title: Resolving spatial inconsistencies in chromosome conformation measurements.
abstract: BACKGROUND
  Chromosome structure is closely related to its function and Chromosome Conformation Capture (3C) is a widely used technique for exploring spatial properties of chromosomes. 3C interaction frequencies are usually associated with spatial distances. However, the raw data from 3C experiments is an aggregation of interactions from many cells, and the spatial distances of any given interaction are uncertain.
  
  
  RESULTS
  We introduce a new method for filtering 3C interactions that selects subsets of interactions that obey metric constraints of various strictness. We demonstrate that, although the problem is computationally hard, near-optimal results are often attainable in practice using well-designed heuristics and approximation algorithms. Further, we show that, compared with a standard technique, this metric filtering approach leads to (a) subgraphs with higher statistical significance, (b) lower embedding error, (c) lower sensitivity to initial conditions of the embedding algorithm, and (d) structures with better agreement with light microscopy measurements. Our filtering scheme is applicable for a strict frequency-to-distance mapping and a more relaxed mapping from frequency to a range of distances.
  
  
  CONCLUSIONS
  Our filtering method for 3C data considers both metric consistency and statistical confidence simultaneously resulting in lower-error embeddings that are biologically more plausible.
authors.affiliation: Lane Center for Computational Biology, School of Computer Science, Carnegie Mellon University, Pittsburgh, PA 15213, USA. carlk@cs.cmu.edu.
authors.forename: Geet
authors.initials: G
authors.lastname: Duggal
authors.forename: Rob
authors.initials: R
authors.lastname: Patro
authors.forename: Emre
authors.initials: E
authors.lastname: Sefer
authors.forename: Hao
authors.initials: H
authors.lastname: Wang
authors.forename: Darya
authors.initials: D
authors.lastname: Filippova
authors.forename: Samir
authors.initials: S
authors.lastname: Khuller
authors.forename: Carl
authors.initials: C
authors.lastname: Kingsford