scholarly journals Molecular Cytogenetic Characterization of the Sicilian Endemic Pond Turtle Emys trinacris and the Yellow-Bellied Slider Trachemys scripta scripta (Testudines, Emydidae)

Genes ◽  
2020 ◽  
Vol 11 (6) ◽  
pp. 702 ◽  
Author(s):  
Rita Scardino ◽  
Sofia Mazzoleni ◽  
Michail Rovatsos ◽  
Luca Vecchioni ◽  
Francesca Dumas
Keyword(s):  
Karyotype Evolution ◽  
Chromosomal Rearrangements ◽  
Trachemys Scripta ◽  
Turtle Species ◽  
Telomeric Sequences ◽  
Pond Turtle ◽  
Rdna Loci ◽  
Cytogenetic Analyses ◽  
Staining Methods ◽  
Emys Trinacris

Turtles, a speciose group consisting of more than 300 species, demonstrate karyotypes with diploid chromosome numbers ranging from 2n = 26 to 2n = 68. However, cytogenetic analyses have been conducted only to 1/3rd of the turtle species, often limited to conventional staining methods. In order to expand our knowledge of the karyotype evolution in turtles, we examined the topology of the (TTAGGG)n telomeric repeats and the rDNA loci by fluorescence in situ hybridization (FISH) on the karyotypes of two emydids: the Sicilian pond turtle, Emys trinacris, and the yellow-bellied slider, Trachemys scripta scripta (family Emydidae). Furthermore, AT-rich and GC-rich chromosome regions were detected by DAPI and CMA3 stains, respectively. The cytogenetic analysis revealed that telomeric sequences are restricted to the terminal ends of all chromosomes and the rDNA loci are localized in one pair of microchromosomes in both species. The karyotype of the Sicilian endemic E. trinacris with diploid number 2n = 50, consisting of 13 pairs of macrochromosomes and 12 pairs of microchromosomes, is presented here for first time. Our comparative examination revealed similar cytogenetic features in Emys trinacris and the closely related E. orbicularis, as well as to other previously studied emydid species, demonstrating a low rate of karyotype evolution, as chromosomal rearrangements are rather infrequent in this group of turtles.

scholarly journals Repetitive Sequence Distribution on Saguinus, Leontocebus and Leontopithecus Tamarins (Platyrrhine, Primates) by Mapping Telomeric (TTAGGG) Motifs and rDNA Loci

Biology ◽  
2021 ◽  
Vol 10 (9) ◽  
pp. 844
Author(s):  
Simona Ceraulo ◽  
Polina L. Perelman ◽  
Sofia Mazzoleni ◽  
Michail Rovatsos ◽  
Francesca Dumas
Keyword(s):  
New World ◽  
Chromosomal Rearrangements ◽  
Repetitive Sequences ◽  
Distinct Group ◽  
New World Monkeys ◽  
Saguinus Oedipus ◽  
Telomeric Sequences ◽  
Rdna Loci ◽  
Cytogenetic Analyses ◽  
Saguinus Geoffroyi

Tamarins are a distinct group of small sized New World monkeys with complex phylogenetic relationships and poorly studied cytogenetic traits. In this study, we applied molecular cytogenetic analyses by fluorescence in situ hybridization with probes specific for telomeric sequences and ribosomal DNA loci after DAPI/CMA3 staining on metaphases from five tamarin species, namely Leontocebus fuscicollis, Leontopithecus rosalia, Saguinus geoffroyi, Saguinus mystax and Saguinus oedipus, with the aim to investigate the distribution of repetitive sequences and their possible role in genome evolution. Our analyses revealed that all five examined species show similar karyotypes, 2n = 46, which differ mainly in the morphology of chromosome pairs 16–17 and 19–22, due to the diverse distribution of rDNA loci, the amplification of telomeric-like sequences, the presence of heterochromatic blocks and/or putative chromosomal rearrangements, such as inversions. The differences in cytogenetic traits between species of tamarins are discussed in a comparative phylogenetic framework, and in addition to data from previous studies, we underline synapomorphies and apomorphisms that appeared during the diversification of this group of New World monkeys.

