title: Cloning and functional characterization of Chondrichthyes, cloudy catshark, Scyliorhinus torazame and whale shark, Rhincodon typus estrogen receptors.
abstract: Sex-steroid hormones are essential for normal reproductive activity in both sexes in all vertebrates. Estrogens are required for ovarian differentiation during a critical developmental stage and promote the growth and differentiation of the female reproductive system following puberty. Recent studies have shown that environmental estrogens influence the developing reproductive system as well as gametogenesis, especially in males. To understand the molecular mechanisms of estrogen actions and to evaluate estrogen receptor-ligand interactions in Elasmobranchii, we cloned a single estrogen receptor (ESR) from two shark species, the cloudy catshark (Scyliorhinus torazame) and whale shark (Rhincodon typus) and used an ERE-luciferase reporter assay system to characterize the interaction of these receptors with steroidal and other environmental estrogens. In the transient transfection ERE-luciferase reporter assay system, both shark ESR proteins displayed estrogen-dependent activation of transcription, and shark ESRs were more sensitive to 17beta-estradiol compared with other natural and synthetic estrogens. Further, the environmental chemicals, bisphenol A, nonylphenol, octylphenol and DDT could activate both shark ESRs. The assay system provides a tool for future studies examining the receptor-ligand interactions and estrogen disrupting mechanisms in Elasmobranchii.
authors.affiliation: Okazaki Institute for Integrative Bioscience, National Institute for Basic Biology, National Institutes of Natural Sciences, 5-1 Higashiyama, Myodaiji, Okazaki 444-8787, Japan.
authors.forename: Yoshinao
authors.initials: Y
authors.lastname: Katsu
authors.forename: Satomi
authors.initials: S
authors.lastname: Kohno
authors.forename: Haruka
authors.initials: H
authors.lastname: Narita
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Urushitani
authors.forename: Koudai
authors.initials: K
authors.lastname: Yamane
authors.forename: Akihiko
authors.initials: A
authors.lastname: Hara
authors.forename: Tonya M
authors.initials: TM
authors.lastname: Clauss
authors.forename: Michael T
authors.initials: MT
authors.lastname: Walsh
authors.forename: Shinichi
authors.initials: S
authors.lastname: Miyagawa
authors.forename: Louis J
authors.initials: LJ
authors.lastname: Guillette
authors.forename: Taisen
authors.initials: T
authors.lastname: Iguchi
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D003001:Cloning, Molecular; D005260:Female; D008297:Male; D008969:Molecular Sequence Data; D010802:Phylogeny; D011960:Receptors, Estrogen / Q000737:chemistry / Q000145:classification / Q000235:genetics / Q000378:metabolism*; D017386:Sequence Homology, Amino Acid; D012754:Sharks / Q000235:genetics / Q000378:metabolism*
chemical_list: D011960:Receptors, Estrogen