Location:2011 Annual Report
1a. Objectives (from AD-416)
1. Develop germplasm and DNA/tissue collection coupled with measurement of diversity. o Continue to develop germplasm collections across species and associated information. o Evaluate, refine and implement pedigree clustering approach for germplasm collection. o Pursue approaches to compare collection to in-situ populations using quantitative and/or molecular approaches. o Develop collections of DNA and/or tissues containing DNA and associated information. 2. Further develop the animal section of the GRIN network. o Develop database information system that documents the germplasm/tissue collection (Version 2) and has multi-location capacity. o Expand descriptors for all species as defined by species committees, and substantially increase data collection efforts. 3. Develop methods for population regeneration. o Computationally determine approaches for population regeneration and their management. 4. Improve cryopreservation methods for tissues. o Development of predictors/evaluation of post-thaw semen viability. o Procedures for collection and freezing of small ruminant and/or beef oocytes. o Determination of optimal semen cryopreservation diluents and freezing methodologies.
1b. Approach (from AD-416)
The over-arching goal of the National Animal Germplasm Program (NAGP) is to increase the security of U.S. livestock genetic resources by the development of a repository containing diverse livestock genetic resources. The proposed objectives of this plan are important because they will: strengthen the genetic diversity contained in the collection; improve the ability and efficiency of reconstituting populations through improved cryopreservation procedures and reconstitution strategies; and provide potential collection users with a more comprehensive understanding of what is contained in the collection through the GRIN database. Executing these objectives will require the utilization of quantitative and molecular genetics, reproductive biology, cryopreservation, and information systems science. The beneficiaries of this effort cover a wide spectrum including: livestock breeders; researchers reconstituting populations and performing various types of molecular studies; and the American public at large which benefits from the increased food security the program provides.
3. Progress Report
Genetic security of livestock populations has been improved as the total collection increased beyond 657,000 samples (a 9.8% increase from the previous year) from 31 species, over 130 breeds and 15,346 animals. Importantly, the collection has grown and is being used. During FY2011 311 samples from 302 animals left the repository for animal generation and DNA studies. This year’s request brings total repository usage to 10,330 samples from 3,269 animals. Viewed another way 21% of the animals collected have been requested for use. Significant collection efforts were placed on successfully completing the acquisition of embryos and semen from Angora goats. This breed is of economic significance particularly in Texas and due to weather related mortalities and market forces a significant contraction in numbers and genetic diversity for this breed has occurred. In addition, the University of Nebraska’s line of pigs, selected for high ovulation rate, was collected and semen samples cryopreserved, enabling the University to discontinue the line. With the development of a collection facility for the project we initiated the collection of semen from rare chicken breeds, previously this activity was not possible. Research under Objective 3 showed that cryopreserving chicken ovaries and semen is significantly cheaper than maintaining live populations. Specifically, if a chicken population is not used in 3 years it is more cost effective to cryopreserve the population and then reconstitute it when needed. Over a twenty year planning horizon the study found costs of population maintenance could be reduced by 90% using tissue cryopreservation. In addition, by using this approach it is possible to reconstitute a population in 43 weeks. Ovaries from a commercial line of broilers were harvested, cryopreserved, and transplanted into recipient chicks from the same line. A 70% success rate was achieved on tissue transfer. The recipient chicks are still growing and will start producing eggs in 2012, the parentage of the resulting progeny will be tested in the next calendar year to completely validate the process. As a result of these findings we believe there are lessons that could potentially be transferred to mammalian species. Under sub-objective 4a large differences between boars' fertility and the state of proteins and lipids in the sperm cell membrane were found, suggesting these may be viable indicators of post-thaw sperm viability. Work is planned to better confirm this finding and quantify its predictive ability with larger numbers of animals. Database development advanced with programmers from Brazil & Canada working at their institutions or our laboratory. A substantial review of the progress in database development was held with programmers and geneticists from all three countries meeting at our lab. The database users felt that the programming team is making substantial progress & the level of sophistication in database functionality is exceeding expectations.
Blackburn, H.D. 2011. The USDA national animal germplasm program and the aquatic species collection. pp. 774-779. In: T.R. Tiersch and C.C. Green (eds.) Cryopreservation in Aquatic Species, 2nd Edition. World Aquaculture Society, Baton Rouge, LA. Book Chapter.