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Our research involves basic and applied studies of hormones and their receptors in domestic animal reproduction. A model for endocrine control of lactational anestrous in the postpartum beef cow has been developed by this laboratory and is based on nursing intensity, increasing hypothalamic sensitivity to the negative feedback of estrogen. Our goals are to use this model to develop practical techniques to decrease the postpartum interval in the cow and increase her overall productivity.
Our laboratory has also been working on the development of sterilization vaccines that can be used either in domestic species or pet animals. We are working on developing an immunogenic chimeric ovalbumin-LHRH molecule using genetic engineering. We have used the cDNA of ovalbumin as a structural gene in which 7 LHRH inserts were constructed into this gene by cassette mutagenesis and oligonucleotide mismatch mutagenesis. These chimeric proteins were over-expressed in the E. coli strain BL21 using a pET expression system, which expresses a target protein with a C-terminal His-Tag. The C-terminal His-Tag allows purification by metal chelation chromatography. This ovalbumin LHRH chimeric protein has then been tested in mice for its ability to produce an antibody against LHRH, as well as its effects on biological action or decreasing reproductive tract weight in the mouse. This vaccine appears to be effective at least in mice and is presently being tested in cattle and pigs. This particular type of vaccine also has potential in human medicine, as it may apply to decreasing androgens in prostate cancer patients.
Geary TW, Gings EE, MacNeil MD, de Avila DM, Reeves JJ. 2006 Use of recombinant gonadotropin-releasing hormone antigens for immunosterilizatoin of beef heifers. J Anim Sci. 84(2):343-50.
Hernandez JA, Zanella EL, Bogden R, de Acila DM, Gaskins CT, Reeves JJ. 2005 Reproductive characteristics of grass-fed, lutenizing hormone-releasing hormone-immunocastrated Bos indicus bulls. J Anim Sci. 83(12):2901-7.
Jiang Z, Kunej T, Michal JJ Gaskins CT, Reeves JJ, Busboom JR, Dovc P, Wright RW Jr. 2005 Significant associations of the mitochondrial transcription factor A promoter polymorphisms with marbling and subcutaneous fat depth in Wagyu x Limousin F2 crosses. Biochem Biophys Res Commun. 334(2):516-23.
Oatley, J.M., D.M. de Avila, J.J. Reeves, and D.J. McLean. 2004. Testis tissue explant culture supports survival and proliferation of spermatogonial stem cells. Biol. Reprod. 70:625-631.