Progress 10/01/05 to 09/30/10
Outputs
OUTPUTS: Work is continuing under new CRIS record. PARTICIPANTS: Nothing significant to report during this reporting period. TARGET AUDIENCES: Nothing significant to report during this reporting period. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Impacts
Work is continuing under new CRIS record.
Publications
- No publications reported this period
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Progress 01/01/09 to 12/31/09
Outputs
OUTPUTS: Artificial semen preservation is a topic subordinate to the project's first objective, i.e. determining physiological constraints affecting gamete viability. In the case of poultry semen, artificial storage induces a profound negative effect upon semen quality. Whereas this fact has long been known, the underlying reason has remained a mystery. In this regard, the participant has deduced why semen storage fails. In this regard, the participant was invited to speak within the Cell Biology Symposium hosted by the joint annual meeting of the American Society of Animal Science, American Dairy Science Association, and Canadian Society of Animal Science in July 2009. The presentation took place in Montreal, Quebec. Subsequent to this meeting, a manuscript was published on-line within the Journal of Animal Science in September 2009. A copy of this manuscript was forwarded to the Director of Research & Developlment at Hy-Line International, a primary breeding company interested in poultry semen preservation. PARTICIPANTS: The effort described above was performed by D. P. Froman and A. J. Feltmann. The former holds the rank of Professor within the Department of Animal Sciences at OSU. The latter holds the rank of Senior Faculty Research Assistant in the same department. The motivation for the work arose from Froman's long-term interaction with Hy-Line International, a primary breeder of egg-type chickens. This interaction began with the introduction of the commercial version of the sperm mobility assay into Hy-Line's male selection program in 2002(Froman was awarded US patent No. 5,866,354 for this assay in 1999). In the course of this effort, Froman learned that Hy-Line had an immediate need for short-term semen preservation. In summary, whereas the approach originated with the participant, the motivation for applying what the participant had learned was derived from industry. TARGET AUDIENCES: Primary and secondary breeders of poultry. PROJECT MODIFICATIONS: Not relevant to this project.
Impacts
Historically, semen preservation experimentation has used a trial-and-error approach. This means that variables external to sperm are changed, e.g. the volume of a sperm suspension, extender composition, cooling rate, storage temperature, and thawing rate. Oftentimes conditions are chosen based upon what has worked or purportedly worked with sperm from another species. In short, this approach has failed to produce a reliable method whereby poultry semen can be stored. In contrast to the historical experimental approach, the participant took into account the nature of the the cell to be preserved (based upon previous research in his lab directed towards defining what enables chicken sperm to remain motile under physiological conditions)and began to choose conditions based upon experimental outcomes as opposed to tradition and hopefulness. In doing so, the participant demonstrated the utility of approaching the question from an entirely new direction. Therefore, future attempts to preserve poultry semen can be based on a theory that addresses: (1)intracellular energy production that enables a sperm cell to be a self-propelled DNA delivery vehicle, (2)the biological context in which sperm cells are motile, i.e. the vaginal surface of the hen's oviduct and the space within the hen's sperm storage tubules found at the junction of vagina and shell gland, and (3) the consequences of mitochondrial failure. In summary, the participant's work yielded a new way of thinking about a longstanding problem. At the time of writing, experiments are underway to: (1) determine whether principles outlined for chicken sperm also apply to turkey sperm, and (2) determine whether the quality of chicken sperm motion after cold storage can match that of freshly ejaculated sperm. If this goal is realized, then the stage will be set to attempt cryopreservation. And should cryopreservation become possible, then poultry semen will have the potential to become an agricultural commodity.
Publications
- Froman, D.P., and A. J. Feltmann, 2009 A New Approach to Sperm Preservation Based on Bioenergetic Theory, Journal of Animal Science, jas.2009-2209v1-20092209.
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Progress 01/01/08 to 12/31/08
Outputs
OUTPUTS: Outputs include the following: (1) submission of research proposal at the request of the largest primary breeder of meat-type chickens in the U.S., (2) presentation of research data at the annual meeting of S1020, and (3) publication of an on-line refereed journal article. Therefore, information was shared with three different communities: poultry industry geneticists, poultry scientists, and biologists at large. PARTICIPANTS: In addition to the principal investigator's research technician (Mr. Allen Feltmann), Dr. Doug Rhoads (University of Arkansas) is the principal investigator's primary collaborator. This working relationship has existed since the inception of the current multi-state project. Dr. Tommaso Pizzari (Oxford University) is an additional collaborator. This collaboration began at the onset of the project and continued until the manuscript cited above was published. A third -- and informal -- collaborator is Mr. Doug Thistlethwaite, and engineer employed by Animal Reproduction Systems in Chino, CA. Animal Reproduction Systems licensed the principal investigator's US patent in 1999 and markets the commercial sperm mobility assay. Efforts to improve and increase the use of this assay by industry are on-going. TARGET AUDIENCES: Primary breeders of poultry constitute the primary target audience. As illustrate by on-going industry-sponsored research aimed at defining genotypes for low and high sperm mobility phenotypes, the target audience was reached. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Impacts
Based upon collaboration with Dr. Doug Rhoads (University of Arkansas), a second industry award was made based upon our initial effort to genotype pedigree line meat-type chickens. There are three noteworthy features of this effort. First, our work was solicited by the sponsor so that an initial data base could be expanded. Second, we are establishing an allelic profile for low and high sperm mobility phenotypes. Previous work has estimated the heritability of the trait, demonstrated that the trait is a primary determinant of male fertility, and has shown that phenotype is subject to genetic selection. Therefore, the third noteworthy feature of our effort is our defining male fitness in terms of the genome rather than progeny. If we are successful, our work may afford a first in animal breeding. Therefore, whereas the overall impact of our work is emerging, it may prove to be highly significant. The key reason for this is that once allelic frequencies are defined, such information can be applied to genome-wide SNPlotyping, a process already in use for other key traits. In our estimation, the collaboration between Oregon State University (Froman) and the University of Arkansas (Rhoads) embodies poultry science of the highest caliber. Whereas the complete series of events transcends the annual evaluation period, an original discovery has nonetheless resulted in technology transfer (commercialization of the sperm mobility assay), substantive long-term collaboration, and application of technology within the U.S. primary breeder industry for the express purpose of improving male fitness. The impact of the collaborative work cited below under publications further defines the mechanism of sperm storage in female poultry. The experimental outcome confirms the model for sperm storage deduced by D. P. Froman as outlined in Biology of Reproduction 69:248-253. Collectively, investigations of sperm mobility and in vivo sperm storage have converged and help define constraints that affect artificial semen storage, a technique sought by the U.S. primary breeder industry. During the period under review, a theoretical approach to sperm preservation has been developed. This approach is based upon mitochondrial energetics as opposed to the conventional trial-and-error method for semen preservation.
