2012 Annual Report
1a.Objectives (from AD-416):
The objective of this research area is to develop novel imaging technologies aimed at confronting critical issues facing production animal agriculture by monitoring, in real-time, cellular and molecular processing in the context of the living organism. Specific research projects will cover a broad range of research in the cellular and molecular biological sciences, disease-environment interactions, animal-plant interfaces, and growth and developmental physiology with applications aimed at understanding physiological mechanisms with a specific emphasis on enhancing production performance in livestock.
1b.Approach (from AD-416):
As part of this initiative, novel technologies which utilize the photon (light), thermal signatures (heat), spectroscopy and fluorescence will be adapted to cellular- and molecular-based strategies to permit physiological processes to be monitored in a dynamic fashion at the levels of single, living cells to entire organisms in vivo. These non-invasive technologies (e.g., biophotonics, using light as a quantitative indicator beacon of molecular events) will enable the expression of genes, the invasiveness of bacteria, the breakdown of plant or dietary components, or hormone-receptor interactions to be visualized in living systems both in the laboratory, the field, and under traditional livestock production environments. Faculty with expertise in functional imaging will interface with collaborating scientists working in the animal, plant and veterinary sciences to develop these novel systems aimed at addressing specific hypothesis-driven and production-based questions. Results from this initiative will not only develop new models to advance scientific progress in reproductive biology, food safety, disease, plant-animal interactions, and environmental physiology, but will also develop technological advancements that will address experimentally critical questions which heretofore have not been addressable in living systems. Finally, we will expand the use of biophotonic-based technologies to address physiological questions in animals with potential applications to field-based monitoring systems.
ARS scientist at Stoneville, MS, have made significant progress on establishing the culture methods and imaging systems to monitor physiology of the bovine and porcine ovarian follicles in situ. Studies are addressing the functionality of this system for transfer to whole animal studies in the near future. In addition, thermography studies have also begun on avian energetics, and we are working with industrial partners to adapt an existing lameness monitoring system for large ungulates (e.g., cattle and horses) which will integrate with thermal imaging diagnostics that we have developed previously under this initiative.
We have begun development of a new imaging modality using quantum dots for tagging spermatozoa and monitoring fluorescence in real-time associated with fertilization events. These studies are being coupled with proteomic and genomic analyses of seminal and spermatozoal collections from boars of high and low fertilization capacity. We have also worked with alternative animal models (amphibians) to use the larger egg masses and size of eggs to advance development of in vivo imaging of markers and probes during developmental processes. While these studies are in their infancy, they will likely yield faster results for implementing imaging modalities for use in livestock once targeted imaging capabilities are refined in these larger gametes and oocytes.
Identification of developmentally important molecules within the gametes and/or their immediate environment will bring in-depth knowledge of paternal contribution during embryo and fetal development in mammals. We performed refined proteomic analyses of follicular fluid (FF) derived from three different follicle developmental stages (small, medium, and large non cystic) to identify protein candidates suitable for the study of oocyte and follicle maturation studies. These analyses are on-going to identify those which will be profiled in in vitro and in vivo models using biophotonic imaging paradigms to unravel their role in gamete development and fertilization processes. In addition, we have adapted Doppler ultrasonography to elucidate circulatory changes occurring in the bovine under varied production-related scenarios, ranging from profiling mammary gland perfusion during bacterial infections, to profiling the shunting of circulatory demands within and around the uterus associated with pregnancy. Finally, studies with L-arginine to assess the molecular mechanisms underlying expression of biophotonic probes in mice models have transitioned to cell culture work that has yielded data on the pathways L-arginine may mediate during pregnancy; which may have implications for litter-bearing species such as swine.
In summary, accomplishments under the Biophotonics Initiative as applied to agricultural livestock, some peripheral applications for novel model development are yielding new research tools which have the potential to develop translatable technologies for an enhanced understanding of physiological processes to improve agricultural livestock production, health and/or overall profitability.