Genomic changes of Chagas disease vector, South America.
We analyzed the main karyologic changes that have occurred during the dispersion of Triatoma infestans, the main vector of Chagas disease. We identified two allopatric groups, named Andean and non-Andean. The Andean specimens present C-heterochromatic blocks in most of their 22 chromosomes, whereas non-Andean specimens have only 4-7 autosomes with C-banding. These heterochromatin differences are the likely cause of a striking DNA content variation (approximately 30%) between Andean and non-Andean insects. Our study, together with previous historical and genetic data, suggests that T. infestans was originally a sylvatic species, with large quantities of DNA and heterochromatin, inhabiting the Andean region of Bolivia. However, the spread of domestic T. infestans throughout the non-Andean regions only involved insects with an important reduction of heterochromatin and DNA amounts. We propose that heterochromatin and DNA variation mainly reflected adaptive genomic changes that contribute to the ability of T. infestans to survive, reproduce, and disperse in different environments.
Panzera
Francisco
F
Instituto de Biología, Sección Genética Evolutiva, Facultad de Ciencias, Universidad Mayor de la República, Iguá 4225, 11400 Montevideo, Uruguay. panzera@fcien.edu.uy
Dujardin
Jean Pierre
JP
Nicolini
Paula
P
Caraccio
María Noel
MN
Rose
Virginia
V
Tellez
Tatiana
T
Bermúdez
Hernán
H
Bargues
María Dolores
MD
Mas-Coma
Santiago
S
O'Connor
José Enrique
JE
Pérez
Ruben
R
D000818:Animals; D014355:Chagas Disease / Q000235:genetics; D004199:Disease Vectors / Q000145:classification; D005260:Female; D005434:Flow Cytometry; D008297:Male; D013020:South America; D014224:Triatoma / Q000145:classification / Q000235:genetics*