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Austrich A, Tomasco IH, Mapelli FJ, Kittlein MJ, Cutrera AP, Mora MS. Appearances are deceptive: a cryptic lineage within the assumed distributional boundaries of Ctenomys talarum (Rodentia, Ctenomyidae). J Mammal 2023. [DOI: 10.1093/jmammal/gyac116] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Abstract
The coastal dunes of the southeast of Buenos Aires province, Argentina, present two different described species of tuco-tucos: Ctenomys talarum and C. australis. Formerly, C. talarum was subdivided into three subspecies (C. t. talarum, C. t. recessus, and C. t. occidentalis), mainly based on its geographic distribution and phenotypic variation in characters of external morphology (e.g., body size and pelage color). This study assesses the phylogenetic relationships of C. talarum, focusing on the populations at the western end of its coastal distribution (localities of Pehuen-Có and Sauce Grande), which have been previously identified as highly genetically divergent. In this regard, populations distributed throughout the range of the species were sampled. Complete DNA sequences of the mitochondrial cytochrome b gene (1,140 bp), partial sequences of the mitochondrial D-loop region (426 bp), and partial sequences of the nuclear DNA intron 8 of the β-fibrinogen (about 870 bp) gene were used for the analyses. Phylogenetic inferences based on mitochondrial and nuclear markers were performed separately or combined to obtain a species tree. Populations distributed at the western end of the coastal dunes (between Pehuen-Có and Sauce Grande), previously assumed as C. talarum, were found to belong to an independent lineage relative to the other populations from the Pampas region. The average genetic distance between these two lineages is within the order of the genetic distances observed between different species of the genus. Also, our results show that this lineage of Ctenomys presents a high affinity with the magellanicus group, which is distributed further south, in Patagonia. In conclusion, tuco-tuco populations occurring in the coastal expanse between these two localities should be considered a possible distinct cryptic species, highly differentiated from C. talarum.
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Affiliation(s)
- Ailin Austrich
- Departamento de Biologia, Facultad de Ciencias Exactas y Naturales, Instituto de Investigaciones Marinas y Costeras (IIMyC, CONICET), Universidad Nacional de Mar del Plata , Dean Funes 3250, 3rd Floor, 7600 Mar del Plata , Argentina
| | - Ivanna Haydée Tomasco
- Departamento de Ecología y Evolución, Facultad de Ciencias, Universidad de la República , Iguá 4225, Montevideo 11400 , Uruguay
| | - Fernando Javier Mapelli
- División Mastozoología, Museo Argentino de Ciencias Naturales “Bernardino Rivadavia” CONICET , Angel Gallardo 470, Buenos Aires C1405DJR , Argentina
| | - Marcelo Javier Kittlein
- Departamento de Biologia, Facultad de Ciencias Exactas y Naturales, Instituto de Investigaciones Marinas y Costeras (IIMyC, CONICET), Universidad Nacional de Mar del Plata , Dean Funes 3250, 3rd Floor, 7600 Mar del Plata , Argentina
| | - Ana Paula Cutrera
- Departamento de Biologia, Facultad de Ciencias Exactas y Naturales, Instituto de Investigaciones Marinas y Costeras (IIMyC, CONICET), Universidad Nacional de Mar del Plata , Dean Funes 3250, 3rd Floor, 7600 Mar del Plata , Argentina
| | - Matías Sebastián Mora
- Departamento de Biologia, Facultad de Ciencias Exactas y Naturales, Instituto de Investigaciones Marinas y Costeras (IIMyC, CONICET), Universidad Nacional de Mar del Plata , Dean Funes 3250, 3rd Floor, 7600 Mar del Plata , Argentina
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2
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Comprehensive cytogenetic analysis of the most chromosomally variable mammalian genus from South America: Ctenomys (Rodentia: Caviomorpha: Ctenomyidae). Mamm Biol 2022. [DOI: 10.1007/s42991-022-00312-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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3
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Highly divergent karyotypes and barcoding of the East African genus Gonatoxia Karsch (Orthoptera: Phaneropterinae). Sci Rep 2021; 11:22781. [PMID: 34815452 PMCID: PMC8610994 DOI: 10.1038/s41598-021-02110-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2021] [Accepted: 10/20/2021] [Indexed: 11/09/2022] Open
Abstract
East Africa is a hotspot of biodiversity of many orthopteran taxa, including bushcrickets. Gonatoxia Karsch, 1889 species are fully alate Phaneropterinae, which are perfectly adapted to the foliage of forests. We examined five species using combined cytogenetic and molecular data to determine the inter- and intraspecific genetic diversity. The variation in the diploid number of chromosomes in males ranged from 2n = 28 + X0 and 26 + X0 to 2n = 6 + X0. Fluorescence in situ hybridization showed from one to many 18S rDNA loci as well as interstitial sequences, especially in G. helleri. 18S rDNA loci coincided with active NOR and C-banding patterns. The isolation of populations of the species explains differences in the number of chromosomes (G. maculata), chromosomal polymorphism and chromosomal heterozygosity (G. helleri). Our molecular phylogeny based on the COI locus supported the monophyly of the genus Gonatoxia and separateness of the five examined species in accordance with their morphological features and chromosome numbers as well as the species' distribution.
