Cytogenetics of Four Species of the Green Clade Aplastodiscus Lutz, 1950 (Anura: Cophomantinae): New Insights into the Chromosomal Evolution of the Genus

2021 ◽  
pp. 1-7
Author(s):  
Késsia L. Souza ◽  
Marco A. Peixoto ◽  
Cynthia A.V. Barreto ◽  
Renato N. Feio ◽  
Jorge A. Dergam
Keyword(s):  
18S Rdna ◽  
Chromosome Pair ◽  
Chromosomal Evolution ◽  
Chromosome Morphology ◽  
Small Chromosome ◽  
Tree Frog ◽  
Chromosome Fusion ◽  
Clade B ◽  
Number Variation ◽  
Molecular Cytogenetic Techniques

The tree frog <i>Aplastodiscus</i> is a Neotropical taxon that encompasses 15 species in the Atlantic forest biome, with one isolated species in the Central Brazilian Cerrado. To date, only 8 species have been karyotyped, showing high levels of diploid number variation, which allowed clustering species in chromosome number groups: 2n = 24 (<i>Aplastodiscus perviridis</i> group), 2n = 22 (<i>Aplastodiscus albofrenatus</i> group), 2n = 20, and 2n = 18 (both within <i>Aplastodiscus albosignatus</i> group). This study aims to report karyotypic information on 4 species from the last 2 groups using classical and molecular cytogenetic techniques and hypothesize chromosomal evolutionary trends within the species groups. <i>Aplastodiscus weygoldti</i> showed 2n = 22; Ag-NOR and FISH 18S rDNA signals were located in the interstitial region of the short arms of chromosome pair 6. <i>Aplastodiscus cavicola, Aplastodiscus</i> sp. 4, and <i>Aplastodiscus</i> sp. 6 showed 2n = 18; Ag-NOR and FISH 18S rDNA bands were located in the terminal region of the long arm of chromosome pair 9. Our results support multiple and independent chromosome fusion events within <i>Aplastodiscus</i>, including a new chromosome fission event<i>.</i> Ag-NOR and FISH 18S rDNA patterns were restricted to the small chromosome pairs, similar to the other species within this genus, and confirm overall chromosome morphology conservation among the genera of Cophomantinae.

Revised karyotypes and chromosome banding of coregonid fishes from the Laurentian Great Lakes

1996 ◽  
Vol 74 (2) ◽  
pp. 323-329 ◽  
Author(s):  
Ruth B. Phillips ◽  
Kent M. Reed ◽  
Petr Ráb
Keyword(s):  
Great Lakes ◽  
Chromosome Pair ◽  
Acrocentric Chromosome ◽  
Chromosome Morphology ◽  
Coregonus Clupeaformis ◽  
Lake Whitefish ◽  
Chromosome Fusion ◽  
C Banding ◽  
The Difference ◽  
Submetacentric Pair

Karyotypes of lake whitefish, Coregonus clupeaformis, and various Great Lakes cisco species, lake herring or cisco, C. artedi, bloater, C. hoyi, blackfin cisco, C. nigripinnis, and shortjaw cisco, C. zenithicus, were analyzed using Giemsa staining, C-banding, silver staining, and Chromomycin A3 fluorescence. Coregonus clupeaformis had a karyotype (2n = 80, NF = 98) indistinguishable from that described for C. laveretus from Europe, with one pair of nuclear organizer regions (NORs) on the short arms of a small acrocentric chromosome pair and a second NOR on the short arms of another acrocentric chromosome pair. This species displayed a size polymorphism involving the heterochromatic short arm of the largest metacentric–submetacentric pair. All four cisco species had similar karyotypes (2n = 80, NF = 98), with the exception of some C. artedi from Lake Superior, which were heterozygous for a chromosome fusion involving the NOR chromosomes (2n = 79). One NOR was located pericentromerically on the long arm of the second largest acrocentric chromosome and a second NOR on the short arms of another acrocentric chromosome pair in several individuals. C-banding revealed that the difference in chromosome morphology between lake whitefish and the ciscoes probably resulted from amplification of heterochromatin on the short arms of one pair of large submetacentric–metacentric chromosomes.

scholarly journals Rapid chromosomal evolution in the bush-cricket Gonatoxia helleri Hemp, 2016 (Orthoptera, Phaneropterinae)

