scholarly journals Comparative cytogenetic survey of the giant bonytongue Arapaima fish (Osteoglossiformes: Arapaimidae), across different Amazonian and Tocantins/Araguaia River basins

2020 ◽  
Vol 18 (4) ◽  
Author(s):  
Ezequiel A. de Oliveira ◽  
Francisco de M. C. Sassi ◽  
Manolo F. Perez ◽  
Luiz A. C. Bertollo ◽  
Petr Ráb ◽  
...  
Keyword(s):  
River Basins ◽  
Comparative Genomic ◽  
South American ◽  
Molecular Cytogenetic ◽  
Araguaia River ◽  
Rdna Sites ◽  
Cytogenetic Survey ◽  
Acrocentric Chromosomes ◽  
Great Portion

Abstract The South American giant fishes of the genus Arapaima, commonly known as pirarucu, are one of the most iconic among Osteoglossiformes. Previously cytogenetic studies have identified their karyotype characteristics; however, characterization of cytotaxonomic differentiation across their distribution range remains unknown. In this study, we compared chromosomal characteristics using conventional and molecular cytogenetic protocols in pirarucu populations from the Amazon and Tocantins-Araguaia river basins to verify if there is differentiation among representatives of this genus. Our data revealed that individuals from all populations present the same diploid chromosome number 2n=56 and karyotype composed of 14 pairs of meta- to submetacentric and 14 pairs of subtelo- to acrocentric chromosomes. The minor and major rDNA sites are in separate chromosomal pairs, in which major rDNA sites corresponds to large heterochromatic blocks. Comparative genomic hybridizations (CGH) showed that the genome of these populations shared a great portion of repetitive elements, due to a lack of substantial specific signals. Our comparative cytogenetic data analysis of pirarucu suggested that, although significant genetic differences occur among populations, their general karyotype patterns remain conserved.

scholarly journals Genomic Organization of Repetitive DNA Elements and Extensive Karyotype Diversity of Silurid Catfishes (Teleostei: Siluriformes): A Comparative Cytogenetic Approach

2019 ◽  
Vol 20 (14) ◽  
pp. 3545
Author(s):  
Sukhonthip Ditcharoen ◽  
Luiz Antonio Carlos Bertollo ◽  
Petr Ráb ◽  
Eva Hnátková ◽  
Wagner Franco Molina ◽  
...  
Keyword(s):  
Evolutionary Dynamics ◽  
Chromosomal Rearrangements ◽  
5S Rdna ◽  
Comparative Genomic ◽  
Molecular Cytogenetic ◽  
Rdna Sites ◽  
Genomic Divergence ◽  
Fish Chromosomes ◽  
Dna Elements ◽  
Repetitive Dna Elements

The catfish family Siluridae contains 107 described species distributed in Asia, but with some distributed in Europe. In this study, karyotypes and other chromosomal characteristics of 15 species from eight genera were examined using conventional and molecular cytogenetic protocols. Our results showed the diploid number (2n) to be highly divergent among species, ranging from 2n = 40 to 92, with the modal frequency comprising 56 to 64 chromosomes. Accordingly, the ratio of uni- and bi-armed chromosomes is also highly variable, thus suggesting extensive chromosomal rearrangements. Only one chromosome pair bearing major rDNA sites occurs in most species, except for Wallago micropogon, Ompok siluroides, and Kryptoterus giminus with two; and Silurichthys phaiosoma with five such pairs. In contrast, chromosomes bearing 5S rDNA sites range from one to as high as nine pairs among the species. Comparative genomic hybridization (CGH) experiments evidenced large genomic divergence, even between congeneric species. As a whole, we conclude that karyotype features and chromosomal diversity of the silurid catfishes are unusually extensive, but parallel some other catfish lineages and primary freshwater fish groups, thus making silurids an important model for investigating the evolutionary dynamics of fish chromosomes.