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Grzywacz B, Warchałowska-Śliwa E, Kociński M, Heller KG, Hemp C. Diversification of the Balloon bushcrickets (Orthoptera, Hexacentrinae, Aerotegmina) in the East African mountains. Sci Rep 2021; 11:9878. [PMID: 33972656 PMCID: PMC8110521 DOI: 10.1038/s41598-021-89364-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2020] [Accepted: 04/26/2021] [Indexed: 02/03/2023] Open
Abstract
East African mountains constitute a network of isolated habitat islands among dry savannah and are thus ideal for studying species diversification processes. This study elucidated the phylogenetic and phylogeographic relationships of all bushcricket species comprising the genus Aerotegmina. Our analysis indicated that large-scale climatic and topographic processes in Africa are likely to have driven speciation in this group, and revealed the cytogenetic traits of the species. Molecular phylogeny supported the monophyly of Aerotegmina and showed that the genus probably originated in the old Eastern Arc Mountains of Tanzania and Kenya. Two lineages were distinguished: small- and large-sized species with geographically distinct habitats. The underlying processes are thought to be eight dispersals, ten vicariance events, and one extinction event linked to repeated fragmentation of the African rainforest. Those processes, in conjunction with habitat change, probably also led to the spatial separation of the species into a northern clade with a diploid number of chromosomes 2n = 32 + X0 or 2n = 30 + neo-XY and a southern clade with a reduced number of chromosomes (2n = 28 + X0 or 24 + neo-X1X2Y). Karyotype analysis suggests that Aerotegmina is currently in the process of speciation.
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Affiliation(s)
- Beata Grzywacz
- grid.413454.30000 0001 1958 0162Institute of Systematics and Evolution of Animals, Polish Academy of Sciences, Sławkowska 17, 31-016 Kraków, Poland
| | - Elżbieta Warchałowska-Śliwa
- grid.413454.30000 0001 1958 0162Institute of Systematics and Evolution of Animals, Polish Academy of Sciences, Sławkowska 17, 31-016 Kraków, Poland
| | - Maciej Kociński
- grid.413454.30000 0001 1958 0162Institute of Systematics and Evolution of Animals, Polish Academy of Sciences, Sławkowska 17, 31-016 Kraków, Poland
| | | | - Claudia Hemp
- grid.7384.80000 0004 0467 6972Department Plant Systematics, University of Bayreuth, Bayreuth, Germany
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Matzenbacher CA, Da Silva J, Garcia ALH, Cappetta M, de Freitas TRO. Anthropogenic Effects on Natural Mammalian Populations: Correlation Between Telomere Length and Coal Exposure. Sci Rep 2019; 9:6325. [PMID: 31004106 PMCID: PMC6474877 DOI: 10.1038/s41598-019-42804-8] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2018] [Accepted: 04/09/2019] [Indexed: 12/31/2022] Open
Abstract
The Candiota coal mine in Rio Grande do Sul (RS) is one of the largest in Brazil. Coal is a fossil fuel that causes environmental impacts from its extraction to combustion due to the release of different agents, such as polycyclic aromatic hydrocarbons (PAH) and heavy metals. Ctenomys torquatus are herbivorous and subterranean rodents that dig tunnels with their paws and teeth and can be exposed to coal through contaminated food. Exposure to pollutants can cause DNA damage and affect different tissues, inducing alterations in the population structure and genetic diversity. Our study aimed to evaluate the effect of exposure to coal and its derivatives on the C. torquatus population and to examine the relationship of coal exposure with variations in absolute telomere length (aTL), global DNA methylation and genotoxicity. Our study showed an inverse correlation between telomere length and coal exposure in addition to an increase in DNA damage. The results indicate that coal and its byproducts can contribute to the alteration of the C. torquatus population structure, as evidenced by a reduction in the number of adults.
