Alan D. Ealy, Ph.D.

The overall goal of our research program is to elucidate the key physiological, endocrine and molecular mechanisms responsible for conceptus development and subsequent establishment and maintenance of pregnancy in ruminants.  From 20 to 40% of all fertile matings in cattle do not result in the birth of a live calf, and a majority of these losses occur within the first month of pregnancy.  Failures in conceptus elongation and maternal recognition of pregnancy undoubtedly contribute to pregnancy loss.  By improving our understanding of the basic biology of embryogenesis and placentation, management schemes can be created to reduce embryonic losses in production livestock.  Work in the laboratory focuses on two areas:     

Early Placental Development: The outer-most layer of the fetal placenta, termed the trophectoderm, undergoes extensive proliferation prior to its attachment to the uterine lining in cattle, sheep and other ruminants. After its attachment, a new cell type, the binucleate cell, emerges as the predominant endocrine cell type.  The laboratory is using a combination of in utero, in vitro and molecular technologies to identify uterine- and conceptus-derived factors that regulate the rate of trophectoderm proliferation.  We also are searching for control points in binucleate cell formation and function during early pregnancy. 

Regulation of Placental Gene Expression:  In ruminants, the developing conceptus must communicate with the maternal system to establish a uterine environment conducive for pregnancy.  Interferon-tau (IFN-t) is the hormone responsible for maintenance of pregnancy in ruminants.  It is secreted by the trophectoderm and interacts with the uterine lining to prevent corpus luteum regression and return to estrus.  The temporal and spatial expression pattern of IFN-t is well documented, but the endocrine and molecular mechanisms that regulate IFN-t gene expression remain largely undefined.  Our laboratory is identifying and characterizing uterine- and conceptus-derived factors that influence IFN-t gene expression during early pregnancy.   

Representative Publications:

Ealy, A.D. and Yang, Q.E. 2009.  Control of interferon-tau expression during early pregnancy in ruminants. Am. J. Reprod. Immunol. 61:95-106.

Egen, T.E., Ealy, A.D., Landon, L.A., Roberts, R.M. and Green, J.A. 2009. Autoimmunization of ewes against pregnancy-associated glycoproteins does not interfere with the establishment and maintenance of pregnancy. Animal 3:850-857.

Cooke, F.N., Pennington, K.A., Yang, Q.E. and Ealy, A.D. 2009. Several fibroblast growth factors are expressed during pre-attachment bovine conceptus development and regulate interferon-tau expression from trophectoderm.  Reproduction  137:259-269.

Rodina, T.M., Cooke, F.N., Hansen, P.J. and Ealy, A.D. 2009. Oxygen tension and medium type actions on blastocyst development and interferon-tau secretion in cattle. Anim. Reprod. Sci. 111:173-188.

Cooke, R.F., Arthington, J.D., Araujo, D.B., Lamb, G.C. and Ealy, A.D. 2008.  Effects of supplementation frequency on performance, reproductive, and metabolic responses of Brahman-crossbred females. J. Anim. Sci. 86:2296-2309.

Ocón-Grove, O.M., Cooke, F.N., Alvarez, I.M., Johnson, S.E., Ott, T.L., and Ealy, A.D. 2008.  Ovine endometrial expression of fibroblast growth factor (FGF) 2 and conceptus expression of FGF receptors during early pregnancy. Domest. Anim. Endocrinol. 34:135-145.

Talbot, N. C., Powell, A. M., Ocón, O. M., Caperna, T. J., Camp, M., Garrett, W. M., and Ealy, A. D. 2008. Comparison of the interferon-tau expression from primary trophectoderm outgrowths derived from IVP, NT, and parthenogenote bovine blastocysts. Mol. Reprod. Devel. 75:299-308.

Kurosaka, S., Eckardt, S., Ealy, A.D. and McLaughlin, K.J. 2007.  Regulation of blastocyst stage gene expression and outgrowth interferon tau activity of somatic cell clone aggregates.  Cloning Stem Cells 9:630-641.

Ealy, A.D., Pennington, K.A., and Rodina, T.M. 2006. Interferon-tau polymorphisms and their potential functions in ruminants. Ann. Rev. Biomed. Sci. 8:9-18.

Michael, D.D., Alvarez, I.M., Ocón, O.M., Powell, A.M., Talbot, N.C., Johnson, S.E., and Ealy, A.D. 2006.  Fibroblast growth factor-2 is expressed by the bovine uterus and stimulates interferon-tau production in bovine trophectoderm. Endocrinology 147:3571-3579.