scholarly journals Comparative analysis based on replication banding reveals the mechanism responsible for the difference in the karyotype constitution of treefrogs Ololygon and Scinax (Arboranae, Hylidae, Scinaxinae)

2017 ◽  
Vol 11 (2) ◽  
pp. 267-283
Author(s):  
Simone Lilian Gruber ◽  
Gabriela Isabela Gomes de Oliveira ◽  
Ana Paula Zampieri Silva ◽  
Hideki Narimatsu ◽  
Célio Fernando Baptista Haddad ◽  
...  
Keyword(s):  
Chromosome Banding ◽  
Diploid Number ◽  
Nucleolus Organizer ◽  
Replication Banding ◽  
Nucleolus Organizer Regions ◽  
The Family ◽  
The Difference ◽  
Size And Morphology ◽  
Phylogenetic Revision ◽  
Dna Incorporation

According to the recent taxonomic and phylogenetic revision of the family Hylidae, species of the former Scinaxcatharinae (Boulenger, 1888) clade were included in the resurrected genus Ololygon Fitzinger, 1843, while species of the Scinaxruber (Laurenti, 1768) clade were mostly included in the genus Scinax Wagler, 1830, and two were allocated to the newly created genus JulianusDuellman et al., 2016. Although all the species of the former Scinax genus shared a diploid number of 2n = 24 and the same fundamental number of chromosome arms of FN = 48, two karyotypic constitutions were unequivocally recognized, related mainly to the distinct size and morphology of the first two chromosome pairs. Some possible mechanisms for these differences had been suggested, but without any experimental evidence. In this paper, a comparison was carried out based on replication chromosome banding, obtained after DNA incorporation of 5-bromodeoxiuridine in chromosomes of Ololygon and Scinax. The obtained results revealed that the loss of repetitive segments in chromosome pairs 1 and 2 was the mechanism responsible for karyotype difference. The distinct localization of the nucleolus organizer regions in the species of both genera also differentiates the two karyotypic constitutions.

scholarly journals Comparative analysis based on replication banding reveals the mechanism responsible for the difference in the karyotype constitution of treefrogs Ololygon and Scinax (Arboranae, Hylidae, Scinaxinae)

2017 ◽  
Vol 11 (2) ◽  
pp. 267-283 ◽  
Author(s):  
Simone Lilian Gruber ◽  
Gabriela Isabela Gomes de Oliveira ◽  
Ana Paula Zampieri Silva ◽  
Hideki Narimatsu ◽  
Célio Fernando Baptista Haddad ◽  
...  
Keyword(s):  
Chromosome Banding ◽  
Diploid Number ◽  
Nucleolus Organizer ◽  
Replication Banding ◽  
Nucleolus Organizer Regions ◽  
The Family ◽  
The Difference ◽  
Size And Morphology ◽  
Phylogenetic Revision ◽  
Dna Incorporation

According to the recent taxonomic and phylogenetic revision of the family Hylidae, species of the former Scinaxcatharinae (Boulenger, 1888) clade were included in the resurrected genus Ololygon Fitzinger, 1843, while species of the Scinaxruber (Laurenti, 1768) clade were mostly included in the genus Scinax Wagler, 1830, and two were allocated to the newly created genus JulianusDuellman et al., 2016. Although all the species of the former Scinax genus shared a diploid number of 2n = 24 and the same fundamental number of chromosome arms of FN = 48, two karyotypic constitutions were unequivocally recognized, related mainly to the distinct size and morphology of the first two chromosome pairs. Some possible mechanisms for these differences had been suggested, but without any experimental evidence. In this paper, a comparison was carried out based on replication chromosome banding, obtained after DNA incorporation of 5-bromodeoxiuridine in chromosomes of Ololygon and Scinax. The obtained results revealed that the loss of repetitive segments in chromosome pairs 1 and 2 was the mechanism responsible for karyotype difference. The distinct localization of the nucleolus organizer regions in the species of both genera also differentiates the two karyotypic constitutions.

scholarly journals Karyotype variability in neotropical catfishes of the family Pimelodidae (Teleostei: Siluriformes)

