Developmental expression of cytochrome P450 aromatase genes (CYP19a and CYP19b) in zebrafish fry (<i>Danio rerio</i>)

Wiley - Tập 290 Số 5 - Trang 475-483 - 2001
John M. Trant1, Sonja Gavasso1, J. Ackers1, Bon‐chu Chung2, Allen R. Place1
1Center of Marine Biotechnology, University of Maryland Biotechnology Institute, Baltimore, Maryland, 21202
2Institute of Molecular Biology, Academia Sinica, Taiwan.

Tóm tắt

AbstractCytochrome P450 aromatase (CYP19) is the terminal enzyme in the steroidogenic pathway that converts androgens (e.g., testosterone) into estrogens (e.g., estradiol). Regulation of this gene dictates the ratio of androgens to estrogens; therefore, appropriate expression of this enzyme is critical for reproduction as well as being pivotal in sex differentiation for most vertebrates. It is assumed that most vertebrates have a single CYP19 gene that is regulated by multiple tissue‐specific promoter regions. However, the zebrafish (Danio rerio) has two genes (CYP19a and CYP19b), each encoding a significantly different protein and possessing its own regulatory mechanism. The primary purpose of this study was to determine the pattern of expression of each of the CYP19 genes in the developing zebrafish. A fluorescent‐based method of real‐time, quantitative RT‐PCR provided the sensitivity and specificity to determine transcript abundance in single embryos/juveniles harvested at days 0 through 41 days post‐fertilization (dpf), which encompasses the developmental events of sex determination and gonadal differentiation. CYP19 transcripts could be detected as early as 3 or 4 dpf, (CYP19a and CYP19b, respectively) and peak abundance was detected on day five. In general, the CYP19 genes differed significantly in the ontogeny of their expression. In most cases, the gonadal form of CYP19 (CYP19a) was more abundant than the brain form (CYP19b); however, unlike CYP19a, the pattern of CYP19b expression could be clearly segregated into two populations, suggesting an association with sex differentiation. Pharmacological steroids (ethinylestradiol and 17α‐methyltestosterone) enhanced the expression of the CYP19b gene at all three days examined (4, 6, and 10 dpf). These data suggest that the timely and appropriate expression of CYP19 is important in development and that the expression of CYP19b (the “extra‐gonadal” form) may be associated with sexual differentiation if not sexual determination. J. Exp. Zool. 290:475–483, 2001. © 2001 Wiley‐Liss, Inc.

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Tài liệu tham khảo

10.1007/s000180050344

10.1002/jez.1402640109

10.1093/icb/23.3.607

10.1016/0016-6480(81)90013-7

Callard GV, 1981, Biochemical evidence for aromatization of androgen to estrogen in the pituitary, Gen Comp Endocrinol, 44, 364, 10.1016/0016-6480(81)90013-7

10.1016/0016-6480(84)90060-1

10.1016/0960-0760(93)90257-W

10.1677/jme.0.0180057

ChiangEF‐L YanY‐L TongS‐K HsiaoP‐H GuiguenY PostlethwaitJ ChungB‐C.2001.Characterization of duplicated zebrafish cyp 19 genes. Second International Symposium on the Biology of Vertebrate Sex Determination. Honolulu Hawaii. April10–14 2000.

10.1089/dna.1997.16.769

Chung B‐C, 2000, Molecular Steroidogenesis, 317

10.1016/S0960-0760(97)80040-4

10.1016/0303-7207(95)03607-9

10.1210/en.140.11.5202

Ekker M, 1996, Stable transfer of zebrafish chromosome segments into mouse cells, Genomics, 33, 57, 10.1006/geno.1996.0159

10.1002/(SICI)1098-2795(199611)45:3<285::AID-MRD4>3.0.CO;2-O

10.1016/S0303-7207(98)00015-X

10.1101/gr.6.10.986

Hudson TJ, 1995, An STS‐based map of the human genome, Science, 270, 1945, 10.1126/science.270.5244.1945

10.1016/S0303-7207(00)00228-8

10.1002/(SICI)1097-010X(19980801)281:5<428::AID-JEZ8>3.0.CO;2-Q

10.1016/0016-6480(82)90208-8

10.1016/0016-6480(80)90026-X

Kwok C, 1998, Characterization of whole genome radiation hybrid mapping resources for non‐mammalian vertebrates, Nucleic Acids Res, 26, 3562, 10.1093/nar/26.15.3562

10.1016/S0091-679X(08)61906-8

10.1016/0165-0173(96)00002-1

Lin Y‐WP, 1991, Proc. of Fourth Intern. Symp. on the Reproductive Physiology of Fish. Fish Symp 91, 74

10.1210/mend-5-12-2005

10.1074/jbc.270.22.13561

10.1016/S0303-7207(97)00178-0

10.1016/0016-6480(85)90344-2

PE Applied Biosystems.1997.ABI PRISM 7700 Sequence Detection System. User Bulletin #2.

10.1210/en.138.12.5125

10.1210/en.139.4.1610

Simpson ER, 1994, Aromatase cytochrome P450, the enzyme responsible for estrogen biosynthesis, Endocr Rev, 15, 342

10.1016/0016-6480(85)90342-9

Tanaka M, 1992, Cloning and sequence analysis of the cDNA encoding P‐450 aromatase (P450arom) from a rainbow trout (Oncorhynchus mykiss) ovary; relationship between the amount of P450arom and the production of oestradiol‐17β in the ovary, J Mol Endocrinol, 8, 10.1677/jme.0.0080053

10.1093/oxfordjournals.jbchem.a124768

10.1210/endo.139.4.5899

Toda K, 1994, Identification and characterization of cis‐acting regulatory elements for the expression of the human aromatase cytochrome P‐450 gene, J Biol Chem, 269, 8099, 10.1016/S0021-9258(17)37165-X

10.1111/j.1432-1033.1990.tb19372.x

10.1006/gcen.1994.1113

Trant JM, 2000, Molecular Steroidogenesis, 313

10.1016/S0960-0760(97)80038-6

Westerfield M, 1995, The zebrafish book—a guide for the laboratory use of zebrafish (Danio rerio)

10.1095/biolreprod29.2.310

10.1016/S0960-0760(97)80031-3

10.1210/me.9.3.340