2020 ◽  
Vol 14 (3) ◽  
pp. 417-435 ◽  
Author(s):  
Elżbieta Warchałowska-Śliwa ◽  
Beata Grzywacz ◽  
Anna Maryańska-Nadachowska ◽  
Klaus-Gerhard Heller ◽  
Claudia Hemp
Keyword(s):  
Chromosome Number ◽  
18S Rdna ◽  
Chromosomal Polymorphism ◽  
Chromosomal Evolution ◽  
Chromosome Morphology ◽  
Telomeric Sequences ◽  
C Banding ◽  
Interstitial Telomeric Sequences ◽  
Rdna Loci ◽  
Bush Crickets

Gonatoxia helleri Hemp, 2016 is one of the most widespread bush-crickets of the genus Gonatoxia Karsch, 1889 in East Africa. This species with seven large chromosomes (2n♂ = 7) differs from other representatives of the genus Gonatoxia drastically by its reduced chromosome number, the asymmetrical karyotype including karyomorphs rarely found in tettigoniids, as well as in irregularities in the course of meiosis. To better understand the origin of such an exceptional karyotype, chromosomes of 29 specimens from four populations/localities were studied using classical techniques, such as C-banding, silver impregnation, fluorochrome double staining and fluorescence in situ hybridization (FISH) technique with 18S rDNA and (TTAGG)n telomeric probes. FISH showed many 18S rDNA loci as well as interstitial telomeric sequences, where chromosome morphology varied in these components in terms of quantity and distribution. The 18S rDNA loci coincided with active NORs and C-banding patterns. We suggest that a combination of Robertsonian rearrangements and/or multiple common tandem fusions involving the same chromosomes contributed to the formation of this karyotype/karyomorphs. The results are the first step towards a better understanding of chromosomal reorganization and evolution within the genus Gonatoxia. Low chromosome number, together with the incidence of chromosomal polymorphism that is higher in G. helleri than previously reported in bush-crickets, implies that this species can be a valuable new model for cytogenetic and speciation studies. Our findings suggest that chromosomal translocations lead to diversification and speciation in this species and could be the driving force of adaptive radiation.

scholarly journals Chromosome Evolution in the Genus Partamona (Apidae: Meliponini), with Comments on B Chromosome Origin

2021 ◽  
pp. 1-9
Author(s):  
Camila M. Novaes ◽  
Marina S. Cunha ◽  
Hugo A. Werneck ◽  
Anderson Fernandes ◽  
Lucio A.O. Campos ◽  
...  
Keyword(s):  
Molecular Mapping ◽  
Phylogenetic Reconstruction ◽  
Chromosomal Evolution ◽  
B Chromosome ◽  
Chromosome Morphology ◽  
B Chromosomes ◽  
Cytogenetic Data ◽  
Clade B ◽  
Molecular Phylogenetic ◽  
Cytogenetic Analyses

The genus <i>Partamona</i> includes 33 species of stingless bees, of which 11 were studied cytogenetically. The main goal of this study was to propose a hypothesis about chromosomal evolution in <i>Partamona</i> by combining molecular and cytogenetic data. Cytogenetic analyses were performed on 3 <i>Partamona</i> species. In addition, the molecular phylogeny included mitochondrial sequences of 11 species. Although the diploid number was constant within the genus, 2n = 34, B chromosomes were reported in 7 species. Cytogenetic data showed karyotypic variations related to chromosome morphology and the amount and distribution of heterochromatin and repetitive DNA. The molecular phylogenetic reconstruction corroborated the monophyly of the genus and separated the 2 clades (A and B). This separation was also observed in the cytogenetic data, in which species within each clade shared most of the cytogenetic characteristics. Furthermore, our data suggested that the B chromosome in the genus <i>Partamona</i> likely originated from a common ancestor of the species that have it in clade B and, through interspecific hybridization, it appeared only in <i>Partamona rustica</i> from clade A. Based on the above, <i>Partamona</i> is an interesting genus for further investigations using molecular mapping of B chromosomes as well as for broadening phylogenetic data.

