High impact information on esr1

• Due to lack of the identity box (I-box) and activation function 2 (AF-2) domain, zFF1B lacks transactivation function and fails to synergize with estrogen receptor (ER) in regulating promoters [1].
• Estradiol-binding sites are nearly identical in zfERs and their human homologs, suggesting that zebrafish will serve as a good model system for studying human ER-binding drugs [2].
• E(subscript)2(/subscript) treatment of U251-MG glial cells cotransfected with zebrafish ER-alpha and the Aro-B promoter-luciferase reporter resulted in a 60- to 80-fold stimulation of luciferase activity [3].
• To this end, the ER-negative glial cell line U251-MG was transfected with the three zebrafish ER subtypes and the Aro-B promoter linked to a luciferase reporter gene [3].
• Dose-response analyses with ethynylestradiol (EE(subscript)2(/subscript)), estrone (E(subscript)1(/subscript)), alpha-zeralenol, and genistein showed that estrogenic potency of these agents markedly differed depending on the ER subtype in the assay [3].

Biological context of esr1

• The estrogen receptor (ER) genes encode a group of nuclear enhancer proteins, which are important ligand-activated transcription factors, modulating estrogen-target gene transcription [4].
• The objective of this study was to determine concentration dependent effects of a weak estrogen receptor agonist, 4-nonylphenol (NP) and a potent estrogen receptor agonist, 17alpha-ethinylestradiol (EE) on sex ratios, gonad morphology, Vtg induction and breeding success in zebrafish (Danio rerio) [5].
• The objective of this study was to determine the effects of binary mixtures of a weak estrogen receptor agonist, nonylphenol (NP) and a potent estrogen receptor agonist, 17alpha-ethinylestradiol (EE) on sex ratios, gametogenesis, VTG induction, heat shock protein 70 (HSP70) expression and reproductive capacity in zebrafish (Danio rerio) [6].

Anatomical context of esr1

• These data also suggest that radial glial cells may express low amounts of ER that escaped detection until now [7].
• In testes, expression of the estrogen receptor- as well as ZP2-mRNA remained unchanged for the entire experiment, except for the individuals exposed for 17 days, which displayed elevated expression levels of ZP2 [8].

Associations of esr1 with chemical compounds

• The animals were exposed to the model estrogenic chemicals ethynylestradiol (EE2), bisphenol A (BPA), and octylphenol (OP), which exert their endocrine activity in vertebrates through the estrogen receptor [9].

Other interactions of esr1

• In 24 h postfertilization (hpf) embryos, high levels of esr2a and esr2b and low levels of esr1 mRNAs are detected in the epidermis, pectoral fin buds, hatching gland and, to a lesser extent, developing brain [4].
• As measured by increased P450aromB mRNA, a functional estrogen response system is first detected 24-48 h post-fertilization (hpf), consistent with the onset of estrogen receptor (ER) expression (alpha, beta, and gamma) [10].
• LOECs for vitellogenin as well as estrogen receptor alpha expression were found to be 2.5 ng/l already after 4 d of exposure [8].

Analytical, diagnostic and therapeutic context of esr1

• In conclusion, we demonstrate that our bioassay provides a fast, reliable, sensitive, and efficient test for evaluating estrogenic potency of endocrine disruptors on ER subtypes in a glial context [3].
• By means of RT-PCR, a sequence fragment of the zebrafish estrogen receptor alpha was cloned and sequenced [8].

References