Molecular evidence of incipient speciation within Anopheles gambiae s.s. in West Africa.

Journal article

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.

Authors: della Torre, A; Fanello, C; Akogbeto, M; Dossou-yovo, J; Favia, G

• Journal: Insect molecular biology
• Volume: 10
• Issue: 1
• Pages: 9-18
• Publication date: 2001-02-01
• DOI: 10.1046/j.1365-2583.2001.00235.x
• EISSN: 1365-2583
• ISSN: 0962-1075
• Language: English
• Keywords: Alleles; Africa, Western; Genes, Insect; Animals; Anopheles