2011 ◽  
Vol 9 (1) ◽  
pp. 97-105 ◽  
Author(s):  
Américo Moraes Neto ◽  
Maelin da Silva ◽  
Daniele Aparecida Matoso ◽  
Marcelo Ricardo Vicari ◽  
Mara Cristina de Almeida ◽  
...  
Keyword(s):  
Fluorescent In Situ Hybridization ◽  
Diploid Number ◽  
Molecular Cytogenetics ◽  
Ribosomal Genes ◽  
Nucleolus Organizer ◽  
Nucleolus Organizer Regions ◽  
Karyotype Variability ◽  
Interspecific Variations ◽  
The Family

Karyotypic data are presented for four species of fish belonging to the Pimelodidae family. These species show a conserved diploid number, 2n = 56 chromosomes, with different karyotypic formulae. The analyzed species showed little amount of heterochromatin located preferentially in the centromeric and telomeric regions of some chromosomes. The nucleolus organizer regions activity (Ag-NORs) and the chromosomal location of ribosomal genes by fluorescent in situ hybridization (FISH), with 18S and 5S probes, showing only one chromosome pair marked bearer of ribosomal genes, the only exception was Pimelodus britskii that presented multiple NORs and syntenic location of the 18S and 5S probes. Non-Robertsonian events, as pericentric inversion and NORs duplication are requested to explain the karyotype diversification in Pseudoplatystoma from the rio Paraguay (MS), Pimelodus from the rio Iguaçu (PR), Sorubim from the rio Paraguay (MS) and Steindachneridion from the rio Paraíba do Sul (SP). The obtained data for the karyotype macrostructure of these species corroborates a conserved pattern observed in Pimelodidae. On the other hand, interspecific variations detected by molecular cytogenetics markers made possible cytotaxonomic inferences and differentiation of the species here analyzed.

scholarly journals Karyotypic characterization of Prochilodus mariae, Semaprochilodus kneri and S. laticeps(Teleostei: Prochilodontidae) from Caicara del Orinoco, Venezuela

2003 ◽  
Vol 1 (1) ◽  
pp. 47-52 ◽  
Author(s):  
Claudio Oliveira ◽  
Mauro Nirchio ◽  
Ángel Granado ◽  
Sara Levy
Keyword(s):  
Chromosome Number ◽  
Chromosome Pair ◽  
Nucleolus Organizer ◽  
Single Chromosome ◽  
Nucleolus Organizer Regions ◽  
The Family ◽  
Structural Chromosome ◽  
Almost All ◽  
Freshwater Environments

Fish of the family Prochilodontidae are considered one of the most important components of commercial and subsistence fishery in freshwater environments in South America. This family consists of 21 species and three genera. In the present study, the karyotypes of Prochilodus mariae, Semaprochilodus kneri, and S. laticeps from Caicara del Orinoco, Bolivar State, Venezuela were studied. The species P. mariae, S. kneri and S. laticeps exhibited 2n=54 chromosomes (40 metacentric and 14 submetacentric), a single chromosome pair with nucleolus organizer regions, and a large amount of heterochromatin found at centromeric and pericentromeric positions in almost all chromosomes. The P. mariae specimens studied displayed 0 to 3 supernumerary microchromosomes. The data obtained here confirm the conservative nature of the chromosome number and morphology of Prochilodontidae and reinforce the hypothesis that small structural chromosome rearrangements were the main cause of the karyotypic diversification seen in this group.

scholarly journals Karyotype description and comparative analysis in Ringed Kingfisher and Green Kingfisher (Coraciiformes, Alcedinidae)

2018 ◽  
Vol 12 (2) ◽  
pp. 163-170
Author(s):  
Tiago Marafiga Degrandi ◽  
Jean Carlo Pedroso de Oliveira ◽  
Amanda de Araújo Soares ◽  
Mario Angel Ledesma ◽  
Iris Hass ◽  
...  
Keyword(s):  
Comparative Analysis ◽  
Chromosome Number ◽  
Chromosome Numbers ◽  
Diploid Number ◽  
Chromosomal Rearrangements ◽  
The Family ◽  
Cytogenetic Studies ◽  
Karyotype Structure ◽  
Chromosome Fusions ◽  
Size And Morphology

