Genetic variability and evolution in natural populations of Scotussa cliens (Stål, 1861) (Acrididae: Melanoplinae)

EMILIANO MARTÍ; DARDO ANDREA MARTÍ; CECILIA LANZONE; ELIO RODRIGO CASTILLO; ALBERTO TAFFAREL

Congreso; International Congress of Genetics; 2018

Geneticvariability within and between populations is crucial for the evolutionarypotential of the species and is determinate by a dynamic interaction amongevolutionary and demographic processes, such as genetic drift, naturalselection and range expansion. Mitochondrial DNA is the most used molecularmarker to perform intraspecific analyses in several taxa. Within neotropical Melanoplinae,some species displays intraspecific chromosomal variation. Despite several cytogeneticstudies in acridids, there is a lack of information concerning intraspecificmolecular variation. Scotussa cliens is an extensively distributed SouthAmerican Melanoplinae. Recently, we detected a polymorphic centric fusion intheir populations. However, the study of molecular variation has never beenaddressed in this species. Here, we study the variability of mtDNA cytochromeoxidase subunit I (COI) to understand evolutionary and demographic processesthat affected their populations.Atotal of 82 individuals of S. cliens were collected from 11 populationsspanning Argentina, Uruguay and Paraguay. We amplified a fragment of 554 basepairs of COI using specific primers. This resulted in 35 polymorphic siteswhich were analyzed at populational and phylogenetic levels. We found 21haplotypes. The overall haplotype and nucleotide diversity were high: Hd=0.8970,Pi=0.01173. Private haplotypes were found in different biogeographicregions. The network showed an important genetic variation in the northernpopulations and expansion in the southern ones. The northern populationspresented the higher frequency of chromosome fusions and were basal in thephylogenetic analyses. Our data suggest that both historical and demographicfactors affected the pattern of genetic variability in this grasshopper.