Two cytochrome P450 aromatase genes in the hermaphrodite ricefield eel Monopterus albus: mRNA expression during ovarian development and sex change

Previously, the ricefield eel (Monopterus albus) was speculated to have only one cytochrome p450 aromatase gene. In this study, however, the cDNAs encoding two distinct cytochrome p450 aromatases, cyp19a1a and cyp19a1b, were isolated. The genomic organizations of both cyp19 genes were conserved when compared with other teleosts. Northern blot detected an abundant expression of cyp19a1a in the ovary, and cyp19a1b in the hypothalamus. RT-PCR coupled with Southern blot showed that cyp19a1a was expressed predominantly in the gonads of both sexes, with higher levels in the ovary than testis, while cyp19a1b was expressed in all the tissues examined in the male, but only in the brain and pituitary in the female. The levels of cyp19a1a mRNA in the ovary were increased significantly during vitellogenesis, but decreased significantly at mature stage. The levels of cyp19a1b mRNA in the brain and pituitary did not vary significantly during vitellogenesis. As ovarian development shifted from vitellogenesis to maturation, the levels of cyp19a1b mRNA was decreased significantly in the brain, but increased significantly in the pituitary. During natural sex change from female to male, the levels of cyp19a1a mRNA in the gonad were significantly decreased. The levels of cyp19a1b mRNA in the hypothalamus were significantly increased at the early intersexual phase, whereas the expression levels in the pituitary were significantly decreased at the intersexual phases. Taken together, these results showed a novel sexual dimorphism of cyp19a1b mRNA tissue distribution, and both CYP19 genes were associated with the ovarian development and natural sex change of the ricefield eel.

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Effect of low dose exposure to the herbicide atrazine and its metabolite on cytochrome P450 aromatase and steroidogenic factor-1 mRNA levels in the brain of premetamorphic bullfrog tadpoles (Rana catesbeiana)

Aquatic Toxicology ◽

10.1016/j.aquatox.2010.12.019 ◽

2011 ◽

Vol 102 (1-2) ◽

pp. 31-38 ◽

Cited By ~ 20

Author(s):

Mark P. Gunderson ◽

Nik Veldhoen ◽

Rachel C. Skirrow ◽

Magnus K. Macnab ◽

Wei Ding ◽

...

Keyword(s):

Cytochrome P450 ◽

Low Dose ◽

Rana Catesbeiana ◽

Mrna Levels ◽

Steroidogenic Factor 1 ◽

P450 Aromatase ◽

Cytochrome P450 Aromatase ◽

Herbicide Atrazine ◽

The Brain

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Differential regulation of the expression of cytochrome P450 aromatase, estrogen and androgen receptor subtypes in the brain–pituitary–ovarian axis of the Japanese eel (Anguilla japonica) reveals steroid dependent and independent mechanisms

General and Comparative Endocrinology ◽

10.1016/j.ygcen.2011.11.005 ◽

2012 ◽

Vol 175 (1) ◽

pp. 163-172 ◽

Cited By ~ 33

Author(s):

Shan-Ru Jeng ◽

Jeremy Pasquier ◽

Wen-Shiun Yueh ◽

Guan-Ru Chen ◽

Yan-Horn Lee ◽

...

Keyword(s):

Cytochrome P450 ◽

Androgen Receptor ◽

Differential Regulation ◽

Anguilla Japonica ◽

Japanese Eel ◽

Receptor Subtypes ◽

P450 Aromatase ◽

Steroid Dependent ◽

Cytochrome P450 Aromatase ◽

The Brain

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Expression of cytochrome P450 aromatase isoforms in female Alburnus tarichi (Guldenstaedtii, 1814)

Ege Journal of Fisheries and Aquatic Sciences ◽

10.12714/egejfas.38.2.15 ◽

2021 ◽

Vol 38 (2) ◽

pp. 247-252

Author(s):

Guler Unal ◽

Emily Marquez ◽

Mara H. O'brien ◽

Pericles Stavropoulos ◽

Ian P. Callard

Keyword(s):

Cytochrome P450 ◽

Endocrine Disruption ◽

Ovarian Development ◽

Expression Level ◽

Lake Van ◽

Expression Levels ◽

Aromatase Gene ◽

P450 Aromatase ◽

Cytochrome P450 Aromatase ◽

Gene Isoforms

In this study, we aimed to clone brain-derived Cyp19b and ovary-derived Cyp19a the P450 aromatase gene isoforms and to indicate the expression levels of these genes in the hypothalamus and ovary tissues from reproductively arrested ovarian development (RA) and non-arrested ovarian development (RN) Alburnus tarichi from Lake Van, Turkey. The expression levels of Cyp19b and Cyp19a genes were predominant in the hypothalamus and ovary, respectively. The level of Cyp19b mRNA was significantly lower in the hypothalamus and ovary from RA fish than in the hypothalamus and ovary from RN fish (P<0.05). The expression level of Cyp19a was significantly lower in the ovary of RA fish (P<0.05) than RN fish while no difference was found in the hypothalamus of both RA and RN fish (P<0.05). According to these findings, we suggest that the RA fish represent a segment of the population and these fish may be more sensitive to endocrine disruption compound/s than others.

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Molecular biology of channel catfish brain cytochrome P450 aromatase (CYP19A2): cloning, preovulatory induction of gene expression, hormonal gene regulation and analysis of promoter region

Journal of Molecular Endocrinology ◽

10.1677/jme.1.01805 ◽

2005 ◽

Vol 35 (3) ◽

pp. 571-583 ◽

Cited By ~ 36

Author(s):

Y Kazeto ◽

J M Trant

Keyword(s):

Gene Expression ◽

Amino Acids ◽

Cytochrome P450 ◽

Channel Catfish ◽

Aromatase Activity ◽

Pituitary Cells ◽

Reproductive Endocrinology ◽

P450 Aromatase ◽

Cytochrome P450 Aromatase ◽

The Brain

Cytochrome P450 aromatase (CYP19) converts androgens to estrogens. Unlike mammals, teleosts have two CYP19 genes, expressed differentially in ovary (CYP19A1) and neuronal tissues (CYP19A2). The primary purpose of this study was to demonstrate the potential involvement of CYP19A2 in the reproductive endocrinology of teleosts. Channel catfish CYP19A2 (ccCYP19A2) cDNAs were isolated from the brain using a PCR-based strategy. The ccCYP19A2 cDNA putatively encodes 500 amino acids which conferred aromatase activity in transfected COS-7 cells. Additionally, an alternatively spliced transcript was isolated which lacks the first 122 amino acids and is catalytically inactive. The brain and the pituitary were predominant sources of ccCYP19A2 transcript and the abundance in both tissues acutely increased prior to spawning. This preovulatory induction of ccCYP19A2 gene in the pituitary is remarkably similar to the pattern of gene expression for luteinizing hormone-β (LHβ). Estradiol-17β (E2) and testosterone enhanced the transcript abundance of ccCYP19A2 and LHβ in catfish pituitary cells cultured in vitro but the stimulatory effects of testosterone were abolished by an aromatase inhibitor, indicating an important role of E2, the product of CYP19A2 activity, in the regulation of CYP19A2 and LHβ. Structural and functional analysis of the 5′-flanking region of the gene suggested that the sequence from −1076 to − 435 bp is critical for the basal promoter activity in the pituitary. This report demonstrates that CYP19A2 functions as an important factor in the reproductive endocrinology of teleosts through the brain-pituitary-gonadal axis.

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