title: Mago nashi is essential for spermatogenesis in Marsilea.
abstract: Spermatogenesis in Marsilea vestita is a rapid process that is activated by placing dry microspores into water. Nine division cycles produce seven somatic cells and 32 spermatids, where size and position define identity. Spermatids undergo de novo formation of basal bodies in a particle known as a blepharoplast. We are interested in mechanisms responsible for spermatogenous initial formation. Mago nashi (Mv-mago) is a highly conserved gene present as stored mRNA and stored protein in the microspore. Mv-mago protein increases in abundance during development and it localizes at discrete cytoplasmic foci (Mago-dots). RNA interference experiments show that new Mv-mago protein is required for development. With Mv-mago silenced, asymmetric divisions become symmetric, cell fate is disrupted, and development stops. The alpha-tubulin protein distribution, centrin translation, and Mv-PRP19 mRNA distribution are no longer restricted to the spermatogenous cells. Centrin aggregations, resembling blepharoplasts, occur in jacket cells. Mago-dots are undetectable after the silencing of Mv-mago, Mv-Y14, or Mv-eIF4AIII, three core components of the exon junction complex (EJC), suggesting that Mago-dots are either EJCs in the cytoplasm, or Mv-mago protein aggregations dependent on EJCs. Mv-mago protein and other EJC components apparently function in cell fate determination in developing male gametophytes of M. vestita.
authors.affiliation: Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, MD 20742, USA.
authors.forename: Corine M
authors.initials: CM
authors.lastname: van der Weele
authors.forename: Chia-Wei
authors.initials: CW
authors.lastname: Tsai
authors.forename: Stephen M
authors.initials: SM
authors.lastname: Wolniak
mesh_terms: D000595:Amino Acid Sequence; D000906:Antibodies / Q000494:pharmacology; D018076:DNA, Complementary; D005854:Germ Cells / Q000166:cytology / Q000187:drug effects; D043964:Marsileaceae / Q000187:drug effects / Q000502:physiology*; D008969:Molecular Sequence Data; D010940:Plant Proteins / Q000737:chemistry / Q000378:metabolism*; D011058:Pollen / Q000166:cytology / Q000187:drug effects; D021381:Protein Transport / Q000187:drug effects; D034622:RNA Interference; D034443:RNA Transport / Q000187:drug effects; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D013091:Spermatogenesis / Q000187:drug effects / Q000502:physiology*; D015662:Trimethoprim, Sulfamethoxazole Drug Combination / Q000378:metabolism; D014404:Tubulin / Q000378:metabolism
chemical_list: D000906:Antibodies; D018076:DNA, Complementary; D010940:Plant Proteins; D012333:RNA, Messenger; D014404:Tubulin; D015662:Trimethoprim, Sulfamethoxazole Drug Combination