scholarly journals Comparative cytogenetics of Astyanax (Teleostei: Characidae) from the upper Paraguay basin

2018 ◽  
Vol 16 (1) ◽  
Author(s):  
Thais K. S. S. Teixeira ◽  
Paulo C. Venere ◽  
Daniela C. Ferreira ◽  
Sandra Mariotto ◽  
Jonathan P. Castro ◽  
...  
Keyword(s):  
Physical Mapping ◽  
18S Rdna ◽  
Diploid Number ◽  
5S Rdna ◽  
Neotropical Region ◽  
Comparative Cytogenetics ◽  
Karyotype Morphology ◽  
Taxonomic Studies

ABSTRACT Astyanax is one of the most abundant and diverse taxa of fishes in the Neotropical region. In order to increase the amount of cytogenetic information for Astyanax as well as to exhibit data to subsidize future taxonomic studies, this work analyzed three species of Astyanax: two species are cryptic, and are here reported to live in syntopy (A. abramis and A. lacustris); the first karyotype description for A. pirapuan is also presented. Cytogenetic analyzes reveal a diploid number of 2n=50 chromosomes for three species, yet with differences in their karyotype morphology. The physical mapping of 18S rDNA showed up to thirteen sites in A. pirapuan and two in A. abramis and A. lacustris. The physical mapping of 5S rDNA has proven to be an effective marker for the characterization of species of Astyanax studied in this work.

scholarly journals B chromosome and NORs polymorphism in Callichthys callichthys (Linnaeus, 1758) (Siluriformes: Callichthyidae) from upper Paraná River, Brazil

2014 ◽  
Vol 12 (3) ◽  
pp. 603-609 ◽  
Author(s):  
Jocicléia Thums Konerat ◽  
Vanessa Bueno ◽  
Lucas Baumgartner ◽  
Isabel Cristina Martins-Santos ◽  
Vladimir Pavan Margarido
Keyword(s):  
Physical Mapping ◽  
18S Rdna ◽  
Diploid Number ◽  
5S Rdna ◽  
B Chromosome ◽  
Paraná River ◽  
Rdna Genes ◽  
Parana River ◽  
Rdna Sites ◽  
Upper Paraná River

B chromosomes are extra chromosomes from the normal chromosomal set, found in different organisms, highlighting their presence on the group of fishes. Callichthys callichthys from the upper Paraná River has a diploid number of 56 chromosomes (26 m-sm + 30 st-a) for both sexes, with the presence of a sporadically acrocentric B chromosome. Moreover, one individual presented a diploid number of 57 chromosomes, with the presence of a morphologically ill-defined acrocentric B chromosome in all analyzed cells. The physical mapping of 5S and 18S rDNA shows multiple 5S rDNA sites and only one pair of chromosomes with 18S sites in C. callichthys, except for two individuals. These two individuals presented a third chromosome bearing NORs (Ag-staining and 18S rDNA) where 5S and 18S rDNA genes are syntenic, differing only in position. The dispersion of the 18S rDNA genes from the main st-achromosome pair 25 to one of the chromosomes from the m-sm pair 4 would have originated two variant individuals, one of which with the ill-defined acrocentric B chromosome. Mechanisms to justify the suggested hypothesis about this B chromosome origin are discussed in the present study.

scholarly journals Karyotype characterization of Epimedium species (Berberidaceae) by fluorescent banding and physical mapping of 45S and 5S rDNA

Caryologia ◽  
2011 ◽  
Vol 64 (1) ◽  
pp. 84-90 ◽  
Author(s):  
Diao Ying ◽  
Chen Qingfu ◽  
Lin Xianming ◽  
Liao Chaolin ◽  
Hu Zhongli ◽  
...  
Keyword(s):  
Physical Mapping ◽  
5S Rdna ◽  
Fluorescent Banding

scholarly journals Contributions to the systematic of Pimelodidae (Osteichthyes, Siluriformes): basic and molecular cytogenetics on seven species of Pimelodus from three Brazilian hydrographic systems

