title: [Murine beta-casein gene sequences direct a human tissue plasminogen activator variant expressed in the milk of transgenic mice].
abstract: To investigate the ability of our cloned murine beta-casein locus to direct the exogenous gene expression in the milk of transgenic mice, the human t-PA variant mammary gland expression vector under the control of murine beta-casein gene regulatory elements was constructed, in which the human t-PA variant signal-pro peptide sequence was replaced with murine beta-casein signal peptide sequence and the human t-PA variant mature peptide cDNA was inserted into the second exon of beta-casein gene. The fusion gene was microinjected in the fertilized mice eggs. A total of 285 embryos were microinjected and transferred into 13 surrogate mother mice. Twelve positive transgenic mice were identified through PCR and Southern blot analysis among 42 new born mice. Human t-PA variant was expressed in the milk of 7 transgenic mice, the highest expression level attained to 3.6593 micrograms/ml. The results demonstrated that the murine beta-casein gene regulatory elements can direct the human t-PA variant gene successfully express in the milk of transgenic mice. It lays great foundation for the research on the beta-casein knock-in mice mammary gland bioreactor model construction.
authors.affiliation: Institute of Biotechnology, Academy of Military Medical Sciences, Beijing 100071, China.
authors.forename: Fu-Yu
authors.initials: FY
authors.lastname: Lin
authors.forename: Xuan
authors.initials: X
authors.lastname: Cheng
authors.forename: Hong-Xing
authors.initials: HX
authors.lastname: Chen
authors.forename: Xiao-Hong
authors.initials: XH
authors.lastname: Tan
authors.forename: Jing
authors.initials: J
authors.lastname: Cheng
authors.forename: Xiao
authors.initials: X
authors.lastname: Yang
authors.forename: Ji-Xian
authors.initials: JX
authors.lastname: Deng
authors.forename: Pei-Tang
authors.initials: PT
authors.lastname: Huang
mesh_terms: D000818:Animals; D002364:Caseins / Q000235:genetics*; D005260:Female; D006801:Humans; D008297:Male; D051379:Mice; D008822:Mice, Transgenic; D008892:Milk / Q000378:metabolism*; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D010959:Tissue Plasminogen Activator / Q000235:genetics* / Q000378:metabolism
chemical_list: D002364:Caseins; D011993:Recombinant Fusion Proteins; C083866:T103N, KHRR 296-299 AAAA; D010959:Tissue Plasminogen Activator