open access

https://hdl.handle.net/2115/76631

Recombination and purifying and balancing selection determine the evolution of major antigenic protein 1 (map 1) family genes in Ehrlichia ruminantium

英語

map1

2019-01-30

Elsevier

Gene

683

216-224

Heartwater is an economically important disease of ruminants caused by the tick-borne bacterium Ehrlichia ruminantium. The disease is present throughout sub-Saharan Africa as well as on several islands in the Caribbean, where it poses a risk of spreading onto the American mainland. The dominant immune response of infected animals is directed against the variable outer membrane proteins of E. ruminantium encoded by a polymorphic multigene family. Here, we examined the full-length sequence of the major antigenic protein 1 (map1) family genes in multiple E. ruminantium isolates from different African countries and the Caribbean, collected at different time points to infer the possible role of recombination breakpoint and natural selection. A high level of recombination was found particularly in map1 and map1-2. Evidence of strong negative purifying selection in map1 and balancing selection to maintain genetic variation across these samples from geographically distinct countries suggests host pathogen co-evolution. This co-evolution between the host and pathogen results in balancing selection by maintaining genetic diversity that could be explained by the demographic history of long-term pathogen pressure. This signifies the adaptive role and the molecular evolutionary forces underpinning E. ruminantium map1 multigene family antigenicity.

学術雑誌論文

Accepted Manuscript

Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International

© 2019. This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/

0378-1119