Molecular Cytogenetic Analysis of Cucumis Wild Species Distributed in Southern Africa: Physical Mapping of 5S and 45S rDNA with DAPI

2015 ◽  
Vol 146 (1) ◽  
pp. 80-87 ◽  
Author(s):  
Kouhei Yagi ◽  
Magdalena Pawełkowicz ◽  
Paweł Osipowski ◽  
Ewa Siedlecka ◽  
Zbigniew Przybecki ◽  
...  
Keyword(s):  
Cytogenetic Analysis ◽  
Chromosomal Rearrangements ◽  
Evolutionary Relationship ◽  
Chromosomal Evolution ◽  
Rdna Site ◽  
45S Rdna ◽  
Polyploid Evolution ◽  
Molecular Cytogenetic ◽  
Rdna Sites ◽  
Cucumis Species

Wild Cucumis species have been divided into Australian/Asian and African groups using morphological and phylogenetic characteristics, and new species have been described recently. No molecular cytogenetic information is available for most of these species. The crossability between 5 southern African Cucumis species (C. africanus, C. anguria, C. myriocarpus, C. zeyheri, and C. heptadactylus) has been reported; however, the evolutionary relationship among them is still unclear. Here, a molecular cytogenetic analysis using FISH with 5S and 45S ribosomal DNA (rDNA) was used to investigate these Cucumis species based on sets of rDNA-bearing chromosomes (rch) types I, II and III. The molecular cytogenetic and phylogenetic results suggested that at least 2 steps of chromosomal rearrangements may have occurred during the evolution of tetraploid C. heptadactylus. In step 1, an additional 45S rDNA site was observed in the chromosome (type III). In particular, C. myriocarpus had a variety of rch sets. Our results suggest that chromosomal rearrangements may have occurred in the 45S rDNA sites. We propose that polyploid evolution occurred in step 2. This study provides insights into the chromosomal characteristics of African Cucumis species and contributes to the understanding of chromosomal evolution in this genus.

scholarly journals Distribution of GC-rich heterochromatin and ribosomal genes in three fungus-farming ants (Myrmicinae, Attini, Attina): insights on chromosomal evolution

2021 ◽  
Vol 15 (4) ◽  
pp. 413-428
Author(s):  
Gisele Amaro Teixeira ◽  
Luísa Antônia Campos Barros ◽  
Hilton Jeferson Alves Cardoso de Aguiar ◽  
Denilce Meneses Lopes
Keyword(s):  
Chromosomal Rearrangements ◽  
Taxonomic Revision ◽  
Chromosomal Evolution ◽  
Ribosomal Genes ◽  
Common Origin ◽  
Rdna Site ◽  
Rdna Genes ◽  
Molecular Cytogenetic ◽  
Cytogenetic Data ◽  
Molecular Cytogenetic Techniques

Cytogenetic studies on fungus-farming ants have shown remarkable karyotype diversity, suggesting different chromosomal rearrangements involved in karyotype evolution in some genera. A notable cytogenetic characteristic in this ant group is the presence of GC-rich heterochromatin in the karyotypes of some ancient and derivative species. It was hypothesized that this GC-rich heterochromatin may have a common origin in fungus-farming ants, and the increase in species studied is important for understanding this question. In addition, many genera within the subtribe Attina have few or no cytogenetically studied species; therefore, the processes that shaped their chromosomal evolution remain obscure. Thus, in this study, we karyotyped, through classical and molecular cytogenetic techniques, the fungus-farming ants Cyphomyrmex transversus Emery, 1894, Sericomyrmex maravalhas Ješovnik et Schultz, 2017, and Mycetomoellerius relictus (Borgmeier, 1934), to provide insights into the chromosomal evolution in these genera and to investigate the presence the GC-rich heterochromatin in these species. Cyphomyrmex transversus (2n = 18, 10m + 2sm + 6a) and S. maravalhas (2n = 48, 28m + 20sm) showed karyotypes distinct from other species from their genera. Mycetomoellerius relictus (2n = 20, 20m) presented the same karyotype as the colonies previously studied. Notably, C. transversus presented the lowest chromosomal number for the genus and a distinct karyotype from the other two previously observed for this species, showing the existence of a possible species complex and the need for its taxonomic revision. Chromosomal banding data revealed GC-rich heterochromatin in all three species, which increased the number of genera with this characteristic, supporting the hypothesis of a common origin of GC-rich heterochromatin in Attina. Although a single chromosomal pair carries rDNA genes in all studied species, the positions of these rDNA clusters varied. The rDNA genes were located in the intrachromosomal region in C. transversus and M. relictus, and in the terminal region of S. maravalhas. The combination of our molecular cytogenetic data and observations from previous studies corroborates that a single rDNA site located in the intrachromosomal region is a plesiomorphic condition in Attina. In addition, cytogenetic data obtained suggest centric fission events in Sericomyrmex Mayr, 1865, and the occurrence of inversions as the origin of the location of the ribosomal genes in M. relictus and S. maravalhas. This study provides new insights into the chromosomal evolution of fungus-farming ants.