Pseudodicentric Chromosome Originating from Autosomes 9 and 21 in a Male Patient with Oligozoospermia

2019 ◽  
Vol 159 (4) ◽  
pp. 201-207
Author(s):  
Marion Beaumont ◽  
Elena J. Tucker ◽  
Laura Mary ◽  
Erika Launay ◽  
Yann Lurton ◽  
...  
Keyword(s):  
Male Infertility ◽  
Genetic Factors ◽  
Chromosomal Rearrangements ◽  
Chromosomal Anomalies ◽  
Derivative Chromosome ◽  
Telomeric Sequences ◽  
Dicentric Chromosomes ◽  
Interstitial Telomeric Sequences ◽  
Cytogenetic Analyses ◽  
Reproductive Phenotype

Genetic factors are responsible for 15% of male infertility conditions. Numerical and structural chromosomal anomalies (related to the Y chromosome or to the autosomes) are validated genetic factors leading to spermatogenic quantitative defects with a frequency depending on the severity of the phenotype. The most frequent structural chromosomal rearrangements of autosomes are translocations and inversions, whereas dicentric chromosomes involving autosomes are rare. We report a man bearing a pseudodicentric chromosome (9;21) and presenting with oligozoospermia. Extensive cytogenetic analyses were necessary to determine the precise nature of the derivative chromosome and to discount the presence of interstitial telomeric sequences. Defects in spermatogenesis and abnormal segregation at meiosis for existing spermatozoa are proposed and are the likely cause of the reproductive phenotype of the patient.

scholarly journals Stand out from the Crowd: Small-Scale Genetic Structuring in the Endemic Sicilian Pond Turtle

Diversity ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 343
Author(s):  
Luca Vecchioni ◽  
Federico Marrone ◽  
Marco Arculeo ◽  
Uwe Fritz ◽  
Melita Vamberger
Keyword(s):  
Genetic Diversity ◽  
Microsatellite Loci ◽  
Small Scale ◽  
Moderate Degree ◽  
Geographical Pattern ◽  
Genetic Structuring ◽  
Pond Turtle ◽  
Emys Trinacris ◽  
Polymorphic Microsatellite ◽  
Entire Distribution

The geographical pattern of genetic diversity was investigated in the endemic Sicilian pond turtle Emys trinacris across its entire distribution range, using 16 microsatellite loci. Overall, 245 specimens of E. trinacris were studied, showing high polymorphic microsatellite loci, with allele numbers ranging from 7 to 30. STRUCTURE and GENELAND analyses showed a noteworthy, geographically based structuring of the studied populations in five well-characterized clusters, supported by a moderate degree of genetic diversity (FST values between 0.075 and 0.160). Possible explanations for the genetic fragmentation observed are provided, where both natural and human-mediated habitat fragmentation of the Sicilian wetlands played a major role in this process. Finally, some conservation and management suggestions aimed at preventing the loss of genetic variability of the species are briefly reported, stressing the importance of considering the five detected clusters as independent Management Units.

scholarly journals Emys trinacris Fritz, Fattizzo, Guicking, Tripepi, Pennisi, Lenk, Joger, and Wink 2005 – Sicilian Pond Turtle, Testuggine Palustre Siciliana

2021 ◽  
Author(s):  
Dario Ottonello ◽  
Stefania D’Angelo ◽  
Federico Marrone ◽  
Fabrizio Oneto ◽  
Filippo Spadola ◽  
...  
Keyword(s):  
Pond Turtle ◽  
Emys Trinacris

Insights into Emydid Turtle Cytogenetics: The European Pond Turtle as a Model Species

2019 ◽  
Vol 157 (3) ◽  
pp. 166-171 ◽  
Author(s):  
Alessio Iannucci ◽  
Marta Svartman ◽  
Massimo Bellavita ◽  
Guido Chelazzi ◽  
Roscoe Stanyon ◽  
...  
Keyword(s):  
Chromosome Banding ◽  
Molecular Cytogenetics ◽  
Comparative Genomic ◽  
Emys Orbicularis ◽  
Rdna Genes ◽  
Telomeric Sequences ◽  
Pond Turtle ◽  
Cytogenetic Data ◽  
Cryptic Sex

