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Lima JF, Carvalho LS, Carvalho MA, Schneider MC. Chromosome diversity in Buthidae and Chactidae scorpions from Brazilian fauna: Diploid number and distribution of repetitive DNA sequences. Genet Mol Biol 2023; 46:e20220083. [PMID: 37216321 DOI: 10.1590/1678-4685-gmb-2022-0083] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2022] [Accepted: 03/23/2023] [Indexed: 05/24/2023] Open
Abstract
In this work, we analyzed cytogenetically eight Chactidae and Buthidae, including the localization of repetitive DNA sequences. The chactids possess monocentric chromosomes and the highest diploid numbers (2n=50 in Brotheas amazonicus, 2n=36 in Chactopsis amazonica, 2n=30 in Neochactas sp.) when compared with buthids (2n=10 in Tityus bahiensis, 2n=14 in Tityus apiacas and Tityus metuendus, 2n=18 in Tityus aba, 2n=26 in Ischnotelson peruassu). The localization of rDNA genes and (TTAGG)n sequences exhibited a conserved pattern of two terminal/subterminal ribosomal cistrons and terminal telomere signals. However, the comparison between the data of C-banding, DAPI after FISH and Cot-DNA fraction indicated a variable quantity and distribution of these regions, as follow: (i) positive heterochromatin and Cot-DNA signals (B. amazonicus and I. peruassu), (ii) small blocks of heterochromatin with large Cot-DNA signals (T. metuendus), (iii) positive heterochromatic regions and absence of Cot-DNA signals (T. aba and T. apiacas), and (iv) negative heterochromatin and Cot-DNA signals (T. bahiensis). Therefore, our results revealed that there still is not a clear relation between quantity of heterochromatin and presence of monocentric or holocentric chromosomes and occurrence of chromosomal rearrangements, indicating that repetitive regions in scorpions must be analyzed using different cytogenetic approaches.
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Affiliation(s)
- Juliana Figueiredo Lima
- Universidade de São Paulo (USP), Instituto de Biociências, Departamento de Zoologia, Programa de Pós-Graduação em Zoologia, São Paulo, SP, Brazil
| | | | - Marcos André Carvalho
- Universidade Federal de Mato Grosso (UFMT), Departamento de Biologia e Zoologia, Cuiabá, MT, Brazil
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Christophoryová J, Krajčovičová K, Šťáhlavský F, Španiel S, Opatova V. Integrative Taxonomy Approach Reveals Cryptic Diversity within the Phoretic Pseudoscorpion Genus Lamprochernes (Pseudoscorpiones: Chernetidae). INSECTS 2023; 14:122. [PMID: 36835691 PMCID: PMC9964657 DOI: 10.3390/insects14020122] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/01/2022] [Revised: 01/13/2023] [Accepted: 01/16/2023] [Indexed: 06/18/2023]
Abstract
Pseudoscorpions represent an ancient, but homogeneous group of arachnids. The genus Lamprochernes comprises several morphologically similar species with wide and overlapping distributions. We implemented an integrative approach combining molecular barcoding (cox1), with cytogenetic and morphological analyses in order to assess species boundaries in European Lamprochernes populations. The results suggest ancient origins of Lamprochernes species accompanied by morphological stasis within the genus. Our integrative approach delimited three nominal Lamprochernes species and one cryptic lineage Lamprochernes abditus sp. nov. Despite its Oligocene origin, L. abditus sp. nov. can be distinguished from its closest relative only by molecular and cytogenetic differences, or alternatively, by a complex multivariate morphometric analysis involving other Lamprochernes species. The population structure and common haplotype sharing across geographically distant populations in most Lamprochernes species suggest that a phoretic manner of dispersal is efficient in this group.
