scholarly journals First chromosome data on Steindachneridion doceanum (Siluriformes: Pimelodidae): a critically endangered catfish endemic of the Doce River basin, Brazil

2018 ◽  
Vol 16 (4) ◽  
Author(s):  
Ana Claudia Swarça ◽  
Mário Luis Orsi ◽  
Fábio Hiroshi Takagui ◽  
Ana Lucia Dias ◽  
Jorge Abdala Dergam ◽  
...  
Keyword(s):  
Secondary Constriction ◽  
Extinction Risk ◽  
Present Report ◽  
5S Rdna ◽  
Rdna Genes ◽  
C Banding ◽  
Endemic Taxon ◽  
Acrocentric Chromosomes ◽  
Doce River ◽  
Submetacentric Pair

ABSTRACT The present report represents the first cytogenetic description of Steindachneridion doceanum, great catfish which is currently at high extinction risk and it is listed as threatened on the red list of the Brazilian Ministry of the Environment, also are suggested karyotype relationships with other species of the same genus endemic from other river basins. The results revealed a diploid number of 2n = 56 and the karyotype composed of 18 metacentric, 20 submetacentric, 10 subtelocentric and 8 acrocentric chromosomes (NF = 104). The AgNORs and CMA3 signals were coincident in location occupying the short arm of an acrocentric chromosome pair (25th), in a secondary constriction. The 5S rDNA genes were localized on the short arms of one subtelocentric pair. C-banding revealed terminal blocks on the short arms on many chromosomes as well as terminal positive bands at the both ends of a submetacentric pair. C banding also revealed a large heterochromatic block in the secondary constriction (25th) region that was coincident with the AgNORs sites and CMA3+ bright bands. In spite S. doceanum represent an endemic taxon, in spite their geographic isolation their cytogenetic characteristics show similarities with other species of the genus.

scholarly journals Cytogenetic description of Bunocephalus doriae Boulenger, 1902 (Siluriformes: Aspredinidae) from the Paraná River (Misiones, Argentina)

2012 ◽  
Vol 10 (2) ◽  
pp. 461-464 ◽  
Author(s):  
Alberto Sérgio Fenocchio ◽  
Ana Cláudia Swarça
Keyword(s):  
Chromosome Pair ◽  
Diploid Number ◽  
Secondary Constriction ◽  
Paraná River ◽  
Parana River ◽  
C Banding ◽  
The Family ◽  
Acrocentric Chromosomes

In this work, Bunocephalus doriae was cytogenetically analyzed. A karyotype with a diploid number of 2n= 50 comprising 6m, 10sm, 6st, and 28a (FN= 72) chromosomes was observed. The occurrence of an asymmetric karyotype with a large number of acrocentric chromosomes distinguishes this species from others the Order Siluriformes. An exclusive character observed is the first pair of subtelocentric as the largest chromosome pair of the complement. NORs detected using AgNO3 were located in the terminal regions, on the short arm of a subtelocentric chromosome pair (pair 11), in a secondary constriction. C-banding revealed heterochromatic centromeric regions on several chromosomes of the complement after C-banding. This is the first cytogenetic description of this species and the first cytogenetic report on a member of the family Aspredinidae.

scholarly journals Chromosomal analyses in Megalonema platanum (Siluriformes: Pimelodidae), an endangered species from South American rivers

2011 ◽  
Vol 9 (1) ◽  
pp. 177-182 ◽  
Author(s):  
Rafael Augusto de Carvalho ◽  
Sebástian Sanchez ◽  
Ana Claudia Swarça ◽  
Alberto Sergio Fenocchio ◽  
Isabel C. Martins-Santos ◽  
...  
Keyword(s):  
Diploid Number ◽  
Secondary Constriction ◽  
Centromeric Heterochromatin ◽  
Large Chromosome ◽  
South American ◽  
Terminal Position ◽  
Chromosomal Data ◽  
First Time ◽  
Secondary Constrictions ◽  
Submetacentric Pair