Kingfishers comprise about 115 species of the family Alcedinidae, and are an interesting group for cytogenetic studies, for they are among birds with most heterogeneous karyotypes. However, cytogenetics knowledge in Kingfishers is extremely limited. Thus, the aim of this study was to describe the karyotype structure of the Ringed Kingfisher (Megaceryletorquata Linnaeus, 1766) and Green Kingfisher (Chloroceryleamericana Gmelin, 1788) and also compare them with related species in order to identify chromosomal rearrangements. The Ringed Kingfisher presented 2n = 84 and the Green Kingfisher had 2n = 94. The increase of the chromosome number in the Green Kingfisher possibly originated by centric fissions in macrochromosomes. In addition, karyotype comparisons in Alcedinidae show a heterogeneity in the size and morphology of macrochromosomes, and chromosome numbers ranging from 2n = 76 to 132. Thus, it is possible chromosomal fissions in macrochromosomes resulted in the increase of the diploid number, whereas chromosome fusions have originated the karyotypes with low diploid number.

Cytogenetic Analysis of Panaqolus tankei Cramer & Sousa, 2016 (Siluriformes, Loricariidae), an Ornamental Fish Endemic to Xingu River, Brazil

2021 ◽  
pp. 1-8
Author(s):  
Alex M.V. Ferreira ◽  
Patrik F. Viana ◽  
Jansen Zuanon ◽  
Tariq Ezaz ◽  
Marcelo B. Cioffi ◽  
...  
Keyword(s):  
18S Rdna ◽  
Diploid Number ◽  
5S Rdna ◽  
Sister Group ◽  
Nucleolus Organizer ◽  
Comparative Genomic ◽  
Nucleolus Organizer Regions ◽  
Chromosomal Changes ◽  
The Impact

Despite conservation of the diploid number, a huge diversity in karyotype formulae is found in the Ancistrini tribe (Loricariidae, Hypostominae). However, the lack of cytogenetic data for many groups impairs a comprehensive understanding of the chromosomal relationships and the impact of chromosomal changes on their evolutionary history. Here, we present for the first time the karyotype of Panaqolus tankei Cramer & Sousa, 2016. We focused on the chromosomal characterization, using conventional and molecular cytogenetic techniques to unravel the evolutionary trends of this tribe. P. tankei, as most species of its sister group Pterygoplichthini, also possessess a conserved diploid number of 52 chromosomes. We observed heterochromatin regions in the centromeres of many chromosomes; pairs 5 and 6 presented interstitial heterochromatin regions, whereas pairs 23 and 24 showed extensive heterochromatin regions in their q arms. In situ localization of 18S rDNA showed hybridization signals correlating with the nucleolus organizer regions, which are located in the q arms of pair 5. However, the 5S rDNA was detected in the centromeric and terminal regions of the q arms of pair 8. (TTAGGG)n hybridized only in the terminal regions of all chromosomes. Microsatellite in situ localization showed divergent patterns, (GA)15 repeated sequences were restricted to the terminal regions of some chromosomes, whereas (AC)15 and (GT)15 showed a scattered hybridization pattern throughout the genome. Intraspecific comparative genomic hybridization was performed on the chromosomes of P. tankei to verify the existence of sex-specific regions. The results revealed only a limited number of overlapping hybridization signals, coinciding with the heterochromatin in centromeric regions without any sex-specific signals in both males and females. Our study provides a karyotype description of P. tankei, highlighting extensive differences in the karyotype formula, the heterochromatin regions, and sites of 5S and 18S rDNA, as compared with data available for the genus.

scholarly journals Banded karyotype of Nelore cattle (Bos taurus indicus Linnaeus, 1758)

2019 ◽  
Vol 13 (3) ◽  
pp. 265-275
Author(s):  
Andréia Pires Amancio ◽  
Sabrina Sara Moreira Duarte ◽  
Rafael Carneiro Silvafael ◽  
Alex Silva da Cruz ◽  
Danilo Conrado Silva ◽  
...  
Keyword(s):  
Chromosome Banding ◽  
Bos Taurus ◽  
Bos Indicus ◽  
Culture Method ◽  
Nucleolus Organizer ◽  
Zebu Cattle ◽  
Metaphase Chromosomes ◽  
Nucleolus Organizer Regions ◽  
Bos Taurus Indicus ◽  
Nelore Cattle