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Affiliation(s)
- Jana Christophoryová
- Department of Zoology, Faculty of Natural Sciences, Comenius University, Mlynská Dolina, Ilkovičova 6, 842 15 Bratislava, Slovakia
| | - Katarína Krajčovičová
- Department of Zoology, Faculty of Natural Sciences, Comenius University, Mlynská Dolina, Ilkovičova 6, 842 15 Bratislava, Slovakia
| | - František Šťáhlavský
- Department of Zoology, Faculty of Science, Charles University, Viničná 7, 128 44 Praha, Czech Republic
| | - Stanislav Španiel
- Institute of Botany, Slovak Academy of Sciences, Dúbravská Cesta 9, 845 23 Bratislava, Slovakia
| | - Vera Opatova
- Department of Zoology, Faculty of Science, Charles University, Viničná 7, 128 44 Praha, Czech Republic
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Just P, Šťáhlavský F, Kovařík F, Štundlová J. Tracking the trends of karyotype differentiation in the phylogenetic context of Gint, a scorpion genus endemic to the Horn of Africa (Scorpiones: Buthidae). Zool J Linn Soc 2022. [DOI: 10.1093/zoolinnean/zlac049] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Abstract
To determine the mechanisms of karyotype differentiation in scorpions of the genus Gint, we employed an integrative approach, combining cytogenetic data and sequence-based phylogeny. We cytogenetically examined six species with emphasis on multivalent meiotic configurations, 18S rDNA and (TTAGG)n distribution and compared chromosomal data with genetic divergence based on analysis of 16S rRNA and COI gene markers. Our results show that Gint species exhibit substantial karyotype diversity (2n = 18–45) and a high incidence of chromosome heterozygosity. Meiotic chromosome chains formed by up to six elements were found in 85% of analysed individuals, causing intraspecific chromosome variation in three species. Fluorescence in situ hybridization revealed that the 18S rDNA distribution pattern differed in Gint species, including at the intrapopulation level, but the chromosomal localization of (TTAGG)n motif was stable across species. Conspicuous interspecific differences in chromosome counts broadly corresponded with genetic divergence among Gint species. Our findings indicate that Gint karyotypes have undergone dynamic reorganization through independent fusions, fissions and reciprocal translocations. Owing to present chromosomal polymorphism, such structural changes shaping the genome architecture appear to be still ongoing in the populations of some Gint species.
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Affiliation(s)
- Pavel Just
- Department of Zoology, Faculty of Science, Charles University , Viničná, Prague , Czech Republic
| | - František Šťáhlavský
- Department of Zoology, Faculty of Science, Charles University , Viničná, Prague , Czech Republic
| | - František Kovařík
- Department of Zoology, Faculty of Science, Charles University , Viničná, Prague , Czech Republic
| | - Jana Štundlová
- Department of Zoology, Faculty of Science, Charles University , Viničná, Prague , Czech Republic
- Faculty of Science, University of South Bohemia in České Budějovice, Branišovská, České Budějovice , Czech Republic
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Moreno-González JA, Pinto-da-Rocha R, Gallão JE. Bringing order to a complex system: phenotypic and genotypic evidence contribute to the taxonomy of Tityus (Scorpiones, Buthidae) and support the description of a new species. Zookeys 2021; 1075:33-75. [PMID: 35046751 PMCID: PMC8671714 DOI: 10.3897/zookeys.1075.67459] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2021] [Accepted: 11/11/2021] [Indexed: 11/12/2022] Open
Abstract
We present a molecular phylogenetic analysis including a survey for overlooked phenotypic characters. Based on both analysis and characters a new cave-dwelling species is described: Tityus (Tityus) spelaeussp. nov. from the Russão II cave, Posse, state of Goiás, Central Brazil. Characters such as the glandular regions of the female pectinal basal piece and basal middle lamellae of pectines, and the distribution of the ventral setae of telotarsi I-IV proved to be useful to constructing the taxonomy of species and species groups of Tityus. The new species is a member of the Tityustrivittatus species-group of Tityus (Tityus) and can be readily recognized by the immaculate coloration pattern and the more developed glandular region on the female pectinal basal piece. In addition, we provide a discussion of the phylogenetic relationships observed within Tityus, on the relevance of the new phenotypic characters to the modern taxonomy of the genus Tityus, and to the records of Brazilian cave scorpions.