2018 ◽  
Vol 16 (2) ◽  
Author(s):  
Simone C. Girardi ◽  
Carla S. Pavanelli ◽  
Vladimir P. Margarido
Keyword(s):  
18S Rdna ◽  
Molecular Cytogenetics ◽  
5S Rdna ◽  
Neotropical Region ◽  
Valid Species ◽  
Rdna Sites ◽  
The Family ◽  
Rdna Fish ◽  
Pimelodus Maculatus ◽  
Cytogenetic Methods

ABSTRACT Pimelodidae harbors several species and is widely distributed throughout the Neotropical region. Pimelodus is the genus with the largest number of species, however it is a polyphyletic group. Cytogenetic analyzes of the valid species still covers less than half of them. Herein, seven Pimelodus species from three Brazilian hydrographic systems were analyzed through basic (Giemsa, AgNORs and C banding) and molecular (5S and 18S rDNA-FISH) cytogenetic methods. All species had 2n=56 chromosomes with different karyotype formulas observed among the species. AgNORs were corresponding to 18S rDNA and localized on long arm of one chromosome pair in all species. Heterochromatin distribution follows the pattern commonly verified in the family and allows to identify each one of the studied species. 5S rDNA marker was interspecifically variable in number and position of cistrons. Pimelodus ortmanni had B chromosomes varying intra and inter-individually. We performed a discussion on our own and available cytogenetic data for Pimelodidae, and the associating of them with available phylogeny enable us identifying features that distinguish subgroups within Pimelodidae, such as NORs location (terminal/long arm for species belonging to “Iheringichthys-Parapimelodus” and “Pimelodus maculatus” subclades) and location of 5S rDNA sites (pericentromeric/interstitial/ long arm for species belonging to Pimelodus group).

Cytogenetic and Molecular Characterization of Three Mimetic Species of the Genus Alagoasa Bechyné 1955 (Coleoptera: Alticinae) from the Neotropical Region

2020 ◽  
Vol 160 (4) ◽  
pp. 214-223
Author(s):  
Matheus Azambuja ◽  
Lucas A.M. Rosolen ◽  
Roberto F. Artoni ◽  
Mateus H. Santos ◽  
Mara C. Almeida
Keyword(s):  
Molecular Genetic ◽  
5S Rdna ◽  
Distinct Species ◽  
Neotropical Region ◽  
Coi Gene ◽  
Similar Species ◽  
Determination System ◽  
Genetic Techniques ◽  
Sex Determination System

Coleoptera is a mega-diverse order, but only about 1% of its species have been analyzed cytogenetically. In this order, the subfamily Alticinae presents many identification problems, mainly due to the occurrence of mimicry. The objective of this work was to cytogenetically characterize 3 very similar species of the genus Alagoasa (A. pantina, A.areata, and A.scissa). We used classical and molecular cytogenetic as well as molecular genetic techniques. All 3 species showed a diploid chromosome number of 2n = 22 (20+X+y), but differences in the morphology of the chromosomes. All had a meiotic formula of 2n = 10II+X+y and an X+y sex determination system with giant, fully asynaptic sex chromosomes, concordant characteristics observed in the subtribe Oedionychina. FISH demonstrated the presence of 18S and 5S rDNA clusters in 1 pair of autosomes, syntenic and colocalizing in the 3 analyzed species. However, in A. areata, heteromorphism between the cistrons was observed. The telomeric (TTAGG)n probe showed signals in all 3 species, with proximal signals in the X and dispersed signals in the y chromosome of A. areata, and 2 proximal signals in the X chromosome of A. scissa. Molecular analysis of the COI gene indicated that they are 3 distinct species, corroborating the observed cytogenetic characteristics.

