Triatoma sordida (Hemiptera, Triatominae) from La Paz, Bolivia: an incipient species or an intraspecific chromosomal polymorphism?

Author(s):Show less -

Madeira, Fernanda Fernandez ^[1] ; Grzyb Delgado, Luiza Maria ^[2] ; Bittinelli, Isadora de Freitas ^[2] ; de Oliveira, Jader ^{[3, 4]} ; Ravazi, Amanda ^[2] ; dos Reis, Yago Visinho ^[2] ; Bortolozo de Oliveira, Ana Beatriz ^[1] ; Cristal, Daniel Cesaretto ^[3] ; Galvao, Cleber ^[5] ; Vilela De Azeredo-Oliveira, Maria Tercilia ^[1] ; da Rosa, Joao Aristeu ^[3] ; Chaboli Alevi, Kaio Cesar ^{[3, 2]}

Affiliation

^[1] Univ Estadual Paulista Julio de Mesquita Filho UN, Lab Biol Celular, Rua Cristovao Colombo 2265, BR-15054000 Sao Jose Do Rio Preto, SP - Brazil

^[2] Univ Estadual Paulista Julio de Mesquita Filho UN, Inst Biociencias, Rua Dr Antonio Celso Wagner Zanin 250, BR-18618689 Botucatu, SP - Brazil

^[3] Univ Estadual Paulista Julio de Mesquita Filho UN, Fac Ciencias Farmaceut, Lab Parasitol, Rodovia Araraquara Jau Km 1, BR-14801902 Araraquara, SP - Brazil

^[4] Univ Sao Paulo, Fac Saude Publ, Dept Epidemiol, Lab Entomol Saude Publ, Sao Paulo, SP - Brazil

^[5] Inst Oswaldo Cruz FIOCRUZ, Lab Nacl & Int Referencia Taxon Triatomineos, Av Brasil 4365, Pavilhao Rocha Lima, Sala 505, BR-21040360 Rio De Janeiro, RJ - Brazil

• Document type: Journal article
• Source: PARASITES & VECTORS; v. 14, n. 1 OCT 27 2021.
• Web of Science Citations: 0

Abstract

Background: Triatomasordida is one of the main Chagas disease vectors in Brazil. In addition to Brazil, this species has already been reported in Bolivia, Argentina, Paraguay, and Uruguay. It is hypothesized that the insects currently identified as T. sordida are a species subcomplex formed by three cytotypes (T. sordida sensu stricto T. sordida La Paz, and T. sordida Argentina). With the recent description of T. rosai from the Argentinean specimens, it became necessary to assess the taxonomic status of T. sordida from La Paz, Bolivia, since it was suggested that it may represent a new species, which has taxonomic, evolutionary, and epidemiological implications. Based on the above, we carried out molecular and experimental crossover studies to assess the specific status of T. sordida La Paz. Methods: To evaluate the pre- and postzygotic barriers between T. sordida La Paz and T. sordida s.s., experimental crosses and intercrosses between F1 hybrids and between F2 hybrids were conducted. In addition, cytogenetic analyses of the F1 and F2 hybrids were applied with an emphasis on the degree of pairing between the homeologous chromosomes, and morphological analyses of the male gonads were performed to evaluate the presence of gonadal dysgenesis. Lastly, the genetic distance between T sordida La Paz and T sordida s.s. was calculated for the CYTB, ND1, and 1TS1 genes. Results: Regardless of the gene used, T. sordida La Paz showed low genetic distance compared to T sordida s.s. (below 2%). Experimental crosses resulted in off spring for both directions, demonstrating that there are no prezygotic barriers installed between these allopatric populations. Furthermore, postzygotic barriers were not observed either (since the F1 x F1 and F2 x F2 intercrosses resulted in viable offspring). Morphological and cytogenetic analyses of the male gonads of the F1 and F2 offspring demonstrated that the testes were not atrophied and did not show chromosome pairing errors. Conclusion: Based on the low genetic distance (which configures intraspecific variation), associated with the absence of prezygotic and postzygotic reproductive barriers, we confirm that T. sordida La Paz represents only a chromosomal polymorphism of T. sordida s. (AU)

• FAPESP's process: 17/05015-7 - Study of hybridization in Triatoma sordida (Stal, 1859) (Hemiptera, Reduviidae): evolutionary dynamics, reproductive viability, morpho-molecular characterization and its taxonomic implications
• Grantee: Kaio Cesar Chaboli Alevi
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• FAPESP's process: 19/17581-2 - Unraveling the process of cryptic speciation of Triatoma sordida (Stål, 1859) (Hemiptera, Triatominae) through integrative taxonomy
• Grantee: Daniel Cesaretto Cristal
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• FAPESP's process: 18/12039-2 - Triatoma sordida (Stål, 1859) (Hemiptera, Triatominae): a Chagas Disease vector or a complex of vectors?
• Grantee: Isadora de Freitas Bittinelli
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• FAPESP's process: 18/24116-1 - Is there a barrier of reproductive isolation between the different cytotypes of Triatoma sordida (Stal, 1859) (Hemiptera, Triatominae)?
• Grantee: Luiza Maria Grzyb Delgado
• Support Opportunities: Scholarships in Brazil - Scientific Initiation