Take a good, hard mental image of a long line of people stretched for blocks. If you expand the line to roughly 100,000, this is the number of people waiting for an organ transplant. The imbalanced patient-to-organ ratio leaves many to die while waiting their turn. In response, some researchers try to tap into animal organs to save human lives, but those organs do not always work.
Research in the University of Missouri’s Division of Animal Sciences may help solve this medical debacle by using genetic modification. When an organ goes from one animal to another (like to a human), preexisting antibodies in the human bind to the organ’s sugar molecules and kill the organ, making it useless. “When you take a pig cell and transfer it to a human, the molecule is immediately recognized as foreign,” explains MU’s Animal Science Professor, Randall Prather. “Within minutes you’ll get hyperacute rejection, and the cells will be destroyed.”
Prather has contributed to research associated with modifying genes to produce healthy bacon. In a study involving the University of Pittsburgh’s School of Medicine, researchers transferred a gene known as fat-1 to fetal pig cells. The fat-1 gene creates an enzyme that converts omega-6 fatty acids to omega-3 fatty acids, the type of fatty acid known to reduce heart disease and cancer. As a collaborator in the research, Prather cloned the pig fetal cells containing the gene that makes omega-3 fatty acids and creates pigs with their their own omega-3 fatty acids.
Severin Stevenson introduces a subfield of biochemistry called quantitative proteomics. Proteomics deals with absolute quantification of proteins at any given time in a given sample compared with other protein samples. Because certain plants produce seeds that are valuable for their oil (e.g., cottonseed, peanuts, grape seed), scientists are interested in the plant’s physiology, specifically, its process of “seed-filling”—a period of development during which the seed produces oil. If scientists can understand the processes that contribute to the seed’s production of oil, they may be able to increase this production for economic gain.
Stevenson has been working with Jay J. Thelen’s Proteomics of Oilseeds Lab in the Bond Life Sciences Center. A typical experiment for Stevenson may involve adding fatty acids to cells growing in a sucrose suspension, taking a sample every hour over a period of days, extracting and treating protein from these samples and, finally, re-suspending the protein and then injecting samples into the mass spectrometer in order to quantify and analyze the chemical composition of the protein samples.
Stevenson and his team are working to elucidate the mechanism behind oil accumulation in seeds during seed filling. Plants sense the levels of various metabolites differently in different tissues, and seeds are unique in the ways in which they do this. Some seeds are well over 40% oil by dry weight, whereas leaves are under 5%. The differences in oil accumulation between these tissues provide evidence for the presence of a unique regulatory mechanism that they wish to understand and which may eventually benefit agricultural industries.