Genetic Variation of North American Triatomines (Insecta: Hemiptera: Reduviidae): Initial Divergence between Species and Populations of Chagas Disease Vector

Abstract

Abstract. The triatomines vectors of Trypanosoma cruzi are principal factors in acquiring Chagas disease. For this reason, increased knowledge of domestic transmission of T. cruzi and control of its insect vectors is necessary. To contribute to genetic knowledge of North America Triatominae species, we studied genetic variations and conducted phylogenetic analysis of different triatomines species of epidemiologic importance. Our analysis showed high genetic variations between different geographic populations of Triatoma mexicana, Meccus longipennis, M. mazzottii, M. picturatus, and T. dimidiata species, suggested initial divergence, hybridation, or classifications problems. In contrast, T. gerstaeckeri, T. bolivari, and M. pallidipennis populations showed few genetics variations. Analysis using cytochrome B and internal transcribed spacer 2 gene sequences indicated that T. bolivari is closely related to the Rubrofasciata complex and not to T. dimidiata. Triatoma brailovskyi and T. gerstaeckeri showed a close relationship with Dimidiata and Phyllosoma complexes.

Biological parameters of Meccus phyllosomus phyllosomus (Burmeister), 1835, Triatoma recurva (Stål), 1868 (Hemiptera, Reduviidae) and their laboratory hybrids

“…Dado que algunos análisis moleculares (7,8) han establecido que T. recurva es filogenéticamente cercana a las subspecies de Meccus, en un estudio se entrecruzaron (incluidos cruces inversos) estas seis subspecies con T. recurva, con un único cruce exitoso: el de ♀ T. recurva y ♂ M. p. phyllosomus (9).…”

Towards a phylogenetic approach to the composition of species complexes in the North and Central American Triatoma, vectors of Chagas disease

“…This leaves T. recurva and T. indictiva as the only other members of a Lecticularia complex, a hypothesis we were unable to test as these were not available. (Espinoza, et al [33] published ITS-2 sequence of T. recurva , however, it is only 400 bp long, and the lack of information on the variable sites in the 3’ end made it unusable for this analysis). However, since T. recurva clusters with the phyllosoma by cyt b [33], and T. indictiva was previously classified as a subspecies of T. sanguisuga [12] these species likely to cluster within Clade C, rather than with T. lecticularia .…”

“…Dipetalogaster maximus , a species of the Baja peninsula, is the only species of its genus, separated due to extreme size as well as additional apomorphic characters [12]. D. maximus was sister to T. lecticularia by a fragment of the mitochondrial cyt b gene, but not by a phylogeny inferred by concatenated fragments of mitochondrial cyt b and nuclear ITS-2; the latter placed D. maximus in close affiliation with T. barberi and T. protracta [33]. …”

“…The validity of some complexes has been supported using molecular phylogenetics; however, some complexes are not monophyletic and/or clades containing the complex members lack bootstrap or posterior probability support [5,7,8,19,33]. Furthermore, a recent update to the complexes lacks detail about assignment criteria [2].…”

Importance of Hybrids of <i>Meccus phyllosomus mazzottii</i>, and <i>M. p. pallidipennis</i>, and <i>M. p. phyllosomus</i> to the Transmission of <i>Trypanosoma cruzi</i> in Mexico

“…However, 37 years later, Lent and Wygodzinsky (13) reinstated their status as bona fide species, based entirely on morphological characters. The debate continued, and recent biological, morphological, and molecular evidence (3,4,9,(14)(15)(16) lead to them being considered subspecies again, based on the concept that`s ubspecies are local populations that are recognizably different from each other but they are nevertheless considered to belong to the same species because they are observed to interbreed in nature or because it is inferred that they are likely to interbreed'' (17). Consequently, M. mazzottii, M. pallidipennis, and M. phyllosomus will be considered subspecies of M. phyllosomus during this study.…”