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Several cytogenetic studies have already been performed in Triatominae, such that different karyotypes could be characterized (ranging from 2n = 21 to 25 chromosomes), being the changes in the number of chromosomes related mainly to fusion and fission events. These changes have been associated with reproductive isolation and speciation events in other insect groups. Thus, we evaluated whether different karyotypes could act in the reproductive isolation of triatomines and we analyzed how the events of karyotypic evolution occurred along the diversification of these vectors. For this, experimental crosses were carried out between triatomine species with different karyotypes. Furthermore, based on a phylogeny with 88 triatomine taxa (developed with different molecular markers), a reconstruction of ancestral karyotypes and of anagenetic and cladogenetic events related to karyotypic alterations was performed through the ChromoSSE chromosomal evolution model. All crosses performed did not result in hybrids (prezygotic isolation in both directions). Our modeling results suggest that during Triatominae diversification, at least nine cladogenetic events may be associated with karyotype change. Thus, we emphasize that these alterations in the number of chromosomes can act as a prezygotic barrier in Triatominae (karyotypic isolation), being important evolutionary events during the diversification of the species of Chagas disease vectors.

Made available in DSpace on 2022-04-29T08:35:44Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-12-01 Background: Triatoma sordida 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 [s.s.], 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 ITS1 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 offspring 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 × F1 and F2 × 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.s. Graphical abstract: [Figure not available: see fulltext.] Laboratório de Biologia Celular Universidade Estadual Paulista “Júlio de Mesquita Filho” (UNESP) Instituto de Biociências Letras e Ciências Exatas, Rua Cristóvão Colombo, 2265 Universidade Estadual Paulista “Júlio de Mesquita Filho” (UNESP) Instituto de Biociências Rua Dr. Antônio Celso Wagner Zanin, 250, Distrito de Rubião Júnior Laboratório de Parasitologia Universidade Estadual Paulista “Júlio de Mesquita Filho” (UNESP) Faculdade de Ciências Farmacêuticas, Rodovia Araraquara-Jaú km 1 Laboratório de Entomologia em Saúde Pública Departamento de Epidemiologia Faculdade de Saúde Pública Universidade de São Paulo, Av. Dr. Arnaldo 715 Laboratório Nacional e Internacional de Referência em Taxonomia de Triatomíneos Instituto Oswaldo Cruz (FIOCRUZ), Av. Brasil 4365, Pavilhão Rocha Lima, sala 505 Laboratório de Biologia Celular Universidade Estadual Paulista “Júlio de Mesquita Filho” (UNESP) Instituto de Biociências Letras e Ciências Exatas, Rua Cristóvão Colombo, 2265 Universidade Estadual Paulista “Júlio de Mesquita Filho” (UNESP) Instituto de Biociências Rua Dr. Antônio Celso Wagner Zanin, 250, Distrito de Rubião Júnior Laboratório de Parasitologia Universidade Estadual Paulista “Júlio de Mesquita Filho” (UNESP) Faculdade de Ciências Farmacêuticas, Rodovia Araraquara-Jaú km 1