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 FISH-mapping of the 5S rDNA locus in chili peppers (Capsicum-Solanaceae)

2016 ◽  
Vol 88 (1) ◽  
pp. 117-125 ◽  
Author(s):  
PATRICIA M. AGUILERA ◽  
HUMBERTO J. DEBAT ◽  
MARISEL A. SCALDAFERRO ◽  
DARDO A. MARTÍ ◽  
MAURO GRABIELE
Keyword(s):  
Physical Mapping ◽  
Chromosome Pair ◽  
5S Rdna ◽  
Rdna Locus ◽  
Metacentric Chromosome ◽  
Haploid Genome ◽  
Fish Mapping ◽  
Chili Peppers

ABSTRACT We present here the physical mapping of the 5S rDNA locus in six wild and five cultivated taxa of Capsicum by means of a genus-specific FISH probe. In all taxa, a single 5S locus per haploid genome that persistently mapped onto the short arm of a unique metacentric chromosome pair at intercalar position, was found. 5S FISH signals of almost the same size and brightness intensity were observed in all the analyzed taxa. This is the first cytological characterization of the 5S in wild taxa of Capsicum by using a genus-derived probe, and the most exhaustive and comprehensive in the chili peppers up to now. The information provided here will aid the cytomolecular characterization of pepper germplasm to evaluate variability and can be instrumental to integrate physical, genetic and genomic maps already generated in the genus.

scholarly journals Corrigenda: Cytogenetic markers as a tool for characterization of hybrids of Astyanax Baird & Girard, 1854 and Hyphessobrycon Eigenmann, 1907. Comparative Cytogenetics 14(2): 231–242. https://doi.org/10.3897/CompCytogen.v14i2.49513

2020 ◽  
Vol 14 (4) ◽  
pp. 639-643
Author(s):  
Caio Augusto Gomes Goes ◽  
Sandro Natal Daniel ◽  
Lucas Henrique Piva ◽  
George Shigueki Yasui ◽  
Roberto Ferreira Artoni ◽  
...  
Keyword(s):  
5S Rdna ◽  
Mendelian Inheritance ◽  
Valid Species ◽  
Comparative Cytogenetics ◽  
Species Complexes ◽  
The Family ◽  
Karyotypic Diversity ◽  
Different Populations ◽  
Genetic Pools

Astyanax Baird et Girard, 1854, is one of the largest genera in the family Characidae and comprises 177 valid species. This genus has been the focus of cytogenetic studies primarily owing to the presence of B chromosomes and high karyotypic diversity among different populations. The intense genetic variability in Astyanax is one of the factors responsible for the occurrence of species complexes, which are groups (1) with certain difficulties in establishing common genetic pools or (2) belonging to different cryptic species. To evaluate cytogenetic marker inheritance and the possibility of the identification of these hybrids, this study aimed to describe cytogenetic hybrids from three strains of species of the genera Astyanax and Hyphessobrycon Eigenmann, 1908. A. lacustris Lütken, 1875, A. schubarti Britski, 1964, A. fasciatus Cuvier, 1819, and H. anisitsi Eigenmann, 1907 were used to generate three hybrid lineages. The diploid number, heterochromatin sites, and ribosomal genes (18S and 5S rDNA) of the parental strains and the hybrids were analyzed. The results indicated that the three hybrid lineages had cytogenetic markers of both parents, presenting Mendelian inheritance. However, differences in distribution of heterochromatic blocks were observed between the hybrids and the parent strains. Our results allowed the identification of the hybrid strains based on the cytogenetic markers applied, reinforcing the efficiency of cytogenetic markers as tools for identification and indicating that such events may increase the karyotypic diversity in the genera Astyanax and Hyphessobrycon.

scholarly journals Molecular Cytogenetics of Eurasian Species of the Genus Hedysarum L. (Fabaceae)