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.

scholarly journals Comparative cytogenetic analyses in Ancistrus species (Siluriformes: Loricariidae)

2020 ◽  
Vol 18 (2) ◽  
Author(s):  
Larissa Glugoski ◽  
Geize Deon ◽  
Stephane Schott ◽  
Marcelo R. Vicari ◽  
Viviane Nogaroto ◽  
...  
Keyword(s):  
Chromosomal Rearrangements ◽  
5S Rdna ◽  
Chromosomal Evolution ◽  
Sister Group ◽  
Fusion Event ◽  
Rdna Cluster ◽  
Strand Breaks ◽  
Rdna Sites ◽  
Cytogenetic Analyses ◽  
Ribosomal Dnas

ABSTRACT Ancistrus is a specious genus of armored catfishes that has been extensively used for cytogenetic studies in the last 17 years. A comparison of the extensive karyotypic plasticity within this genus is presented with new cytogenetic analysis for Ancistrus cf. multispinis and Ancistrus aguaboensis. This study aims to improve our understanding of chromosomal evolution associated with changes in the diploid number (2n) and the dispersion of ribosomal DNAs (rDNAs) within Ancistrus. Ancistrus cf. multispinis and A. aguaboensis exhibit 2n of 52 and 50 chromosomes, respectively. Given that A. cf. multispinis shares a 2n = 52 also found in Pterygoplichthyini, the sister group for Ancistrini, a Robertsonian (Rb) fusion event is proposed for the 2n reduction in A. aguaboensis. 5S rDNAs pseudogenes sites have already been associated with Rb fusion in Ancistrus and our analysis suggests that the 2n reduction in A. aguaboensis was triggered by double strand breaks (DSBs) and chromosomal rearrangements at 5S rDNA sites. The presence of evolutionary breakpoint regions (EBRs) into rDNA cluster is proposed to explain part of the Rb fusion in Ancistrus. Cytogenetic data presented extends the diversity already documented in Ancistrus to further understand the role of chromosomal rearrangements in the diversification of Ancistrini.

Chromosomal Mapping of Repeat DNA in Bergiaria westermanni (Pimelodidae, Siluriformes): Localization of 45S rDNA in B Chromosomes

2018 ◽  
Vol 154 (2) ◽  
pp. 99-106 ◽  
Author(s):  
Geovana C. Malimpensa ◽  
Josiane B. Traldi ◽  
Danyelle Toyama ◽  
Flávio Henrique-Silva ◽  
Marcelo R. Vicari ◽  
...  
Keyword(s):  
Chromosomal Rearrangements ◽  
Indirect Evidence ◽  
5S Rdna ◽  
B Chromosomes ◽  
Chromosomal Mapping ◽  
Interindividual Variation ◽  
Rrna Genes ◽  
45S Rdna ◽  
Rdna Sites ◽  
Repeat Dna

The occurrence of repetitive DNA in autosomes and B chromosomes of Bergiaria westermanni was examined using conventional and molecular cytogenetic techniques. This species exhibited 2n = 56 chromosomes, with intra- and interindividual variation in the number of heterochromatic B chromosomes (from 0 to 4). The 5S rDNA was localized in pairs 1 and 5, and histone probes (H1, H3, and H4) and U2 small nuclear RNA were syntenic with 5S rDNA in pair 5. Histone sequences were also located in chromosome pair 14. The (GATA)n sequence was dispersed throughout the autosomes and B chromosomes, with clusters (microsatellite accumulation) in some chromosome regions. The telomeric probe revealed no signs of chromosomal rearrangements in the genome of B. westermanni. The 45S rDNA sites were detected in the terminal region of pair 27; these sites corresponded to a GC-rich heterochromatin block. In addition, 3 of the 4 B chromosomes also contained 45S rDNA copies. Silver nitrate staining in interphase nuclei provided indirect evidence of the expression of these rRNA genes in B chromosomes, indicating the probable origin of these elements. This report shows plasticity in the chromosomal localization of repeat DNA in B. westermanni and features a discussion of genomic diversification.

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.

Cytogenetic analysis of two Coprophanaeus species (Scarabaeidae) revealing wide constitutive heterochromatin variability and the largest number of 45S rDNA sites among Coleoptera

Micron ◽  
2010 ◽  
Vol 41 (8) ◽  
pp. 960-965 ◽  
Author(s):  
Sárah Gomes de Oliveira ◽  
Rita de Cássia de Moura ◽  
Ana Emília Barros e Silva ◽  
Maria José de Souza
Keyword(s):  
Cytogenetic Analysis ◽  
Constitutive Heterochromatin ◽  
45S Rdna ◽  
Rdna Sites

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.