Comparative Cytogenetics of Hoplerythrinus unitaeniatus (Agassiz, 1829) (Characiformes, Erythrinidae) Species Complex from Different Brazilian Hydrographic Basins

2016 ◽  
Vol 149 (3) ◽  
pp. 191-200 ◽  
Author(s):  
Juliana F. Martinez ◽  
Roberto L. Lui ◽  
Josiane B. Traldi ◽  
Daniel R. Blanco ◽  
Orlando Moreira-Filho
Keyword(s):  
Silver Nitrate ◽  
Species Complex ◽  
5S Rdna ◽  
River Basins ◽  
Telomeric Sequence ◽  
Comparative Cytogenetics ◽  
C Banding ◽  
Araguaia River ◽  
Rdna Sites ◽  
Hoplerythrinus Unitaeniatus

Chromosomal characteristics of Hoplerythrinus unitaeniatus populations from 5 Brazilian river basins, namely Arinos (Amazonas basin), Araguaia, Paraguai, Alto Paraná, and São Francisco were analyzed by conventional Giemsa staining, C-banding, silver nitrate impregnation, and fluorescence in situ hybridization (FISH) with 18S and 5S rDNA and telomeric sequence (TTAGGG)n probes. The diploid chromosome number was 2n = 48 in representatives of the populations from Paraguai and Alto Paraná River basins and 2n = 52 for those from the Arinos and Araguaia River basins. The São Francisco population had individuals with 2n = 50 and 52 occurring in sympatry. C-banding showed heterochromatic blocks mainly located at interstitial and pericentromeric positions in most of the chromosomes. Silver nitrate impregnation demonstrated simple NORs for representatives from Arinos and Araguaia River populations and multiple NORs for specimens from Paraguai, Alto Paraná, and São Francisco River populations. FISH with 18S and 5S rDNA probes revealed many chromosomes carrying these cistrons, with up to 21 chromosomes bearing 18S rDNA sites (Alto Rio Paraná basin) and up to 12 chromosomes with 5S rDNA sites (Paraguai basin), besides the occurrence of colocalization in all populations. FISH with telomeric sequence (TTAGGG)n detected sites in the terminal portion of the chromosomes in all populations. These data reinforce the idea that H. unitaeniatus is a species complex. Evolutionary and biogeographical aspects of the group in the Neotropical region are discussed.

scholarly journals Genotype-Phenotype Characterization of Wolf-Hirschhorn Syndrome Confirmed by FISH: Case Reports

2012 ◽  
Vol 2012 ◽  
pp. 1-5 ◽  
Author(s):  
F. Sheth ◽  
O. R. Akinde ◽  
C. Datar ◽  
O. V. Adeteye ◽  
J. Sheth
Keyword(s):  
Cytogenetic Study ◽  
Case Reports ◽  
Normal Karyotype ◽  
Comparative Genomic ◽  
Molecular Cytogenetic ◽  
Contiguous Gene ◽  
Multiple Malformation ◽  
Molecular Cytogenetic Techniques

The Wolf-Hirschhorn syndrome (WHS) is a multiple malformation and contiguous gene syndrome resulting from the deletion encompassing a 4p16.3 region. A microscopically visible terminal deletion on chromosome 4p (4p16→pter) was detected in Case 1 with full blown features of WHS. The second case which had an interstitial microdeletion encompassingWHSC 1andWHSC 2genes at 4p16.3 presented with less striking clinical features of WHS and had an apparently “normal” karyotype. The severity of the clinical presentation was as a result of haploinsufficiency and interaction with surrounding genes as well as mutations in modifier genes located outside the WHSCR regions. The study emphasized that an individual with a strong clinical suspicion of chromosomal abnormality and a normal conventional cytogenetic study should be further investigated using molecular cytogenetic techniques such as fluorescencein situhybridization (FISH) or array-comparative genomic hybridization (a-CGH).