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Affiliation(s)
- Cristina A Matzenbacher
- Department of Genetics, Federal University of Rio Grande do Sul, C.P. 15053, 91501-970, Porto Alegre, RS, Brazil
| | - Juliana Da Silva
- Laboratory of Genetic Toxicology, Lutheran University of Brazil, ULBRA, Canoas, 92425-900, Rio Grande do Sul, Brazil.
| | - Ana Leticia H Garcia
- Laboratory of Genetic Toxicology, Lutheran University of Brazil, ULBRA, Canoas, 92425-900, Rio Grande do Sul, Brazil.,Laboratory of Ecotoxicology, Postgraduate Program in Environmental Quality, University Feevale, ERS-239, 2755, 93525-075, Novo Hamburgo, RS, Brazil
| | - Mónica Cappetta
- Laboratorio de Epidemiología Genética, Departamento de Genética, Facultad de Medicina, Universidad de la República, Montevideo, Uruguay
| | - Thales R O de Freitas
- Department of Genetics, Federal University of Rio Grande do Sul, C.P. 15053, 91501-970, Porto Alegre, RS, Brazil
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Štundlová J, Šmíd J, Nguyen P, Šťáhlavský F. Cryptic diversity and dynamic chromosome evolution in Alpine scorpions (Euscorpiidae: Euscorpius). Mol Phylogenet Evol 2019; 134:152-163. [PMID: 30743063 DOI: 10.1016/j.ympev.2019.02.002] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2018] [Revised: 01/09/2019] [Accepted: 02/03/2019] [Indexed: 12/28/2022]
Abstract
Over time, mountain biota has undergone complex evolutionary histories that have left imprints on its genomic arrangement, geographical distribution and diversity of contemporary lineages. Knowledge on these biogeographical aspects still lags behind for invertebrates inhabiting the Alpine region. In the present study, we examined three scorpion species of the subgenus Euscorpius (Alpiscorpius) from the European Alps using cytogenetic and molecular phylogenetic approaches to determine the variation and population structure of extant lineages at both chromosome and genetic level, and to provide an insight into the species diversification histories. We detected considerable intraspecific variability in chromosome complements and localization of the 18S rDNA loci in all studied species. Such chromosome differences were noticeable as the existence of three [in E. (A.) alpha and E. (A.) germanus] or four [in E. (A.) gamma] range-restricted karyotypic races. These races differed from one another either by 2n [in E. (A.) alpha 2n = 54, 60, 90; in E. (A.) gamma 2n = 58, 60, 88, 86-92], or by the karyotypic formula [in E. (A.) germanus 2n = 34m + 12sm; 36m + 10sm; 42m + 4sm]. Using mitochondrial (16S rRNA, COI) and nuclear (28S rDNA) genetic markers, we examined genetic variation and reconstructed phylogenetic relationships among the karyotypic races. Both approaches provided evidence for the existence of ten deeply divergent lineages exhibiting the features of local endemics and indicating the presence of cryptic species. Molecular dating analyses suggest that these lineages diversified during the Plio-Pleistocene and this process was presumably accompanied by dynamic structural changes in the genome organization.