Plants ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 89
Author(s):  
Olga Yu. Yurkevich ◽  
Tatiana E. Samatadze ◽  
Inessa Yu. Selyutina ◽  
Svetlana I. Romashkina ◽  
Svyatoslav A. Zoshchuk ◽  
...  
Keyword(s):  
Chromosome Pair ◽  
Molecular Cytogenetics ◽  
5S Rdna ◽  
Genomic Diversity ◽  
45S Rdna ◽  
Species Specific ◽  
Taxonomic Studies ◽  
First Time ◽  
Eurasian Species

The systematic knowledge on the genus Hedysarum L. (Fabaceae: Hedysareae) is still incomplete. The species from the section Hedysarum are valuable forage and medicinal resources. For eight Hedysarum species, we constructed the integrated schematic map of their distribution within Eurasia based on currently available scattered data. For the first time, we performed cytogenomic characterization of twenty accessions covering eight species for evaluating genomic diversity and relationships within the section Hedysarum. Based on the intra- and interspecific variability of chromosomes bearing 45S and 5S rDNA clusters, four main karyotype groups were detected in the studied accessions: (1) H.arcticum, H. austrosibiricum, H. flavescens, H. hedysaroides, and H. theinum (one chromosome pair with 45S rDNA and one pair bearing 5S rDNA); (2) H. alpinum and one accession of H. hedysaroides (one chromosome pair with 45S rDNA and two pairs bearing 5S rDNA); (3) H. caucasicum (one chromosome pair with 45S rDNA and one chromosome pair bearing 5S rDNA and 45S rDNA); (4) H. neglectum (two pairs with 45S rDNA and one pair bearing 5S rDNA). The species-specific chromosomal markers detected in karyotypes of H. alpinum, H. caucasicum, and H. neglectum can be useful in taxonomic studies of this section.

Comparative Cytogenetics in Four Leptodactylus Species (Amphibia, Anura, Leptodactylidae): Evidence of Inner Chromosomal Diversification in Highly Conserved Karyotypes

2021 ◽  
pp. 1-11
Author(s):  
David S. da Silva ◽  
Heriberto F. da Silva Filho ◽  
Marcelo B. Cioffi ◽  
Edivaldo H.C. de Oliveira ◽  
Anderson J.B. Gomes
Keyword(s):  
18S Rdna ◽  
Repetitive Sequences ◽  
Molecular Cytogenetics ◽  
Comparative Cytogenetics ◽  
The Family ◽  
Agnor Staining ◽  
Dna Elements ◽  
Conventional Cytogenetics ◽  
Species Specific ◽  
Repetitive Dna Elements

With 82 species currently described, the genus <i>Leptodactylus</i> is the most diverse and representative one in the family Leptodactylidae. Concerning chromosomal organization, this genus represents an interesting and underexplored group since data from molecular cytogenetics are incipient, and little is known about the organization and distribution of repetitive DNA elements in the karyotypes. In this sense, this study aimed at providing a comparative analysis in 4 <i>Leptodactylus</i> species (<i>L. macrosternum, L. pentadactylus, L. fuscus,</i> and <i>Leptodactylus</i> cf<i>. podicipinus</i>), combining conventional cytogenetics (Giemsa staining, C-banding, and AgNOR staining) and mapping of molecular markers (18S rDNA, telomeric and microsatellite probes), to investigate mechanisms underlying their karyotype differentiation process. The results showed that all species had karyotypes with 2n = 22 and FN = 44, except for <i>Leptodactylus</i> cf. <i>podicipinus</i> which presented FN = 36. The 18S rDNA was observed in pair 8 of all analyzed species (corresponding to pair 4 in <i>L. pentadactylus</i>), coinciding with the secondary constrictions and AgNOR staining. FISH with microsatellite DNA probes demonstrated species-specific patterns, as well as an association of these repetitive sequences with constitutive heterochromatin blocks and ribosomal DNA clusters, revealing the dynamics of microsatellites in the genome of the analyzed species. In summary, our data demonstrate an ongoing process of genomic divergence inside species with almost similar karyotype, driven most likely by a series of pericentric inversions, followed by differential accumulation of repetitive sequences.

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