding programs by the National Park Service do not need to treat the two groups as separate populations or classify these two groups as subspecies. Under subobjective 2a we compared performance measures (e.g., weaning weight, fertility traits, carcass characteristics) of animals contributing samples to the repository with breed averages from 1950 to 2010 for Hereford, Angus, Charolais, and Brangus breeds. It was determined that the collection mirrors the breed average for the measured traits over time. It was also determined that the variability of the collection for these performance characteristics is large and substantial which better insures the collections use over time. Ovaries and testes from three industry lines of chickens were collected and cryopreserved. Based upon the successes with chicken ovary cryopreservation, experimentation on various cryopreservation techniques on other species was initiated under subobjective 3b. Results to date indicate that extraction and utilization of oocytes from vitrified mammalian tissue is feasible. The efficiencies of the techniques, coupled with the labor and reagent expenses, make the techniques completely impractical for cryo storage. However, emerging cryopreservation techniques for roosters by Japanese researchers may offer increases in the efficiency of using cryopreserved sperm (subobjective 3c) and are planned for FY2014.
Random genetic change and policy development. Many countries are considering Nagoya Protocol ratification for the access and benefit sharing of genetic resources. But, little information about genetic change of imported populations has been available for developing a policy with impact on international germplasm exchange. The Fort Collins gene bank contains original samples from Meishan pigs imported from China in 1989 and samples from two present day research populations of Meishan. Using molecular genetic approaches, ARS researchers at Fort Collins found the impact of genetic drift (random change) was large and substantial, thereby drawing into question the utility of long term agreements and payments for genetic resources with governments tracking payments and genetic resource use. Due to an inability to effectively monitor gene flow of imported populations, the current method of exchange, private treaty contracts, are the most effective mechanism for exchanging genetic resources and promoting access and benefit sharing.
U. S. genetic resources secured. Nationally genetic diversity of livestock populations is contracting. The development and maintenance of a broad based collection of germplasm at the ARS location, Fort Collins, CO, from diverse livestock populations contributes to U.S. and global food security by making genetic variability readily available for the livestock industry. The germplasm collection gives the U. S. livestock sector an unprecedented level of security in terms of genetic diversity collected and quantity of germplasm acquired. The addition of three private sector lines of chickens validates this assertion. The germplasm collection has been shown to be robust and used by producers, and public and private researchers. In addition, it serves as a ready resource in the event of a critical national need.
Silversides, F., Purdy, P.H., Blackburn, H.D. 2013. Comparative costs of programmes to conserve chicken genetic variation based on maintaining living populations or storing cryopreserved material. British Poultry Science. 53:599-607.
Liu, J., Cheng, K.M., Purdy, P.H., Silversides, F.G. 2012. A simple vitrification method for cryobanking avian testicular tissue. Poultry Science. 91:3209-3213.
Freking, B.A., Purdy, P.H., Spiller, S.F., Welsh, C.S., Blackburn, H.D. 2012. Boar sperm quality in lines of pigs selected for either ovulation rate or uterine capacity. Journal of Animal Science. 90(8):2515-2523.
Cronin, M., Macneil, M., Ninh, V., Leesburg, V.L., Blackburn, H.D., Derr, J. 2013. Genetic variation and differentiation of bison (Bison bison) subspecies and cattle (Bos taurus) breeds and subspecies. Journal of Heredity. 104:500-509.