Assessing the molecular divergence between <it>Anopheles </it>(<it>Kerteszia</it>) <it>cruzii </it>populations from Brazil using the <it>timeless </it>gene: further evidence of a species complex

• Main Authors: Grisard Edmundo C, Gentile Carla, Carvalho-Pinto Carlos J, Rona Luísa DP, Peixoto Alexandre A
• Format: Article
• Language: English
• Published: BMC 2009-04-01
• Series: Malaria Journal
• Online Access: http://www.malariajournal.com/content/8/1/60

<p>Abstract</p> <p>Background</p> <p><it>Anopheles </it>(<it>Kerteszia) cruzii </it>was the most important vector of human malaria in southern Brazil between 1930–1960. Nowadays it is still considered an important <it>Plasmodium </it>spp. vector in southern and south-eastern Brazil, incriminated for oligosymptomatic malaria. Previous studies based on the analysis of <it>X </it>chromosome banding patterns and inversion frequencies in <it>An. cruzii </it>populations from these areas have suggested the occurrence of three sibling species. In contrast, two genetically distinct groups among <it>An. cruzii </it>populations from south/south-east and north-east Brazil have been revealed by isoenzyme analysis. Therefore, <it>An. cruzii </it>remains unclear.</p> <p>Methods</p> <p>In this study, a partial sequence of the <it>timeless </it>gene (~400 bp), a locus involved in the control of circadian rhythms, was used as a molecular marker to assess the genetic differentiation between <it>An. cruzii </it>populations from six geographically distinct areas of Brazil.</p> <p>Results</p> <p>The <it>timeless </it>gene revealed that <it>An. cruzii </it>from Itaparica Island, Bahia State (north-east Brazil), constitutes a highly differentiated group compared with the other five populations from south and south-east Brazil. In addition, significant genetic differences were also observed among some of the latter populations.</p> <p>Conclusion</p> <p>Analysis of the genetic differentiation in the <it>timeless </it>gene among <it>An. cruzii </it>populations from different areas of Brazil indicated that this malaria vector is a complex of at least two cryptic species. The data also suggest that further work might support the occurrence of other siblings within this complex in Brazil.</p>