Breakdown in the Process of Incipient Speciation in Anopheles gambiae
| Autor: | Kovana M. Loua, Ibrahima Dia, David J. Conway, Amabelia Rodrigues, Daniel E. Neafsey, Majidah Adiamoh, Marc A. T. Muskavitch, Davis Nwakanma, Lassana Konate, Musa Jawara, T. Samson Awolola, Ngayo Sy, Emily Lund |
|---|---|
| Rok vydání: | 2013 |
| Předmět: |
X Chromosome
Genotype Genetic Speciation Anopheles gambiae Genome Insect Population 030231 tropical medicine introgression Introgression mosquito Breeding Investigations Polymorphism Single Nucleotide 03 medical and health sciences 0302 clinical medicine Gene Frequency Anopheles parasitic diseases Genetics Animals Population and Evolutionary Genetics hybridization 030304 developmental biology 0303 health sciences Panmixia biology Chimera Assortative mating Genomics Reproductive isolation Incipient speciation biology.organism_classification Chromosomes Insect 3. Good health Africa Western Phylogeography speciation Sympatric speciation Backcrossing Seasons |
| Zdroj: | Genetics |
| ISSN: | 1943-2631 |
| Popis: | Understanding genetic causes and effects of speciation in sympatric populations of sexually reproducing eukaryotes is challenging, controversial, and of practical importance for controlling rapidly evolving pests and pathogens. The major African malaria vector mosquito Anopheles gambiae sensu stricto (s.s.) is considered to contain two incipient species with strong reproductive isolation, hybrids between the M and S molecular forms being very rare. Following recent observations of higher proportions of hybrid forms at a few sites in West Africa, we conducted new surveys of 12 sites in four contiguous countries (The Gambia, Senegal, Guinea-Bissau, and Republic of Guinea). Identification and genotyping of 3499 A. gambiae s.s. revealed high frequencies of M/S hybrid forms at each site, ranging from 5 to 42%, and a large spectrum of inbreeding coefficient values from 0.11 to 0.76, spanning most of the range expected between the alternative extremes of panmixia and assortative mating. Year-round sampling over 2 years at one of the sites in The Gambia showed that M/S hybrid forms had similar relative frequencies throughout periods of marked seasonal variation in mosquito breeding and abundance. Genome-wide scans with an Affymetrix high-density single-nucleotide polymorphism (SNP) microarray enabled replicate comparisons of pools of different molecular forms, in three separate populations. These showed strong differentiation between M and S forms only in the pericentromeric region of the X chromosome that contains the molecular form-specific marker locus, with only a few other loci showing minor differences. In the X chromosome, the M/S hybrid forms were more differentiated from M than from S forms, supporting a hypothesis of asymmetric introgression and backcrossing. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|