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Affiliation(s)
- Jairo A Moreno-González
- Instituto de Biociências - Universidade de São Paulo, Departamento de Zoologia. Rua do Matão, travessa 14, 321, 005508-900, São Paulo, Brazil Universidade de São Paulo São Paulo Brazil
| | - Ricardo Pinto-da-Rocha
- Instituto de Biociências - Universidade de São Paulo, Departamento de Zoologia. Rua do Matão, travessa 14, 321, 005508-900, São Paulo, Brazil Universidade de São Paulo São Paulo Brazil
| | - Jonas E Gallão
- Instituto de Biociências - Universidade de São Paulo, Departamento de Zoologia. Rua do Matão, travessa 14, 321, 005508-900, São Paulo, Brazil Universidade de São Paulo São Paulo Brazil
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Piñeiro JM, Cajade R, Hernando AB, Courtis A, Ingaramo MR, Marangoni F. The isolated rocky outcrops of northeastern Argentina and their role on the herpetofauna conservation. AN ACAD BRAS CIENC 2021; 93:e20190932. [PMID: 34259793 DOI: 10.1590/0001-3765202120190932] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2019] [Accepted: 03/22/2020] [Indexed: 11/22/2022] Open
Abstract
Isolated rocky outcrops represent biodiversity centers, refuges for endangered species, and favorable scenarios for endemism. Most studies in these ecosystems have been focused mainly on their flora and secondarily on different groups of animals. To highlight the value of rocky outcrops as ecosystems for biodiversity conservation, in the present study, we describe the diversity of herptiles of three isolated rocky outcrops of northeastern Argentina and compare it with that of other natural areas of the region. We conducted fieldwork from September 2010 to March 2017. We calculated the alpha diversity and the number of rare, threatened and endemic species. For comparative diversity analysis, we calculated the importance of each area for amphibians and reptiles and the beta diversity. Were recorded a total of 56 species (23 amphibians and 33 reptiles), representing 35% of the herptiles recorded for Corrientes province. These species included 19 rare species, seven threatened species, and two endemic species. The overall beta diversity showed considerably differences in species composition between the compared areas. The rocky outcrops showed higher importance for amphibians and reptiles than the other areas studied. Our study contributes to the knowledge of rocky outcrops and highlights their importance in biodiversity conservation.
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Affiliation(s)
- José M Piñeiro
- Laboratorio de Herpetología, Departamento de Biología, Facultad de Ciencias Exactas y Naturales y Agrimensura, Universidad Nacional del Nordeste (FACENA-UNNE), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Av. Libertad 5470, Corrientes, Argentina.,Fundación Amado Bonpland, San Juan 1182, Corrientes, Argentina
| | - Rodrigo Cajade
- Laboratorio de Herpetología, Departamento de Biología, Facultad de Ciencias Exactas y Naturales y Agrimensura, Universidad Nacional del Nordeste (FACENA-UNNE), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Av. Libertad 5470, Corrientes, Argentina.,Fundación Amado Bonpland, San Juan 1182, Corrientes, Argentina
| | | | - Azul Courtis
- Laboratorio de Herpetología, Departamento de Biología, Facultad de Ciencias Exactas y Naturales y Agrimensura, Universidad Nacional del Nordeste (FACENA-UNNE), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Av. Libertad 5470, Corrientes, Argentina
| | - María R Ingaramo
- Laboratorio de Herpetología, Departamento de Biología, Facultad de Ciencias Exactas y Naturales y Agrimensura, Universidad Nacional del Nordeste (FACENA-UNNE), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Av. Libertad 5470, Corrientes, Argentina
| | - Federico Marangoni
- Departamento de Biología, Facultad de Ciencias Exactas y Naturales y Agrimensura, Universidad Nacional del Nordeste (FACENA-UNNE), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Av. Libertad 5470, Corrientes, Argentina
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Borges A, Rojas de Arias A, de Almeida Lima S, Lomonte B, Díaz C, Chávez-Olórtegui C, Graham MR, Kalapothakis E, Coronel C, de Roodt AR. Genetic and toxinological divergence among populations of Tityus trivittatus Kraepelin, 1898 (Scorpiones: Buthidae) inhabiting Paraguay and Argentina. PLoS Negl Trop Dis 2020; 14:e0008899. [PMID: 33315884 PMCID: PMC7769620 DOI: 10.1371/journal.pntd.0008899] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2020] [Revised: 12/28/2020] [Accepted: 10/20/2020] [Indexed: 11/22/2022] Open