This study presents chromosomal data of Megalonema platanum from rio Tibagi, Paraná, Brazil and from rio Paraná, Argentina. The diploid number was equal 54 with karyotype composition of 24m+16sm+2st+12a in both populations. The AgNOR sites were detected in the terminal position of a submetacentric pair of the two analyzed populations, coinciding with secondary constrictions on the short arm of pair 15. CMA3 and FISH with 18S rDNA probe displayed fluorescent signals that correspond to the AgNOR sites and secondary constriction. The presence of a small acrocentric supernumerary chromosome can be observed in M. platanum from rio Tibagi, with centromeric heterochromatin. Others heterochromatic blocks were evidenced in the terminal position of some chromosome and one metacentric large chromosome pair, probably the first pair, showed an interstitial heterochromatin. In the population of the rio Paraná were still observed heterochromatic blocks in both ends in some chromosomes. This work brings for the first time cytogenetic date of M. platanum, which is a very rare species in the rio Paraná basin and may be endangered.

The use of double fluorescence in situ hybridization to physically map the positions of 5S rDNA genes in relation to the chromosomal location of 18S–5.8S–26S rDNA and a C genome specific DNA sequence in the genus Avena

Genome ◽  
1996 ◽  
Vol 39 (3) ◽  
pp. 535-542 ◽  
Author(s):  
Concha Linares ◽  
Juan González ◽  
Esther Ferrer ◽  
Araceli Fominaya
Keyword(s):  
In Situ Hybridization ◽  
Dna Sequence ◽  
Diploid Species ◽  
5S Rdna ◽  
Rdna Genes ◽  
26S Rdna ◽  
A Genome ◽  
Rdna Loci ◽  
C Genome

A physical map of the locations of the 5S rDNA genes and their relative positions with respect to 18S–5.8S–26S rDNA genes and a C genome specific repetitive DNA sequence was produced for the chromosomes of diploid, tetraploid, and hexaploid oat species using in situ hybridization. The A genome diploid species showed two pairs of rDNA loci and two pairs of 5S loci located on both arms of one pair of satellited chromosomes. The C genome diploid species showed two major pairs and one minor pair of rDNA loci. One pair of subtelocentric chromosomes carried rDNA and 5S loci physically separated on the long arm. The tetraploid species (AACC genomes) arising from these diploid ancestors showed two pairs of rDNA loci and three pairs of 5S loci. Two pairs of rDNA loci and 2 pairs of 5S loci were arranged as in the A genome diploid species. The third pair of 5S loci was located on one pair of A–C translocated chromosomes using simultaneous in situ hybridization with 5S rDNA genes and a C genome specific repetitive DNA sequence. The hexaploid species (AACCDD genomes) showed three pairs of rDNA loci and six pairs of 5S loci. One pair of 5S loci was located on each of two pairs of C–A/D translocated chromosomes. Comparative studies of the physical arrangement of rDNA and 5S loci in polyploid oats and the putative A and C genome progenitor species suggests that A genome diploid species could be the donor of both A and D genomes of polyploid oats. Key words : oats, 5S rDNA genes, 18S–5.8S–26S rDNA genes, C genome specific repetitive DNA sequence, in situ hybridization, genome evolution.

Karyotype analysis of Lilium longiflorum and Lilium rubellum by chromosome banding and fluorescence in situ hybridisation

Genome ◽  
2001 ◽  
Vol 44 (5) ◽  
pp. 911-918 ◽  
Author(s):  
Ki-Byung Lim ◽  
Jannie Wennekes ◽  
J Hans de Jong ◽  
Evert Jacobsen ◽  
Jaap M van Tuyl
Keyword(s):  
In Situ Hybridisation ◽  
5S Rdna ◽  
Lilium Longiflorum ◽  
Fluorescence In Situ Hybridisation ◽  
45S Rdna ◽  
C Banding ◽  
Rdna Sequences ◽  
Rdna Signal ◽  
5S And 45S Rdna