Chromosome banding techniques were applied and standardized to obtain karyotype characteristics for the first time in Brazil of Nelore cattle – Bos taurus indicus Linnaeus, 1758 – (bovine subspecies most prominent in Brazilian livestock). Blood samples were collected from the animals of the School of Agrarian and Biological Sciences of the Pontifical Catholic University of Goiás, two males and two females of pure breed. These samples were submitted to the cell culture method to study metaphase chromosomes. Chromosome banding techniques (C, G and NOR) revealed the karyotype architecture of Nelore cattle common with that of other breeds of zebu cattle formerly karyotyped. The diploid chromosome number was invariably normal, 2n = 60. C-banding revealed C-positive heterochromatin in centromeric regions almost in all chromosomes. G-banding presented the expected band pattern in the respective chromosome pairs in correspondence with the established chromosomal patterns for the species. Ag-staining for nucleolus organizer regions (AgNOR) was identified on the telomeric end of the long arm in 7 autosomal chromosomes. In this study we found more regions in chromosomes with staining than presented in the literature for the Bos indicus group (BIN). These NOR regions were repeated on the same chromosomes for the 4 animals studied.

scholarly journals Evolutionary pattern of karyotypes and meiosis in pholcid spiders (Araneae: Pholcidae): implications for reconstructing chromosome evolution of araneomorph spiders

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Ivalú M. Ávila Herrera ◽  
Jiří Král ◽  
Markéta Pastuchová ◽  
Martin Forman ◽  
Jana Musilová ◽  
...  
Keyword(s):  
Sex Chromosomes ◽  
Chromosome Evolution ◽  
Karyotype Evolution ◽  
Sex Chromosome ◽  
Genomic Analysis ◽  
Nucleolus Organizer ◽  
Evolutionary Pattern ◽  
Holokinetic Chromosomes ◽  
Nucleolus Organizer Regions ◽  
The Family

Abstract Background Despite progress in genomic analysis of spiders, their chromosome evolution is not satisfactorily understood. Most information on spider chromosomes concerns the most diversified clade, entelegyne araneomorphs. Other clades are far less studied. Our study focused on haplogyne araneomorphs, which are remarkable for their unusual sex chromosome systems and for the co-evolution of sex chromosomes and nucleolus organizer regions (NORs); some haplogynes exhibit holokinetic chromosomes. To trace the karyotype evolution of haplogynes on the family level, we analysed the number and morphology of chromosomes, sex chromosomes, NORs, and meiosis in pholcids, which are among the most diverse haplogyne families. The evolution of spider NORs is largely unknown. Results Our study is based on an extensive set of species representing all major pholcid clades. Pholcids exhibit a low 2n and predominance of biarmed chromosomes, which are typical haplogyne features. Sex chromosomes and NOR patterns of pholcids are diversified. We revealed six sex chromosome systems in pholcids (X0, XY, X1X20, X1X2X30, X1X2Y, and X1X2X3X4Y). The number of NOR loci ranges from one to nine. In some clades, NORs are also found on sex chromosomes. Conclusions The evolution of cytogenetic characters was largely derived from character mapping on a recently published molecular phylogeny of the family. Based on an extensive set of species and mapping of their characters, numerous conclusions regarding the karyotype evolution of pholcids and spiders can be drawn. Our results suggest frequent autosome–autosome and autosome–sex chromosome rearrangements during pholcid evolution. Such events have previously been attributed to the reproductive isolation of species. The peculiar X1X2Y system is probably ancestral for haplogynes. Chromosomes of the X1X2Y system differ considerably in their pattern of evolution. In some pholcid clades, the X1X2Y system has transformed into the X1X20 or XY systems, and subsequently into the X0 system. The X1X2X30 system of Smeringopus pallidus probably arose from the X1X20 system by an X chromosome fission. The X1X2X3X4Y system of Kambiwa probably evolved from the X1X2Y system by integration of a chromosome pair. Nucleolus organizer regions have frequently expanded on sex chromosomes, most probably by ectopic recombination. Our data suggest the involvement of sex chromosome-linked NORs in achiasmatic pairing.