Abstract
Envenoming by scorpions in genus Tityus is a public health problem in Tropical America. One of the most medically significant species is Tityus trivittatus, which is known to occur from southwest Brazil to central-northern and eastern Argentina. In this work, we studied the lethality, composition, antigenicity, and enzymatic activity of venom from a T. trivittatus population found further north in urban areas of eastern Paraguay, where it has caused serious envenomation of children. Our results indicate that the population is of medical importance as it produces a potently toxic venom with an LD50 around 1.19 mg/kg. Venom neutralization in preliminary mouse bioassays was complete when using Brazilian anti-T. serrulatus antivenom but only partial when using Argentinean anti-T. trivittatus antivenom. Venom competitive solid-phase enzyme immunoassays and immunoblotting from Argentinean and Paraguayan T. trivittatus populations indicated that antigenic differences exist across the species range. SDS-PAGE showed variations in type and relative amounts of venom proteins between T. trivitattus samples from Argentina and Paraguay. MALDI-TOF mass spectrometry indicated that while some sodium channel toxins are shared, including β-toxin Tt1g, others are population-specific. Proteolytic activity by zymography and peptide identification through nESI-MS/MS also point out that population-specific proteases may exist in T. trivitattus, which are postulated to be involved in the envenoming process. A time-calibrated molecular phylogeny of mitochondrial COI sequences revealed a significant (8.14%) genetic differentiation between the Argentinean and Paraguayan populations, which appeared to have diverged between the mid Miocene and early Pliocene. Altogether, toxinological and genetic evidence indicate that T. trivitattus populations from Paraguay and Argentina correspond to distinct, unique cryptic species, and suggest that further venom and taxonomic diversity exists in synanthropic southern South American Tityus than previously thought.
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Affiliation(s)
- Adolfo Borges
- Centro para el Desarrollo de la Investigación Científica (CEDIC), Asunción, Paraguay
- Laboratorio de Biología Molecular de Toxinas y Receptores, Instituto de Medicina Experimental, Facultad de Medicina, Universidad Central de Venezuela, Caracas, Venezuela
| | | | - Sabrina de Almeida Lima
- Laboratorio de Inmunoquimica, Departamento de Bioquímica e Inmunologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brasil
| | - Bruno Lomonte
- Instituto Clodomiro Picado, Universidad de Costa Rica, San José, Costa Rica
| | - Cecilia Díaz
- Instituto Clodomiro Picado, Universidad de Costa Rica, San José, Costa Rica
| | - Carlos Chávez-Olórtegui
- Laboratorio de Inmunoquimica, Departamento de Bioquímica e Inmunologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brasil
| | - Matthew R. Graham
- Department of Biology, Eastern Connecticut State University, Willimantic, Connecticut, United States of America
| | - Evanguedes Kalapothakis
- Departamento de Biologia Geral, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brasil
| | - Cathia Coronel
- Centro para el Desarrollo de la Investigación Científica (CEDIC), Asunción, Paraguay
| | - Adolfo R. de Roodt
- Instituto Nacional de Producción de Biológicos “Carlos G. Malbrán”, Buenos Aires, Argentina
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Šťáhlavský F, Nguyen P, Sadílek D, Štundlová J, Just P, Haddad CR, Koç H, Ranawana KB, Stockmann M, Yağmur EA, Kovařík F. Evolutionary dynamics of rDNA clusters on chromosomes of buthid scorpions (Chelicerata: Arachnida). Biol J Linn Soc Lond 2020. [DOI: 10.1093/biolinnean/blaa118] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
Abstract
