[Genetic differentiation of three Colombian populations of Triatoma dimidiata (Heteroptera: Reduviidae) by ND4 mitochondrial gene molecular analysis]

Abstract

Introduction: Triatoma dimidiata is the second most important vector of Chagas disease in Colombia after Rhodnius prolixus. Population genetic studies are essential for the adequate design and implementation of vector control and surveillance strategies.

Objective: The level of genetic variability and population differentiation was surveyed among three Colombian populations of T. dimidiata from different geographic locations and ecotopes, using ND4 mitochondrial gene.

Materials and methods: Genetic comparison was made between two wild populations from La Guajira (n=10) and Santander (n=10) provinces, and one intra (n=15) and one peridomiciliary (n=5) population from the Cesar province. The polymorphism frequencies of the ND4 mitochondrial gene sequence were analyzed to deduce population structure based on the 40 samples.

Results: Colombian T. dimidiata showed a high nucleotide (π: 0.034) and haplotype diversity (Hd: 0.863), as well as significant population subdivision (fST: 0.761) and a low migration rate (Nm: 0.157). Genetic distances and variability differences among populations indicate distinct population subdivision amongst the three provinces.

Conclusion: ND4 proved useful in elucidating the significant genetic differentiation that has occurred among T. dimidiata populations from La Guajira, Cesar and Santander. The analysis suggested a relationship between population subdivision and some eco-epidemiological attributes of this vector from the central eastern and northwestern regions of Colombia.