Characterization of transgenic mice expressing EGFP under the control of the monkey 20α-hydroxysteroid dehydrogenase promoter
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摘要
To directly assess the molecular function of the monkey 20α-hydroxysteroid dehydrogenase(20α-HSD) promoter, we generated transgenic mice(tg) expressing enhanced green fluorescent protein(EGFP) under control of this promoter. We demonstrated that prostaglandin F2α induced 20α-HSD promoter activity in CHO cells in a dose-dependent manner. Furthermore, forskolin treatment markedly reduced 20α-HSD promoter activity, and prolactin exhibited weak inhibitory activity. The transgenic mouse obtained one positive founder male. The transgene was propagated in 10 successive generations without any notable defects to the progeny. EGFP and 20α-HSD in the tg mice were colocalized in the luteal cells of the ovary during late pregnancy. Strong EGFP and 20α-HSD protein signals were also detected in the adult testis. Immunohistochemical analysis revealed high EGFP levels in the seminiferous epithelium, whereas 20α-HSD was expressed in the seminiferous tubules. Our data suggest that the ovaries in monkey and mouse exhibit similar expression patterns of 20α-HSD during pregnancy. However, the expression pattern of EGFP in tg mice testis slightly differed from that of the endogenous 20α-HSD. Further investigation is required to elucidate the functional mechanisms underlying regulation of the monkey 20α-HSD promoter in the tg mice.
To directly assess the molecular function of the monkey 20α-hydroxysteroid dehydrogenase(20α-HSD) promoter, we generated transgenic mice(tg) expressing enhanced green fluorescent protein(EGFP) under control of this promoter. We demonstrated that prostaglandin F2α induced 20α-HSD promoter activity in CHO cells in a dose-dependent manner. Furthermore, forskolin treatment markedly reduced 20α-HSD promoter activity, and prolactin exhibited weak inhibitory activity. The transgenic mouse obtained one positive founder male. The transgene was propagated in 10 successive generations without any notable defects to the progeny. EGFP and 20α-HSD in the tg mice were colocalized in the luteal cells of the ovary during late pregnancy. Strong EGFP and 20α-HSD protein signals were also detected in the adult testis. Immunohistochemical analysis revealed high EGFP levels in the seminiferous epithelium, whereas 20α-HSD was expressed in the seminiferous tubules. Our data suggest that the ovaries in monkey and mouse exhibit similar expression patterns of 20α-HSD during pregnancy. However, the expression pattern of EGFP in tg mice testis slightly differed from that of the endogenous 20α-HSD. Further investigation is required to elucidate the functional mechanisms underlying regulation of the monkey 20α-HSD promoter in the tg mice.
To directly assess the molecular function of the monkey 20α-hydroxysteroid dehydrogenase(20α-HSD) promoter, we generated transgenic mice(tg) expressing enhanced green fluorescent protein(EGFP) under control of this promoter. We demonstrated that prostaglandin F2α induced 20α-HSD promoter activity in CHO cells in a dose-dependent manner. Furthermore, forskolin treatment markedly reduced 20α-HSD promoter activity, and prolactin exhibited weak inhibitory activity. The transgenic mouse obtained one positive founder male. The transgene was propagated in 10 successive generations without any notable defects to the progeny. EGFP and 20α-HSD in the tg mice were colocalized in the luteal cells of the ovary during late pregnancy. Strong EGFP and 20α-HSD protein signals were also detected in the adult testis. Immunohistochemical analysis revealed high EGFP levels in the seminiferous epithelium, whereas 20α-HSD was expressed in the seminiferous tubules. Our data suggest that the ovaries in monkey and mouse exhibit similar expression patterns of 20α-HSD during pregnancy. However, the expression pattern of EGFP in tg mice testis slightly differed from that of the endogenous 20α-HSD. Further investigation is required to elucidate the functional mechanisms underlying regulation of the monkey 20α-HSD promoter in the tg mice.
引文
Albarracin,C.T.,and Gibori,G.(1991).Prolactin action on luteal protein expression in the corpus luteum.Endocrinology 129,1821-1830.
Albarracin,C.T.,Parmer,T.G.,Duan,W.R.,Nelson,S.E.,and Gibori,G.(1994).Identification of a major prolactin-regulated protein as 20 alphahydroxysteroid dehydrogenase:coordinate regulation of its activity,protein content,and messenger ribonucleic acid expression.Endocrinology 134,2453-2460.
