POPULATION GENETIC STRUCTURE OF AMBLYOMMA NEUMANNI (ACARI: IXODIDAE) IN ARGENTINA

NAVA S, MANGOLD AJ, GUGLIELMONE AA

Buenos Aires, Argentina

Conferencia; VI International Conference on Ticks and Ticks-borne Pathogens; 2008

<!-- /* Style Definitions */ p.MsoNormal, li.MsoNormal, div.MsoNormal {mso-style-parent:""; margin:0cm; margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:10.0pt; font-family:Arial; mso-fareast-font-family:"Times New Roman";} @page Section1 {size:612.0pt 792.0pt; margin:72.0pt 90.0pt 72.0pt 90.0pt; mso-header-margin:36.0pt; mso-footer-margin:36.0pt; mso-paper-source:0;} div.Section1 {page:Section1;} --> Amblyomma neumanni is essentially an Argentinean tick, with a bona fide record from Colombia and uncertain records from Uruguay. Domestic animals and man are frequent hosts. The aim of this work is to infer the population genetic structure of Amblyomma neumanni in Argentina to detect the presence of cryptic species. DNA was extracted from specimens identified as A. neumanni collected in eight Argentinean localities. Five ticks per locality were included in the analysis, and the DNA obtained was used to amplify a 460-bp fragment of the mitochondrial 16S rDNA gene. The sequences were edited and aligned, and differentiation among populations was evaluated by an analysis of molecular variance (AMOVA) and by calculating pairwise FST between populations. The 16S rDNA sequences showed just 0.0 %-0.5 % divergence among the ticks analyzed, and only 4 haplotypes were identified. Population genetic structure in relation to geographic origin of tick populations was not detected with AMOVA, because 99.73% of the sequence variation was attributable to variation within of populations and 0.27% to variation among populations. In agreement with AMOVA results, the value of FST was 0.0026 (P = 0.67), showing also absence of genetic differentiation between populations. Indeed, A. neumanni does not have population genetic subdivision on a regional scale in Argentina, and the conclusion is that there are not elements to support that Argentinean specimens identified as A. neumanni belong to more than one species.