M E S '9 8 - University of Georgia College of Veterinary Medicine

14Dr. Fred Thompson, a recognized authority in fescue toxicosis, has been workingin this area of research for 15 years.target molecules on host cells. Using the DNAsequence of this gene, several other putativeadhesion molecules have been identified.There are significant similarities between P.falciparum and several parasite pathogens ofveterinary importance, most notably speciesBabesia (parasites of cattle, horses, and dogs).The techniques and reagents developed for thestudy of adhesion molecules in Plasmodiumare now being used to detect similar moleculesin Babesia. The discovery of novel adhesionmolecules in Babesia will allow these techniquesto be adapted to the detection of adhesionmolecules in a wider array of pathogenicparasites that impact human and animal health,such as Cryptosporidium and Eimeria. Theseadhesion molecules are expected to provideimportant new targets for development of vaccinesand antiparasite drugs.David S. Peterson and David Allred*dpeterso@calc.vet.uga.edu*University of FloridaSequential Western Blot Analysis of BovineHumoral Immunity to ParatuberculosisJohne’s disease (paratuberculosis) causedby Mycobacterium avium subs. paratuberculosis(MPTB) is a chronic wasting disease ofruminants that spreads slowly and may be presentin a herd for years prior to diagnosis. Inthe United States, it is estimated that the prevalenceof infection is between 5-20%. Infectedcows have diarrhea, decreased milk production,and body condition. Losses to the dairyindustry alone exceed $1.5 billion per year.Though controversial, MPTB may also be ahuman pathogen. Crohn’s disease is a chronictransmural inflammatory disease of the intestinaltract that has clinical and pathologic featuressimilar to paratuberculosis. The sequentialhumoral immune response to MPTB is notwell studied, and this lack of information hindersdevelopment of serologic tests that targetmolecules recognized early in the immuneresponse. The objective of this project is toanalyze by Western blot, the sequentialhumoral immune response of calves infectedwith MPTB. Our long-term goal is to developserologic diagnostic assays that have greaterpotential to diagnose this chronic disease thanis currently possible. Detection of early infectionwould allow producers a better tool toidentify and eliminate MPTB infected cattleand limit spread to other animals and the environment.Holstein calves obtained from herds withMPTB test-negative status were orally inoculatedwith MPTB strain 19698. A Western blotassay to detect MPTB antibody has beendeveloped utilizing enhanced chemiluminescence.Serum samples are collected and analyzedevery four weeks for antibody to MPTBby Western blot. Preliminary data suggest thatby 18 months postinfection, three of six MPTBchallenged calves have developed an immuneresponse to an antigen comigrating at the sameapparent molecular mass. One other MPTBchallenged calf has a similar weak immuneresponse that is considered suspicious. Thisimmune response is not seen in sera from anycontrol calves. Antibody from only one of theMPTB challenged calves identified this antigenbefore 15 months indicating that the numberof MPTB calves mounting an immuneresponse to this antigen is significantlyincreasing. Identification of MPTB specificantigens may provide candidate molecules thatcan be targeted for improved diagnostic assaysfor this chronic disease.Gordon A. Hullinger, Murray E. Hines II,John R. Cole, Charles A. Baldwingah@tifton.cpes.peachnet.eduA Survey of Genes Expressed in BovineSkeletal MuscleBeef, a major food commodity, is comprisedof the products of genes expressed inbovine muscle tissue, yet our knowledge ofthese genes is currently limited. Accordingly,as a first step toward the identification, characterization,genetic mapping, and monitoring ofexpression of muscle genes influencing beefquality traits, we have initiated a bovine muscleEST (Expressed Sequence Tag) project.This work involves the isolation and partialsequencing of numerous unique cDNAs from abovine skeletal muscle cDNA library. Thesequences can be analyzed in light oftheir homologies to the expanding databases ofhuman sequences; inferences can be madeabout their map locations via comparativemapping; and the set of sequences provides abasis for further study into the molecular regulationof muscle structure and function.Royal A. McGrawmcgraw@bscr.uga.edu