Estimating viral haplotypes in a population using k-mer counting

Abstract

Viral haplotype estimation in a population is an important problem in virology. Viruses undergo a high number of mutations and recombinations during replication for their survival in host cells and exist as a population of closely related genetic variants. Due to this, estimating the number of haplotypes and their relative frequencies in the population becomes a challenging task. The usage of a sequenced reference genome has its limitations due to the high mutational rates in viruses. We propose a method for estimating viral haplotypes based only on the counts of k-mers present in the viral population without using the reference genome. We compute k-mer pairs that are related to each other by one mutation, and compute a minimal set of viral haplotypes that explain the whole population based on these k-mer pairs. We compare our method to the software ShoRAH (which uses a reference genome) on simulated dataset and obtained comparable results, even without using a reference genome. © 2013 Springer-Verlag Berlin Heidelberg.