Made available in DSpace on 2022-04-29T08:36:44Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-11-01 Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) Triatoma petrocchiae is a species morphologically similar to T. b. brasiliensis (which resulted in a synonymization event); despite this similarity, genetic, morphological, and experimental crossbreed-ing studies confirmed the specific status of T. petrocchiae. Considering that both species have been reported living in sympatry and that, for a long time, most species of the T. brasiliensis complex were considered only chromatic variants of T. b. brasiliensis, we carried out experimental crosses between T. b. brasiliensis and T. petrocchiae (to confirm whether these species are reproductively isolated) and between T. lenti and T. petrocchiae (to assess whether T. petrocchiae also presents prezygotic isolation with the other species of the T. brasiliensis complex). Reciprocal experimental crosses were conducted, and weekly, the eggs were collected, counted, and separated in new containers to assess the hatch rate. Neither cross resulted in hybrids, demonstrating that there are pre-zygotic reproductive barriers installed between T. petrocchiae and the other species of the T. brasiliensis complex. On the basis of the results above, we demonstrated that T. petrocchiae is reproductively isolated from T. b. brasilien-sis and T. lenti. Furthermore, we suggest that T. petrocchiae is the species most derived from the T. brasiliensis complex. Instituto de Biociências Universidade Estadual Paulista “Júlio de Mesquita Filho” (UNESP), Rua Dr. Antônio Celso Wagner Zanin, 250, Distrito de Rubião Júnior Laboratório de Entomologia em Saúde Pública Departamento de Epidemiologia Faculdade de Saúde Pública Universidade de São Paulo (USP), Av. Dr. Arnaldo 715 Laboratório de Parasitologia Departamento de Ciências Biológicas Universidade Estadual Paulista “Júlio de Mesquita Filho” (UNESP) Faculdade de Ciências Farmacêuticas, Câmpus de Araraquara, Rod. Araraquara-Jaú km 1 Laboratório de Biologia Celular Departamento de Biologia Instituto de Biociências Letras e Ciências Exatas Câmpus de São José do Rio Preto Universidade Estadual Paulista “Júlio de Mesquita Filho” (UNESP), Rua Cristóvão Colombo 2265 Instituto de Biologia Universidade Estadual de Campinas (UNICAMP), Rua Monteiro Lobato, 255 Centro de Ciências Aplicadas e Educação Laboratório de Ecologia Animal Departamento de Engenharia e Meio Ambiente Universidade Federal de Paraíba (UFPB), Av. Santa Elizabete, 160, Rio Tinto Laboratório Nacional e Internacional de Referência em Taxonomia de Triatomíneos Instituto Oswaldo Cruz (IOC/FIOCRUZ), Av. Brasil 4365, Pavilhão Rocha Lima, Sala 505 Instituto de Biociências Universidade Estadual Paulista “Júlio de Mesquita Filho” (UNESP), Rua Dr. Antônio Celso Wagner Zanin, 250, Distrito de Rubião Júnior Laboratório de Parasitologia Departamento de Ciências Biológicas Universidade Estadual Paulista “Júlio de Mesquita Filho” (UNESP) Faculdade de Ciências Farmacêuticas, Câmpus de Araraquara, Rod. Araraquara-Jaú km 1 Laboratório de Biologia Celular Departamento de Biologia Instituto de Biociências Letras e Ciências Exatas Câmpus de São José do Rio Preto Universidade Estadual Paulista “Júlio de Mesquita Filho” (UNESP), Rua Cristóvão Colombo 2265 CAPES: 001

Made available in DSpace on 2021-06-25T10:52:37Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-02-01 Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) Although all triatomines are considered as potential vectors of the Chagas disease, the Triatoma, Panstrongylus, and Rhodnius genera are the most important from the epidemiological point of view. Based on cytogenetic analyzes carried out so far (C banding and FISH), the species of the genus Rhodnius show little interspecific chromosomal variation. Thus, we analyzed the distribution of AT- and CG-rich DNA in the chromatin and chromosomes of the genus Rhodnius and discuss the chromosome evolution of these vectors. Except for Rhodnius domesticus, Rhodnius nasutus, Rhodnius pictipes, Rhodnius colombiensis, and Rhodnius pallescens, all Rhodnius species have euchromatic autosomes with the absence of AT- and CG-rich blocks. Curiously, the same species that have heterochromatin blocks in the autosomes also have chromomycin A3 (CMA3+) blocks dispersed in the prophasic nucleus (demonstrating that the heterochromatin of these species is rich in CG). Thus, we characterize the AT- and CG-rich DNA pattern for the genus Rhodnius, and we suggest that the pattern of CG-rich heterochromatin in the autosomes of these vectors evolved independently in pallescens, pictipes, and prolixus groups. Instituto de Biociências Universidade Estadual Paulista “Júlio de Mesquita Filho” (IBB/UNESP) Departamento de Ciências Biológicas Laboratório de Parasitologia Faculdade de Ciências Farmacêuticas Universidade Estadual Paulista “Júlio de Mesquita Filho” (FCFAR/UNESP) Departamento de Biologia Laboratório de Biologia Celular Instituto de Biociências Letras e Ciências Exatas Universidade Estadual Paulista “Júlio de Mesquita Filho” (IBILCE/UNESP) Instituto de Biociências Universidade Estadual Paulista “Júlio de Mesquita Filho” (IBB/UNESP) Departamento de Ciências Biológicas Laboratório de Parasitologia Faculdade de Ciências Farmacêuticas Universidade Estadual Paulista “Júlio de Mesquita Filho” (FCFAR/UNESP) Departamento de Biologia Laboratório de Biologia Celular Instituto de Biociências Letras e Ciências Exatas Universidade Estadual Paulista “Júlio de Mesquita Filho” (IBILCE/UNESP)

