Reconstruction of the molecular phylogeny of Conus mustelinus using the 12S ribosomal RNA gene

The Philippines is rich in biodiversity. A small but significant percent of its wealth is comprised of the Conus genus, more popularly known as the cone snails (Spring­steen and Leobrera 1986). In addition, these gastropods have been long known to utilize their venom in a combinatorial drug therapy fashion for survival (Terlau et al. 2004). This feature then makes them extremely valuable to neuropharmacology and neuroscience studies. Due to the large number and similarities in appearance, morphological examination of this vast and successful group of marine organisms has been problematic. As a better alternative, molecular ap­proaches have been used to ascertain the identity of these gastropods like the use of molecular markers (i.e., genes that possess conserved se­quences such as 12S and 16S rRNA and mtCO1). In particular, phylogenetic trees displaying classifications according to phylum, class and order may be constructed using the 125 rRNA gene (Hwang and Kim 1999). Conus mustelinus is one of the species of interest in our laboratory and has been characterized in terms of its 125 and 165 rRNA and mtCO1 DNA sequences (Salazar 2006). In the case of the 12S rRNA gene, a 490 bp partial sequence has been obtained. While the 16S and mtCO1 data showed strong support for vermivory, the 12S phylogeny revealed ambi­guity as majority of the species included in the phylogenetic reconstruc­tion were non-Conus such as Melongena, Fasciolaria, and Echinolittorina. This study aims to reconstruct a phylogenetic tree based on the 12S rRNA gene sequence of C. mustelinus. From this data, a framework illus­trating its relationship with other Conus species will be established. This framework could eventually be used by future investigators on poorly studied or newly-discovered cone snails