Our knowledge of Testudines evolution is limited by the lack of modern cytogenetic data. Compared to other reptiles, there is little information even on chromosome banding, let alone molecular cytogenetic data. Here, we provide detailed information on the karyotype of the European pond turtle Emys orbicularis, a model Emydidae, employing both chromosome banding and molecular cytogenetics. We provide a high-resolution G-banded karyotype and a map of rDNA genes and telomeric sequences using fluorescence in situ hybridization. We test hypotheses of sex-determining mechanisms in Emys by comparative genomic hybridization to determine if Emys has a cryptic sex-specific region. Our results provide valuable data to guide future efforts on genome sequencing and anchoring in Emydidae and for understanding karyotype evolution in Testudines.

scholarly journals Impact of Chromosomal Rearrangements on the Interpretation of Lupin Karyotype Evolution

Genes ◽  
2019 ◽  
Vol 10 (4) ◽  
pp. 259 ◽  
Author(s):  
Karolina Susek ◽  
Wojciech Bielski ◽  
Katarzyna B. Czyż ◽  
Robert Hasterok ◽  
Scott A. Jackson ◽  
...  
Keyword(s):  
Karyotype Evolution ◽  
Chromosomal Rearrangements ◽  
Chromosome Mapping ◽  
Artificial Chromosome ◽  
Basic Chromosome Number ◽  
Plant Genome ◽  
Old World ◽  
Whole Genome Duplications ◽  
Genome Duplications

Plant genome evolution can be very complex and challenging to describe, even within a genus. Mechanisms that underlie genome variation are complex and can include whole-genome duplications, gene duplication and/or loss, and, importantly, multiple chromosomal rearrangements. Lupins (Lupinus) diverged from other legumes approximately 60 mya. In contrast to New World lupins, Old World lupins show high variability not only for chromosome numbers (2n = 32–52), but also for the basic chromosome number (x = 5–9, 13) and genome size. The evolutionary basis that underlies the karyotype evolution in lupins remains unknown, as it has so far been impossible to identify individual chromosomes. To shed light on chromosome changes and evolution, we used comparative chromosome mapping among 11 Old World lupins, with Lupinus angustifolius as the reference species. We applied set of L. angustifolius-derived bacterial artificial chromosome clones for fluorescence in situ hybridization. We demonstrate that chromosome variations in the species analyzed might have arisen from multiple changes in chromosome structure and number. We hypothesize about lupin karyotype evolution through polyploidy and subsequent aneuploidy. Additionally, we have established a cytogenomic map of L. angustifolius along with chromosome markers that can be used for related species to further improve comparative studies of crops and wild lupins.

Distribution of Interstitial Telomeric Sequences in Primates and the Pygmy Tree Shrew (Scandentia)

2017 ◽  
Vol 151 (3) ◽  
pp. 141-150 ◽  
Author(s):  
Sofia Mazzoleni ◽  
Odessa Schillaci ◽  
Luca Sineo ◽  
Francesca Dumas
Keyword(s):  
Dna Sequences ◽  
Tree Shrew ◽  
Chromosomal Rearrangements ◽  
Primate Species ◽  
Telomeric Dna ◽  
Erythrocebus Patas ◽  
Telomeric Sequences ◽  
Interstitial Telomeric Sequences ◽  
Cercopithecus Petaurista ◽  
Almost All

It has been hypothesized that interstitial telomeric sequences (ITSs), i.e., repeated telomeric DNA sequences found at intrachromosomal sites in many vertebrates, could be correlated to chromosomal rearrangements and plasticity. To test this hypothesis, we hybridized a telomeric PNA probe through FISH on representative species of 2 primate infraorders, Strepsirrhini (Lemur catta, Otolemur garnettii, Nycticebus coucang) and Catarrhini (Erythrocebus patas, Cercopithecus petaurista, Chlorocebus aethiops, Colobus guereza), as well as on 1 species of the order Scandentia, Tupaia minor, used as an outgroup for primates in phylogenetic reconstructions. In almost all primate species analyzed, we found a telomeric pattern only. In Tupaia, the hybridization revealed many bright ITSs on at least 11 chromosome pairs, both biarmed and acrocentric. These ITS signals in Tupaia correspond to fusion points of ancestral human syntenic associations, but are also present in other chromosomes showing synteny to only a single human chromosome. This distribution pattern was compared to that of the heterochromatin regions detected through sequential C-banding performed after FISH. Our results in the analyzed species, compared with literature data on ITSs in primates, allowed us to discuss different mechanisms responsible for the origin and distribution of ITSs, supporting the correlation between rearrangements and ITSs.