Made available in DSpace on 2021-06-25T11:13:10Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-07-01 Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) There are currently 156 species, grouped into 18 genera and five tribes included in the subfamily Triatominae. All of them are potential vectors of Chagas disease. Triatoma is paraphyletic and the species of this genus have been grouped into complexes and subcomplexes. Triatoma brasiliensis complex is a monophyletic group composed of eight taxa: T. b. brasiliensis, T. b. macromelanosoma, T. juazeirensis, T. sherlocki, T. petrocchiae, T. lenti, T. bahiensis, T. melanica. Experimental crosses have helped in systematic, taxonomic and evolutionary issues of these vectors. Based on this, we carried out experimental crosses between T. lenti and four other species of the T. brasiliensis complex and analyzed the segregation pattern of phenotypic characteristics of T. lenti, T. b. brasiliensis, T. b. macromelasoma, T. juazeirensis and T. melanica in the hybrids. The hybrids resulting from the crosses between T. b. brasiliensis ♀ x T. lenti ♂, T. juazeirensis ♀ x T. lenti ♂, and T. melanica ♀ x T. lenti ♂ showed segregation of characteristics of both parental species. On the other hand, the hybrids between T. lenti ♀ x T. juazeirensis ♂, T. b. macromelasoma ♀ x T. lenti ♂, and T. lenti ♀ x T. melanica ♂ showed a specific pattern of T. lenti, T. lenti and T. melanica, respectively. Thus, the pattern of segregation of morphological characteristics between species of the T. brasiliensis complex was characterized. These results highlight the importance of integrative taxonomy for the correct identification of Chagas disease vectors grouped in the T. brasiliensis complex if natural hybridization events occur. Faculdade de Ciências Farmacêuticas Universidade Estadual Paulista “Júlio de Mesquita Filho” (UNESP), Rodovia Araraquara-Jaú km 1 Instituto de Biociências Universidade Estadual Paulista “Júlio de Mesquita Filho” (UNESP), Rua Dr. Antônio Celso Wagner Zanin, 250, Distrito de Rubião Júnior Instituto de Biociências Universidade Estadual Paulista “Júlio de Mesquita Filho” (UNESP) Rua Cristóvão Colombo 2265, Letras e Ciências Exatas Faculdade de Ciências Farmacêuticas Universidade Estadual Paulista “Júlio de Mesquita Filho” (UNESP), Rodovia Araraquara-Jaú km 1 Instituto de Biociências Universidade Estadual Paulista “Júlio de Mesquita Filho” (UNESP), Rua Dr. Antônio Celso Wagner Zanin, 250, Distrito de Rubião Júnior Instituto de Biociências Universidade Estadual Paulista “Júlio de Mesquita Filho” (UNESP) Rua Cristóvão Colombo 2265, Letras e Ciências Exatas FAPESP: 2017/05015-7 CNPq: 307398/2018-8

The genus Psammolestes within the subfamily Triatominae and tribe Rhodniini comprises the species Psammolestes arthuri, Psammolestes coreodes, and Psammolestes tertius, all potential vectors of Chagas disease. A feature of Psammolestes is their close association with birds, which makes them an interesting model for evolutionary studies. We analyzed cytogenetically Psammolestes spp., with the aim of contributing to the genetic and evolutionary knowledge of these vectors. All species of the Psammolestes showed the same chromosomal characteristics: chromocenter formed only by sex chromosomes X and Y, karyotype 2n = 22 and constitutive heterochromatin, and AT base pairs restricted to the sex chromosome Y. These results corroborate the monophyly of the genus and lead to the hypothesis that during the derivation of P. tertius, P. coreodes, and P. arthuri from their common ancestor, there was no reorganization in the number or structure of chromosomes.

The genus Psammolestes within the subfamily Triatominae and tribe Rhodniini comprises the species Psammolestes arthuri, Psammolestes coreodes, and Psammolestes tertius, all potential vectors of Chagas disease. A feature of Psammolestes is their close association with birds, which makes them an interesting model for evolutionary studies. We analyzed cytogenetically Psammolestes spp., with the aim of contributing to the genetic and evolutionary knowledge of these vectors. All species of the Psammolestes showed the same chromosomal characteristics: chromocenter formed only by sex chromosomes X and Y, karyotype 2n = 22 and constitutive heterochromatin, and AT base pairs restricted to the sex chromosome Y. These results corroborate the monophyly of the genus and lead to the hypothesis that during the derivation of P. tertius, P. coreodes, and P. arthuri from their common ancestor, there was no reorganization in the number or structure of chromosomes.

