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Almeida BRRD, Milhomem-Paixão SSR, Noronha RCR, Nagamachi CY, Costa MJRD, Pardal PPDO, Coelho JS, Pieczarka JC. Karyotype diversity and chromosomal organization of repetitive DNA in Tityus obscurus (Scorpiones, Buthidae). BMC Genet 2017; 18:35. [PMID: 28412934 PMCID: PMC5392961 DOI: 10.1186/s12863-017-0494-6] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2016] [Accepted: 03/25/2017] [Indexed: 01/22/2023] Open
Abstract
Background Holocentric chromosomes occur in approximately 750 species of eukaryotes. Among them, the genus Tityus (Scorpiones, Buthidae) has a labile karyotype that shows complex multivalent associations during male meiosis. Thus, taking advantage of the excellent model provided by the Buthidae scorpions, here we analyzed the chromosomal distribution of several repetitive DNA classes on the holocentric chromosomes of different populations of the species Tityus obscurus Gervais, 1843, highlighting their involvement in the karyotypic differences found among them. Results This species shows inter- and intrapopulational karyotype variation, with seven distinct cytotypes: A (2n = 16), B (2n = 14), C (2n = 13), D (2n = 13), E (2n = 12), F (2n = 12) and G (2n = 11). Furthermore, exhibits achiasmatic male meiosis and lacks heteromorphic sex chromosomes. Trivalent and quadrivalent meiotic associations were found in some cytotypes. In them, 45S rDNAs were found in the terminal portions of two pairs, while TTAGG repeats were found only at the end of the chromosomes. In the cytotype A (2n = 16), the U2 snRNA gene mapped to pair 1, while the H3 histone cluster and C0t-1 DNA fraction was terminally distributed on all pairs. Mariner transposons were found throughout the chromosomes, with the exception of one individual of cytotype A (2n = 16), in which it was concentrated in heterochromatic regions. Conclusions Chromosomal variability found in T. obscurus are due to rearrangements of the type fusion/fission and reciprocal translocations in heterozygous. These karyotype differences follow a geographical pattern and may be contributing to reproductive isolation between populations analyzed. Our results also demonstrate high mobility of histone H3 genes. In contrast, other multigene families (45S rDNA and U2 snRNA) have conserved distribution among individuals. The accumulation of repetitive sequences in distal regions of T. obscurus chromosomes, suggests that end of chromosome are not covered by the kinetochore.
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Affiliation(s)
- Bruno Rafael Ribeiro de Almeida
- Laboratório de Citogenética, Centro de Estudos Avançados da Biodiversidade, Instituto de Ciências Biológicas, Universidade Federal do Pará, Avenida Augusto Corrêa, n°01, Av. Perimetral, s/n. Guamá, 66075-900, Belém, Pará, Brazil
| | - Susana Suely Rodrigues Milhomem-Paixão
- Instituto Federal de Educação, Ciência e Tecnologia de Goiás, Campus Valparaíso de Goiás, BR-040, km 6, Avenida Saia Velha, S/N, Área 8, Parque Esplanada V, 72876-601, Valparaíso de Goiás, Goiás, Brazil
| | - Renata Coelho Rodrigues Noronha
- Laboratório de Citogenética, Centro de Estudos Avançados da Biodiversidade, Instituto de Ciências Biológicas, Universidade Federal do Pará, Avenida Augusto Corrêa, n°01, Av. Perimetral, s/n. Guamá, 66075-900, Belém, Pará, Brazil
| | - Cleusa Yoshiko Nagamachi
- Laboratório de Citogenética, Centro de Estudos Avançados da Biodiversidade, Instituto de Ciências Biológicas, Universidade Federal do Pará, Avenida Augusto Corrêa, n°01, Av. Perimetral, s/n. Guamá, 66075-900, Belém, Pará, Brazil
| | - Marlyson Jeremias Rodrigues da Costa
- Laboratório de Citogenética, Centro de Estudos Avançados da Biodiversidade, Instituto de Ciências Biológicas, Universidade Federal do Pará, Avenida Augusto Corrêa, n°01, Av. Perimetral, s/n. Guamá, 66075-900, Belém, Pará, Brazil
| | - Pedro Pereira de Oliveira Pardal
- Laboratório de Entomologia Médica e Artrópodes Peçonhentos, Núcleo de Medicina Tropical, Universidade Federal do Pará, Avenida Generalíssimo Deodoro, 92, 66055-240, Belém, Pará, Brazil
| | - Johne Souza Coelho
- Laboratório de Entomologia Médica e Artrópodes Peçonhentos, Núcleo de Medicina Tropical, Universidade Federal do Pará, Avenida Generalíssimo Deodoro, 92, 66055-240, Belém, Pará, Brazil
| | - Julio Cesar Pieczarka
- Laboratório de Citogenética, Centro de Estudos Avançados da Biodiversidade, Instituto de Ciências Biológicas, Universidade Federal do Pará, Avenida Augusto Corrêa, n°01, Av. Perimetral, s/n. Guamá, 66075-900, Belém, Pará, Brazil.
