Multidisciplinary approach detects speciation within the kissing bug Panstrongylus rufotuberculatus populations (Hemiptera, Heteroptera, Reduviidae)

Abstract

BACKGROUND Panstrongylus rufotuberculatus (Hemiptera-Reduviidae) is a triatomine species with a wide geographic distribution and a broad phenotypic variability. In some countries, this species is found infesting and colonising domiciliary ecotopes representing an epidemiological risk factor as a vector of Trypanosoma cruzi, etiological agent of Chagas disease. In spite of this, little is known about P. rufotuberculatus genetic diversity.METHODS Cytogenetic studies and DNA sequence analyses of one nuclear (ITS-2) and two mitochondrial DNA sequences (cyt b and coI) were carried out in P. rufotuberculatus individuals collected in Bolivia, Colombia, Ecuador and Mexico. Moreover, a geometric morphometrics study was applied to Bolivian, Colombian, Ecuadorian and French Guiana samples.OBJECTIVES To explore the genetic and phenetic diversity of P. rufotuberculatus from different countries, combining chromosomal studies, DNA sequence analyses and geometric morphometric comparisons.FINDINGS We found two chromosomal groups differentiated by the number of X chromosomes and the chromosomal position of the ribosomal DNA clusters. In concordance, two main morphometric profiles were detected, clearly separating the Bolivian sample from the other ones. Phylogenetic DNA analyses showed that both chromosomal groups were closely related to each other and clearly separated from the remaining Panstrongylus species. High nucleotide divergence of cyt b and coI fragments were observed among P. rufotuberculatus samples from Bolivia, Colombia, Ecuador and Mexico (Kimura 2-parameter distances higher than 9%).MAIN CONCLUSIONS Chromosomal and molecular analyses supported that the two chromosomal groups could represent different closely related species. We propose that Bolivian individuals constitute a new Panstrongylus species, being necessary a detailed morphological study for its formal description. The clear morphometric discrimination based on the wing venation pattern suggests such morphological description might be conclusive.

Panstrongylus noireaui, a remarkable new species of Triatominae (Hemiptera, Reduviidae) from Bolivia

“…At the genetic level, P. noireaui sp. nov. presents very different chromosomal and molecular characteristics compared to the other Panstrongylus species studied so far ( Pita et al 2021 ) (Table 7 ). Out of the eight Panstrongylus species cytogenetically described, P. noireaui sp.…”

“…Both chromosomal markers (sex chromosome system and location of ribosomal clusters) are species-specific characters, being their variation within the same species an exceptional event ( Pita et al 2021 , 2022 ). Moreover, mitochondrial DNA markers showed a remarkable genetic diversity between this new species with all others Panstrongylus species, higher than the expected for conspecific populations ( Pita et al 2021 ). Sequence analyses of cyt b and coI fragments revealed high nucleotide divergence between P. noireaui sp.…”

“… Panstrongylus has been considered monophyletic based on morphological features ( Lent and Wygodzinsky 1979 ). However, molecular studies using several nuclear (ITS-2, 18S, 28S, ultraconserved elements), and mitochondrial (16S, coI, coII, cyt b) markers demonstrated a paraphyletic status for Panstrongylus ( Hypša et al 2002 ; Marcilla et al 2002 ; Justi et al 2014 ; Monteiro et al 2018 ; Kieran et al 2021 ; Pita et al 2021 ).…”

“… Pita et al (2021) through a multidisciplinary approach suggested speciation within populations of P. rufotuberculatus . Extensive chromosomal analyses supported that the two chromosomal groups could represent different closely related species.…”

Trends in evolution of the Triatomini tribe (Hemiptera, Triatominae): reproductive incompatibility between four species of geniculatus clade

“…Absence of hybrids between P. megistus and other species of geniculatus clade is expected, mainly because this species presents a karyotype (2n = 21) [ 40 ] different from the other species of Panstrongylus (2n = 22, 23 and 24) [ 40 , 41 ] and Nesotriatoma spp. (2n = 23) [ 40 ], and the number of chromosomes can act as a barrier of reproductive isolation for Triatomini tribe [ 39 ].…”