El uso de características sutiles como características de diagnóstico de especies en taxones con una gran similitud morfológica a veces falla en discriminar la variación intraespecífica de las diferencias interespecíficas, lo que lleva a una delimitación incorrecta de la especie. Una evaluación clara de los límites de las especies es particularmente relevante en los organismos vectores de enfermedades para comprender los procesos epidemiológicos y evolutivos que afectan la capacidad de transmisión. Aquí, evaluamos la validez del Rhodnius taquarussuensis recientemente descrito (da Rosa et al., 2017) utilizando cruces interespecíficos y marcadores moleculares. No detectamos diferencias en las tasas de eclosión en cruces interespecíficos entre R. taquarussuensis y R. negligencias (Lent, 1954). Además, los análisis de divergencia genética y delimitación de especies muestran que R. taquarussuensis no es un linaje independiente en el grupo R. prolixus. Estos resultados sugieren que R. taquarussuensis es una forma fenotípica de R. negligenciaus en lugar de una especie distinta. Nos gustaría enfatizar que se necesitan diferentes fuentes de evidencia para delimitar correctamente las especies. Consideramos que este es un paso importante en la comprensión de la propagación y transmisión vectorial de la enfermedad de Chagas. The use of subtle features as species diagnostic traits in taxa with high morphological similarity sometimes fails in discriminating intraspecific variation from interspecific differences, leading to an incorrect species delimitation. A clear assessment of species boundaries is particularly relevant in disease vector organisms in order to understand epidemiological and evolutionary processes that affect transmission capacity. Here, we assess the validity of the recently described Rhodnius taquarussuensis (da Rosa et al., 2017) using interspecific crosses and molecular markers. We did not detect differences in hatching rates in interspecific crosses between R. taquarussuensis and R. neglectus (Lent, 1954). Furthermore, genetic divergence and species delimitation analyses show that R. taquarussuensis is not an independent lineage in the R. prolixus group. These results suggest that R. taquarussuensis is a phenotypic form of R. neglectus instead of a distinct species. We would like to stress that different sources of evidence are needed to correctly delimit species. We consider this is an important step in understanding vectorial Chagas disease spread and transmission. © 2019 Nascimento et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

Rhodnius colombiensis, in conjunction with R. pallescens and R. ecuadoriensis, forms the monophyletic pallescens group. Cytogenetic analyses of these closely related species would further our understanding of the taxonomy and evolution of this group. In this study, R. colombiensis was cytogenetically analyzed, and the results were compared with cytogenetic data from other species of the pallescens group, particularly their chromosomal evolution. We found that this triatomine has heteropycnotic blocks in five autosomal bivalents at both metaphase I and II. The derivation of R. colombiensis from R. pallescens led to significant loss of heteropycnotic and heterochromatic regions (approximately 50%). R. ecuadoriensis is the most differentiated of the group because it has lost all heterochromatin and heteropyknotic blocks in the autosomes. Based on the heteropyknotic and heterochromatic pattern of R. colombiensis and the chromosomal evolution analysis of the pallescens group, we suggest that the karyotype of R. colombiensis and R. ecuadoriensis lost its heteropycnotic and heterochromatic blocks during speciation. Furthermore, this loss could be related to adaptation to different environments.

Chagas disease is caused by Trypanosoma cruzi and transmitted by feces of a triatomine that has the habit of defecating during blood feeding. The salivary glands of triatomines are important to hematophagy because their saliva is rich in anticoagulant and hemolytic proteins. The salivary glands of some Rhodnius species analyzed are reddish due to the presence of nitrophorins (antihemostatic activity). The present study aimed to analyze the color pattern of the salivary glands of 67 triatomine species to evaluate whether the presence of nitrophorins is a synapomorphy of Rhodnius or the tribe Rhodniini, or if it is shared with triatomines of the tribes Triatomini and Cavernicolini. Since only the species of the tribe Rhoniini present red glands, it is admitted that the presence of nitrophorin proteins is a synapomorphy of the tribe Rhodniini and that this tribe has derived more recently when compared with Triatomini and Cavernicolini.

The Triatominae subfamily is comprised of 18 genera and six tribes. The tribe Rhodniini is comprised of two genera (Rhodnius and Psammolestes). Nucleolar persistence is defined by the presence of the nucleolus or nucleolar corpuscles during the meiotic metaphase. To date, this phenomenon has been described for 13 species of triatomine that are included in the genera Triatoma, Rhodnius, and Panstrongylus. Thus, because the phenomenon of nucleolar persistence has been described in only two species of the genus Rhodnius, we have analyzed the nucleolar behavior during spermatogenesis of eight species of the genus Rhodnius (R. colombiensis, R. montenegrensis, R. nasutus, R. neglectus, R. neivai, R. pictipes, R. prolixus, and R. robustus), with a focus on nucleolar persistence. By means of cytogenetic analysis with silver ions, nucleolar behavior during spermatogenesis is described in the eight species of Rhodnius analyzed. In all of them nucleolar behavior was similar and the phenomenon of nucleolar persistence was often observed. Therefore, we confirm nucleolar persistence as a peculiarity of the genus Rhodnius. However, it is emphasized that new cytogenetic analysis should be performed in the Triatominae subfamily, more specifically among the 15 genera that do not exhibit the nucleolar behavior described, in order to assess whether this phenomenon is truly a synapomorphy of these hematophagous insects.

