Species identification of mussels (Mytilus spp.) is challenging not only because there are 7 species commercialised globally, but there is hybridisation of species where they coexist in the same geographical area. The most popular approach to specimen identification is sequencing analysis, which can be performed by different methods.One of them is the Forensically Informative Nucleotide Sequencing (FINS), which involves the estimation of sequence similarity among specimens by phylogenetic methods is based on genetic distances and drawing a phylogenetic tree. However, methodologies based on tree topologies perform poorly for species identification.
In this study, the performance of two mono-locus approaches for species identification in 61 Mytilus mussels are compared: the high-resolution melting analysis of the PAP (polyphenolic adhesive protein) gene and the partial sequencing of the H1C (histone) gene. The H1C sequences were analysed with five different methods. Both approaches show discrepancies in the identification of putative hybrids, but if the putative hybrids are excluded, the two methods show substantial to perfect agreement. This study highlights the need to use standardised molecular tools, as well as the use of multi-locus methods for SI of Mytilus mussels in testing laboratories.
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