Secondary structure of domains IV and V of the gene 16S rRNA of Heleobia hatcheri (Pilsbry, 1911) (Gastropoda: Tateidae).

MAGÍARATE, EMMANUEL; CIOCCO, NÉSTOR; KOCH E

Congreso; XXXIV Reunión Científica de la Sociedad de Biología de Cuyo; 2018

Sociedad Biología de Cuyo

Phylogenetic studies aim to recover the accumulated historical signal in the evolution of nucleotide or amino acid sequences. Thealignments of these sequences represent hypotheses that allow us to infer genealogies in a set of species. Thus, an adequatealignment is essential to reconstruct evolutionary relationships. Mitochondrial markers commonly used in molluscs to infer suchrelationships include rRNA genes. The alignment of sequences of this type of genes is usually difficult due to the presence ofinsertion/deletion events, which increase in number with the inclusion of divergent species, evidenced by multiple ambiguouspositions in the final alignment produced. These difficulties can be overcome through the use of complementary information suchas the secondary structure of rRNA. Based on the complementarity of bases along the molecule, the ribosomal RNA sequencesform complex structures composed of helical stems connected by loops. Consequently, at a structural level, in these molecules itis feasible to recognize sections, subdivided in turn into domains. Here we present a structural model of the fourth and fifthdomains of the 16S rRNA gene of Heleobia hatcheri (Caenogastropoda, Rissoidea). The partial sequences of the 16S rRNA genewere obtained using universal primers from a specimen of H. hatcheri collected in the town of Uspallata (Mendoza, Argentina).The amplified product was sequenced in both directions in the laboratories of the Genomics Unit of the Institute ofBiotechnology (INTA, Castelar).Once the consensus sequence was obtained, and after alignment with reference sequencesavailable in GenBank, the molecule was folded manually by direct comparison with reference models for molluscs. Thesecondary model derived here represents the first one for the Heleobia species and it is expected to allow future comparativeapproaches of structural changes in this genus, as well as to complement the phylogenetic analyzes of the group.