Publications
- Pizzari, T., K. Worley, T. Burke, and D. P. Froman. 2008. Sperm competition dynamics: ejaculate fertilising efficiency changes differentially with time. BMC Evolutionary Biology 8:332-338.
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Progress 01/01/07 to 12/31/07
Outputs
OUTPUTS: Presentation of research data at the annual meeting of S1020 was the sole output during the reporting period covered. It is noteworthy that this meeting was attended by R&D personnel from a primary breeder of egg-type chickens and a primary breeder of turkeys. Semen storage is a topic of interest to such companies. Data were presented to show that a theoretical basis had been developed for artificial semen storage. Likewise, Dr. Doug Rhoads, the investigator's in-project collaborator from the University of Arkansas, presented data outlining the genetic analysis of sperm mobility phenotype.
PARTICIPANTS: The investigator collaborates with Dr. Doug Rhoads, a molecular biologist from the University of Arkansas. Whereas Dr. Rhoads is a professor within the Biology Department, he also holds a joint appointment within the Center for Excellence in Poultry Science.
TARGET AUDIENCES: Primary breeders of poultry constitute the primary target audience. In view of the investigator's on-going work relationship with two such companies, the target audience was reached.
Impacts
Collaboration with Dr. Rhoads during the reporting period resulted in the award of a competitive grant from a primary breeder of meat-type birds. This award, in part, was based upon the investigator's demonstration that significant variation in sperm mobility phenotype does indeed exist within pedigree lines of meat-type chickens and that such variation cannot be explained in terms of mitochondrial DNA (unpublished proprietary data). Likewise, the award, in part, was based upon the co-investigator's progress with identifying loci within nuclear DNA that have the potential to explain phenotypic variation.
Publications
- No publications reported this period
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Progress 01/01/06 to 12/31/06
Outputs
The reproductive tract transcriptome was evaluated by expressed sequence tag analysis in collaboration with researchers at the University of Arkansas. This effort, led by Dr. Doug Rhoads, identififed novel transcripts from the fowl's reproductive tract. In fact, our experimental outcome confirmed that the chicken reproductive tract transcriptome is poorly documented. Funding is currently being sought to continue the analysis of reproductive tract-specific genes.
Impacts
The analysis of the chicken reproductive tract transcriptome affords a first step at developing analytical tools that will enable genomic analysis of quantitative traits such as sperm mobility. Such an analysis would be the first of its kind in the evaluation of male reproductive fitness in poultry, to the best of the investigator's knowledge. In other words, our research could serve as the basis for a systematic evaluation of genes that control male reproductive efficiency in poultry.
Publications
- Froman, D.P., J. D. Kirby, and D. D. Rhoads. 2006. An expressed sequence tag analysis of the chicken reproductive tract transcriptome. Poultry Science 85: 1438-1441.
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Progress 01/01/05 to 12/31/05
Outputs
The PI applied the commercial version of the sperm mobility assay (Animal Reproduction Systems, Chino, CA) to pedigree line broiler breeders. This work entailed preliminary experiments designed to increase the sensitivity of the assay and the assessment of the value of the modified assay when applied to pedigree line broiler breeders. Deletion of glucose from assay media improved the assay's senstitivity by increasing the range of observational values. Whereas glucose may improve sperm motility when semen is extended, it is unlikely that fowl sperm oxidize glucose when ascending the oviduct. Rather, they oxidize endogenous fatty acids. Thus, deletion of glucose afforded a more realistic estimate of in vitro sperm mobility, which is predictive of sperm mobility in vivo and hence male fertility. When applied to pedigree line males, the assay demonstrated that sperm mobility phenotype is independent of age, corroborating previous work with other types of chickens as well
as turkeys. Additionally, significant variation (P < 0.0001) was observed among males within a flock following repeated measure analysis. Finally, neither body weight at 6 weeks of age nor sperm concentration were correlated with the sperm mobility index.
Impacts
Sperm mobility is a primary determinant of male fertility, and phenotype is subject to genetic selection. As evidenced by a 52% coefficient of variation, considerable variation in phenotype was found within the line evaluated. Thus, selection against low sperm mobilty males or selection for high sperm mobility males is possible. Such selection should not affect body weight because of the correlation between body weight at 6 weeks of age and adult phenotype (r = 0.04). In summary, selection for sperm mobility has potential for improving male reproductive efficiency without compromising the body weight of breeders, which in turn, affects the market weight of broiler chicks.
Publications
- Froman, D.P., 2005. Application of the sperm mobility assay to primary broiler breeder stock. Journal of Applied Poultry Research. (accepted for publication).
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