title: Excess estrogen sulfoconjugation as the possible cause for a poor sign of parturition in pregnant cows carrying somatic cell clone fetuses.
abstract: We conducted this study to elucidate a factor causing a poor sign of parturition and prolonged gestation, which is frequently observed in cows carrying somatic clone fetuses. Pre-partum rises in concentrations of plasma estrone and estradiol-17beta in the recipient cows pregnant with clones were subtle. By contrast, the plasma concentration of estrone sulfate in clone pregnancies increased gradually from pre-initiation of parturition induction whereas control cows that received in vivo-derived embryos showed a significant increase at parturition. Therefore, in clone pregnancies, the ratio of estrone/estrone sulfate was low during the pre-partum period compared with control. Messenger RNA expression of estrogen sulfotransferase (SULT1E1) in the placenta at parturition was significantly higher in clone pregnancies than control pregnancies and was localized in binucleate cells (BNC). SULT1E1 mRNA abundance was negatively and positively correlated with concentrations of maternal estrone and estrone sulfate at parturition respectively. Messenger RNA expressions of estrogen sulfatase (STS) and aromatase (CYP19) were similar between clone and control pregnancies and were localized in BNC and caruncular epithelial cells. STS and CYP19 mRNA abundances showed positive correlations with maternal estradiol-17beta concentration. The population of BNC in the placenta did not differ between clone and control pregnancies. Plasma cortisol concentration of vaginally delivered newborn clone calves was comparable with those of control, although cesarean section delivered clone calves showed a low concentration. These results suggest that excess estrogen sulfoconjugation is the reason for the perturbed low ratio of active to inactive estrogens and the resulting hormonal imbalance contributes to the lack of overt signs of readiness for parturition in cows pregnant with clones.
authors.affiliation: Hokkaido Animal Research Center, Shintoku, Hokkaido 081-0038, Japan. h.hirayama@agri.pref.hokkaido.jp
authors.forename: Hiroki
authors.initials: H
authors.lastname: Hirayama
authors.forename: Ken
authors.initials: K
authors.lastname: Sawai
authors.forename: Satoru
authors.initials: S
authors.lastname: Moriyasu
authors.forename: Muneyuki
authors.initials: M
authors.lastname: Hirayama
authors.forename: Yuji
authors.initials: Y
authors.lastname: Goto
authors.forename: Etsushi
authors.initials: E
authors.lastname: Kaneko
authors.forename: Akio
authors.initials: A
authors.lastname: Miyamoto
authors.forename: Koichi
authors.initials: K
authors.lastname: Ushizawa
authors.forename: Toru
authors.initials: T
authors.lastname: Takahashi
authors.forename: Akira
authors.initials: A
authors.lastname: Minamihashi
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D001141:Aromatase / Q000032:analysis; D015415:Biomarkers / Q000097:blood; D002417:Cattle; D002678:Chimera; D019976:Cloning, Organism / Q000379:methods*; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods; D004958:Estradiol / Q000097:blood; D004970:Estrone / Q000097:blood; D005260:Female; D006854:Hydrocortisone / Q000097:blood; D007150:Immunohistochemistry; D053652:Nuclear Transfer Techniques; D036801:Parturition / Q000097:blood*; D010920:Placenta / Q000737:chemistry / Q000378:metabolism*; D011247:Pregnancy; D011374:Progesterone / Q000097:blood; D012333:RNA, Messenger / Q000032:analysis; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000379:methods; D013429:Sulfatases / Q000032:analysis / Q000235:genetics; D015238:Sulfotransferases / Q000032:analysis* / Q000235:genetics
chemical_list: D015415:Biomarkers; D012333:RNA, Messenger; D004970:Estrone; D011374:Progesterone; D004958:Estradiol; D001141:Aromatase; D015238:Sulfotransferases; C020122:estrone sulfotransferase; D013429:Sulfatases; C039596:estrogen sulfatase; D006854:Hydrocortisone