Bryndová,J.,Klusonová,P.,Kucka,M.,Mazancová-Vagnerová,K.,Miksík,I.,and Pácha,J.(2006).Cloning and expression of chicken 20-hydroxysteroid dehydrogenase.J Mol Endocrinol 37,453-462.
Deis,R.P.(1971).Induction of lactogenesis and abortion by prostaglandin F2αin pregnant rats.Nature 229,568-568.
Duleba,A.J.,Kim,K.S.,Yuen,B.H.,and Moon,Y.S.(1985).Inhibition of20α-hydroxysteroid dehydrogenase activity by follicle-stimulating hormone and androgens in cultured rat granulosa cells:a search for the mechanism of action.Biol Reproduct 33,401-410.
Ge,R.S.,and Hardy,M.P.(1988).Variation in the end products of androgen biosynthesis and metabolism during postnatal differentiation of rat L-eydig cells.Endocrinology 139,3787-3795.
Fanjul,L.F.,Ruiz de Galarreta,C.M.,and Hsueh,A.J.W.(1984).Estrogen regulation of progestin biosynthetic enzymes in cultured rat granulosa cells.Biol Reprod 30,903-912.
Hara,A.,Taniguchi,H.,Nakayama,T.,and Sawada,H.(1990).Purification and properties of multiple forms of dihydrodiol dehydrogenase from human liver.J Biochem 108,250-254.
Higaki,Y.,Kamiya,T.,Usami,N.,Shintani,S.,Shiraishi,H.,Ishikura,S.,Yamamoto,I.,and Hara,A.(2002).Molecular characterization of two monkey dihydrodiol dehydrogenases.Drug Metab Pharmacokinet 17,348-356.
Hirabayashi,K.,Ishida,M.,Suzuki,M.,Yamanouchi,K.,and Nishihara,M.(2004).Characterization and functional analysis of the 5′-flanking region of the mouse 20α-hydroxysteroid dehydrogenase gene.Biochem J 382,975-980.
Jez,J.M.,Bennett,M.J.,Schlegel,B.P.,Lewis,M.,and Penning,T.M.(1997).Comparative anatomy of the aldo-keto reductase superfamily.Biochem J 326,625-636.
Kim,H.H.,Kwak,D.H.,Yon,J.M.,Baek,I.J.,Lee,S.R.,Lee,J.E.,Nahm,S.S.,Jeong,J.H.,Lee,B.J.,Yun,Y.W.,et al.(2007).Differential expression of 3β-hydroxysteroid dehydrogenase m RNA in rat testes exposed to endocrine disruptors.J Reprod Dev 53,465-471.
Kim,S.H.,Shin,Y.S.,Kang,M.H.,Yoon,J.T.,and Min,K.S.(2014).Gene expression and localization of 20α-hydroxysteroid dehydrogenase(H-SD)in reproductive tissues during early pregnancy of cattle.Animal Reprod Sci 147,1-9.
Liu,H.,Bellemare,V.,Labrie,F.,and Luu-The,V.(2007).Molecular characterization of the cynomolgus monkey Macaca fascicularis steroidogenic enzymes belonging to the aldo-keto reductase family.J Steroid Biochem Mol Biol 104,75-80.
Madore,E.,Harvey,N.,Parent,J.,Chapdelaine,P.,Arosh,J.A.,and Fortier,M.A.(2003).An aldose reductase with 20α-hydroxysteroid dehydrogenase activity is most likely the enzyme responsible for the production of prostaglandin F2αin the bovine endometrium.J Biol Chem 278,11205-11212.
Nakajima,T.,Yasuda,K.,Nishizawa,M.,Okada,H.,Yoshimura,T.,Ito,S.,and Kanzaki,H.(2003).Expression of 20.ALPHA.-hydroxysteroid dehydrogenase m RNA in human endometrium and decidua.Endocr J 50,105-111.
Nakajin,S.,Ohno,S.,and Shinoda,M.(1988).20β-hydroxysteroid dehydrogenase of neonatal pig testis:purification and some properties.JBiochem 104,565-569.
Naidansuren,P.,Park,C.W.,Kim,S.H.,Nanjidsuren,T.,Park,J.J.,Yun,S.J.,Sim,B.W.,Hwang,S.,Kang,M.H.,Ryu,B.Y.,et al.(2011).Molecular characterization of bovine placental and ovarian 20α-hydroxysteroid dehydrogenase.Reproduction 142,723-731.
