"Junk" DNA Proves to be Highly Valuable 1 • What was once thought of as DNA with zero value in plants--dubbed "junk" DNA--may turn out to be key in helping scientists improve the control of gene expression in transgenic crops. 2 • Cooper and collaborators investigated "junk" DNA in the model plant Arabidopsis thaliana, using a computer program to find short segments of DNA that appeared as molecular patterns…These linked patterns are called pyknons… • This discovery in plants illustrates that the link between coding DNA and junk DNA crosses higher orders of biology and suggests a universal genetic mechanism at play that is not yet fully understood. 1-Alfredo Flores , June 2, 2009; http://www.ars.usda.gov/is/pr/2009/090602.htm . 2-Bret Cooper , Soybean Genomics and Improvement Laboratory , Agricultural Research Service , USDA.
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"Junk" DNA Proves to be Highly Valuable1
• What was once thought of as DNA with zero value in plants--dubbed "junk" DNA--may turn out to be key in helping scientists improve the control of gene expression in transgenic crops.2
• Cooper and collaborators investigated "junk" DNA in the model plant Arabidopsis thaliana, using a computer program to find short segments of DNA that appeared as molecular patterns…These linked patterns are called pyknons…
• This discovery in plants illustrates that the link between coding DNA and junk DNA crosses higher orders of biology and suggests a universal genetic mechanism at play that is not yet fully understood.
1-Alfredo Flores, June 2, 2009; http://www.ars.usda.gov/is/pr/2009/090602.htm.2-Bret Cooper, Soybean Genomics and Improvement Laboratory, Agricultural Research Service, USDA.
“Perhaps it is time to bid farewell to the term ‘junk’ DNA – we knew not your true nature.” (Regulatory RNAs and the demise of ‘junk’ DNA. Genome Biology 2006, 7:328)
"...a certain amount of hubris was required for anyone to call any part of the genome 'junk,' given our level of ignorance."(Francis Collins, 2006)
Rigoutsos, Isidore et al. (2006) Proc. Natl. Acad. Sci. USA 103, 6605-6610
Fig. 1. Pyknons in the 3' UTRs of the apoptosis inhibitor birc4 (shown above the horizontal line) and nine other genes
WordSeeker
A Software Suite for Discovery
and Characterization of Genomic Words
and Genome-Wide Patterns
www.word-seeker.org
word discovery methods
sequence-driven(alignment-based)
pattern-driven(enumerative)
exhaustive optimizeddeterministicoptimization
probabilisticoptimization
AlignAceMEMEpreprocesscombine
short patterns
heuristic exact
suffix tree,Weeder
YMF
Teiresias,WordSeeker
WINNOWER
GuhaThakurta D., Computational identification of transcriptional regulatory elements in DNA sequence. Nucleic Acids Res. 2006 Jul 19;34(12):3585-98. Print 2006. Review. Sandve GK, Drabløs F., A survey of motif discovery methods in an integrated framework. Biol Direct. 2006 Apr 6;1:11.
• Thomas Bitterman, OSC• Laura Elnitski, NHGRI• Susan Evans, OU• Matt Geisler, SIU• Erich Grotewold , OSU• Edwin Jacox, NHGRI• Stephen S. Lee, U. Idaho• Pooja M. Majmudar, OU• Paul Morris, BGSU• Chase Nelson, Oberlin• Eric Stockinger , OSU• Sarah Wyatt, OU• Alper Yilmaz, OSU• Jeffrey Parvin, OSU• Kun Huang, OSU• Thomas Mitchell , OSU• Kengo Morohashi, OSU• Rebecca Lamb , OSU• John Finer, OSU
Lonnie Welch
Jens Lichtenberg
Rami Alouran
Frank Drews
Kyle Kurz
Xiaoyu Liang
Lee Nau
Matt Wiley
Razvan Bunescu
Joshua D. Welch
Klaus Ecker
Mohit Alam
Nathaniel George
Dazhang Gu
Eric Petri
Josiah Seaman
Kaiyu ShenWo
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Acknowledgements
a pattern “describes a problem which occurs over and over again in our environment, and then describes the core of the solution to that problem, in such a way that you can use the solution a million times over, without ever doing it the same way twice [1].”
C. Alexander, S. Ishikawa, and M. Silverstein, A Pattern Language: Towns, Buildings, Construction. Oxford University Press, 1977.
Alexander Pattern Format 1. Picture – a representative example 2. Introductory paragraph - sets the context 2. Headline - the essence of the problem in one or two sentences. 3. Body –
• empirical background of the pattern • evidence for its validity • range of different ways the pattern can be manifested
4. Solution• relationships which are required to solve the stated problem in the stated context. • stated in the form of an instruction—so that you know exactly what you need to do, to
build the pattern5. Diagram - shows the solution, with labels to indicate its main components6. A paragraph which ties the pattern to all those smaller patterns in the language,
which are needed to complete this pattern, to embellish it, to fill it out…
Picture, Introduction, Headline
With the availability of the genomic sequences ofnumerous organisms, life scientists are working in conjunction with bioinformaticians to decipher the meanings of the genomes. Projects such as Encyclopedia of Genomic Elements (ENCODE) [2] and Pyknons [3], seek to identify and charatcetrize the functional elements in genomes. The functional elements are often referred to as words.
The WORDIFIER Pattern for Functional and Regulatory Genomics
Given a genomic sequence (or a set of sequences), an important problem is the enumeration of all subsequences (words) contained in the sequence (or the set of sequences).