Karyotype and Mapping of Repetitive DNAs in the African Butterfly Fish Pantodon buchholzi, the Sole Species of the Family Pantodontidae

2016 ◽  
Vol 149 (4) ◽  
pp. 312-320 ◽  
Author(s):  
Petr Ráb ◽  
Cassia F. Yano ◽  
Sébastien Lavoué ◽  
Oladele I. Jegede ◽  
Luiz A.C. Bertollo ◽  
...  
Keyword(s):  
18S Rdna ◽  
Trinucleotide Repeat ◽  
Pericentromeric Region ◽  
Chromosomal Evolution ◽  
River Population ◽  
U2 Snrna ◽  
Molecular Cytogenetic ◽  
Rdna Sites ◽  
The Family ◽  
Acrocentric Chromosomes

The monophyletic order Osteoglossiformes represents one of the most ancestral groups of teleosts and has at least 1 representative in all continents of the southern hemisphere, with the exception of Antarctica. However, despite its phylogenetic and biogeographical importance, cytogenetic data in Osteoglossiformes are scarce. Here, karyotype and chromosomal characteristics of the lower Niger River population of the African butterfly fish Pantodon buchholzi, the sole species of the family Pantodontidae (Osteoglossiformes), were examined using conventional and molecular cytogenetic approaches. All specimens examined had 2n = 46 chromosomes, with a karyotype composed of 5 pairs of metacentric, 5 pairs of submetacentric, and 13 pairs of acrocentric chromosomes in both sexes. No morphologically differentiated sex chromosomes were identified. C-bands were located in the centromeric/pericentromeric region of all chromosomes and were associated with the single AgNOR site. FISH with ribosomal DNA probes revealed that both 5S and 18S rDNA were present in only 1 pair of chromosomes each, but did not colocalize. CMA3+ bands were observed near the telomeres in several chromosome pairs and also at the 18S rDNA sites. The mapping of di- and trinucleotide repeat motifs, Rex6 transposable element, and U2 snRNA showed a scattered distribution over most of the chromosomes, but for some microsatellites and the U2 snRNA also a preferential accumulation at telomeric regions. This study presents the first detailed cytogenetic analysis in the African butterfly fish by both conventional and molecular cytogenetic protocols. This is the first of a series of further cytogenetic and cytogenomic studies on osteoglossiforms, aiming to comprehensively examine the chromosomal evolution in this phylogenetically important fish order.

scholarly journals Tracking the Evolutionary Trends Among Small-Size Fishes of the Genus Pyrrhulina (Characiforme, Lebiasinidae): New Insights From a Molecular Cytogenetic Perspective

2021 ◽  
Vol 12 ◽  
Author(s):  
Renata Luiza Rosa de Moraes ◽  
Francisco de Menezes Cavalcante Sassi ◽  
Luiz Antonio Carlos Bertollo ◽  
Manoela Maria Ferreira Marinho ◽  
Patrik Ferreira Viana ◽  
...  
Keyword(s):  
Repetitive Dna ◽  
Sex Chromosome ◽  
Comparative Genomic ◽  
Comparative Genome Hybridization ◽  
Molecular Cytogenetic ◽  
Rdna Sites ◽  
Previous Hypothesis ◽  
History Of ◽  
Cytogenetic Analyses ◽  
High Dynamics

Miniature fishes have always been a challenge for cytogenetic studies due to the difficulty in obtaining chromosomal preparations, making them virtually unexplored. An example of this scenario relies on members of the family Lebiasinidae which include miniature to medium-sized, poorly known species, until very recently. The present study is part of undergoing major cytogenetic advances seeking to elucidate the evolutionary history of lebiasinids. Aiming to examine the karyotype diversification more deeply in Pyrrhulina, here we combined classical and molecular cytogenetic analyses, including Giemsa staining, C-banding, repetitive DNA mapping, comparative genomic hybridization (CGH), and whole chromosome painting (WCP) to perform the first analyses in five Pyrrhulina species (Pyrrhulina aff. marilynae, Pyrrhulina sp., P. obermulleri, P. marilynae and Pyrrhulina cf. laeta). The diploid number (2n) ranged from 40 to 42 chromosomes among all analyzed species, but P. marilynae is strikingly differentiated by having 2n = 32 chromosomes and a karyotype composed of large meta/submetacentric chromosomes, whose plesiomorphic status is discussed. The distribution of microsatellites does not markedly differ among species, but the number and position of the rDNA sites underwent significant changes among them. Interspecific comparative genome hybridization (CGH) found a moderate divergence in the repetitive DNA content among the species’ genomes. Noteworthy, the WCP reinforced our previous hypothesis on the origin of the X1X2Y multiple sex chromosome system in P. semifasciata. In summary, our data suggest that the karyotype differentiation in Pyrrhulina has been driven by major structural rearrangements, accompanied by high dynamics of repetitive DNAs.