Karyological study in fifteen Leucocoryne taxa (Alliaceae)

Biologia ◽  
2012 ◽  
Vol 67 (2) ◽  
Author(s):  
Paola Jara-Arancio ◽  
Pedro Jara-Seguel ◽  
Claudio Palma-Rojas ◽  
Gina Arancio ◽  
Raul Moreno
Keyword(s):  
Chromosome Number ◽  
Secondary Constriction ◽  
Chromosome Morphology ◽  
Chromosome Size ◽  
Chromosome Fusion ◽  
Karyological Study ◽  
Karyotype Asymmetry ◽  
Additional Chromosome ◽  
Karyotype Formula ◽  
Haploid Karyotype

AbstractThe karyotype of fifteen Leucocoryne taxa was studied, assessing characteristics such as chromosome morphology and size, secondary constriction location, and asymmetry level. Two groups of Leucocoryne taxa were described based on chromosome number (2n = 10 and 2n = 18) and karyotype asymmetry. The haploid karyotype formula for the group 2n = 10 was 3m + 2st (or 2t), whereas for the group 2n = 18 was 7m + 2st (or 2t). Such results corroborate the karyotype descriptions previously carried out for some taxa of the genus. Leucocoryne taxa showed a high resemblance in chromosome morphology, but inter-specific differences were found in mean chromosome size. These data and previous studies based on gross chromosome morphology support Crosa’s hypothesis, which suggests that the cytotype 2n = 10 is diploid and perhaps ancestral, whereas that the cytotype 2n = 18 is tetraploid but with an additional chromosome fusion being probably a derived status.

Distribution of Telomeric Sequences (TTAGGG)n in Rearranged Chromosomes of Phyllotine Rodents (Cricetidae, Sigmodontinae)

2015 ◽  
Vol 147 (4) ◽  
pp. 247-252 ◽  
Author(s):  
Cecilia Lanzone ◽  
Carolina Labaroni ◽  
Natalia Suárez ◽  
Daniela Rodríguez ◽  
Macarena L. Herrera ◽  
...  
Keyword(s):  
Sex Chromosomes ◽  
Chromosomal Evolution ◽  
Robertsonian Translocations ◽  
Telomeric Sequences ◽  
Molecular Cytogenetic ◽  
Interstitial Telomeric Sequences ◽  
Robertsonian Rearrangements ◽  
Recent Origin ◽  
Chromosome Fusions ◽  
Molecular Cytogenetic Techniques

Phyllotines are sigmodontine rodents endemic to South America with broad genetic variability, Robertsonian polymorphisms being the most frequent. Moreover, this taxon includes a species with multiple sex chromosomes, which is infrequent in mammals. However, molecular cytogenetic techniques have never been applied to phyllotines to elucidate their karyotypic evolution. We studied the chromosomes of 4 phyllotine species using FISH with a pantelomeric probe (TTAGGG)n. Graomys griseoflavus, Eligmodontia puerulus, and E. morgani are polymorphic for Robertsonian translocations, whereas Salinomys delicatus possesses XX/ XY1Y2 sex chromosomes. Telomeric signals were detected at both ends of all chromosomes of the studied species. In S. delicatus interstitial telomeric sequences (ITS) were observed in the 3 major chromosome pairs, which are equidistant from one of the telomeres in these chromosomes. These results suggest that ITS are important in the reshuffling of the highly derived karyotype of S. delicatus. Considering the phylogeny of phyllotines, the Robertsonian rearrangements of G. griseoflavus, E. puerulus, and E. morgani possibly represent chromosome fusions which have occurred independently. The pericentromeric regions of the biarmed chromosomes of these species do not contain telomeric sequences characteristic for strict fusions of recent origin, suggesting a common pattern of telomeric repeat loss during chromosomal evolution of these rodents.

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 Chromosome spreading of the (TTAGGG)n repeats in the Pipa carvalhoi Miranda-Ribeiro, 1937 (Pipidae, Anura) karyotype

2019 ◽  
Vol 13 (3) ◽  
pp. 297-309 ◽  
Author(s):  
Michelle Louise Zattera ◽  
Luana Lima ◽  
Iraine Duarte ◽  
Deborah Yasmin de Sousa ◽  
Olívia Gabriela dos Santos Araújo ◽  
...  
Keyword(s):  
Chromosome Pair ◽  
Diploid Number ◽  
Centromeric Region ◽  
Chromosomal Evolution ◽  
Unique Combination ◽  
Significant Component ◽  
Aquatic Life ◽  
Telomeric Sequences ◽  
Interstitial Telomeric Sequences ◽  
Chromosome Spreading

