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

MARTÍ EMILIANO; LANZONE, CECILIA; TAFFAREL, ALBERTO; MARTÍ, DARDO A.; CASTILLO ELIO R.D

FOZ DO IGUAZÚ

Congreso; 2018 INTERATIONAL CONGRESS OF GENETICS; 2018

Genetic variability within and between populations is crucial for the evolutionary potential of the species and is determinate by a dynamic interaction among evolutionary and demographic processes, such as genetic drift, natural selection and range expansion. Mitochondrial DNA is the most used molecular marker to perform intraspecific analyses in several taxa. Within neotropical Melanoplinae, some species displays intraspecific chromosomal variation. Despite several cytogenetic studies in acridids, there is a lack of information concerning intraspecific molecular variation. Scotussa cliens is an extensively distributed South American Melanoplinae. Recently, we detected a polymorphic centric fusion in their populations. However, the study of molecular variation has never been addressed in this species. Here, we study the variability of mtDNA cytochrome oxidase subunit I (COI) to understand evolutionary and demographic processes that affected their populations.A total of 82 individuals of S. cliens were collected from 11 populations spanning Argentina, Uruguay and Paraguay. We amplified a fragment of 554 base pairs of COI using specific primers.This resulted in 35 polymorphic sites which were analyzed at populational and phylogenetic levels. We found 21 haplotypes. The overall haplotype and nucleotide diversity were high:Hd=0.8970, Pi=0.01173. Private haplotypes were found in different biogeographic regions. The network showed an important genetic variation in the northern populations and expansion in the southern ones. The northern populations presented the higher frequency of chromosome fusions and were basal in the phylogenetic analyses. Our data suggest that both historical and demographic factors affected the pattern of genetic variability in this grasshopper.