Molecular Cytogenetic Characterization of the Murine Melanoma Cell Lines S91 Clone M3 and B16-F1 with Variant B16-4A5

2021 ◽  
pp. 1-11
Author(s):  
Katja Piaszinski ◽  
Martina Rincic ◽  
Thomas Liehr ◽  
Shaymaa Azawi
Keyword(s):  
Cell Lines ◽  
Tumor Suppressor Genes ◽  
Survival Rates ◽  
Human Melanoma ◽  
Model Systems ◽  
Comparative Genomic ◽  
Skin Melanoma ◽  
Molecular Cytogenetic ◽  
Cytogenetic Characterization

Melanoma is considered to be one of the most aggressive human tumors. Thus, early molecular diagnosis with risk factor stratification could be an efficacious strategy to increase the survival rates in affected patients. Murine cell lines B16-F1, B16-4A5, and S91 clone M3 are the ones most commonly applied in melanoma research. However, genetic peculiarities of these 3 cell lines have not been studied in detail before. Here, we closed this gap by molecular cytogenetic and array-comparative genomic hybridization studies and the translation of the characterized imbalances into the human genome. This study revealed severely rearranged karyotypes with in parts similar imbalances for all 3 cell lines. Interestingly, they involve genes known to play major roles in human melanoma. These are specifically the oncogenes and tumor suppressor genes, being associated with aggressive forms of melanoma. B16-F1, B16-4A5, and S91 clone M3 revealed aberrations which were similarly observed in human eye and skin but not in human uveal melanoma. Thus, they can be considered as model systems for advanced eye and skin melanoma.

scholarly journals Molecular cytogenetic characterization and phylogenetic analysis of four Miscanthus species (Poaceae)

2019 ◽  
Vol 13 (3) ◽  
pp. 211-230 ◽  
Author(s):  
Yan-Mei Tang ◽  
Liang Xiao ◽  
Yasir Iqbal ◽  
Jian-Feng Liao ◽  
Long-Qian Xiao ◽  
...  
Keyword(s):  
Genomic Dna ◽  
Phylogenetic Trees ◽  
Repetitive Sequences ◽  
Comparative Genomic ◽  
45S Rdna ◽  
Molecular Cytogenetic ◽  
Rdna Sites ◽  
Molecular Phylogenetic ◽  
Cytogenetic Characterization

Chromosomes of four Miscanthus (Andersson, 1855) species including M. sinensis (Andersson, 1855), M. floridulus (Schumann & Lauterb, 1901), M. sacchariflorus (Hackel, 1882) and M. lutarioriparius (Chen & Renvoize, 2005) were analyzed using sequentially combined PI and DAPI (CPD) staining and fluorescence in situ hybridization (FISH) with 45S rDNA probe. To elucidate the phylogenetic relationship among the four Miscanthus species, the homology of repetitive sequences among the four species was analyzed by comparative genomic in situ hybridization (cGISH). Subsequently four Miscanthus species were clustered based on the internal transcribed spacer (ITS) of 45S rDNA. Molecular cytogenetic karyotypes of the four Miscanthus species were established for the first time using chromosome measurements, fluorochrome bands and 45S rDNA FISH signals, which will provide a cytogenetic tool for the identification of these four species. All the four have the karyotype formula of Miscanthus species, which is 2n = 2x = 38 = 34m(2SAT) + 4sm, and one pair of 45S rDNA sites. The latter were shown as strong red bands by CPD staining. A non-rDNA CPD band emerged in M. floridulus and some blue DAPI bands appeared in M. sinensis and M. floridulus. The hybridization signals of M. floridulus genomic DNA to the chromosomes of M. sinensis and M. lutarioriparius genomic DNA to the chromosomes of M. sacchariflorus were stronger and more evenly distributed than other combinations. Molecular phylogenetic trees showed that M. sinensis and M. floridulus were closest relatives, and M. sacchariflorus and M. lutarioriparius were also closely related. These findings were consistent with the phylogenetic relationships inferred from the cGISH patterns.

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