title: Tet-on inducible system combined with in ovo electroporation dissects multiple roles of genes in somitogenesis of chicken embryos.
abstract: The in ovo electroporation technique in chicken embryos has enabled investigators to uncover the functions of numerous developmental genes. In this technique, the ubiquitous promoter, CAGGS (CMV base), has often been used for overexpression experiments. However, if a given gene plays a role in multiple steps of development and if overexpression of this gene causes fatal consequences at the time of electroporation, its roles in later steps of development would be overlooked. Thus, a technique with which expression of an electroporated DNA can be controlled in a stage-specific manner needs to be formulated. Here we show for the first time that the tetracycline-controlled expression method, "tet-on" and "tet-off", works efficiently to regulate gene expression in electroporated chicken embryos. We demonstrate that the onset or termination of expression of an electroporated DNA can be precisely controlled by timing the administration of tetracycline into an egg. Furthermore, with this technique we have revealed previously unknown roles of RhoA, cMeso-1 and Pax2 in early somitogenesis. In particular, cMeso-1 appears to be involved in cell condensation of a newly forming somite by regulating Pax2 and NCAM expression. Thus, the novel molecular technique in chickens proposed in this study provides a useful tool to investigate stage-specific roles of developmental genes.
authors.affiliation: Graduate School of Biological Sciences, Nara Institute of Science and Technology, 8916-5, Takayama, Ikoma, Nara, 630-0192, Japan.
authors.forename: Tadayoshi
authors.initials: T
authors.lastname: Watanabe
authors.forename: Daisuke
authors.initials: D
authors.lastname: Saito
authors.forename: Koji
authors.initials: K
authors.lastname: Tanabe
authors.forename: Rinako
authors.initials: R
authors.lastname: Suetsugu
authors.forename: Yukiko
authors.initials: Y
authors.lastname: Nakaya
authors.forename: Shinichi
authors.initials: S
authors.lastname: Nakagawa
authors.forename: Yoshiko
authors.initials: Y
authors.lastname: Takahashi
mesh_terms: D000818:Animals; D030801:Animals, Genetically Modified; D002642:Chick Embryo; D002645:Chickens / Q000235:genetics*; D018274:Electroporation; D018507:Gene Expression Regulation, Developmental / Q000502:physiology*; D049452:Green Fluorescent Proteins / Q000235:genetics; D010957:Plasmids; D019170:Somites / Q000502:physiology*; D013752:Tetracycline / Q000378:metabolism
chemical_list: C485184:enhanced green fluorescent protein; D049452:Green Fluorescent Proteins; D013752:Tetracycline