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Affiliation(s)
- Jana Štundlová
- Department of Zoology, Faculty of Science, Charles University, Viničná 7, 12844 Prague, Czech Republic.
| | - Jiří Šmíd
- Department of Zoology, Faculty of Science, Charles University, Viničná 7, 12844 Prague, Czech Republic; Department of Zoology, National Museum, Cirkusová 1740, Prague, Czech Republic
| | - Petr Nguyen
- Institute of Entomology, Biology Centre CAS, Branišovská 31, 37005 České Budějovice, Czech Republic; Faculty of Science, University of South Bohemia in České Budějovice, Branišovská 1760, 37005 České Budějovice, Czech Republic
| | - František Šťáhlavský
- Department of Zoology, Faculty of Science, Charles University, Viničná 7, 12844 Prague, Czech Republic
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Integrative analysis of chromosome banding, telomere localization and molecular genetics in the highly variable Ctenomys of the Corrientes group (Rodentia; Ctenomyidae). Genetica 2018; 146:403-414. [PMID: 30076493 DOI: 10.1007/s10709-018-0032-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2018] [Accepted: 07/27/2018] [Indexed: 02/04/2023]
Abstract
The genus Ctenomys comprises about 70 species with great chromosome diversity. The Corrientes group is one of the most chromosomally variable lineages in the genus, where the diploid number (2n) varies from 41 to 70. In this group, three nominal species and numerous polymorphic and polytypic populations have been described. In order to get insight into the chromosomal evolution of this species complex, we applied different banding and molecular cytogenetic techniques. The results were interpreted in an evolutionary context, based on mitochondrial cytochrome b analyses. Studied samples are representative of the broad chromosomal variability in the group, including specimens with 2n = 42 to 2n = 70. Heterochromatin was scarce but concentrated in a few chromosomes. Centromeric DAPI-negative heterochromatin was observed in some autosomal pairs, which differed among populations. Location and amount of DAPI-neutral heterochromatin within the Y chromosome varied among populations. The variable distribution of heterochromatin indicates its dynamic behavior. NORs were detected in one pair of autosomes, which also differed among some populations. Telomeric FISH signals were observed in all complements only at the chromosome ends. The Corrientes group belongs to a clade that also includes C. pearsoni, C. lami, C. minutus, C. ibicuiensis and C. torquatus. Almost all of these species are variable at the chromosomal level, suggesting that this is the ancestral condition of the clade. Within the Corrientes group, the observed low genetic divergence, in contrast with its high chromosomal variability, is indicative of decoupling between the rates of chromosomal and mitochondrial evolution.
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Fornel R, Cordeiro-Estrela P, de Freitas TRO. Skull shape and size variation within and between mendocinus and torquatus groups in the genus Ctenomys (Rodentia: Ctenomyidae) in chromosomal polymorphism context. Genet Mol Biol 2018; 41:263-272. [PMID: 29668015 PMCID: PMC5913726 DOI: 10.1590/1678-4685-gmb-2017-0074] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2017] [Accepted: 11/23/2017] [Indexed: 11/22/2022] Open
Abstract
We tested the association between chromosomal polymorphism and skull shape and size variation in two groups of the subterranean rodent Ctenomys. The hypothesis is based on the premise that chromosomal rearrangements in small populations, as it occurs in Ctenomys, produce reproductive isolation and allow the independent diversification of populations. The mendocinus group has species with low chromosomal diploid number variation (2n=46-48), while species from the torquatus group have a higher karyotype variation (2n=42-70). We analyzed the shape and size variation of skull and mandible by a geometric morphometric approach, with univariate and multivariate statistical analysis in 12 species from mendocinus and torquatus groups of the genus Ctenomys. We used 763 adult skulls in dorsal, ventral, and lateral views, and 515 mandibles in lateral view and 93 landmarks in four views. Although we expected more phenotypic variation in the torquatus than the mendocinus group, our results rejected the hypothesis of an association between chromosomal polymorphism and skull shape and size variation. Moreover, the torquatus group did not show more variation than mendocinus. Habitat heterogeneity associated to biomechanical constraints and other factors like geography, phylogeny, and demography, may affect skull morphological evolution in Ctenomys.