Pipidae is a clade of Anura that diverged relatively early from other frogs in the phylogeny of the group. Pipids have a unique combination of morphological features, some of which appear to represent a mix of adaptations to aquatic life and plesiomorphic characters of Anura. The present study describes the karyotype of Pipa carvalhoi Miranda-Ribeiro, 1937, including morphology, heterochromatin distribution, and location of the NOR site. The diploid number of P. carvalhoi is 2n=20, including three metacentric pairs (1, 4, 8), two submetacentric (2 and 7), three subtelocentric (3, 5, 6), and two telocentric pairs (9 and 10). C-banding detected centromeric blocks of heterochromatin in all chromosome pairs and the NOR detected in chromosome pair 9, as confirmed by FISH using the rDNA 28S probe. The telomeric probes indicated the presence of interstitial telomeric sequences (ITSs), primarily in the centromeric region of the chromosomes, frequently associated with heterochromatin, suggesting that these repeats are a significant component of this region. The findings of the present study provide important insights for the understanding of the mechanisms of chromosomal evolution in the genus Pipa, and the diversification of the Pipidae as a whole.

scholarly journals A study of constitutive heterochromatin and NOR banding in three species of Indian major carps from the State of Haryana, India

2018 ◽  
Vol 10 (2) ◽  
pp. 535-539 ◽  
Author(s):  
Neeru Neeru ◽  
Anita Bhatnagar ◽  
Abhay Singh Yadav
Keyword(s):  
Chromosome Pair ◽  
Constitutive Heterochromatin ◽  
Organizer Region ◽  
Nucleolus Organizer Region ◽  
Chromosomal Evolution ◽  
Nucleolus Organizer ◽  
Catla Catla ◽  
Indian Major Carps ◽  
Cytogenetic Survey ◽  
Pair Number

Cytogenetic survey of fishes becomes increasingly important to establish chromosomal relation between the teleosts, to have a glimpse of the relation between chromosomal evolution and differentiation of vertebrate species. In the present study, Chromosome banding studies was done in three species of carps i.e. Catla catla (Hamilton, 1822), Labeo rohita (Hamilton, 1822) and Cirrhinus mrigala (Hamilton, 1822). Diploid chromosome number 50 was observed in all 3 species of carps. The chromosomes of C. catla, L. rohita and C. mrigala showed constitutive heterochromatin at telomeric and centromeric regions of chromosomes. The Ag-NOR (Argyrophilic-Nucleolus Organizer Region) bands were observed on homologous chromosome pair number 11 in C. catla, 15th chromosome pair in L. rohita. In C. mrigala, the Ag- NOR staining elucidated the presence of darkly stained NORs on the terminal region of the long arms of one of the chromosome. Another homologue of this chromosome pair could not be localized due to scattering of chromosomes. The results depict that variation in ecological conditions with time due to human activities can not only affect the chromosomal number but also chromosomal morphology.  

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.

Chromosomal characterization in native populations of Elymus scabrifolius from Argentina through classical and molecular cytogenetics (FISH–GISH)

Genome ◽  
2012 ◽  
Vol 55 (8) ◽  
pp. 591-598 ◽  
Author(s):  
P.A. Tomas ◽  
G.E. González ◽  
G.E. Schrauf ◽  
L. Poggio
Keyword(s):  
In Situ Hybridization ◽  
Chromosome Pair ◽  
Molecular Cytogenetics ◽  
Chromosome Morphology ◽  
Genomic In Situ Hybridization ◽  
Dapi Staining ◽  
Accurate Identification ◽  
Native Populations ◽  
Strong Hybridization

The karyotype of Elymus scabrifolius (Döll) J.H. Hunz. (2n = 4x = 28) was investigated by DAPI staining and in situ hybridization. All the accessions studied presented a symmetric and uniform karyotype constituted by 9m+2m–sm+3sm. DAPI stain showed 1–7 conspicuous bands in all the chromosomes and polymorphisms between accessions. FISH experiments carried out with 45S rDNA as probe (pTa71) showed strong hybridization signals on the metacentric SAT-chromosome pair 8; the submetacentric SAT-chromosome pair 13 presented weaker hybridization. FISH using pSc119.2 clone as probe identified five chromosome pairs. Then, the combination of chromosome morphology, DAPI-staining, and FISH enabled the accurate identification of each chromosome pair in E. scabrifolius. Genomic in situ hybridization (GISH) experiments using Hordeum DNA as probe on mitotic metaphases confirmed unequivocally the presence of the H genome in E. scabrifolius, allowing us to observe six uniformly labeled chromosome pairs and two chromosome pairs with only one arm labeled. The remaining six chromosome pairs were weakly labeled. The rehybridization of FISH slides with Hordeum DNA as probe allow us to assign the genomic provenance of most of the chromosomes in the studied accessions. Moreover, intergenomic rearrangement was detected between genome H and the still unknown progenitor genome.

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