We examined the distribution of genes for major ribosomal RNAs (rDNA) on holokinetic chromosomes of 74 species belonging to 19 genera of scorpions from the family Buthidae using fluorescence in situ hybridization (FISH). Our analysis revealed differences between the two main evolutionary lineages within the family. The genera belonging to the ‘Buthus group’, with a proposed Laurasian origin, possess one pair of rDNA mainly in an interstitial position, with the only exceptions being the terminal location found in some Hottentotta and Buthacus species, possibly as a result of chromosome fissions. All the remaining buthid ‘groups’ possess rDNA found strictly in a terminal position. However, the number of signals may increase from an ancestral state of one pair of rDNA loci to up to seven signals in Reddyanus ceylonensis Kovařík et al., 2016. Despite the differences in evolutionary dynamics of the rDNA clusters between the ‘Buthus group’ and other lineages investigated, we found a high incidence of reciprocal translocations and presence of multivalent associations during meiosis in the majority of the genera studied. These phenomena seem to be typical for the whole family Buthidae.
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Affiliation(s)
- František Šťáhlavský
- Department of Zoology, Faculty of Science, Charles University, Viničná, Prague, Czech Republic
| | - Petr Nguyen
- Biology Centre of the Czech Academy of Sciences, Institute of Entomology, České Budějovice, Czech Republic
- Faculty of Science, University of South Bohemia in České Budějovice, Branišovská, České Budějovice, Czech Republic
| | - David Sadílek
- Department of Zoology, Faculty of Science, Charles University, Viničná, Prague, Czech Republic
| | - Jana Štundlová
- Department of Zoology, Faculty of Science, Charles University, Viničná, Prague, Czech Republic
| | - Pavel Just
- Department of Zoology, Faculty of Science, Charles University, Viničná, Prague, Czech Republic
| | - Charles R Haddad
- Department of Zoology and Entomology, University of the Free State, Bloemfontein, South Africa
| | - Halil Koç
- Department of Biology, Faculty of Arts and Science, Sinop University, Sinop, Turkey
| | - Kithsiri B Ranawana
- Department of Zoology, Faculty of Science, University of Peradeniya, Sri Lanka
| | | | - Ersen Aydin Yağmur
- Alaşehir Vocational School, Celal Bayar University, Alaşehir, Manisa, Turkey
| | - František Kovařík
- Department of Zoology, Faculty of Science, Charles University, Viničná, Prague, Czech Republic
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Adilardi RS, Ojanguren-Affilastro AA, Martí DA, Mola LM. Chromosome puzzle in the southernmost populations of the medically important scorpion Tityus bahiensis (Perty 1833) (Buthidae), a polymorphic species with striking structural rearrangements. ZOOL ANZ 2020. [DOI: 10.1016/j.jcz.2020.08.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
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de Almeida BRR, Noronha RCR, da Costa MJR, Nagamachi CY, Pieczarka JC. Meiosis in the scorpion Tityus silvestris: new insights into achiasmatic chromosomes. Biol Open 2019; 8:bio.040352. [PMID: 31072909 PMCID: PMC6550081 DOI: 10.1242/bio.040352] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
Achiasmatic male meiosis in scorpions is characterized by a high frequency of gaps, asynaptic regions and multivalent associations. Here, we performed an immunocytogenetic analysis to investigate recombination, and synapsis and chromatin-remodeling events during meiosis of the scorpion Tityus silvestris Our results demonstrate that the synaptonemal complex (SC) begins its organization in the zygotene stage and persists until metaphase I. The advancement of the synaptic process is related to the epigenetic modification histone H3 lysine 27 trimethylation (H3K27m3). The distribution and dynamics patterns of variant γH2AX and recombinase Rad51 during achiasmatic meiosis suggests formation and repair of DNA double-strand breaks (DSBs) during early stages of prophase I. The epigenetic modifications, histone H3 lysine 4 trimethylation (H3K4m3) and histone H3 lysine 9 acetylation (H3K9ac), showed a dispersed distribution along the bivalents, suggesting that transcriptional activity is maintained constitutively during prophase I. However, H3K9ac modifications are absent in constitutive heterochromatin carrying the 45S rDNA in pachytene and post-pachytene stages. Collectively, our data demonstrate that T. silvestris exhibits adaptations to the achiasmatic mode, and suggest that epigenetic modifications may act in the regulation of these mechanisms to favor the normal continuation of meiosis in this scorpion.
