Download 세미나 제목:Identification and Functional Analysis of Novel Light

세미나 제목:Identification
and Functional Analysis of Novel Light-Responsive Genes in
Rice Using a NSF 45K Gene Microarray
세미나 초록:
Using a validated NSF 45K gene microarray, we performed expression-profiling
experiments on 2 week-old light- and dark-grown rice leaf tissue from four different rice
varieties to identify light-responsive genes. Then, we identified 10,361, 4,962, 1933, and
453 genes that were differentially expressed at FDR p-values of 0.01, 1.00E-04, 1.00E-06,
and 1.00E-08, respectively. Until now, 26,310 (46%) of the 56,278 rice loci (TIGRassembled pseudo-molecules/annotation Version 5.0,
(http://www.tigr.org/tdb/e2k1/osa1/pseudomolecules/info.shtml#feat) contain insertions
of various DNA elements such as T-DNA, Tos17, and Ds/dSpm in their genic regions or
5’untranslated regions (http://signal.salk.edu/cgi-bin/RiceGE?DATA=At5g53850). To
validate the function of the light-regulated genes, we screened mutant rice “knockout”
lines for 37 of 356 at least 8 fold light induced genes that were at least two mutant alleles.
We observed phenotypic changes associated with light perception or transduction in 7 out
of 12 unique genes tested and 4 out of 25 genes belonging to multi-gene families; four of
the latter were the predominantly expressed family member in the light. Of the 11
identified light response-related gene functions, none except one has been previously
characterized in rice and five have never been characterized in any plant species before
now. A survey of the nineteen genes and gene family members encoding proteins for the
seven steps in the well-characterized chlorophyll biosynthetic pathway showed that
identification of unique or predominantly expressed gene family members allows for
more efficient functional analyses. To date, more than 400 rice hybridizations using
various rice array platforms (Affymetrix, BGI, Agilent and NSF45K) have been released
and the data has been compiled at National Center for Biotechnology Information (NCBI)
Gene Expression Omnibus (GEO) database (www.ncbi.nlm.nih.gov/geo/). Rice
multiplatform microarray search tool (http://www.ricearray.org/matrix.search.shtml)
helped us to extract expression profile data for interesting genes from microarray
experiments using different array platforms. This tool is very useful to even more
precisely find out predominantly expressed gene family members. In the study, we
demonstrated the efficiency of combining rice gene expression profiles with rice
insertional mutant analyses to identify novel genes and their functions, even among
members of multi-gene families.