caa a22 4500 445840331 CHVBK 20180317145342.0 cr unu---uuuuu 170323e20110701xx s 000 0 eng 10.1007/s00709-011-0276-3 doi (NATIONALLICENCE)springer-10.1007/s00709-011-0276-3 Extremes in rapid cellular morphogenesis: post-transcriptional regulation of spermatogenesis in Marsilea vestita [Elektronische Daten] [Stephen Wolniak, Corine van der Weele, Faten Deeb, Thomas Boothby, Vincent Klink] The endosporic male gametophyte of the water fern, Marsilea vestita, provides a unique opportunity to study the mechanisms that control cell fate determination during a burst of rapid development. In this review, we show how the spatial and temporal control of development in this simple gametophyte involves several distinct modes of RNA processing that allow the translation of specific mRNAs at distinct stages during gametogenesis. During the early part of development, nine successive cell division cycles occur in precise planes within a closed volume to produce seven sterile cells and 32 spermatids. There is no cell movement in the gametophyte; so, cell position and size within the spore wall define cell fate. After the division cycles have been completed, the spermatids become sites for the de novo formation of basal bodies, for the assembly of a complex cytoskeleton, for nuclear and cell elongation, and for ciliogenesis. In contrast, the adjacent sterile cells exhibit none of these changes. The spermatids differentiate into multiciliated, corkscrew-shaped gametes that resemble no other cells in the entire plant. Development is controlled post-transcriptionally. The transcripts stored in the microspore are released (unmasked) in the gametophyte at different times during development. At the start of these studies, we identified several key mRNAs that undergo translation at specific stages of gametophyte development. We developed RNA silencing protocols that enabled us to block the translation of these proteins and thereby establish their necessity and sufficiency for the completion of specific stages of gametogenesis. In addition, RNAi enabled us to identify additional proteins that are essential for other phases of development. Since the distributions of mRNAs and the proteins they encode are not identical in the gametophyte, transcript processing is apparently important in allowing translation to occur under strict temporal and spatial control. Transcript polyadenylation occurs in the spermatogenous cells in ways that match the translation of specific mRNAs. We have found that the exon junction complex plays key roles in transcript regulation and modifications that underlie cell specification in the gametophyte. We have recently become interested in the mechanisms that control the unmasking of the stored transcripts and have linked the synthesis and redistribution of spermidine in the gametophyte to the control of mRNA release from storage during early development and later to basal body formation, cytoskeletal assembly, and nuclear and cell elongation in the differentiating spermatids. Springer-Verlag, 2011 Gametogenesis nationallicence Morphogenesis nationallicence Spermatogenesis nationallicence Marsilea vestita nationallicence Cell division nationallicence Blepharoplast nationallicence Post-transcriptional regulation nationallicence Wolniak Stephen Department of Cell Biology and Molecular Genetics, University of Maryland, 20742, College Park, MD, USA aut van der Weele Corine Department of Cell Biology and Molecular Genetics, University of Maryland, 20742, College Park, MD, USA aut Deeb Faten Department of Cell Biology and Molecular Genetics, University of Maryland, 20742, College Park, MD, USA aut Boothby Thomas Department of Cell Biology and Molecular Genetics, University of Maryland, 20742, College Park, MD, USA aut Klink Vincent Department of Cell Biology and Molecular Genetics, University of Maryland, 20742, College Park, MD, USA aut Protoplasma Springer Vienna 248/3(2011-07-01), 457-473 0033-183X 248:3<457 2011 248 709 https://doi.org/10.1007/s00709-011-0276-3 text/html Onlinezugriff via DOI 1 review-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s00709-011-0276-3 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Wolniak Stephen Department of Cell Biology and Molecular Genetics, University of Maryland, 20742, College Park, MD, USA aut NATIONALLICENCE 700 1- van der Weele Corine Department of Cell Biology and Molecular Genetics, University of Maryland, 20742, College Park, MD, USA aut NATIONALLICENCE 700 1- Deeb Faten Department of Cell Biology and Molecular Genetics, University of Maryland, 20742, College Park, MD, USA aut NATIONALLICENCE 700 1- Boothby Thomas Department of Cell Biology and Molecular Genetics, University of Maryland, 20742, College Park, MD, USA aut NATIONALLICENCE 700 1- Klink Vincent Department of Cell Biology and Molecular Genetics, University of Maryland, 20742, College Park, MD, USA aut NATIONALLICENCE 773 0- Protoplasma Springer Vienna 248/3(2011-07-01), 457-473 0033-183X 248:3<457 2011 248 709 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer