rdf-syntax-grammar
mods:
  schema location: http://www.loc.gov/mods/v3 http://www.loc.gov/standards/mods/v3/mods-3-2.xsd
  title info:
    title: Study of gene silencing in rice
    sub title: a root-preferential gene RCg2
  name:
    name part: Shi, Xiangyu.
    role:
      role term: creator
  name:
    name part: Hall, Timothy C.
    role:
      role term: thesis advisor.
  type of resource: text
  genre: bibliography
  origin info:
    place:
      place term: txu
    date issued: 2010
    issuance: monographic
  language:
    language term: eng
  physical description:
    form: remote
    extent: 1 online resource.
  abstract: The RCg2 promoter was identified in a search for root-specific genes to combat the rice water weevil (RWW) but expressed at low frequency (~10%). Spatial expression of RCg2 was investigated using two reporter constructs YXA (RCg2-gus-ocs) and YXB (RCg2-gus-RCg2) that included 1.6 kb of the RCg2 5' sequence fused to the [beta]-glucuronidase (gus) coding region. YXB plants were generated via Agrobacterium-mediated transformation but only 8 of 158 plants analyzed showed strong GUS activity despite the presence of an intact construct. Reactivation of RCg2 gene in rice was investigated by treatment of R0 and R1 of YXB transgenic plants with 5-azacytidine. Reactivation of RCg2-gus was observed in some transgenic plants indicating different mechanisms involved in the gene silencing of the YXB lines. DNA methylation analysis, northern blotting, RT-PCR and small RNA analysis supported the conclusion that PTGS and TGS are present in the silenced plants. Promoter analysis in silico and using promoter deletion assays predicted that the RCg2 promoter contains a complex region that includes miRNA homologs, MITEs and repetitive sequences. The high frequency of promoter-related silencing suggests functional interactions of these elements of the transgene and the homologous endogenous gene. To identify key elements contributing to the root-preferential expression of RCg2 and the high frequency of silencing observed in transgenic (YXB) lines, several RCg2 promoter deletion constructs were designed. These include 5' deletions MC1, MC2, MC4, MC7 and MC8 and internal deletions MC5, MC11, MC12 and MC13. The frequency with which silencing was encountered in populations of the deletion mutants was used to characterize the effects of various promoter elements. Deletion of the region from -406 to -208 (compared MC11 to YXB, and MC13 to MC1) revealed that region contains a negative element. Among 36 independent transformants, 33% with MC11 expressed GUS and 85% with MC13 showed GUS expression…
  note: by Xiangyu Shi.
  note: "Major Subject: Genetics"
  note: Title from author supplied metadata (automated record created 2010-08-20 08:31:34).
  note: Electronic resource.
  note: Doctor of Philosophy Texas A&M University 2009 http://hdl.handle.net/1969.1/ETD-TAMU-2009-05-460
  note: Includes bibliographical references.
  note: Text (Dissertation)
  subject:
    topic: Major genetics
  subject:
    topic: DNA methylation sequence
  subject:
    topic: Agrobacterium
  subject:
    topic: Rice (Oryza sativa L.)
  subject:
    topic: gene silencing
  identifier: http://hdl.handle.net/1969.1/ETD-TAMU-2009-05-460
  record info:
    record content source: TXA
    record creation date: 100915
    record change date: 20151201155337.0
    record identifier: in00002600921