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Sebestova H, Vozdova M, Kubickova S, Cernohorska H, Kotrba R, Rubes J. Effect of species-specific differences in chromosome morphology on chromatin compaction and the frequency and distribution of RAD51 and MLH1 foci in two bovid species: cattle (Bos taurus) and the common eland (Taurotragus oryx). Chromosoma 2015; 125:137-49. [PMID: 26194101 DOI: 10.1007/s00412-015-0533-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2014] [Revised: 06/29/2015] [Accepted: 07/08/2015] [Indexed: 10/23/2022]
Abstract
Meiotic recombination between homologous chromosomes is crucial for their correct segregation into gametes and for generating diversity. We compared the frequency and distribution of MLH1 foci and RAD51 foci, synaptonemal complex (SC) length and DNA loop size in two related Bovidae species that share chromosome arm homology but show an extreme difference in their diploid chromosome number: cattle (Bos taurus, 2n = 60) and the common eland (Taurotragus oryx, 2nmale = 31). Compared to cattle, significantly fewer MLH1 foci per cell were observed in the common eland, which can be attributed to the lower number of initial double-strand breaks (DSBs) detected as RAD51 foci in leptonema. Despite the significantly shorter total autosomal SC length and longer DNA loop size of the common eland bi-armed chromosomes compared to those of bovine acrocentrics, the overall crossover density in the common eland was still lower than in cattle, probably due to the reduction in the number of MLH1 foci in the proximal regions of the bi-armed chromosomes. The formation of centric fusions during karyotype evolution of the common eland accompanied by meiotic chromatin compaction has greater implications in the reduction in the number of DSBs in leptonema than in the decrease of MLH1 foci number in pachynema.
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Affiliation(s)
- Hana Sebestova
- Central European Institute of Technology-Veterinary Research Institute, Hudcova 70, 621 00, Brno, Czech Republic
| | - Miluse Vozdova
- Central European Institute of Technology-Veterinary Research Institute, Hudcova 70, 621 00, Brno, Czech Republic.
| | - Svatava Kubickova
- Central European Institute of Technology-Veterinary Research Institute, Hudcova 70, 621 00, Brno, Czech Republic
| | - Halina Cernohorska
- Central European Institute of Technology-Veterinary Research Institute, Hudcova 70, 621 00, Brno, Czech Republic
| | - Radim Kotrba
- Faculty of Tropical AgriSciences, Czech University of Life Sciences Prague, Kamýcká 129, 165 21, Prague, Czech Republic
| | - Jiri Rubes
- Central European Institute of Technology-Veterinary Research Institute, Hudcova 70, 621 00, Brno, Czech Republic
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Reduced recombination patterns in Robertsonian hybrids between chromosomal races of the house mouse: chiasma analyses. Heredity (Edinb) 2014; 114:56-64. [PMID: 25074574 DOI: 10.1038/hdy.2014.69] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2014] [Revised: 06/03/2014] [Accepted: 06/10/2014] [Indexed: 11/09/2022] Open
Abstract
The recombination suppression models of chromosomal speciation posit that chromosomal rearrangements act as partial barriers to gene flow allowing these regions to accumulate genetic incompatibilities, thus contributing to the divergence of populations. Empirical and theoretical studies exploring the requirements of these models have mostly focused on the role of inversions. Here, the recombination landscape of heterozygosity for Robertsonian (Rb) fusions is investigated in the house mouse. Laboratory-bred F1 males and females between highly differentiated races from Tunisia (Rb: 2n=22, Standard, St: 2n=40) were produced in which all Rb fusions are present as trivalents in meiosis. Recombination patterns were determined by the analysis of chiasmata and compared with previous data on the Tunisian parental mice. A comparative analysis was performed on wild-caught male mice spanning the hybrid zone between two Italian races (2n=40, 2n=22). The results showed that the chiasma characteristics of both male and female Tunisian F1 and Italian hybrids clearly differed from those of Rb and St mice. Not only was the mean chiasma number (CN) intermediate between those of the parental mice in both geographic samples, but the distribution of chiasmata along the chromosomal arms of the F1 showed a distinct mosaic pattern. In short, the proximal region in the F1 exhibited a reduced CN similar to that observed in homozygous Rb, whereas distal regions more closely matched those in St mice. These results suggest that Rb rearrangements (homozygous or heterozygous) reduce recombination in the proximal regions of the chromosomes supporting their potential role in recombination-mediated speciation models.
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Kuznetsova VG, Golub NV, Aguin-Pombo D. Karyotypes, B-chromosomes and meiotic abnormalities in 13 populations of Alebra albostriella and A. wahlbergi (Hemiptera, Auchenorrhyncha, Cicadellidae) from Greece. COMPARATIVE CYTOGENETICS 2013; 7:305-25. [PMID: 24455103 PMCID: PMC3890659 DOI: 10.3897/compcytogen.v7i4.6411] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/08/2013] [Accepted: 10/30/2013] [Indexed: 06/03/2023]
Abstract
In this work 13 populations of the leafhopper species Alebra albostriella (Fallén, 1826) (6 populations) and A. wahlbergi (Boheman, 1845) (7 populations) (Cicadellidae: Typhlocybinae) from Greece were studied cytogenetically. We examined chromosomal complements and meiosis in 41 males of A. albostriella sampled from Castanea sativa, Fagus sylvatica and Quercus cerris and in 21 males of A. wahlbergi sampled from C. sativa, Acer opalus and Ulmus sp. The species were shown to share 2n = 22 + X(0) and male meiosis of the chiasmate preductional type typical for Auchenorrhyncha. In all populations of A. albostriella and in all but two populations of A. wahlbergi B chromosomes and/or different meiotic abnormalities including the end-to-end non-homologous chromosomal associations, translocation chains, univalents, anaphasic laggards besides aberrant sperms were encountered. This study represents the first chromosomal record for the genus Alebra and one of the few population-cytogenetic studies in the Auchenorrhyncha.
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Affiliation(s)
| | - Natalia V. Golub
- Department of Karyosystematics, Zoological Institute, Saint Petersburg, 199034, Russia
| | - Dora Aguin-Pombo
- University of Madeira, 9000-390 Funchal, Madeira, Portugal
- Centro de Investigaçao en Biodiversidade e Recursos Genéticos (CIBIO), Vairão, Portugal
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