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Affiliation(s)
- Rodrigo Fornel
- Departamento de Genética, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil.,Universidade Regional Integrada do Alto Uruguai e das Missões - Campus de Erechim, Erechim, RS, Brazil
| | - Pedro Cordeiro-Estrela
- Departamento de Genética, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil.,Departamento de Sistemática e Ecologia, Centro de Ciências Exatas e da Natureza - Campus I, Universidade Federal da Paraíba, João Pessoa, PB, Brazil
| | - Thales Renato O de Freitas
- Departamento de Genética, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil.,Programa de Pós-Graduação em Genética e Biologia Molecular, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil
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9
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Di-Nizo CB, Banci KRDS, Sato-Kuwabara Y, Silva MJDJ. Advances in cytogenetics of Brazilian rodents: cytotaxonomy, chromosome evolution and new karyotypic data. COMPARATIVE CYTOGENETICS 2017; 11:833-892. [PMID: 29362668 PMCID: PMC5769678 DOI: 10.3897/compcytogen.v11i4.19925] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/01/2017] [Accepted: 10/23/2017] [Indexed: 05/31/2023]
Abstract
Rodents constitute one of the most diversified mammalian orders. Due to the morphological similarity in many of the groups, their taxonomy is controversial. Karyotype information proved to be an important tool for distinguishing some species because some of them are species-specific. Additionally, rodents can be an excellent model for chromosome evolution studies since many rearrangements have been described in this group.This work brings a review of cytogenetic data of Brazilian rodents, with information about diploid and fundamental numbers, polymorphisms, and geographical distribution. We point out that, even with the recent efforts on cytogenetic studies in this group, many species lack karyotypic data. Moreover, we describe for the first time the karyotype of Carterodon sulcidens (Lund, 1838) (Family Echimyidae), a new fundamental number for an undescribed species of Neacomys Thomas, 1900 (Family Cricetidae, Subfamily Sigmodontinae), and illustrate the karyotype of a Brazilian specimen of Mus musculus Linnaeus, 1758 (Family Muridae). This review compiles the cytogenetic data on Brazilian rodents reported in the last three decades, after the last revision published in 1984, including synonyms, chromosomal variations, and geographic distribution. Additionally, it also reinforces that Brazilian biodiversity is still poorly known, considering the new data reported here.
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Affiliation(s)
- Camilla Bruno Di-Nizo
- Laboratório de Ecologia e Evolução, Instituto Butantan, Avenida Vital Brazil, 1500, CEP 05503-900, São Paulo, SP, Brazil
| | | | - Yukie Sato-Kuwabara
- Departamento de Genética e Biologia Evolutiva, Instituto de Biociências, Universidade de São Paulo, Rua do Matão 277, CEP 05508-900, São Paulo, SP, Brazil
| | - Maria José de J. Silva
- Laboratório de Ecologia e Evolução, Instituto Butantan, Avenida Vital Brazil, 1500, CEP 05503-900, São Paulo, SP, Brazil
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10
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Mora MS, Mapelli FJ, López A, Gómez Fernández MJ, Mirol PM, Kittlein MJ. Landscape genetics in the subterranean rodent Ctenomys "chasiquensis" associated with highly disturbed habitats from the southeastern Pampas region, Argentina. Genetica 2017; 145:575-591. [PMID: 28905157 DOI: 10.1007/s10709-017-9983-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2015] [Accepted: 09/07/2017] [Indexed: 11/29/2022]
Abstract
Studies of genetic differentiation in fragmented environments help us to identify those landscape features that most affect gene flow and dispersal patterns. Particularly, the assessment of the relative significance of intrinsic biological and environmental factors affecting the genetic structure of populations becomes crucial. In this work, we assess the current dispersal patterns and population structure of Ctenomys "chasiquensis", a vulnerable and endemic subterranean rodent distributed on a small area in Central Argentina, using 9 polymorphic microsatellite loci. We use landscape genetics approaches to assess the relationship between genetic connectivity among populations and environmental attributes. Our analyses show that populations of C. "chasiquensis" are moderately to highly structured at a regional level. This pattern is most likely the outcome of substantial gene flow on the more homogeneous sand dune habitat of the Northwest of its distributional range, in conjunction with an important degree of isolation of eastern and southwestern populations, where the optimal habitat is surrounded by a highly fragmented landscape. Landscape genetics analysis suggests that habitat quality and longitude were the environmental factors most strongly associated with genetic differentiation/uniqueness of populations. In conclusion, our results indicate an important genetic structure in this species, even at a small spatial scale, suggesting that contemporary habitat fragmentation increases population differentiation.
