title: Secreted phosphoprotein 1 expression in endometrium and placental tissues of hyperprolific large white and meishan gilts.
abstract: Increased litter size and within-litter uniformity in birth weight would improve pig reproductive efficiency. This study compared the location and gene and protein expression of secreted phosphoprotein 1 in placental and uterine tissues supplying a normally sized and the smallest fetus carried by hyperprolific Large White and Meishan gilts on Days 41-42 of pregnancy. Immunohistochemistry and in situ hybridization showed that the protein and gene encoding secreted phosphoprotein 1 were located in the glandular and luminal epithelium of the endometrium and in the placenta. Secreted phosphoprotein 1 protein levels were higher in glandular epithelium, luminal epithelium, and placenta from Meishan gilts compared to corresponding tissues from hyperprolific Large White gilts. Reverse transcription quantitative PCR demonstrated secreted phosphoprotein 1 mRNA levels were higher in endometrium, but not placenta, from Meishan compared to hyperprolific Large White gilts. In hyperprolific Large White gilts, secreted phosphoprotein 1 protein levels were higher in glandular epithelium and placenta surrounding small fetuses than corresponding tissues supplying normal-sized fetuses. Similarly, in Meishan gilts, secreted phosphoprotein 1 protein levels were higher in luminal epithelium surrounding small compared to normal-sized fetuses. Within hyperprolific Large White, but not Meishan, gilts secreted phosphoprotein 1 mRNA was higher in endometrium surrounding the normal-sized fetus than the control fetus. The contradictory relationship between fetal size and secreted phosphoprotein 1 protein and mRNA in the hyperprolific Large White is intriguing and may reflect breed differences in posttranslational modification. The striking breed differences in secreted phospoprotein 1 expression suggest that SPP1 may be associated with placental efficiency.
authors.affiliation: The Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, Easter Bush, Midlothian, Scotland, United Kingdom.
authors.forename: Silvia C
authors.initials: SC
authors.lastname: Hernandez
authors.forename: Charis O
authors.initials: CO
authors.lastname: Hogg
authors.forename: Yvon
authors.initials: Y
authors.lastname: Billon
authors.forename: Marie-Pierre
authors.initials: MP
authors.lastname: Sanchez
authors.forename: Jean-Pierre
authors.initials: JP
authors.lastname: Bidanel
authors.forename: Christopher S
authors.initials: CS
authors.lastname: Haley
authors.forename: Alan L
authors.initials: AL
authors.lastname: Archibald
authors.forename: Cheryl J
authors.initials: CJ
authors.lastname: Ashworth
mesh_terms: D000818:Animals; D004717:Endometrium / Q000378:metabolism*; D004847:Epithelial Cells / Q000378:metabolism; D005260:Female; D047109:Fetal Development; D005333:Fetus / Q000378:metabolism; D008098:Litter Size / Q000235:genetics; D053495:Osteopontin / Q000235:genetics / Q000378:metabolism*; D010920:Placenta / Q000378:metabolism*; D011247:Pregnancy; D013045:Species Specificity; D013552:Swine / Q000378:metabolism*
chemical_list: D053495:Osteopontin
keywords: fetus; pig; pregnancy; secreted phosphoprotein 1