title: Identification and characterization of an ovary-selective isoform of epoxide hydrolase.
abstract: A novel ovary-selective gene was identified by suppression subtractive hybridization (SSH) that is expressed only during the mouse periovulatory phase of a stimulated estrous cycle. Analysis of the protein encoded by the full-length cDNA revealed that the majority of it, with the exception of the first 44 amino acids, matched soluble epoxide hydrolase (Ephx2, referred to as Ephx2A). By comparing the cDNA sequence of this newly identified variant of soluble epoxide hydrolase (referred to as Ephx2B) with the mouse genome database, an exon was identified that corresponds to its unique 5' cDNA sequence. Through the use of an Ephx2A-specific probe, Northern blot analysis revealed that this mRNA was also expressed in the ovary, with the highest level of expression occurring during the luteal phase of a stimulated estrous cycle. In situ hybridization revealed that Ephx2B mRNA expression was restricted to granulosa cells of preovulatory follicles. Ephx2A mRNA expression, however, was detectable in follicles at different stages of development, as well as in the corpus luteum. Total ovarian epoxide hydrolase activity increased following the induction of follicular development, and remained elevated through the periovulatory and postovulatory stages of a stimulated estrous cycle. The change in enzyme activity paralleled the combined mRNA expression profiles for both Ephx2A and Ephx2B, thus supporting a role for epoxide metabolism in ovarian function.
authors.affiliation: Division of Reproductive Sciences, Oregon National Primate Research Center, Beaverton, Oregon 97006, USA. henneboj@ohsu.edu
authors.forename: Jon D
authors.initials: JD
authors.lastname: Hennebold
authors.forename: Kuni
authors.initials: K
authors.lastname: Mah
authors.forename: Wilma
authors.initials: W
authors.lastname: Perez
authors.forename: Jessica E
authors.initials: JE
authors.lastname: Vance
authors.forename: Richard L
authors.initials: RL
authors.lastname: Stouffer
authors.forename: Christophe
authors.initials: C
authors.lastname: Morisseau
authors.forename: Bruce D
authors.initials: BD
authors.lastname: Hammock
authors.forename: Eli Y
authors.initials: EY
authors.lastname: Adashi
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D003338:Corpus Luteum / Q000201:enzymology; D004851:Epoxide Hydrolases / Q000235:genetics* / Q000378:metabolism; D030762:Estrous Cycle / Q000502:physiology*; D005260:Female; D006107:Granulosa Cells / Q000201:enzymology; D007527:Isoenzymes / Q000235:genetics* / Q000378:metabolism; D051379:Mice; D008810:Mice, Inbred C57BL; D008969:Molecular Sequence Data; D009928:Organ Specificity; D010053:Ovary / Q000166:cytology / Q000201:enzymology*; D010060:Ovulation / Q000502:physiology
chemical_list: D007527:Isoenzymes; D004851:Epoxide Hydrolases; C518648:Ephx2 protein, mouse