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Affiliation(s)
- Bruno Rafael Ribeiro de Almeida
- Laboratório de Citogenética, Centro de Estudos Avançados em Biodiversidade, Instituto de Ciências Biológicas, Universidade Federal do Pará, Avenida Augusto Corrêa, s/n, 66075-900, Guamá, Belém, Pará, Brazil
| | - Renata Coelho Rodrigues Noronha
- Laboratório de Citogenética, Centro de Estudos Avançados em Biodiversidade, Instituto de Ciências Biológicas, Universidade Federal do Pará, Avenida Augusto Corrêa, s/n, 66075-900, Guamá, Belém, Pará, Brazil
| | - Marlyson Jeremias Rodrigues da Costa
- Laboratório de Citogenética, Centro de Estudos Avançados em Biodiversidade, Instituto de Ciências Biológicas, Universidade Federal do Pará, Avenida Augusto Corrêa, s/n, 66075-900, Guamá, Belém, Pará, Brazil
| | - Cleusa Yoshiko Nagamachi
- Laboratório de Citogenética, Centro de Estudos Avançados em Biodiversidade, Instituto de Ciências Biológicas, Universidade Federal do Pará, Avenida Augusto Corrêa, s/n, 66075-900, Guamá, Belém, Pará, Brazil
| | - Julio Cesar Pieczarka
- Laboratório de Citogenética, Centro de Estudos Avançados em Biodiversidade, Instituto de Ciências Biológicas, Universidade Federal do Pará, Avenida Augusto Corrêa, s/n, 66075-900, Guamá, Belém, Pará, Brazil
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Ubinski CV, Carvalho LS, Schneider MC. Mechanisms of karyotype evolution in the Brazilian scorpions of the subfamily Centruroidinae (Buthidae). Genetica 2018; 146:475-486. [PMID: 30206751 DOI: 10.1007/s10709-018-0038-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2018] [Accepted: 09/05/2018] [Indexed: 01/09/2023]
Abstract
The recently-revised subfamily Centruroidinae is part of the New World clade of buthid scorpions. In this study, we analyzed the cytogenetic characteristics of nine of the 10 Brazilian centruroidines, and one undescribed species of the genus Ischnotelson, using a phylogenetic approach to determine the chromosomal rearrangements responsible for the differentiation of karyotypes among the species. The cytogenetic data recorded in the present study supported the new taxonomic arrangement of the Centruroidinae, with all the species of the same genus sharing the same or similar diploid numbers, i.e., 2n = 20 or 22 in Troglorhopalurus lacrau and T. translucidus, 2n = 25 or 26 in Ischnotelson sp., I. guanambiensis and I. peruassu, and 2n = 28 in Jaguajir agamemnon, J. pintoi and J. rochae. The karyotype modelling in the ChromEvol software indicated 2n = 18 as the ancestral diploid number of the Centruroidinae. The differentiation of karyotypes among the centruroidine genera was based on increasing chromosome numbers resulting from progressive fission events. These changes probably occurred prior to the diversification of the genera Ischnotelson, Jaguajir, Physoctonus and Rhopalurus, and appear to have played a more important role in karyotype evolution at the intergeneric level than the interspecific one. However, the observed increase in diploid numbers was not accompanied by changes in the number or location of ribosomal genes or telomeric sequences. The identification of meiotic cells in female specimens also allowed us to discuss the mechanisms of achiasmatic meiosis in scorpions.
