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Landscape genetics of Culicoides (Diptera: Ceratopogonidae) vector species: evaluation of cryptic diversity and gene flow in the Palearctic region. [P88]

Mignotte A., Huber K., Gardes L., Balenghien T., Duhayon M., Rakotoarivony I., Tabourin L., De La Puente J.M., Lucientes J., Ibáñez-Justicia A., Kampen H., Werner D., England M., Carpenter S., Garros C.. 2018. In : 21st E-SOVE (European Society for Vector Ecology) Meeting Abstract Book. Arthropod Vector Science for the benefit of society: Educate, Empathize, Engage. Palermo : ESOVE, p. 191-191. E-SOVE (European Society for Vector Ecology) Meeting. 21, 2018-10-22/2018-10-26, Palermo (Italie).

Landscape genetics is an approach for understanding how geographical and environ-mental features structure genetic variation. Whether landscape patterns, in particular those created by human land uses, influence gene flow and its intensity to understand the spread of vector-borne diseases. Culicoides dispersal capacities are described as 'dis-persive stratified' which results from the combination of processes occurring at a short distance combined with jumps over long distances. Although winds and local air move-ments have an undeniable role in the dispersal of Culicoides, anthropogenic factors also play a predominant role, particularly at the local level (host distribution, landscape patterns). Our overall objective is to characterize the dispersal abilities of two main vector species in Europe, C. obsoletus and C. chiopterus, showing different host-vector behaviors. However, Culicoides obsoletus is reported in sympatry with one morpholog-ically indistinguishable species, C. scoticus, and other morphologically related species, C. chiopterus, C. dewul¿ and C. montanus. Moreover, recently, several authors have report-ed the existence of cryptic diversity within the species commonly called C. obsoletus. Se-quencing a portion of the Cox1 mitochondrial gene of 3,200 C. obsoletus/C. scoticus individ-uals from 17 European countries revealed two clades within C. scoticus and confirmed the presence of at least three undescribed phylogenetic clades (C. obsoletus clade O2, C. obso-letus clade Dark and one not yet named) close to C. obsoletus. These results are reinforced by rDNA16S mitochondrial gene sequences and a gene coding for ribosomal rDNA18S, over the entire haplotypic diversity resulting from Cox1 barcoding. Then, we investigated how dispersion shapes the spatial arrangement of C. obsoletus genetic diversity in Europe using 13 microsatellite markers by observing patterns of allelic frequency distributions. This work is the first step to a more comprehensive study on the landscape genetics of two main vector species in the Palearctic region, C. obsoletus and C. chiopterus.

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