Naidansuren,P.J.,Park,C.W.,Nanjidsuren,T.M.,Park,J.J.,Yun,S.J.,K-ang,M.H.,Yamanouchi,K.,and Min,K.S.(2012).Ovarian and placental expression of 20α-hydroxysteroid dehydrogenase during pregnancy in deer.Animal Reprod Sci 130,63-73.
Nanjidsuren,T.,Naidansuren,P.,Park,C.W.,Park,J.J.,Yun,S.J.,Sim,B.W.,Kang,M.H.,Lee,S.R.,Chang,K.T.,and Min,K.S.(2011).Expression and localization of the 20α-hydroxysteroid dehydrogenase(H-SD)enzyme in the reproductive tissues of the cynomolgus monkey Macaca fascicularis.J Steroid Biochem Mol Biol 127,337-344.
Nanjidsuren,T.,and Min,K.S.(2014).The transcription factor Ap-1 regulates monkey 20α-hydroxysteroid dehydrogenase promoter activity in CHO cells.BMC Biotechnol 14,71.
Nanjidsuren,T.,Yun,S.J.,Park,C.W.,Kim,M.S.,Kang,M.H.,and Min,K.S.(2014).Expression and localization of 20α-hydroxysteroid dehydrogenase(20α-HSD)in porcine reproductive tissues during pregnancy.Animal Reprod Sci 148,63-71.
Nishizawa,M.,Nakajima,T.,Yasuda,K.,Kanzaki,H.,Sasaguri,Y.,Watanabe,K.,and Ito,S.(2000).Close kinship of human 20alpha-hydroxysteroid dehydrogenase gene with three aldo-keto reductase genes.Genes Cells 5,111-125.
Olofsson,J.,Norjavaara,E.,and Selstam,G.(1992).Synthesis of prostaglandin F2α,E2 and prostacyclin in isolated corpora lutea of adult pseudopregnant rats throughout the luteal life-span.Prostaglandins L-eukot Essent Fatty Acids 46,151-161.
Ozaki,Y.,Higuchi,M.,Miura,C.,Yamaguchi,S.,Tozawa,Y.,and Miura,T.(2006).Roles of 11β-hydroxysteroid dehydrogenase in fish spermatogenesis.Endocrinology 147,5139-5146.
Park,C.W.,Kang,M.H.,and Min,K.S.(2015).Secretion of human protein C in mouse milk.Int J Mol Sci 16,4904-4917.
Penning,TM.(1997).Molecular endocrinology of hydroxysteroid dehydrogenase.Endocr Rev 18,281-305.
Penning,T.M.(2011).Human hydroxysteroid dehydrogenases and prereceptor regulation:insights into inhibitor design and evaluation.J Steroid Biochem Mol Biol 125,46-56.
Seo,K.S.,Naidansuren,P.,Kim,S.H.,Yun,S.J.,Park,J.J.,Sim,B.W.,Park,C.W.,Nanjidsuren,T.,Kang,M.H.,Seo,H.,et al.(2011).Expression of aldo-keto reductase family 1 member C1(AKR1C1)gene in porcine ovary and uterine endometrium during the estrous cycle and pregnancy.Reprod Biol Endocrinol 9,139.
Seong,H.H.,Min,K.S.,Kang,M.H.,Yoon,J.T.,Jin,H.J.,Chung,H.J.,Chang,W.K.,Yun,S.G.,and Shiota,K.(2002).Changes in ovarian and placental 20α-hydroxysteroid dehydrogenase activity during the pregnancy in the rat.Asian Aust J Anim Sci 16,342-347.
Shiota,K.,Seong,H.H.,Noda,K.,Hattori,N.,Ikeda,A.,Ogura,A.,and Itagaki,S.I.(1993).20.ALPHA.-hydroxysteroid dehydrogenase activity in rat placenta.Endocr J 40,673-681.
Sim,B.W.,and Min,K.S.(2014).Production of cloned mice by aggregation of tetraploid embryo.Animal Cells Syst 18,324-332.
Sreenivasulu,G.,Senthilkumaran,B.,Sridevi,P.,Rajakumar,A.,and Rasheeda,M.K.(2012).Expression and immunolocalization of 20β-hydroxysteroid dehydrogenase during testicular cycle and after h CGinduction,in vivo in the catfish,Clarias gariepinus.General Comp Endocrinol 175,48-54.
