Tetracycline-dependent expression of the human erythropoietin gene in transgenic chickens.
A critical problem in the production of transgenic animals is the uncontrolled constitutive expression of the foreign gene, which occasionally results in serious physiological disorders in the transgenic animal. In this study, we report successful production of transgenic chickens that express the human erythropoietin (hEPO) gene under the control of a tetracycline-inducible promoter. A recombinant Moloney murine leukemia virus (MoMLV)-based retrovirus vector encapsidated with vesicular stomatitis virus G glycoprotein (VSV-G) was injected beneath the blastoderm of unincubated chicken embryos (stage X). Out of 198 injected eggs, 15 chicks hatched after 21 days of incubation and 14 hatched chicks expressed the vector-encoded hEPO gene when fed doxycycline, a tetracycline derivative, without any significant physiological dysfunctions. The expression of hEPO reverted to the pre-induction state by removing doxycycline from the diet. The biological activity of the hEPO produced in the transgenic chickens was comparable to commercially available CHO cell-derived hEPO. Successful germline transmission of the transgene was also confirmed in G1 transgenic chicks produced from crossing G0 transgenic roosters with non-transgenic hens. Tetracycline-inducible expression of the hEPO gene was also confirmed in the blood and eggs of the transgenic chickens.
Department of Physiology, Catholic University of Daegu School of Medicine, Daegu, Korea.
Bon Chul
BC
Koo
Mo Sun
MS
Kwon
Hyuna
H
Lee
Minjee
M
Kim
Dohyang
D
Kim
Ji Yeol
JY
Roh
Yoon-Yub
YY
Park
Xiang-Shun
XS
Cui
Nam-Hyung
NH
Kim
Sung June
SJ
Byun
Teoan
T
Kim
D000818:Animals; D030801:Animals, Genetically Modified / Q000235:genetics / Q000378:metabolism*; D002645:Chickens / Q000235:genetics / Q000378:metabolism*; D017931:DNA Primers / Q000235:genetics; D004921:Erythropoietin / Q000235:genetics* / Q000378:metabolism*; D005786:Gene Expression Regulation / Q000187:drug effects*; D018014:Gene Transfer Techniques; D005822:Genetic Vectors / Q000235:genetics; D006801:Humans; D016014:Linear Models; D008562:Membrane Glycoproteins; D008979:Moloney murine leukemia virus; D011401:Promoter Regions, Genetic / Q000187:drug effects*; D013752:Tetracycline / Q000494:pharmacology*; D014759:Viral Envelope Proteins
D017931:DNA Primers; C028391:G protein, vesicular stomatitis virus; D008562:Membrane Glycoproteins; D014759:Viral Envelope Proteins; D004921:Erythropoietin; D013752:Tetracycline