Searchable, peer-reviewed, open-access proceedings from bioscience and biomedical conferences

bp0006rdr24 | Fetal-maternal Interactions | REDR2006

Fetal-maternal interactions during the establishment of pregnancy in ruminants

Spencer TE , Johnson GA , Bazeru FW , Burghardt RC

This review integrates established information with new insights into molecular and physiological mechanisms responsible for events leading to pregnancy recognition, endometrial receptivity, and implantation with emphasis on sheep. After formation of the corpus luteum, progesterone acts on the endometrium and stimulates blastocyst growth and elongation to form a filamentous conceptus (embryo/fetus and associated extraembryonic membranes). Recurrent early pregnancy loss in the ...

bp0007rdr7 | Ruminant Transcriptome | REDR2010

Endogenous retroviruses of sheep: a model system for understanding physiological adaptation to an evolving ruminant genome

Spencer TE , Black SG , Arnaud F , Palmarini M

Endogenous retroviruses (ERVs) are present in the genome of all vertebrates and are remnants of ancient exogenous retroviral infections of the host germline transmitted vertically from generation to generation. Sheep betaretroviruses offer a unique model system to study the complex interaction between retroviruses and their host. The sheep genome contains 27 endogenous betaretroviruses (enJSRVs) related to the exogenous and pathogenic Jaagsiekte sheep retrovirus (JSRV), the ca...

bp0004rdr22 | Embryonic Survival | REDR1998

Uterine differentiation as a foundation for subsequent fertility

Bartol FF , Wiley AA , Floyd JG , Ott TL , Bazer FW , Gray CA , Spencer TE

Uterine differentiation in cattle and sheep begins prenatally, but is completed postnatally. Mechanisms regulating this process are not well defined. However, studies of urogenital tract development in murine systems, particularly those involving tissue recombination and targeted gene mutation, indicate that the ideal uterine organizational programme evolves epigenetically through dynamic cell–cell and cell–matrix interactions that define the microenvironmental conte...

bp0018cpr37 | State-of-The Art in Conceptus-Uterus Interactions/Early Pregnancy Signaling | CPR2009

Conceptus-uterus interactions in pigs: endometrial gene expression in response to estrogens and interferons from conceptuses

Johnson G.A. , Bazer F.W. , Burghardt R.C. , Spencer T.E. , Wu G. , Bayless K.J.

This review highlights information on conceptus-uterus interactions in the pig with respect to uterine gene expression in response to estrogens and interferons (IF Ns) secreted from elongating conceptuses. Pig conceptuses release estrogens for pregnancy recognition, but also secrete IENs that do not appear to be antiluteolytic. Estrogens and IFNs induce expression of largely non-overlapping sets of genes, and evidence suggests that pig conceptuses orchestrate essential e...