Chromosomal Instability and Origin of B Chromosomes in the Amazonian Glass Tetra Moenkhausia oligolepis (Günther, 1864) (Characiformes, Characidae)

2021 ◽  
pp. 249-256
Author(s):  
Luana Pereira dos Santos ◽  
Carine M. Francisco ◽  
Edimar O. Campos Júnior ◽  
Jonathan P. Castro ◽  
Ricardo Utsunomia ◽  
...  
Keyword(s):  
Chromosomal Instability ◽  
Diploid Number ◽  
Karyotype Analysis ◽  
Pericentromeric Region ◽  
Nucleolus Organizer ◽  
B Chromosomes ◽  
Interindividual Variation ◽  
Nucleolus Organizer Regions ◽  
Karyotypic Formula ◽  
Whole Chromosome Painting

B chromosomes occur in different species of the small characid fishes of the genus <i>Moenkhausia.</i> These supernumerary elements, that do not recombine with chromosomes of the standard A complement and follow their own evolutionary mechanism vary in number, morphology, and distribution. Here, we show karyotypic data of individuals of 2 populations of <i>Moenkhausia oligolepis</i> of the Brazilian Amazon (Pedro Correia and Taboquinha streams, Tocantins river basin), both with a diploid number of 50 chromosomes and karyotypic formula of 10m + 32sm + 8a. In addition to the normal complement, we also observed the occurrence of B chromosomes in the 2 populations with intra- and interindividual variation ranging from 0 to 10 Bs, independent of sex. The C-banding pattern evidenced heterochromatic blocks located mainly in the pericentromeric region of the chromosomes, while the B chromosomes appeared euchromatic. Silver-stained nucleolus organizer regions were identified in multiples sites, and some of these blocks were positive when stained with chromomycin A<sub>3.</sub> The karyotype analysis and the application of whole-chromosome painting in populations of <i>M. oligolepis</i> reinforce the conservation of the basal diploid number for the genus, as well as the evolutionary tendency in these fishes to carry B chromosomes. Both populations turned out to be in different stages of stability and expansion of their B chromosomes. We further suggest that the origin of these chromosomes is due to the formation of isochromosomes. Here, we identified a pair of complement A chromosomes involved in this process.

The banded chromosomes of the muskox (Ovibos moschatus)

1989 ◽  
Vol 67 (5) ◽  
pp. 1155-1158 ◽  
Author(s):  
Daniel M. Desaulniers ◽  
W. A. King ◽  
Janice E. Rowell ◽  
Peter F. Flood
Keyword(s):  
Silver Nitrate ◽  
X Chromosome ◽  
Water Buffalo ◽  
Nucleolus Organizer ◽  
Rrna Genes ◽  
Ovibos Moschatus ◽  
Nucleolus Organizer Regions ◽  
The Family ◽  
Silver Nitrate Staining ◽  
Acrocentric Chromosomes

The muskox (Ovibos moschatus), a member of the family Bovidae, has 48 chromosomes consisting of 12 biarmed and 34 acrocentric autosomes, an acrocentric X chromosome, and a small metacentric Y chromosome. To obtain more information about this species, chromosome preparations from cultured lymphocytes were R-banded, C-banded, or stained with silver nitrate. R-banding was sufficient to identify individual chromosomes. C-banding revealed prominent centromeric bands on all acrocentric chromosomes and very faint staining of the centromeric regions of the biarmed chromosomes. This pattern has been observed in other bovids, such as sheep and water buffalo, which also have biarmed and acrocentric chromosomes. Silver nitrate staining revealed a per metaphase average of 5.23 nucleolus organizer regions, the chromosomal sites of rRNA genes. The nucleolus organizer regions were located on the ends of the long arm of three pairs of submetacentric and two pairs of acrocentric autosomes. Similar numbers of terminally located nucleolus organizer regions have been observed in other bovids such as cattle, sheep, and goats. These results parallel those obtained in other members of the family and emphasize the general cytogenetic similarity within the Bovidae.

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