Inapproximability Results for the Lateral Gene Transfer Problem
This paper concerns the Lateral Gene Transfer Problem. This minimization problem, defined by Hallet and Lagergren , is that of finding the most parsimonious lateral gene transfer scenario for a given pair of gene and species trees. Our main results are the following:
– (a) We show that it is not possible to approximate the problem in polynomial time within an approximation ratio of 1+ε, for some constant ε > 0 unless P=NP. We also provide explicit values of ε for the above claim.
– (b) We provide an upper bound on the cost of any 1-active scenario and prove the tightness of this bound.
KeywordsSpecies Tree Gene Tree Internal Node Approximation Ratio Lateral Gene Transfer
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- 3.Berman, P., Karpinski, M.: On some tighter inapproximability results, further improvements, Technical Report TR98-065. Electronic Colloquium on Computational Complexity, ECCC (1998); available online from http://eccc.uni-trier.de/eccc-reports/1998/TR98065/index.html
- 6.Hallett, M., Lagergren, J.: Efficient algorithms for lateral gene transfer problems. In: Proc. 5th Annual International Conference on Computational Molecular Biology (RECOMB), Montreal, Canada, pp. 141–148 (2001)Google Scholar
- 7.Hallett, M., Lagergren, J.: Identifying lateral gene transfer events, submitted to SIAM Journal of Computing (2004), available online from http://www.mcb.mcgill.ca/~hallett/Lateral.pdf