Publications des scientifiques de l'IRD

Barnabé Christian, Buitrago R., Brémond Philippe, Aliaga C., Salas R., Vidaurre P., Herrera C., Cerqueira F., Bosseno Marie-France, Waleckx E., Brenière Simone Frédérique. (2013). Putative panmixia in restricted populations of Trypanosoma cruzi isolated from wild Triatoma infestans in Bolivia. PloS One, 8 (11), p. e82269. ISSN 1932-6203.

Titre du document
Putative panmixia in restricted populations of Trypanosoma cruzi isolated from wild Triatoma infestans in Bolivia
Année de publication
2013
Type de document
Article référencé dans le Web of Science WOS:000327670300077
Auteurs
Barnabé Christian, Buitrago R., Brémond Philippe, Aliaga C., Salas R., Vidaurre P., Herrera C., Cerqueira F., Bosseno Marie-France, Waleckx E., Brenière Simone Frédérique
Source
PloS One, 2013, 8 (11), p. e82269 ISSN 1932-6203
Trypanosoma cruzi, the causative agent of Chagas disease, is subdivided into six discrete typing units (DTUs; TcI-TcVI) of which TcI is ubiquitous and genetically highly variable. While clonality is the dominant mode of propagation, recombinant events play a significant evolutive role. Recently, foci of wild Triatoma infestans have been described in Bolivia, mainly infected by TcI. Hence, for the first time, we evaluated the level of genetic exchange within TcI natural potentially panmictic populations (single DTU, host, area and sampling time). Seventy-nine TcI stocks from wild T. infestans, belonging to six populations were characterized at eight microsatellite loci. For each population, Hardy-Weinberg equilibrium (HWE), linkage disequilibrium (LD), and presence of repeated multilocus genotypes (MLG) were analyzed by using a total of seven statistics, to test the null hypothesis of panmixia (H-0). For three populations, none of the seven statistics allowed to rejecting H-0; for another one the low size did not allow us to conclude, and for the two others the tests have given contradictory results. Interestingly, apparent panmixia was only observed in very restricted areas, and was not observed when grouping populations distant of only two kilometers or more. Nevertheless it is worth stressing that for the statistic tests of "HWE", in order to minimize the type I error (i.e. incorrect rejection of a true H-0), we used the Bonferroni correction (BC) known to considerably increase the type II error (i.e. failure to reject a false H-0). For the other tests (LD and MLG), we did not use BC and the risk of type II error in these cases was acceptable. Thus, these results should be considered as a good indicator of the existence of panmixia in wild environment but this must be confirmed on larger samples to reduce the risk of type II error.
Plan de classement
Sciences fondamentales / Techniques d'analyse et de recherche [020] ; Entomologie médicale / Parasitologie / Virologie [052]
Description Géographique
BOLIVIE
Localisation
Fonds IRD [F B010061369]
Identifiant IRD
fdi:010061369
Contact