  BLAST is a standard tool in bioinformatics for creating local sequence
alignments using a "seed-and-extend" approach. Here we introduce an analogous
seed-and-extend algorithm that produces local network alignments: BLANT, for
Basic Local Alignment of Network Topology. This paper introduces BLANT-seed:
given an input graph, BLANT-seed uses network topology alone to create a
limited, high-specificity index of k-node induced subgraphs called k-graphlets
(analogous to BLASTS's k-mers). The index is constructed so that, if
significant common network topology exists between two graphs, their indexes
are likely to overlap. BLANT-seed then queries the indexes of two networks to
generate a list of common k-graphlets which, when paired, form a seed pair. Our
companion paper (submitted elsewhere) describes BLANT-extend, which "grows"
these seeds to larger local alignments, again using only topological
information.