Detailed karyotypes of Lilium longiflorum and L. rubellum were constructed on the basis of chromosome arm lengths, C-banding, AgNO3 staining, and PI-DAPI banding, together with fluorescence in situ hybridisation (FISH) with the 5S and 45S rDNA sequences as probes. The C-banding patterns that were obtained with the standard BSG technique revealed only few minor bands on heterologous positions of the L. longiflorum and L. rubellum chromosomes. FISH of the 5S and 45S rDNA probes on L. longiflorum metaphase complements showed overlapping signals at proximal positions of the short arms of chromosomes 4 and 7, a single 5S rDNA signal on the secondary constriction of chromosome 3, and one 45S rDNA signal adjacent to the 5S rDNA signal on the subdistal part of the long arm of chromosome 3. In L. rubellum, we observed co-localisation of the 5S and 45S rDNA sequences on the short arm of chromosomes 2 and 4 and on the long arms of chromosomes 2 and 3, and two adjacent bands on chromosome 12. Silver staining (Ag-NOR) of the nucleoli and NORs in L. longiflorum and L. rubellum yielded a highly variable number of signals in interphase nuclei and only a few faint silver deposits on the NORs of mitotic metaphase chromosomes. In preparations stained with PI and DAPI, we observed both red- and blue-fluorescing bands at different positions on the L. longiflorum and L. rubellum chromosomes. The red-fluorescing or so-called reverse PI-DAPI bands always coincided with rDNA sites, whereas the blue-fluorescing DAPI bands corresponded to C-bands. Based on these techniques, we could identify most of chromosomes of the L. longiflorum and L. rubellum karyotypes.Key words: fluorescence in situ hybridisation, FISH, 5S rDNA, 45S rDNA, C-banding, reverse PI-DAPI banding.

scholarly journals A cytomegalovirus DNA sequence containing tracts of tandemly repeated CA dinucleotides hybridizes to highly repetitive dispersed elements in mammalian cell genomes.

1983 ◽  
Vol 3 (8) ◽  
pp. 1389-1402 ◽  
Author(s):  
K T Jeang ◽  
G S Hayward
Keyword(s):  
Plasmid Dna ◽  
Genomic Library ◽  
Mammalian Species ◽  
5S Rdna ◽  
Rdna Genes ◽  
Left Handed ◽  
Mammalian Genomes ◽  
Genomic Dnas ◽  
Human And Mouse ◽  
Mouse Genomic

A single 880-base-pair region within the genome of simian cytomegalovirus strain Colburn contains sequences that hybridize intensely with both human and mouse total genome DNA probes. This sequence was also found in a second simian cytomegalovirus isolate and was retained in both plaque-purified virus subclones and in plasmid DNA clones containing the SalI P fragment. Cleaved genomic DNAs from several mammalian species all exhibited strong dispersed hybridization with the SalI-P probes, and over 70% of the lambda clones in a mouse genomic library plus several selected clones containing globin, 45S rDNA, or 5S rDNA genes all formed hybrids with SalI-P. The appropriate region of cytomegalovirus SalI-P contains relatively A + T-rich unique sequences interrupted by three stretches of the simple alternating dinucleotides, (CA)15, (CA)22, and (CA)21, which we show to be responsible for most of the cell-virus homology. We conclude that discrete, tandemly repeated (CA) dinucleotide tracts capable of forming left-handed Z-DNA helices punctuate mammalian genomes at greater than 10(5) copies per cell and that three adjacent copies of what appear to be a family of interspersed repetitive elements containing these (CA)n stretches are carried in the genomes of simian cytomegaloviruses.

scholarly journals Comparative cytogenetic patterns in Carangidae fishes in association with their distribution range

