Evidence that the ancestral lineage leading to Aedes aegypti colonization of America is present in Argentina

BALCAZAR DARIO; N. ROSE; JR POWELL; J. CRAWFORD; A. GLORIA-SORIA

Maryland

Congreso; Entomology 2023; 2023

Aedes aegyptimosquito is a major mosquito vector of viruses that cause human disease. Thereare two known subspecies: Aedes aegypti formosus (Aaf), is found exclusivelyin sub-Saharan Africa, breeds in nonhuman-disturbed habitats and uses nonhumansfor bloodmeals; and Aedes aegypti aegypti (Aaa), which is widelydistributed around world, breeds in human habitats and prefers human bloodmeals.The two subspecies are genetically different. Populations of Ae. aegypti in Argentina display a mixedgenetic signature between both subspecies. This admixture pattern may beexplained by two hypotheses. One is that African Aaf populations were recentlyreintroduced into Argentina and interbred with the local Aaa populations. Alternatively,Argentinian populations represent the remnant of the original African proto-Aaapopulation that arrived in America ~500 years ago with the slave trade.To test these hypotheses,we used pair-wise comparisons of phased genomes of Aedes aegypti mosquitoesfrom Africa, outside Africa and from El Dorado (Argentina) to infer times ofdivergence based on coalescence time estimation implemented by MSMC2. Anisolation-migration model through MSMC-IM tool was then applied to differentiaterecent admixture events from shared ancestral population background. Our analysis uncovereda single high migratory peak that coincides with the timing of the slave trade,likely representing the mosquito’s migration from Africa to America. Moreover, theanalysis did not detect any evidence of recent introduction of Aaf intoArgentina. These results suggest that modern populations from Argentina areclosely related to the proto-Aedes aegypti populations that first emigrated to America.@font-face{font-family:"Cambria Math";panose-1:2 4 5 3 5 4 6 3 2 4;mso-font-charset:0;mso-generic-font-family:roman;mso-font-pitch:variable;mso-font-signature:3 0 0 0 1 0;}@font-face{font-family:Calibri;panose-1:2 15 5 2 2 2 4 3 2 4;mso-font-charset:0;mso-generic-font-family:swiss;mso-font-pitch:variable;mso-font-signature:-536859905 -1073732485 9 0 511 0;}p.MsoNormal, li.MsoNormal, div.MsoNormal{mso-style-unhide:no;mso-style-qformat:yes;mso-style-parent:"";margin:0in;mso-pagination:widow-orphan;font-size:12.0pt;font-family:"Calibri",sans-serif;mso-ascii-font-family:Calibri;mso-ascii-theme-font:minor-latin;mso-fareast-font-family:Calibri;mso-fareast-theme-font:minor-latin;mso-hansi-font-family:Calibri;mso-hansi-theme-font:minor-latin;mso-bidi-font-family:"Times New Roman";mso-bidi-theme-font:minor-bidi;}.MsoChpDefault{mso-style-type:export-only;mso-default-props:yes;font-family:"Calibri",sans-serif;mso-ascii-font-family:Calibri;mso-ascii-theme-font:minor-latin;mso-fareast-font-family:Calibri;mso-fareast-theme-font:minor-latin;mso-hansi-font-family:Calibri;mso-hansi-theme-font:minor-latin;mso-bidi-font-family:"Times New Roman";mso-bidi-theme-font:minor-bidi;}div.WordSection1{page:WordSection1;}