Molecular evidence of incipient speciation within Anopheles gambiae s.s. in West Africa
Article first published online: 20 DEC 2001
Insect Molecular Biology
Volume 10, Issue 1, pages 9–18, 2001
How to Cite
Torre, A. d., Fanello, C., Akogbeto, M., Dossou-yovo, J., Favia, G., Petrarca, V. and Coluzzi, M. (2001), Molecular evidence of incipient speciation within Anopheles gambiae s.s. in West Africa. Insect Molecular Biology, 10: 9–18. doi: 10.1046/j.1365-2583.2001.00235.x
- Issue published online: 20 DEC 2001
- Article first published online: 20 DEC 2001
- Received 15 February 2000;accepted after revision 28 August 2000.
- Anopheles gambiae;
- chromosomal forms;
- molecular forms;
We karyotyped and identified by polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP) analysis Anopheles gambiae s.s. samples collected in several African countries. The data show the existence of two non-panmictic molecular forms, named S and M, whose distribution extended from forest to savannahs. Mosquitoes of the S and M forms are homosequential standard for chromosome-2 inversions in forest areas. In dry savannahs, S is characterized mainly by inversion polymorphisms typical of Savanna and Bamako chromosomal forms, while M shows chromosome-2 arrangements typical of Mopti and/or Savanna and/or Bissau, depending on its geographical origin. Chromosome-2 inversions therefore seem to be involved in ecotypic adaptation rather than in mate-recognition systems. Strong support for the reproductive isolation of S and M in Ivory Coast comes from the observation that the kdr allele is found at high frequencies in S specimens and not at all in chromosomal identical M specimens. However, the kdr allele does not segregate with molecular forms in Benin.