Stocco,C.O.,Zhong,L.,Sugimoto,Y.,Ichikawa,A.,Lau,L.F.,and Gibori,G.(2000).Prostaglandin F2α-induced expression of 20α-hydroxysteroid dehydrogenase involves the transcription factor NUR77.J Biol C-hem 275,37202-37211.
Stocco,C.O.,Lau,L.F.,and Gibori,G.(2002).A calcium/calmodulindependent activation of ERK1/2 mediates Jun D phosphorylation and induction of nur77 and 20α-hsd genes by prostaglandin F2αin ovarian cells.J Biol Chem 277,3293-3302.
Sudeshna,T.,Anand,K.,and Medhamurthy,R.(2013).Analysis of 20alpha-hydroxysteroid dehydrogenase expression in the corpus luteum of the buffalo cow:effect of prostaglandin F2-alpha treatment on circulating 20alpha-hydroxyprogesterone levels.Reprod Biol Endocrinol 11,111.
Telleria,C.M.,Stocco,C.O.,Stati,A.O.,and Deis,R.P.(1999).Progesterone receptor is not required for progesterone action in the rat corpus luteum of pregnancy.Steroids 64,760-766.
Yun,S.J.,Naidansuren,P.,Sim,B.W.,Park,J.J.,Park,C.W.,Nanjidsuren,T.,Kang,M.H.,Hwang,S.Y.,Yoon,J.T.,and Min,K.S.(2012).Aberrant phenotypes of transgenic mice expressing dimeric human erythropoietin.Reprod Biol Endocrinol 10,6.
Zhang,Y.,Dufort,I.,Rheault,P,and Luu-The,V(2000).Characterization of a human 20alpha-hydroxysteroid dehydrogenase.J Mol Endocrinol25,221-228.
Zhong,L.,Ou,J.,Barkai,U.,Mao,JF.,Frasor,J.,and Gibori,G.(1998).Molecular cloning and characterization of the rat ovarian 20alpha-hydroxysteroid dehydrogenase gene.BBRC 249,797-803.
Albarracin,C.T.,Parmer,T.G.,Duan,W.R.,Nelson,S.E.,and Gibori,G.(1994).Identification of a major prolactin-regulated protein as 20 alphahydroxysteroid dehydrogenase:coordinate regulation of its activity,protein content,and messenger ribonucleic acid expression.Endocrinology 134,2453-2460.
Bryndová,J.,Klusonová,P.,Kucka,M.,Mazancová-Vagnerová,K.,Miksík,I.,and Pácha,J.(2006).Cloning and expression of chicken 20-hydroxysteroid dehydrogenase.J Mol Endocrinol 37,453-462.
Deis,R.P.(1971).Induction of lactogenesis and abortion by prostaglandin F2αin pregnant rats.Nature 229,568-568.
Duleba,A.J.,Kim,K.S.,Yuen,B.H.,and Moon,Y.S.(1985).Inhibition of20α-hydroxysteroid dehydrogenase activity by follicle-stimulating hormone and androgens in cultured rat granulosa cells:a search for the mechanism of action.Biol Reproduct 33,401-410.
Ge,R.S.,and Hardy,M.P.(1988).Variation in the end products of androgen biosynthesis and metabolism during postnatal differentiation of rat L-eydig cells.Endocrinology 139,3787-3795.
Fanjul,L.F.,Ruiz de Galarreta,C.M.,and Hsueh,A.J.W.(1984).Estrogen regulation of progestin biosynthetic enzymes in cultured rat granulosa cells.Biol Reprod 30,903-912.
Hara,A.,Taniguchi,H.,Nakayama,T.,and Sawada,H.(1990).Purification and properties of multiple forms of dihydrodiol dehydrogenase from human liver.J Biochem 108,250-254.
Higaki,Y.,Kamiya,T.,Usami,N.,Shintani,S.,Shiraishi,H.,Ishikura,S.,Yamamoto,I.,and Hara,A.(2002).Molecular characterization of two monkey dihydrodiol dehydrogenases.Drug Metab Pharmacokinet 17,348-356.
Hirabayashi,K.,Ishida,M.,Suzuki,M.,Yamanouchi,K.,and Nishihara,M.(2004).Characterization and functional analysis of the 5′-flanking region of the mouse 20α-hydroxysteroid dehydrogenase gene.Biochem J 382,975-980.
