Putative panmixia in restricted populations of Trypanosoma cruzi isolated from wild Triatoma infestans in Bolivia.

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.

[G-protein-coupled receptors: general features and activation mechanisms].

G-protein-coupled receptors (GPCRs) are 7-transmembrane-domain proteins that recognize external messages such as photons and odorants, and also internal messages such as hormones and neurotransmitters. Following activation by these messages, GPCRs activate one or several heterotrimeric G proteins (each composed of 3 subunits alpha, beta and gamma) by stimulating GDP/GTP exchange on the nucleotide binding site of the alpha subunit. The GTP form of the alpha subunit then activates effectors such as enzymes (adenylyl cyclase for example) or ion channels.

Scarce events of mitochondrial introgression in Trypanosoma cruzi: new case with a Bolivian strain.

Trypanosoma cruzi, the agent of Chagas disease, presents a predominantly clonal structure that has been shaped by recombination events leading to six genetic groups (DTUs, discrete typing units, TcI-TcVI). Several conventional and unconventional genetic exchange events have been described, including hybridization and mitochondrial introgression, which is explored here among Bolivian and Peruvian strains belonging to TcI because recombination events have been previously suspected by means of the MLMT method (multilocus microsatellite typing). We analyzed the variation of one nuclear (Gpi) and one mitochondrial (Nd1) gene among 60 TcI strains and 15 reference strains belonging to the six DTUs.

Trypanosoma cruzi discrete typing units (DTUs): microsatellite loci and population genetics of DTUs TcV and TcI in Bolivia and Peru.

Trypanosoma cruzi, the agent of Chagas disease, is usually subdivided into six discrete typing units (DTUs), TcI to TcVI, among which TcI and TcV are most common in human infections in Bolivia. Multilocus microsatellite typing (MLMT) was selected to further explore the structure of the natural populations belonging to these DTUs. The analysis showed that microsatellite clustering does not fully match the six DTUs, but it is relevant for the within DTUs analyses.