Analysis and Classification of Constrained DNA Elements with N-gram Graphs and Genomic Signatures

  • Dimitris Polychronopoulos
  • Anastasia Krithara
  • Christoforos Nikolaou
  • Giorgos Paliouras
  • Yannis Almirantis
  • George Giannakopoulos
Part of the Lecture Notes in Computer Science book series (LNCS, volume 8542)


Most common methods for inquiring genomic sequence composition, are based on the bag-of-words approach and thus largely ignore the original sequence structure or the relative positioning of its constituent oligonucleotides. We here present a novel methodology that takes into account both word representation and relative positioning at various lengths scales in the form of n-gram graphs (NGG). We implemented the NGG approach on short vertebrate and invertebrate constrained genomic sequences of various origins and predicted functionalities and were able to efficiently distinguish DNA sequences belonging to the same species (intra-species classification). As an alternative method, we also applied the Genomic Signatures (GS) approach to the same sequences. To our knowledge, this is the first time that GS are applied on short sequences, rather than whole genomes. Together, the presented results suggest that NGG is an efficient method for classifying sequences, originating from a given genome, according to their function.


genomic sequence representation n-gram graphs conserved non-coding elements CNEs UCEs ultraconserved elements classification genomic signatures 


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Copyright information

© Springer International Publishing Switzerland 2014

Authors and Affiliations

  • Dimitris Polychronopoulos
    • 1
    • 4
  • Anastasia Krithara
    • 2
  • Christoforos Nikolaou
    • 3
  • Giorgos Paliouras
    • 2
  • Yannis Almirantis
    • 1
  • George Giannakopoulos
    • 2
  1. 1.Institute of Biosciences and ApplicationsNCSR DemokritosAthensGreece
  2. 2.Institute of Informatics and TelecommunicationsNCSR DemokritosAthensGreece
  3. 3.Department of BiologyUniversity of CreteHeraklionGreece
  4. 4.Department of Biochemistry and Molecular Biology, Faculty of BiologyNational and Kapodistrian University of AthensAthensGreece

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