Jez,J.M.,Bennett,M.J.,Schlegel,B.P.,Lewis,M.,and Penning,T.M.(1997).Comparative anatomy of the aldo-keto reductase superfamily.Biochem J 326,625-636.
Kim,H.H.,Kwak,D.H.,Yon,J.M.,Baek,I.J.,Lee,S.R.,Lee,J.E.,Nahm,S.S.,Jeong,J.H.,Lee,B.J.,Yun,Y.W.,et al.(2007).Differential expression of 3β-hydroxysteroid dehydrogenase m RNA in rat testes exposed to endocrine disruptors.J Reprod Dev 53,465-471.
Kim,S.H.,Shin,Y.S.,Kang,M.H.,Yoon,J.T.,and Min,K.S.(2014).Gene expression and localization of 20α-hydroxysteroid dehydrogenase(H-SD)in reproductive tissues during early pregnancy of cattle.Animal Reprod Sci 147,1-9.
Liu,H.,Bellemare,V.,Labrie,F.,and Luu-The,V.(2007).Molecular characterization of the cynomolgus monkey Macaca fascicularis steroidogenic enzymes belonging to the aldo-keto reductase family.J Steroid Biochem Mol Biol 104,75-80.
Madore,E.,Harvey,N.,Parent,J.,Chapdelaine,P.,Arosh,J.A.,and Fortier,M.A.(2003).An aldose reductase with 20α-hydroxysteroid dehydrogenase activity is most likely the enzyme responsible for the production of prostaglandin F2αin the bovine endometrium.J Biol Chem 278,11205-11212.
Nakajima,T.,Yasuda,K.,Nishizawa,M.,Okada,H.,Yoshimura,T.,Ito,S.,and Kanzaki,H.(2003).Expression of 20.ALPHA.-hydroxysteroid dehydrogenase m RNA in human endometrium and decidua.Endocr J 50,105-111.
Nakajin,S.,Ohno,S.,and Shinoda,M.(1988).20β-hydroxysteroid dehydrogenase of neonatal pig testis:purification and some properties.JBiochem 104,565-569.
Naidansuren,P.,Park,C.W.,Kim,S.H.,Nanjidsuren,T.,Park,J.J.,Yun,S.J.,Sim,B.W.,Hwang,S.,Kang,M.H.,Ryu,B.Y.,et al.(2011).Molecular characterization of bovine placental and ovarian 20α-hydroxysteroid dehydrogenase.Reproduction 142,723-731.
Naidansuren,P.J.,Park,C.W.,Nanjidsuren,T.M.,Park,J.J.,Yun,S.J.,K-ang,M.H.,Yamanouchi,K.,and Min,K.S.(2012).Ovarian and placental expression of 20α-hydroxysteroid dehydrogenase during pregnancy in deer.Animal Reprod Sci 130,63-73.
Nanjidsuren,T.,Naidansuren,P.,Park,C.W.,Park,J.J.,Yun,S.J.,Sim,B.W.,Kang,M.H.,Lee,S.R.,Chang,K.T.,and Min,K.S.(2011).Expression and localization of the 20α-hydroxysteroid dehydrogenase(H-SD)enzyme in the reproductive tissues of the cynomolgus monkey Macaca fascicularis.J Steroid Biochem Mol Biol 127,337-344.
Nanjidsuren,T.,and Min,K.S.(2014).The transcription factor Ap-1 regulates monkey 20α-hydroxysteroid dehydrogenase promoter activity in CHO cells.BMC Biotechnol 14,71.
Nanjidsuren,T.,Yun,S.J.,Park,C.W.,Kim,M.S.,Kang,M.H.,and Min,K.S.(2014).Expression and localization of 20α-hydroxysteroid dehydrogenase(20α-HSD)in porcine reproductive tissues during pregnancy.Animal Reprod Sci 148,63-71.
Nishizawa,M.,Nakajima,T.,Yasuda,K.,Kanzaki,H.,Sasaguri,Y.,Watanabe,K.,and Ito,S.(2000).Close kinship of human 20alpha-hydroxysteroid dehydrogenase gene with three aldo-keto reductase genes.Genes Cells 5,111-125.
Olofsson,J.,Norjavaara,E.,and Selstam,G.(1992).Synthesis of prostaglandin F2α,E2 and prostacyclin in isolated corpora lutea of adult pseudopregnant rats throughout the luteal life-span.Prostaglandins L-eukot Essent Fatty Acids 46,151-161.
