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Approximation algorithms for sorting by k-cuts on signed permutations

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Autor(es):
Oliveira, Andre Rodrigues ; Alexandrino, Alexsandro Oliveira ; Jean, Geraldine ; Fertin, Guillaume ; Dias, Ulisses ; Dias, Zanoni
Número total de Autores: 6
Tipo de documento: Artigo Científico
Fonte: JOURNAL OF COMBINATORIAL OPTIMIZATION; v. 45, n. 1, p. 30-pg., 2023-01-01.
Resumo

Sorting by Genome Rearrangements is a classic problem in Computational Biology. Several models have been considered so far, each of them defines how a genome is modeled (for example, permutations when assuming no duplicated genes, strings if duplicated genes are allowed, and/or use of signs on each element when gene orientation is known), and which rearrangements are allowed. Recently, a new problem, called Sorting by Multi-Cut Rearrangements, was proposed. It uses the k-cut rearrangement which cuts a permutation (or a string) at k >= 2 places and rearranges the generated blocks to obtain a new permutation (or string) of same size. This new rearrangement may model chromoanagenesis, a phenomenon consisting of massive simultaneous rearrangements. Similarly as the Double-Cut-and-Join, this new rearrangement also generalizes several genome rearrangements such as reversals, transpositions, revrevs, transreversals, and block-interchanges. In this paper, we extend a previous work based on unsigned permutations and strings to signed permutations. We show the complexity of this problem for different values of k, and that the approximation algorithm proposed for unsigned permutations with any value of k can be adapted to signed permutations. We also show a 1.5-approximation algorithm for the specific case k = 4, as well as a generic approximation algorithm applicable for any k >= 5, that always reaches constant ratio. The latter makes use of the cycle graph, a well-known structure in genome rearrangements. We implemented and tested the proposed algorithms on simulated data. (AU)

Processo FAPESP: 19/27331-3 - Problemas de ordenação por rearranjos de genomas
Beneficiário:André Rodrigues Oliveira
Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado
Processo FAPESP: 13/08293-7 - CECC - Centro de Engenharia e Ciências Computacionais
Beneficiário:Munir Salomao Skaf
Modalidade de apoio: Auxílio à Pesquisa - Centros de Pesquisa, Inovação e Difusão - CEPIDs
Processo FAPESP: 15/11937-9 - Investigação de problemas difíceis do ponto de vista algorítmico e estrutural
Beneficiário:Flávio Keidi Miyazawa
Modalidade de apoio: Auxílio à Pesquisa - Temático