To establish a genetic tool for conditional deletion or expression of gene in neurons in a temporally controlled manner, we generated a transgenic mouse (NSE-MerCreMer), which expressed a tamoxifen inducible type of Cre recombinase specifically in neurons. The tamoxifen inducible Cre recombinase (MerCreMer) is a fusion protein containing Cre recombinase with two modified estrogen receptor ligand binding domains at both ends, and is driven by the neural-specific rat neural specific enolase (NSE) promoter. A total of two transgenic lines were established, and expression of MerCreMer in neurons of the central and enteric nervous systems was confirmed. Transcript of MerCreMer was detected in several non-neural tissues such as heart, liver, and kidney in these lines. In the background of the Cre reporter mouse strain Rosa26R, Cre recombinase activity was inducible in neurons of adult NSE-MerCreMer mice treated with tamoxifen by intragastric gavage, but not in those fed with corn oil only. We conclude that NSE-MerCreMer lines will be useful for studying gene functions in neurons for the conditions that Cre-mediated recombination resulting in embryonic lethality, which precludes investigation of gene functions in neurons through later stages of development and in adult.
References
[1]
Abremski K, Hoess R (1984) Bacteriophage P1 site-specific recombination. Purification and properties of the Cre recombinase protein. J Biol Chem 259: 1509–1514.
[2]
Hamilton DL, Abremski K (1984) Site-specific recombination by the bacteriophage P1 lox-Cre system. Cre-mediated synapsis of two lox sites. J Mol Biol 178: 481–486.
[3]
Nagy A (2000) Cre recombinase: the universal reagent for genome tailoring. Genesis 26: 99–109.
[4]
Metzger D, Feil R (1999) Engineering the mouse genome by site-specific recombination. Curr Opin Biotechnol 10: 470–476.
[5]
Yu Y, Bradley A (2001) Engineering chromosomal rearrangements in mice. Nat Rev Genet 2: 780–790.
[6]
Lewandoski M (2001) Conditional control of gene expression in the mouse. Nat Rev Genet 2: 743–755.
[7]
Danielian PS, Muccino D, Rowitch DH, Michael SK, McMahon AP (1998) Modification of gene activity in mouse embryos in utero by a tamoxifen-inducible form of Cre recombinase. Curr Biol 8: 1323–1326.
[8]
Hayashi S, McMahon AP (2002) Efficient recombination in diverse tissues by a tamoxifen-inducible form of Cre: a tool for temporally regulated gene activation/inactivation in the mouse. Dev Biol 244: 305–318.
[9]
Zhang Y, Riesterer C, Ayrall AM, Sablitzky F, Littlewood TD, et al. (1996) Inducible site-directed recombination in mouse embryonic stem cells. Nucleic Acids Res 24: 543–548.
[10]
Garcia EL, Mills AA (2002) Getting around lethality with inducible Cre-mediated excision. Semin Cell Dev Biol 13: 151–158.
[11]
Rossant J, McMahon A (1999) “Cre”-ating mouse mutants-a meeting review on conditional mouse genetics. Genes Dev 13: 142–145.
[12]
Schmechel DE, Marangos PJ (1983) Neuron specific enolase as a marker for differentiation in neurons and endocrine cells; Mckel-vey J, editor: New York: John Wiley & Sons.
[13]
Forss-Petter S, Danielson PE, Catsicas S, Battenberg E, Price J, et al. (1990) Transgenic mice expressing beta-galactosidase in mature neurons under neuron-specific enolase promoter control. Neuron 5: 187–197.
[14]
Marangos PJ, Schmechel DE, Parma AM, Goodwin FK (1980) Developmental profile of neuron-specific (NSE) and non-neuronal (NNE) enolase. Brain Res 190: 185–193.
[15]
Castillo MB, Celio MR, Andressen C, Gotzos V, Rulicke T, et al. (1995) Production and analysis of transgenic mice with ectopic expression of parvalbumin. Arch Biochem Biophys 317: 292–298.
[16]
Cinato E, Mirotsou M, Sablitzky F (2001) Cre-mediated transgene activation in the developing and adult mouse brain. Genesis 31: 118–125.
[17]
Hwang DY, Cho JS, Lee SH, Chae KR, Lim HJ, et al. (2004) Aberrant expressions of pathogenic phenotype in Alzheimer’s diseased transgenic mice carrying NSE-controlled APPsw. Exp Neurol 186: 20–32.
[18]
Kwon CH, Zhou J, Li Y, Kim KW, Hensley LL, et al. (2006) Neuron-specific enolase-cre mouse line with cre activity in specific neuronal populations. Genesis 44: 130–135.
[19]
Patzke H, Maddineni U, Ayala R, Morabito M, Volker J, et al. (2003) Partial rescue of the p35？/？ brain phenotype by low expression of a neuronal-specific enolase p25 transgene. J Neurosci 23: 2769–2778.
[20]
Soriano P (1999) Generalized lacZ expression with the ROSA26 Cre reporter strain. Nat Genet 21: 70–71.
[21]
Gillies K, Price DJ (1993) Cell migration and subplate loss in explant cultures of murine cerebral cortex. Neuroreport 4: 911–914.
[22]
Levers TE, Edgar JM, Price DJ (2001) The fates of cells generated at the end of neurogenesis in developing mouse cortex. J Neurobiol 48: 265–277.
[23]
Young HM, Newgreen D (2001) Enteric neural crest-derived cells: origin, identification, migration, and differentiation. Anat Rec 262: 1–15.