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Affiliation(s)
- Matías Sebastián Mora
- Departamento de Biología, Facultad de Ciencias Exactas y Naturales, Instituto de Investigaciones Marinas y Costeras, (IIMyC, CONICET), Universidad Nacional de Mar del Plata, Funes 3250, 3rd floor, 7600, Mar del Plata, Argentina.
| | - Fernando J Mapelli
- Departamento de Biología, Facultad de Ciencias Exactas y Naturales, Instituto de Investigaciones Marinas y Costeras, (IIMyC, CONICET), Universidad Nacional de Mar del Plata, Funes 3250, 3rd floor, 7600, Mar del Plata, Argentina
| | - Aldana López
- Área de Recursos Naturales, CONICET INTA EEA Bariloche, CC 277 8400, Bariloche, Río Negro, Argentina
| | - María Jimena Gómez Fernández
- Grupo de Genética y Ecología en Conservación y Biodiversidad, Museo Argentino de Ciencias Naturales "Bernardino Rivadavia", CONICET, Ángel Gallardo 470, Buenos Aires, Argentina
| | - Patricia M Mirol
- Grupo de Genética y Ecología en Conservación y Biodiversidad, Museo Argentino de Ciencias Naturales "Bernardino Rivadavia", CONICET, Ángel Gallardo 470, Buenos Aires, Argentina
| | - Marcelo J Kittlein
- Departamento de Biología, Facultad de Ciencias Exactas y Naturales, Instituto de Investigaciones Marinas y Costeras, (IIMyC, CONICET), Universidad Nacional de Mar del Plata, Funes 3250, 3rd floor, 7600, Mar del Plata, Argentina
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11
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Abstract
Abstract
The tuco-tucos rodents (genus Ctenomys) of the Corrientes group comprise several populations that inhabit the vast area under the influence of the Iberá wetland. Lineage delimitation within the recently diverged Corrientes group is a challenging task as morphological differentiation is not conspicuous between populations. However, delimitation is crucial for evolutionary studies and conservation issues. In this study, we performed a phylogenetic analysis including cytochrome b (cyt-b) sequences from taxa that had never been studied in a comprehensive context. We integrated previously published chromosomal studies, mitochondrial phylogenies and simple sequence repeat (SSR) variability analyses, and applied a delimitation criterion over the basis of chromosomal incompatibilities and genetic exclusivity. Under this integrative approach seven independently evolving lineages were delimited in the Corrientes group: Ctenomys roigi, which conserves its former definition, Ctenomys dorbignyi and Ctenomys perrensi complex which were redefined, Sarandicito which includes the population of Paraje Sarandicito and probably a group of nearby poorly studied populations, and Iberá i, ii and iii distributed at both sides of the Iberá wetland. We discuss future perspectives to evaluate the proposed lineages and conservation issues concerning these tuco-tucos.
