title: Inducible and reversible regulation of endogenous gene in mouse.
abstract: Methods for generating loss-of-function mutations, such as conventional or conditional gene knockout, are widely used in deciphering gene function in vivo. By contrast, inducible and reversible regulation of endogenous gene expression has not been well established. Using a mouse model, we demonstrate that a chimeric transcriptional repressor molecule (tTS) can reversibly inhibit the expression of an endogenous gene, Nmyc. In this system, a tetracycline response element (TRE) artificially inserted near the target gene's promoter region turns the gene on and off in a tetracycline-inducible manner. Nmyc(TRE) mice were generated by inserting a TRE into the first intron of Nmyc by the knockin technique. Nmyc(TRE) mice were crossed to tTS transgenic mice to produce Nmyc(TRE/TRE): tTS embryos. In these embryos, tTS blocked Nmyc expression, and embryonic lethality was observed at E11.5d. When the dam was exposed to drinking water containing doxycycline (dox), normal endogenous Nmyc expression was rescued, and the embryo survived to birth. This novel genetic modification strategy based on the tTS-dox system for inducible and reversible regulation of endogenous mouse genes will be a powerful tool to investigate target genes that cause embryonic lethality or other defects where reversible regulation or temporary shutdown of the target gene is needed.
authors.affiliation: Shanghai Research Center for Model Organisms, Shanghai 201210, People's Republic of China.
authors.forename: Ruilin
authors.initials: R
authors.lastname: Sun
authors.forename: Kai
authors.initials: K
authors.lastname: Zhao
authors.forename: Ruling
authors.initials: R
authors.lastname: Shen
authors.forename: Lei
authors.initials: L
authors.lastname: Cai
authors.forename: Xingyu
authors.initials: X
authors.lastname: Yang
authors.forename: Ying
authors.initials: Y
authors.lastname: Kuang
authors.forename: Jifang
authors.initials: J
authors.lastname: Mao
authors.forename: Fang
authors.initials: F
authors.lastname: Huang
authors.forename: Zhugang
authors.initials: Z
authors.lastname: Wang
authors.forename: Jian
authors.initials: J
authors.lastname: Fei
mesh_terms: D000818:Animals; D002525:Cerebellar Cortex / Q000002:abnormalities / Q000254:growth & development / Q000378:metabolism; D004318:Doxycycline / Q000494:pharmacology; D005786:Gene Expression Regulation / Q000187:drug effects; D055879:Gene Knock-In Techniques; D018390:Gene Targeting / Q000379:methods*; D005804:Genes, Lethal; D049452:Green Fluorescent Proteins / Q000032:analysis / Q000235:genetics; D051379:Mice; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D016271:Proto-Oncogene Proteins c-myc / Q000235:genetics* / Q000378:metabolism; D012097:Repressor Proteins / Q000235:genetics; D020218:Response Elements; D013576:Syndactyly / Q000209:etiology
chemical_list: C489428:Myc protein, mouse; D016271:Proto-Oncogene Proteins c-myc; D012097:Repressor Proteins; C485184:enhanced green fluorescent protein; C034811:tetracycline resistance-encoding transposon repressor protein; D049452:Green Fluorescent Proteins; D004318:Doxycycline