Ozaki,Y.,Higuchi,M.,Miura,C.,Yamaguchi,S.,Tozawa,Y.,and Miura,T.(2006).Roles of 11β-hydroxysteroid dehydrogenase in fish spermatogenesis.Endocrinology 147,5139-5146.
Park,C.W.,Kang,M.H.,and Min,K.S.(2015).Secretion of human protein C in mouse milk.Int J Mol Sci 16,4904-4917.
Penning,TM.(1997).Molecular endocrinology of hydroxysteroid dehydrogenase.Endocr Rev 18,281-305.
Penning,T.M.(2011).Human hydroxysteroid dehydrogenases and prereceptor regulation:insights into inhibitor design and evaluation.J Steroid Biochem Mol Biol 125,46-56.
Seo,K.S.,Naidansuren,P.,Kim,S.H.,Yun,S.J.,Park,J.J.,Sim,B.W.,Park,C.W.,Nanjidsuren,T.,Kang,M.H.,Seo,H.,et al.(2011).Expression of aldo-keto reductase family 1 member C1(AKR1C1)gene in porcine ovary and uterine endometrium during the estrous cycle and pregnancy.Reprod Biol Endocrinol 9,139.
Seong,H.H.,Min,K.S.,Kang,M.H.,Yoon,J.T.,Jin,H.J.,Chung,H.J.,Chang,W.K.,Yun,S.G.,and Shiota,K.(2002).Changes in ovarian and placental 20α-hydroxysteroid dehydrogenase activity during the pregnancy in the rat.Asian Aust J Anim Sci 16,342-347.
Shiota,K.,Seong,H.H.,Noda,K.,Hattori,N.,Ikeda,A.,Ogura,A.,and Itagaki,S.I.(1993).20.ALPHA.-hydroxysteroid dehydrogenase activity in rat placenta.Endocr J 40,673-681.
Sim,B.W.,and Min,K.S.(2014).Production of cloned mice by aggregation of tetraploid embryo.Animal Cells Syst 18,324-332.
Sreenivasulu,G.,Senthilkumaran,B.,Sridevi,P.,Rajakumar,A.,and Rasheeda,M.K.(2012).Expression and immunolocalization of 20β-hydroxysteroid dehydrogenase during testicular cycle and after h CGinduction,in vivo in the catfish,Clarias gariepinus.General Comp Endocrinol 175,48-54.
Stocco,C.O.,Zhong,L.,Sugimoto,Y.,Ichikawa,A.,Lau,L.F.,and Gibori,G.(2000).Prostaglandin F2α-induced expression of 20α-hydroxysteroid dehydrogenase involves the transcription factor NUR77.J Biol C-hem 275,37202-37211.
Stocco,C.O.,Lau,L.F.,and Gibori,G.(2002).A calcium/calmodulindependent activation of ERK1/2 mediates Jun D phosphorylation and induction of nur77 and 20α-hsd genes by prostaglandin F2αin ovarian cells.J Biol Chem 277,3293-3302.
Sudeshna,T.,Anand,K.,and Medhamurthy,R.(2013).Analysis of 20alpha-hydroxysteroid dehydrogenase expression in the corpus luteum of the buffalo cow:effect of prostaglandin F2-alpha treatment on circulating 20alpha-hydroxyprogesterone levels.Reprod Biol Endocrinol 11,111.
Telleria,C.M.,Stocco,C.O.,Stati,A.O.,and Deis,R.P.(1999).Progesterone receptor is not required for progesterone action in the rat corpus luteum of pregnancy.Steroids 64,760-766.
Yun,S.J.,Naidansuren,P.,Sim,B.W.,Park,J.J.,Park,C.W.,Nanjidsuren,T.,Kang,M.H.,Hwang,S.Y.,Yoon,J.T.,and Min,K.S.(2012).Aberrant phenotypes of transgenic mice expressing dimeric human erythropoietin.Reprod Biol Endocrinol 10,6.
Zhang,Y.,Dufort,I.,Rheault,P,and Luu-The,V(2000).Characterization of a human 20alpha-hydroxysteroid dehydrogenase.J Mol Endocrinol25,221-228.
Zhong,L.,Ou,J.,Barkai,U.,Mao,JF.,Frasor,J.,and Gibori,G.(1998).Molecular cloning and characterization of the rat ovarian 20alpha-hydroxysteroid dehydrogenase gene.BBRC 249,797-803.