This study developed a quantitative reverse transcription-polymerase chain reaction (RT-PCR) method to measure estrogen receptor-alpha (ERalpha) mRNA in the rainbow trout (Oncorhynchus mykiss). Using RT-PCR, and primers based on the known ERalpha DNA sequence in this species, cDNA sequences representing most of the protein coding region were obtained from ovary poly A(+) RNA. Using these DNA sequences as probes in Northern blot hybridizations confirmed that a single transcript of 4.2 kilobases in poly A(+) RNA could be detected in liver and ovary RNA. For the quantitative RT-PCR assay an internal standard RNA molecule was produced to control for inherent inter-tube differences in amplification efficiency and permit accurate quantification of ERalpha mRNAs. The quantitative RT-PCR assay proved to be highly specific for ERalpha mRNA with a detection limit of 6.9 fg, which corresponds to 273 fg ERalpha mRNA/microg total RNA. The quantitative RT-PCR assay was used to measure the levels of ERalpha mRNA in ovaries of rainbow trout at different stages of reproductive development. Ovarian ERalpha mRNA expression was found during two distinct periods of reproductive development, in pre-vitellogenic ovaries of fish with ovarian follicle diameters (OFDs) 1000 microm. ERalpha mRNA could not be detected in the ovaries of fish with OFDs >100 microm but 2000 microm.

This article has been cited by other articles:

				B. Campbell, J. Dickey, B. Beckman, G. Young, A. Pierce, H. Fukada, and P. Swanson Previtellogenic Oocyte Growth in Salmon: Relationships among Body Growth, Plasma Insulin-Like Growth Factor-1, Estradiol-17beta, Follicle-Stimulating Hormone and Expression of Ovarian Genes for Insulin-Like Growth Factors, Steroidogenic-Acute Regulatory Protein and Receptors for Gonadotropins, Growth Hormone, and Somatolactin Biol Reprod, July 1, 2006; 75(1): 34 - 44. [Abstract] [Full Text] [PDF]

				C.-L. He, J.-L. Du, Y.-H. Lee, Y.-S. Huang, Y. Nagahama, and C.-F. Chang Differential Messenger RNA Transcription of Androgen Receptor and Estrogen Receptor in Gonad in Relation to the Sex Change in Protandrous Black Porgy, Acanthopagrus schlegeli Biol Reprod, August 1, 2003; 69(2): 455 - 461. [Abstract] [Full Text] [PDF]

				A. Menuet, I. Anglade, G. Flouriot, F. Pakdel, and O. Kah Tissue-Specific Expression of Two Structurally Different Estrogen Receptor Alpha Isoforms along the Female Reproductive Axis of an Oviparous Species, the Rainbow Trout Biol Reprod, November 1, 2001; 65(5): 1548 - 1557. [Abstract] [Full Text] [PDF]