scholarly journals Karyotype asymmetry shapes diversity within the physaloids (Physalidinae, Physalideae, Solanaceae)

2020 ◽  
Author(s):  
Julieta Rodríguez ◽  
Rocío Deanna ◽  
Franco Chiarini
Keyword(s):  
Chromosome Number ◽  
Karyotype Evolution ◽  
Phylogenetic Signal ◽  
Monotypic Genus ◽  
Independent Events ◽  
Phylogenetic Methods ◽  
Karyotype Asymmetry ◽  
Chromosome Arm ◽  
Cytogenetic Analyses ◽  
Diploid Ancestor

AbstractWithin the cosmopolitan family Solanaceae, Physalideae is the tribe with the highest generic diversity (30 genera and more than 200 species). This tribe embraces subtribe Physalidinae, in which positions of some genera are not entirely resolved. Chromosomes may help on this goal, by providing information on the processes underlying speciation. Thus, cytogenetic analyses were carried out in the subtribe in order to establish its chromosome number and morphology. Physalidinae is characterized by x = 12 and most species shows a highly asymmetric karyotype. These karyotype traits were mapped onto a molecular phylogeny to test the congruence between karyotype evolution and clade differentiation. A diploid ancestor was reconstructed for the subtribe, and five to six polyploidy independent events were estimated, plus one aneuploidy event (X = 11 in the monotypic genus Quincula). Comparative phylogenetic methods showed that asymmetry indices and chromosome arm ratio (r) have a high phylogenetic signal, whereas the number of telocentric and submetacentric chromosomes presented a conspicuous amount of changes. Karyotype asymmetry allow us to differentiate genera within the subtribe. Overall, our study suggests that Physalidineae diversification has been accompanied by karyotype changes, which can be applied to delimit genera within the group.

scholarly journals Comparative Cytogenetics Analysis Among Peckoltia Species (Siluriformes, Loricariidae): Insights on Karyotype Evolution and Biogeography in the Amazon Region

2021 ◽  
Vol 12 ◽  
Author(s):  
Kevin Santos da Silva ◽  
Augusto Cesar Paes de Souza ◽  
Ananda Marques Pety ◽  
Renata Coelho Rodrigues Noronha ◽  
Marcelo Ricardo Vicari ◽  
...  
Keyword(s):  
Karyotype Evolution ◽  
5S Rdna ◽  
Nucleolus Organizer ◽  
Valid Species ◽  
Left Bank ◽  
Comparative Cytogenetics ◽  
Telomeric Sequences ◽  
Nucleolus Organizer Regions ◽  
Karyotype Formula ◽  
Distal Location

Peckoltia is widely distributed genus in the Amazon and Orinoco basins and the Guiana Shield, containing 18 valid species, and distinct morphotypes still needing description in the scientific literature due to its great taxonomic complexity. This study performed a comparative chromosomal analysis of two undescribed Peckoltia species (Peckoltia sp. 3 Jarumã and Peckoltia sp. 4 Caripetuba) from the Brazilian Amazon using conventional chromosome bands methods and in situ localization of the repetitive DNA (5S and 18S rRNA and U1 snRNA genes and telomeric sequences). Both species presented 2n = 52 but differed in their karyotype formula, probably due to inversions or translocations. The nucleolus organizer regions (NORs) showed distal location on a probably homeologous submetacentric pair in both species, besides an extra signal in a subtelocentric chromosome in Peckoltia sp. 4 Caripetuba. Heterochromatin occurred in large blocks, with different distributions in the species. The mapping of the 18S and 5S rDNA, and U1 snDNA showed differences in locations and number of sites. No interstitial telomeric sites were detected using the (TTAGGG)n probes. Despite 2n conservationism in Peckoltia species, the results showed variation in karyotype formulas, chromosomal bands, and locations of repetitive sites, demonstrating great chromosomal diversity. A proposal for Peckoltia karyotype evolution was inferred in this study based on the diversity of location and number of chromosomal markers analyzed. A comparative analysis with other Peckoltia karyotypes described in the literature, their biogeography patterns, and molecular phylogeny led to the hypothesis that the derived karyotype was raised in the left bank of the Amazon River.

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