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Affiliation(s)
- Crislaine Vanessa Ubinski
- Departamento de Ecologia e Biologia Evolutiva, Universidade Federal de São Paulo, UNIFESP, Av. Prof. Artur Riedel, 275, Diadema, São Paulo, 09972-270, Brazil
| | - Leonardo Sousa Carvalho
- Universidade Federal do Piauí, UFPI, Campus Amílcar Ferreira Sobral, BR 343, Km 3.5, Floriano, Piauí, 64800-000, Brazil
| | - Marielle Cristina Schneider
- Departamento de Ecologia e Biologia Evolutiva, Universidade Federal de São Paulo, UNIFESP, Av. Prof. Artur Riedel, 275, Diadema, São Paulo, 09972-270, Brazil.
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Šťáhlavský F, Štundlová J, Lowe G, Stockmann M, Kovařík F. Application of cytogenetic markers in the taxonomy of flat rock scorpions (Scorpiones: Hormuridae), with the description of Hadogenes weygoldti sp. n. ZOOL ANZ 2018. [DOI: 10.1016/j.jcz.2018.01.007] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
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12
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Mattos VF, Carvalho LS, Carvalho MA, Schneider MC. Insights into the origin of the high variability of multivalent-meiotic associations in holocentric chromosomes of Tityus (Archaeotityus) scorpions. PLoS One 2018; 13:e0192070. [PMID: 29466400 PMCID: PMC5821447 DOI: 10.1371/journal.pone.0192070] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2017] [Accepted: 01/16/2018] [Indexed: 12/21/2022] Open
Abstract
Scorpions represent an intriguing group of animals characterized by a high incidence of heterozygous chromosomal rearrangements. In this work, we examined six species of Tityus (Archaeotityus) from Brazilian fauna with a particular focus on elucidating the rearrangements responsible for the intraspecific variability of diploid number and the presence of long chromosomal chains in meiosis. To access any interpopulation diversity, we also studied individuals from four species representing distinct localities. Most species demonstrated intraspecific polymorphism in diploid number (2n = 19 and 2n = 20 in T. clathratus, T. mattogrossensis, and T. pusillus, 2n = 16, 2n = 17 and 2n = 18 in T. paraguayensis, and 2n = 16 and 2n = 24 in T. silvestris) and multi-chromosomal associations during meiosis I, which differed even among individuals with the same chromosome number. In some species, the heterozygous rearrangements were not fixed, resulting such as in Tityus clathatrus, in 11 different chromosomal configurations recognized within a same population. Based on meiotic chromosome behaviour, we suggested that independent rearrangements (fusion/fission and reciprocal translocations), occurring in different combinations, originated the multi-chromosomal chains. To evaluate the effects of these chromosome chains on meiotic segregation, we applied the chi-square test in metaphase II cells. The non-significant occurrence of aneuploid nuclei indicated that non-disjunction was negligible in specimens bearing heterozygous rearrangements. Finally, based on our analysis of many chromosome characteristics, e.g., holocentricity, achiasmate meiosis, endopolyploidy, ability to segregate heterosynaptic or unsynapsed chromosomes, (TTAGG)n sequence located in terminal regions of rearranged chromosomes, we suggest that the maintenance of multi-chromosomal associations may be evolutionarily advantageous for these species.
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Affiliation(s)
- Viviane Fagundes Mattos
- Universidade Estadual Paulista “Júlio de Mesquita Filho”, UNESP, Departamento de Biologia, Rio Claro, São Paulo, Brazil
| | | | - Marcos André Carvalho
- Universidade Federal de Mato Grosso, UFMT, Departamento de Biologia e Zoologia, Cuiabá, Mato Grosso, Brazil
| | - Marielle Cristina Schneider
- Universidade Federal de São Paulo, UNIFESP, Departamento de Ecologia e Biologia Evolutiva, Diadema, São Paulo, Brazil
- * E-mail:
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