title: Rapid conceptus elongation in the pig: An interleukin 1 beta 2 and estrogen-regulated phenomenon.
abstract: Establishment and maintenance of pregnancy in the pig involves activating many physiological, cellular, and molecular signaling pathways between the developing conceptus and hormonally regulated maternal endometrium. Rapid elongation of the pig trophoblast allows for the establishment of sufficient placental surface area for the transport of nutrients to the fetus throughout pregnancy. Estrogens secreted by the conceptus during elongation act on uterine epithelia to induce secretion of uterine factors required for conceptus development and for preventing endocrine secretion of prostaglandin F2α, which would cause luteolysis. Thus, trophoblast expansion within the uterine lumen during early gestation is an essential process for implantation and maintenance of pregnancy in species with an epitheliochorial form of placentation. In the pig, rapid conceptus elongation involves the unique expression of interleukin-1 beta 2 (IL1B2), which establishes pro-inflammatory effects that may be tempered by the spatiotemporal secretion of estrogen from the conceptuses. The present review provides current information on pig conceptus remodeling and signaling via estrogen and IL1B2 pathways, as well as endometrial responses to those conceptus factors leading to establishment of pregnancy.
authors.affiliation: Division of Animal Sciences, University of Missouri, Columbia, Missouri.
authors.forename: Rodney D
authors.identifier: http://orcid.org/0000-0001-9438-8146
authors.initials: RD
authors.lastname: Geisert
authors.affiliation: Division of Animal Sciences, University of Missouri, Columbia, Missouri.
authors.forename: Jeffrey J
authors.initials: JJ
authors.lastname: Whyte
authors.affiliation: Division of Animal Sciences, University of Missouri, Columbia, Missouri.
authors.forename: Ashley E
authors.initials: AE
authors.lastname: Meyer
authors.affiliation: Division of Animal Sciences, University of Missouri, Columbia, Missouri.
authors.forename: Daniel J
authors.initials: DJ
authors.lastname: Mathew
authors.affiliation: Division of Animal Sciences, University of Missouri, Columbia, Missouri.
authors.forename: María R
authors.initials: MR
authors.lastname: Juárez
authors.affiliation: Division of Animal Sciences, University of Missouri, Columbia, Missouri.
authors.forename: Matthew C
authors.identifier: http://orcid.org/0000-0001-5771-9460
authors.initials: MC
authors.lastname: Lucy
authors.affiliation: Division of Animal Sciences, University of Missouri, Columbia, Missouri.
authors.forename: Randall S
authors.identifier: http://orcid.org/0000-0002-6012-4035
authors.initials: RS
authors.lastname: Prather
authors.affiliation: Division of Animal Sciences, University of Missouri, Columbia, Missouri.
authors.forename: Thomas E
authors.initials: TE
authors.lastname: Spencer
mesh_terms: D000818:Animals; D015237:Dinoprost / Q000378:metabolism; D010064:Embryo Implantation / Q000502:physiology*; D004622:Embryo, Mammalian / Q000378:metabolism*; D047108:Embryonic Development / Q000502:physiology*; D005260:Female; D053583:Interleukin-1beta / Q000378:metabolism*; D011247:Pregnancy / Q000502:physiology*; D013552:Swine / Q000196:embryology*
chemical_list: D053583:Interleukin-1beta; D015237:Dinoprost
keywords: embryo; endometrium; placenta; pregnancy