Journal of Insect Science (2006) 6 (46), p. 55 (Sharakhova et al.)
M.V. Sharakhova, A. Xia, I.V. Brusentsova and I.V. Sharakhov (2006)
Evolutionary genomics of malaria vectors
Journal of Insect Science 6 (46), 55-55
in M. Adams et al. [editors] Abstracts of the Fifth International Symposium on Molecular Insect Science (May 20-24, 2006, Tucson, Arizona USA), 76 pp.
Abstract: The chromosomal model of speciation by suppression of recombination suggests that genome rearrangements promote differentiation by acting as a genetic filter between populations. Genomic regions of low recombination, such as the areas around inversion breakpoints and pericentric heterochromatin, may contain genes important for adaptations, speciation, and evolution of vectorial capacity. The availability of polytene chromosomes in malaria mosquitoes provides the opportunity to identify the evolutionary changes in the genome structure. We studied the correspondence of chromosomal elements between three malaria vectors, Anopheles gambiae, An. funestus, and An. stephensi, the members of different series of the subgenus Cellia. The An. stephensi cytogenetic and physical genome maps were developed and compared with the existing genome maps of An. funestus and An. gambiae. We have found preservation of synteny but substantial shuffling of gene order along corresponding chromosome arms due to paracentric inversions. Three-way analysis has allowed us to assign the rearrangement events to one of the three lineages. Using a computer algorithm we have calculated the number of rearrangements fixed between the species and identified genomic segments repeatedly occurring inside of the inversions. The analysis of the polytene chromosomes revealed extensive variations in morphology of heterochromatin among An. stephensi, An. funestus, and An. gambiae. An. funestus has only compact heterochromatin in the proximal centromeric region of autosomes, while the An. gambiae centromeric regions consist of mostly diffuse heterochromatin. The types of centric heterochromatin vary among chromosomal arms in An. stephensi. An antibody against the Drosophila heterochromatin protein 1 was used to localize the regions of intercalary and pericentric heterochromatin on the mosquito chromosomes. As a result, genomic segments that have undergone euchromatin-heterochromatin transition have been identified. Thus, comparison of chromosome structure between distant mosquito species is useful for identifying 'hot spots' or 'islands' of genome evolution.
Database assignments for author(s): Igor V. Sharakhov
Research topic(s) for pests/diseases/weeds:
molecular biology - genes
Pest and/or beneficial records:
| Beneficial | Pest/Disease/Weed | Crop/Product | Country | Quarant.
|
|---|---|---|---|---|
| Anopheles gambiae | ||||
| Anopheles funestus | ||||
| Anopheles stephensi |
