Abstract
The X-linkedXist gene is imprinted and is expressed from the paternal allele only in preimplantation development.Mouse Xist was analysed in preimplantation embryos. We found that the onset ofXist expression occurs at the G2-phase of the 2-cell embryos. At this same stage of development a number of newly synthesised embryonic transcripts appear, marking the passage from maternal to embryonic control of development. Some of these genes have been proved to be regulated by a zygotic clock which is set upon egg-activation at fertilization. Following treatment of 1-cell embryos with aphidicolin and cytochalasin D inhibitors of DNA replication and cytokinesis, respectively, here we show thatXist expression is dependent on first and second round of DNA replications and is regulated by a zygotic clock.
Riassunto
Il gene «imprintato»Xist, localizzato sul cromosoma X, viene espresso solo dall’allele paterno durante lo sviluppo preimpianto dell’embrione. In questa ricerca abbiamo analizzato l’espressione diXist durante i primi due cicli cellulari dello sviluppo preimpianto dell’embrione di topo. L’attivazione dell’espressione diXist avviene precisamente durante la fase G2 nell’embrione a 2 cellule. A questo stadio dello sviluppo embrionale diversi trascritti di nuova sintesi appaiono nell’embrione, marcando il passaggio dal controllo materno a quello embrionale dello sviluppo. Alcuni di questi geni sono regolati da un «orologio zigotico» che viene attivato al momento della fecondazione della cellula uovo. In questo studio dimostriamo che, in seguito a trattamento di embrioni ad 1 cellula con afidicolina e citocalasina D, inibitori della replicazione del DNA e della citodieresi, rispettivamente, l’espressione diXist è dipendente dalla prima e seconda replicazione del DNA e da un «orologio zigotico».
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References
Ariel M., Robinson E., McCarrey J. R., Cedar H., 1995.Gamete-specific methylation correlates with imprinting of the murine Xist gene. Nat. Genet., 9: 312–315.
Borsani G., Tonlorenzi R., Simmler M. C., Dandolo L., Arnaud D., Capra V., Grompe M., Pizzuti A., Muzny D., Lawrence C., Willard H. F., Avner P., Ballabio A., 1991.Characterization of a murine gene expressed from the inactive X chromosome. Nature, 23: 325–329.
Davis W. Jr.,De Sousa P. A., Schultz R. M., 1996.Transient expression of t*ranslation initiation factor eIF-4C during the 2-cell stage of the preimplantation mouse embryo: identification by mRNA differential display and the role of DNA replication in zygotic gene activation. Dev. Biol., 174: 190–201.
Felsenfeld G., 1992.Chromatin as an essential part of the transcriptional mechanism. Nature, 355: 219–224.
Fulton B.P., Whittingham D.G., 1978.Activation of mammalian oocytes by intracellular injection of calcium. Nature, 273: 149–151.
Heard E., Clerc P., Avner P., 1997.X-chromosome inactivation in mammals. Annu. Rev. Genet., 31: 571–610.
Kay G. F., Penny G. D., Patel D., Ashworth A., Brockdorff N., Rastan S., 1993.Expression of Xist during mouse development suggests a role in the initiation of X chromosome inactivation. Cell, 72: 171–182.
Kay G. F., Barton S. C., Surani M. A., Rastan S., 1994.Imprinting and X chromosome counting mechanisms determine Xist expression in early mouse development. Cell, 77: 639–650.
Lyon M.F., 1961.Gene action in the X chromosome of the mouse (Mus musculusL.). Nature, 190: 373–374.
Majumder S., DePamphilis M. L., 1995.Unique role for enhancers is revealed during early mouse development. Bioessays, 17: 879–889.
Monk M., Harper M. I., 1979.Sequential X chromosome inactivation coupled with cellular differentiation in early mouse embryos. Nature, 281: 311–313.
Norris D. P., Patel D., Kay G. F., Penny G. D., Brockdorff N., Sheardown S. A., Rastan S., 1994.Evidence that random and imprinted Xist expression is controlled by preemptive methylation. Cell, 8: 41–51.
Schultz R.M., 1993.Regulation of zygotic gene activation in the mouse. Bioessays, 15: 531–538.
Takagi N., Sasaki M., 1975.Preferential inactivation of the paternally derived X chromosome in the extraembryonic membranes of the mouse. Nature, 21: 640–642.
Whittingham D. G., 1971.Culture of mouse ova. J. Reprod. Fertil. Suppl., 14: 7–21.
Zuccotti M., Monk M., 1995.Methylation of the mouse Xist gene in sperm and eggs correlates with imprinted Xist expression and paternal X-inactivation. Nat. Genet., 9: 316–320.
Zuccotti M., Giorgi Rossi P., Garagna S., Redi C. A., 1998.Meiotic and developmental competence of mouse antral oocytes. Biol. Reprod., 58: 700–704.
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Nella seduta del 24 aprile 1998.
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Zuccotti, M., Boiani, M., Garagna, S. et al. Timing of mouse xist expression during preimplantation development. Rend. Fis. Acc. Lincei 9, 139–147 (1998). https://doi.org/10.1007/BF02904396
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DOI: https://doi.org/10.1007/BF02904396