title: Effects of estrogen on estrogen receptor expression in the bursal cells of chick embryos and steroidogenic enzymes gene expression in the bursa: relevance of estrogen receptor and estrogen synthesis in the bursa of chick embryos.
abstract: Estrogen has been reported to act on B cell genesis in the bursa of Fabricius of chick embryos. In this study, we attempted to demonstrate the hypothesis that B cell genesis is controlled by estrogen receptor (ER) in the bursal cells and steroidogenic enzymes synthesized in the bursa. We previously reported the presence of estrogen receptor α (ERα) in the bursa during the late stage of embryogenesis and an increase in the expression of ERα messenger RNA (mRNA) between the 13th day and 16th day. The number of ER-positive cells was maximal on the 16th day. In the present study, ER-positive cells in the bursa during the late stage of embryogenesis increased 4 h after β-estradiol treatment on the 14th to 18th day. The concentration of β-estradiol in the embryonic bursa increased. These results suggest that this stage of embryogenesis is critical in B cell development in the bursa in connection with the effect of estrogen treatment. Our findings also showed that the mRNA expression of five steroidogenic enzymes occurred in the bursa of chick embryos. These results suggest that estrogen is synthesized in the embryonic bursa and estrogen acts on the bursal cells in a paracrine fashion.
authors.affiliation: Graduate School of Natural Science and Technology, Okayama University, Okayama, Japan.
authors.forename: Young-Ha
authors.initials: YH
authors.lastname: Shin
authors.forename: Shunta
authors.initials: S
authors.lastname: Shiraishi
authors.forename: Kiyoaki
authors.initials: K
authors.lastname: Narabara
authors.forename: Asaki
authors.initials: A
authors.lastname: Abe
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Kondo
mesh_terms: D015067:17-Hydroxysteroid Dehydrogenases / Q000235:genetics / Q000378:metabolism; D015096:3-Hydroxysteroid Dehydrogenases / Q000235:genetics / Q000378:metabolism; D000818:Animals; D001141:Aromatase / Q000235:genetics / Q000378:metabolism; D001402:B-Lymphocytes; D002478:Cells, Cultured; D002642:Chick Embryo / Q000166:cytology / Q000201:enzymology* / Q000378:metabolism*; D003577:Cytochrome P-450 Enzyme System / Q000235:genetics / Q000378:metabolism*; D047108:Embryonic Development / Q000502:physiology; D004958:Estradiol / Q000096:biosynthesis* / Q000494:pharmacology / Q000502:physiology*; D047628:Estrogen Receptor alpha / Q000378:metabolism*; D015971:Gene Expression Regulation, Enzymologic; D019899:Paracrine Communication; D012333:RNA, Messenger / Q000378:metabolism; D013997:Time Factors
chemical_list: D047628:Estrogen Receptor alpha; D012333:RNA, Messenger; D004958:Estradiol; D003577:Cytochrome P-450 Enzyme System; D015067:17-Hydroxysteroid Dehydrogenases; D015096:3-Hydroxysteroid Dehydrogenases; D001141:Aromatase