The tribe Rhodniini is a monophyletic group composed of 22 species, with 19 in the Rhodnius genus and three in the Psammolestes genus. These insects are morphologically very similar (cryptic species), and new tools are important for investigating the taxonomy of these vectors. Spermiotaxonomy is an important tool in differentiating between related species, and this study analyzed the spermatids of Rhodniini species to elucidate their spermiotaxonomy. All of the Rhodniini species contained two heteropyknotic filaments in the extremities of their cells. Although spermiotaxonomy has been an important tool in differentiating between species of the Triatoma genus, all of the species in the Rhodnius genus exhibited the same characteristics in their male gametes. However, spermatid analysis made it possible to confirm the monophyly of the Rhodniini tribe, because Psammolestes tertius had the same pattern as that described for Rhodnius. The results of this study demonstrate that spermiotaxonomy, in addition to being an important tool for differentiating between related species of Triatoma, can be used as an optimization tool in phylogenetic analyses.

All species of triatomines are considered potential vectors of Chagas disease and the reproductive biology of these bugs has been studied by different approaches. In 1999, nucleolar persistence during meiosis was observed in the subfamily for the first time. Recently, it has been observed that all species within the genus Rhodnius exhibit the same phenomenon, suggesting that it may be a synapomorphy of the triatomines. Thus, this article aims to analyze the nucleolar behavior during spermatogenesis of 59 triatomine species. All analyzed species exhibited nucleolar persistence during meiosis. Recently, it has been suggested that nucleolar persistence may be fundamental for the spermatogenesis of these vectors, since it is related to the formation of the chromatoid body. Therefore, we emphasize that this phenomenon is a peculiarity of the Triatominae subfamily and that further studies are required to analyze whether the nucleolar material that persists is active.

The Triatominae subfamily comprises 6 tribes. The tribe Rhodniini comprises 2 genera and 22 nominal species. Rhodnius montenegrensis (Hemiptera, Triatominae) was recently described as evolutionarily related to R. robustus. Therefore, in order to contribute to karyosystematic study of the tribe Rhodniini, this report describes the number of chromosomes and compares the karyotype of R. montenegrensis to that of all other species in the tribe, in order to determine the karyotypic evolution of the tribe Rhodniini. The seminiferous tubules of adult males, after being removed and fixated on a cover slip, were processed with lacto-aceto-orcein for cytogenetic analysis. R. montenegrensis, as well as all other species of the tribe Rhodniini showed 22 chromosomes (20 autosomes + XY). Thus, we hereby describe the karyotype of the species R. montenegrensis and mainly highlight that the tribe Rhodniini displays karyotypic homogeneity, demonstrating itself as a derived group to a lesser extent when compared to the number of chromosomes of the common ancestors of the subfamily Triatominae.

Made available in DSpace on 2015-04-27T11:55:53Z (GMT). No. of bitstreams: 0 Previous issue date: 2014Bitstream added on 2015-04-27T12:08:29Z : No. of bitstreams: 1 ISSN2161-0983-2014-03-02.pdf: 652239 bytes, checksum: a475b41ffd8eb9c826022c2465cc014d (MD5) We did an overhaul on morphophysiology characteristics, cryptonephric system and secondary specializations in the Malpighian tubules of the class Insecta. This review grouped the most important information about this important organ that has different functions essential for insects. Universidade Estadual Paulista Júlio de Mesquita Filho, Departamento de Biologia, Instituto de Biociências Letras e Ciências Exatas de São José do Rio Preto, São José do Rio Preto, Rua Cristovão Colombo, 2265, Jardim Nazareth, CEP 15054000, SP, Brasil Universidade Estadual Paulista Júlio de Mesquita Filho, Departamento de Biologia, Instituto de Biociências Letras e Ciências Exatas de São José do Rio Preto, São José do Rio Preto, Rua Cristovão Colombo, 2265, Jardim Nazareth, CEP 15054000, SP, Brasil