The molecular–cytogenetic analysis of grasses and its application to studying relationships among species of the Triticeae

Genome ◽  
1989 ◽  
Vol 31 (1) ◽  
pp. 122-133 ◽  
Author(s):  
R. Appels ◽  
P. Reddy ◽  
C. L. McIntyre ◽  
L. B. Moran ◽  
O. H. Frankel ◽  
...  
Keyword(s):  
Cytogenetic Analysis ◽  
Sequence Data ◽  
Evolutionary Relationship ◽  
Repeated Sequence ◽  
Time Span ◽  
Distribution Data ◽  
Molecular Cytogenetic ◽  
Dna Sequence Data ◽  
5S Dna ◽  
Close Relationship

An analysis of four species from the genus Secale, including the study of different accessions, has shown that the properties of DNA clones of monomer units from three repeated sequence loci, namely, Ter, Nor, and 5S DNA, proved to be representative of the entire loci from which they were isolated. This finding in Secale species, including the discovery of a new locus for 5S DNA on chromosome 5R, has been used to interpret information on the Ter, Nor, and 5S DNA loci from 15 species in the Triticeae complex. The evolutionary relationship among species suggested by the DNA sequence data has shown many consistencies with a number of other characters such as those used in classical systematics, as well as geographical distribution data and isozyme and chromosome-pairing studies. Apparent inconsistencies such as a close relationship between the R and P genomes at the Ter loci are interpreted in terms of amplification–deletion phenomena known to occur at repetitive sequence loci. In addition, this study included species endemic to Australia and thus provided a broad time span in which to consider some features of repeated sequence family evolution, such as the conservation of certain parts of 5S DNA spacer regions.Key words: Secale, Triticeae, molecular–cytogenetic analysis.

scholarly journals Comparative molecular cytogenetic characterization of five wild Vigna species (Fabaceae)

2020 ◽  
Vol 14 (2) ◽  
pp. 243-264
Author(s):  
Chao-Wen She ◽  
Ying Mao ◽  
Xiang-Hui Jiang ◽  
Chun-Ping He
Keyword(s):  
Genomic Dna ◽  
Interspecific Variation ◽  
Rrna Genes ◽  
Fluorochrome Banding ◽  
45S Rdna ◽  
Molecular Cytogenetic ◽  
Rdna Sites ◽  
Cytogenetic Characterization ◽  
Rdna Fish

To extend our knowledge on karyotype variation of the genus Vigna Savi, 1824, the chromosomal organization of rRNA genes and fluorochrome banding patterns of five wild Vigna species were studied. Sequential combined PI (propidium iodide) and DAPI (4',6-diamidino-2-phenylindole) (CPD) staining and fluorescence in situ hybridization (FISH) with 5S and 45S rDNA probes were used to analyze the karyotypes of V. luteola (Jacquin, 1771) Bentham, 1959, V. vexillata (Linnaeus, 1753) A. Richard, 1845, V. minima (Roxburgh, 1832) Ohwi & H. Ohashi, 1969, V. trilobata (Linnaeus, 1753) Verdcourt, 1968, and V. caracalla (Linnaeus, 1753) Verdcourt,1970. For further phylogenetic analysis, genomic in situ hybridization (GISH) with the genomic DNA of V. umbellata (Thunberg, 1794) Ohwi & H.Ohashi, 1969 onto the chromosomes of five wild Vigna species was also performed. Detailed karyotypes were established for the first time using chromosome measurements, fluorochrome bands, and rDNA-FISH signals. All species had chromosome number 2n = 2x = 22, and symmetrical karyotypes that composed of only metacentric or metacentric and submetacentric chromosomes. CPD staining revealed all 45S rDNA sites in the five species analyzed, (peri)centromeric GC-rich heterochromatin in V. luteola, V. trilobata and V. caracalla, interstitial GC-rich and pericentromeric AT-rich heterochromatin in V. caracalla. rDNA-FISH revealed two 5S loci in V. caracalla and one 5S locus in the other four species; one 45S locus in V. luteola and V. caracalla, two 45S loci in V. vexillata and V. trilobata, and five 45S loci in V. minima. The karyotypes of the studied species could be clearly distinguished by the karyotypic parameters, and the patterns of the fluorochrome bands and the rDNA sites, which revealed high interspecific variation among the five species. The V. umbellata genomic DNA probe produced weak signals in all proximal regions of V. luteola and all (peri)centromeric regions of V. trilobata. The combined data demonstrate that distinct genome differentiation has occurred among the five species during evolution. The phylogenetic relationships between the five wild species and related cultivated species of Vigna are discussed based on our present and previous molecular cytogenetic data.

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