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Affiliation(s)
- Diego A. Caraballo
- IFIBYNE-CONICET, Laboratorio de Fisiología y Biología Molecular , Departamento de Fisiología, Biología Molecular y Celular , Universidad de Buenos Aires, Ciudad Universitaria , Pabellón II, 2do piso, EHA1428 , Buenos Aires , Argentina
| | - María Susana Rossi
- IFIBYNE-CONICET, Laboratorio de Fisiología y Biología Molecular , Departamento de Fisiología, Biología Molecular y Celular , Universidad de Buenos Aires, Ciudad Universitaria , Pabellón II, 2do piso, EHA1428 , Buenos Aires , Argentina
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12
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Felappi JF, Vieira RC, Fagundes NJR, Verrastro LV. So far away, yet so close: strong genetic structure in Homonota uruguayensis (Squamata, Phyllodactylidae), a species with restricted geographic distribution in the Brazilian and Uruguayan Pampas. PLoS One 2015; 10:e0118162. [PMID: 25692471 PMCID: PMC4334718 DOI: 10.1371/journal.pone.0118162] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2014] [Accepted: 01/08/2015] [Indexed: 11/19/2022] Open
Abstract
The Pampas is a biologically rich South American biome, but is poorly represented in phylogeographic studies. While the Pleistocene glacial cycles may have affected the evolutionary history of species distributed in forested biomes, little is known about their effects on the habitats that remained stable through glacial cycles. The South American Pampas have been covered by grasslands during both glacial and interglacial periods and therefore represent an interesting system to test whether the genetic structure in such environments is less pronounced. In this study, we sampled Pampean populations of Homonota uruguayensis from Southern Brazil and Uruguay to assess the tempo and mode of population divergence, using both morphological measurements and molecular markers. Our results indicate that, in spite of its narrow geographic distribution, populations of H. uruguayensis show high levels of genetic structure. We found four major well-supported mtDNA clades with strong geographic associations. Estimates of their divergence times fell between 3.16 and 1.82 million years before the present. Populations from the central portion of the species distribution, on the border between Uruguay and Brazil, have high genetic diversity and may have undergone a population expansion approximately 250,000 years before the present. The high degree of genetic structure is reflected in the analyses of morphological characters, and most individuals could be correctly assigned to their parental population based on morphology alone. Finally, we discuss the biogeographic and conservation implications of these findings.
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Affiliation(s)
- Jéssica F. Felappi
- Departamento de Zoologia, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
| | - Renata C. Vieira
- Departamento de Zoologia, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
| | - Nelson J. R. Fagundes
- Departamento de Genética, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
| | - Laura V. Verrastro
- Departamento de Zoologia, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
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13
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de Freitas TRO, Fernandes FA, Fornel R, Roratto PA. An endemic new species of tuco-tuco, genusCtenomys(Rodentia: Ctenomyidae), with a restricted geographic distribution in southern Brazil. J Mammal 2012. [DOI: 10.1644/12-mamm-a-007.1] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
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14
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Lopes CM, de Freitas TRO. Human impact in naturally patched small populations: genetic structure and conservation of the burrowing rodent, tuco-tuco (Ctenomys lami). ACTA ACUST UNITED AC 2012; 103:672-81. [PMID: 22585970 DOI: 10.1093/jhered/ess027] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Isolated or semi-isolated small populations are commonly found among species, due to a naturally patchy occupancy of suitable habitats or also as a result of habitat alterations. These populations are subject to an increased risk of local extinction because they are more vulnerable to demographic, genetic, and environmental stochasticity. Considering that natural areas have been becoming progressively more fragmented and smaller, understanding the genetic structure and evolutionary dynamics of small populations is critical. Ctenomys lami has 26 karyotypes distributed in a small area (936 km(2)) continually modified by human actions. We assessed the genetic geographical structure of this species, examining 178 specimens sampled on a fine scale, using information from chromosomal variability, mitochondrial DNA control region and cytochrome c oxidase subunit I sequences, and 14 microsatellite loci. The observed isolation-by-distance pattern and a clinal genetic variation suggest a stepping-stone population model. The results did not indicate genetic structuring associated with distinct karyotypes. However, mitochondrial and nuclear molecular markers demonstrated the existence of 2 demes, which are not completely isolated but are probably reinforced by a geographical barrier. The vulnerability of C. lami is greater than previously supposed, and our data support the designation of one Evolutionary Significant Unit and one Management Unit, and also the inclusion of this species' conservation status as vulnerable.
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Affiliation(s)
- Carla M Lopes
- Departamento de Genética, Universidade Federal do Rio Grande do Sul. Caixa Postal 15053, CEP 91501-970, Porto Alegre, Rio Grande do Sul, Brazil.
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MIROL PATRICIA, GIMÉNEZ MABELD, SEARLE JEREMYB, BIDAU CLAUDIOJ, FAULKES CHRISG. Population and species boundaries in the South American subterranean rodent Ctenomys in a dynamic environment. Biol J Linn Soc Lond 2010. [DOI: 10.1111/j.1095-8312.2010.01409.x] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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