Selective Introgression of Paracentric Inversions between Two Sibling Species of the Anopheles Gambiae Complex

AUTOR(ES)

Torre, A. D.

RESUMO

The Anopheles gambiae complex includes the major vectors of malaria in sub-Saharan Africa where >80% of all world-wide cases occur. These mosquitoes are characterized by chromosomal inversions associated to the speciation process and to intraspecific ecological and behavioral flexibility. It has been postulated that introgressive hybridization has selectively transferred inversions on the second chromosome between A. gambiae and A. arabiensis, the two most important vectors of malaria. Here we directly test this hypothesis with laboratory experiments in which hybrid populations were established and the fate of chromosomal inversions were followed. Consistent with the hypothesis, ``foreign'' X chromosomes were eliminated within two generations, while some ``foreign'' second chromosomes persisted for the duration of the experiments and, judging from the excess of heterozygotes, established stable heterotic polymorphisms. Only those second chromosome inversions found naturally in the species could be introgressed.

Documentos Relacionados

• Molecular phylogeny of the Anopheles gambiae complex suggests genetic introgression between principal malaria vectors.
• Distribution of the species of the Anopheles gambiae complex and first evidence of Anopheles merus as a malaria vector in Madagascar
• Semipermeable species boundaries between Anopheles gambiae and Anopheles arabiensis: Evidence from multilocus DNA sequence variation
• Paracentric inversions in man.
• The distribution of two major malaria vectors, Anopheles gambiae and Anopheles arabiensis, in Nigeria