
Google ha implementado una nueva característica a su sistema de búsqueda que ahorrara mucho tiempo. Ahora traducir palabras a diferentes idiomas es mucho mas fácil. para aprovechar al máximo el servicio simplemente busca “traducir palabra a idioma”. Es un tip practico.













José Ma. Morelos 139c Centro CP. 76000, Santiago de Querétaro, Querétaro, MX
Tel: 442 2240585
info@gdideas.com [
hola mami
Published online February 16, 2009
doi:10.1083/jcb.200809077
The Journal of Cell Biology
The Rockefeller University Press, 0021-9525 $30.00
© 2009 Daniels et al.
________________________________________REPORT
Asymmetric enrichment of PIE-1 in the Caenorhabditis elegans zygote mediated by binary counterdiffusion
Brian R. Daniels1, Edward M. Perkins2, Terrence M. Dobrowsky1,3, Sean X. Sun1,3,4, and Denis Wirtz1,3
1 Department of Chemical and Biomolecular Engineering, 2 Integrated Imaging Center, 3 Howard Hughes Medical Institute Graduate Training Program and Institute for NanoBioTechnology, and 4 Department of Mechanical Engineering, The Johns Hopkins University, Baltimore, MD 21218
To generate cellular diversity in developing organisms while simultaneously maintaining the developmental potential of the germline, germ cells must be able to preferentially endow germline daughter cells with a cytoplasmic portion containing specialized cell fate determinants not inherited by somatic cells. In Caenorhabditis elegans, germline inheritance of the protein PIE-1 is accomplished by first asymmetrically localizing the protein to the germplasm before cleavage and subsequently degrading residual levels of the protein in the somatic cytoplasm after cleavage. Despite its critical involvement in cell fate determination, the enrichment of germline determinants remains poorly understood. Here, combining live-cell fluorescence methods and kinetic modeling, we demonstrate that the enrichment process does not involve protein immobilization, intracellular compartmentalization, or localized protein degradation. Instead, our results support a heterogeneous reaction/diffusion model for PIE-1 enrichment in which the diffusion coefficient of PIE-1 is reversibly reduced in the posterior, resulting in a stable protein gradient across the zygote at steady state.
Abbreviations used in this paper: A/P, anterior/posterior; FCS, fluorescence correlation spectroscopy; ROI, region of interest; UTR, untranslated region.
© 2009 Daniels et al. This article is distributed under the terms of an Attribution–Noncommercial–Share Alike–No Mirror Sites license for the first six months after the publication date (see http://www.jcb.org/misc/terms.shtml).