2021 ◽  
Vol 15 (4) ◽  
pp. 429-445
Author(s):  
Rodrigo Xavier Soares ◽  
Clóvis Coutinho da Motta Neto ◽  
Gideão Wagner Werneck Félix da Costa ◽  
Marcelo de Bello Cioffi ◽  
Luiz Antonio Carlos Bertollo ◽  
...  
Keyword(s):  
5S Rdna ◽  
Fluorochrome Staining ◽  
Western Atlantic ◽  
Migratory Capacity ◽  
The Family ◽  
Pericentric Inversions ◽  
Acrocentric Chromosomes ◽  
Predatory Fishes ◽  
Ribosomal Dnas ◽  
Large Distribution

Carangidae are an important and widespreaded family of pelagic predatory fishes that inhabit reef regions or open ocean areas, some species occupying a vast circumglobal distribution. Cytogenetic comparisons among representatives of its different tribes help to understand the process of karyotype divergence in marine ecosystems due to the variable migratory ability of species. In this sense, conventional cytogenetic investigations (Giemsa staining, Ag-NORs, and C-banding), GC base-specific fluorochrome staining and FISH mapping of ribosomal DNAs were performed. Four species, Elagatis bipinnulata (Quoy et Gaimard, 1825) and Seriola rivoliana (Valenciennes, 1883) (Naucratini), with circumtropical distributions, Gnathanodon speciosus (Forsskål, 1775) (Carangini), widely distributed in the tropical and subtropical waters of the Indian and Pacific oceans, and Trachinotus carolinus (Linnaeus, 1766) (Trachinotini), distributed along the western Atlantic Ocean, were analyzed, thus encompassing representatives of three out its four tribes. All species have diploid chromosome number 2n = 48, with karyotypes composed mainly by acrocentric chromosomes (NF = 50–56). The 18S rDNA/Ag-NORs/GC+ and 5S rDNA loci were located on chromosomes likely homeologs. Karyotypes showed a pattern considered basal for the family or with small variations in their structures, apparently due to pericentric inversions. The migratory capacity of large pelagic swimmers, in large distribution areas, likely restricts the fixation of chromosome changes in Carangidae responsible for a low level of karyotype diversification.

A cytomegalovirus DNA sequence containing tracts of tandemly repeated CA dinucleotides hybridizes to highly repetitive dispersed elements in mammalian cell genomes

1983 ◽  
Vol 3 (8) ◽  
pp. 1389-1402
Author(s):  
K T Jeang ◽  
G S Hayward
Keyword(s):  
Plasmid Dna ◽  
Genomic Library ◽  
Mammalian Species ◽  
5S Rdna ◽  
Rdna Genes ◽  
Left Handed ◽  
Mammalian Genomes ◽  
Genomic Dnas ◽  
Human And Mouse ◽  
Mouse Genomic

A single 880-base-pair region within the genome of simian cytomegalovirus strain Colburn contains sequences that hybridize intensely with both human and mouse total genome DNA probes. This sequence was also found in a second simian cytomegalovirus isolate and was retained in both plaque-purified virus subclones and in plasmid DNA clones containing the SalI P fragment. Cleaved genomic DNAs from several mammalian species all exhibited strong dispersed hybridization with the SalI-P probes, and over 70% of the lambda clones in a mouse genomic library plus several selected clones containing globin, 45S rDNA, or 5S rDNA genes all formed hybrids with SalI-P. The appropriate region of cytomegalovirus SalI-P contains relatively A + T-rich unique sequences interrupted by three stretches of the simple alternating dinucleotides, (CA)15, (CA)22, and (CA)21, which we show to be responsible for most of the cell-virus homology. We conclude that discrete, tandemly repeated (CA) dinucleotide tracts capable of forming left-handed Z-DNA helices punctuate mammalian genomes at greater than 10(5) copies per cell and that three adjacent copies of what appear to be a family of interspersed repetitive elements containing these (CA)n stretches are carried in the genomes of simian cytomegaloviruses.

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