Comparative study of G- and C-banded chromosomes of five species of Microtidae: a chromosomal evolution analysis

Genome ◽  
1988 ◽  
Vol 30 (4) ◽  
pp. 540-546 ◽  
Author(s):  
M. Burgos ◽  
R. Jiménez ◽  
R. Díaz de la Guardia
Keyword(s):  
Comparative Study ◽  
Chromosomal Evolution ◽  
Karyotypic Evolution ◽  
Banding Patterns ◽  
Robertsonian Translocations ◽  
Interspecific Differences ◽  
Evolution Analysis ◽  
Pericentric Inversions

G-banded karyotypes were compared in the following species of Microtidae: Microtus nivalis, M. cabrerae, M. arvalis, and Arvicola sapidus. Previous observations on A. sapidus and A. terrestris were also incorporated in this study. The results show that Robertsonian translocations and pericentric inversions are common mechanisms involved in the karyotypic evolution of this group. Interspecific differences on the G-banding patterns were also analysed, and an attempt was made to establish a presumptive phylogenetic tree.Key words: chromosomal evolution, Microtidae, G-bands, C-bands.

Diversity and Karyotypic Evolution in the Genus Neacomys (Rodentia, Sigmodontinae)

2015 ◽  
Vol 146 (4) ◽  
pp. 296-305 ◽  
Author(s):  
Willam O. da Silva ◽  
Julio C. Pieczarka ◽  
Rogério V. Rossi ◽  
Horacio Schneider ◽  
Iracilda Sampaio ◽  
...  
Keyword(s):  
Molecular Phylogeny ◽  
Diploid Number ◽  
Constitutive Heterochromatin ◽  
Chromosomal Evolution ◽  
The Other ◽  
Karyotypic Evolution ◽  
Drastic Reduction ◽  
Ancestral Species ◽  
Pericentric Inversions ◽  
Amazonian Region

Neacomys (Sigmodontinae) comprises 8 species mainly found in the Amazonian region. We describe 5 new karyotypes from Brazilian Amazonia: 2 cytotypes for N. paracou (2n = 56/FNa = 62-66), 1 for N. dubosti (2n = 64/FNa = 68), and 2 for Neacomys sp. (2n = 58/FNa = 64-70), with differences in the 18S rDNA. Telomeric probes did not show ITS. We provide a phylogeny using Cytb, and the analysis suggests that 2n = 56 with a high FNa is ancestral for the genus, as found in N. paracou, being retained by the ancestral forms of the other species, with an increase in 2n occurring independently in N. spinosus and N. dubosti. Alternatively, an increase in 2n may have occurred in the ancestral taxon of the other species, followed by independent 2n-reduction events in Neacomys sp. and in the ancestral species of N. tenuipes, N. guianae, N. musseri, and N. minutus. Finally, a drastic reduction event in the diploid number occurred in the ancestral species of N. musseri and N. minutus which exhibit the lowest 2n of the genus. The karyotypic variations found in both intra- and interspecific samples, associated with the molecular phylogeny, suggest a chromosomal evolution with amplification/deletion of constitutive heterochromatin and rearrangements including fusions, fissions, and pericentric inversions.

Cytogenetic studies on Sauria (Reptilia). I. Mitotic chromosomes of the Agamidae

1988 ◽  
Vol 9 (3) ◽  
pp. 301-310 ◽  
Author(s):  
E. Solleder ◽  
M. Schmid
Keyword(s):  
Chromosome Number ◽  
Chromosome Morphology ◽  
Mitotic Chromosomes ◽  
Metaphase Chromosomes ◽  
Banding Patterns ◽  
The Family ◽  
Telocentric Chromosomes ◽  
Cytogenetic Studies ◽  
Pericentric Inversions ◽  
Dna Organization

The karotypes of nine species of the family Agamidae were analyzed with various banding techniques and conventional cytogenetic stainings. Whereas the examined species of the genera Calotes and Leiolepis exhibit conservative karyotypes, the chromosome number and chromosome morphology varies considerably within the genus Agama. This is attributed to centric fusions between telocentric chromosomes and pericentric inversions within the chromosomes. None of the species demonstrated multiple quinacrine banding patterns in the euchromatic segments of the metaphase chromosomes. This is probably due to the special DNA organization in these organisms.

Chromosomal evolution in finches and their allies (families: Ploceidae, Fringillidae, and Emberizidae)

1986 ◽  
Vol 28 (5) ◽  
pp. 762-769 ◽  
Author(s):  
L. Christidis
Keyword(s):  
Chromosome Banding ◽  
Chromosomal Evolution ◽  
Inversion Polymorphism ◽  
Chromosome Change ◽  
C Banding ◽  
Pericentric Inversions

Five species of sparrows, weavers, and finches belonging to the Ploceidae, Fringillidae, and Emberizidae were examined cytogenetically by G- and C-banding. There was significant G-band homology between the families, with pericentric inversions being the principal form of chromosome change both at the intra- and inter-specific levels. In some instances there was more homology between species from different families than there was between species within a family. Possible explanations for this phenomenon are discussed.Key words: chromosome banding, inversion polymorphism, Passeriformes, Aves.

Variable conservation of nucleolus organizer regions during karyotypic evolution in Microtidae

Genome ◽  
1990 ◽  
Vol 33 (1) ◽  
pp. 119-122 ◽  
Author(s):  
A. Sánchez ◽  
M. Burgos ◽  
R. Jiménez ◽  
R. Díaz de la Guardia
Keyword(s):  
Comparative Study ◽  
Nucleolus Organizer ◽  
Chromosome Rearrangements ◽  
Karyotypic Evolution ◽  
Nucleolus Organizer Regions ◽  
The Comparative Study

The location of the nucleolus organizer regions (NORs) was studied in four species of Microtidae (Microtus nivalis, M. cabrerae, M. arvalis, and Arvicola sapidus). The comparative study of these locations shows that some NORs have been conserved despite the chromosome rearrangements that have occurred through karyotypic evolution, while others have been lost. In addition, there are many chromosomes in which NORs seem to have appeared or been lost without apparent relation to the chromosome rearrangements. Some hypotheses regarding these facts are discussed in the text.Key words: nucleolus organizer regions, Microtidae, karyotypic evolution.

scholarly journals Cytogenetic analyses in Trinomys (Echimyidae, Rodentia), with description of new karyotypes

PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e5316 ◽  
Author(s):  
Naiara Pereira Araújo ◽  
Cayo Augusto Rocha Dias ◽  
Rodolfo Stumpp ◽  
Marta Svartman
Keyword(s):  
Chromosome Mapping ◽  
Nucleolar Organizer ◽  
Interspecific Variation ◽  
Nucleolar Organizer Regions ◽  
45S Rdna ◽  
Banding Patterns ◽  
Pericentric Inversions ◽  
Cytogenetic Analyses ◽  
First Time

Trinomys Thomas (1921) is a terrestrial genus of spiny rats endemic to the Brazilian areas of Atlantic Forest and the transitional areas of Cerrado and Caatinga. Although most species have been already karyotyped, the available cytogenetic information is mostly restricted to diploid and fundamental numbers. We analyzed the chromosomes of two Trinomys species: Trinomys moojeni (2n = 56, FN = 106) and Trinomys setosus setosus (2n = 56, FN = 106 and 2n = 56, FN = 108). Our analyses included GTG- and CBG-banding, silver-staining of the nucleolar organizer regions, and chromosome mapping of telomeres and 45S rDNA by fluorescent in situ hybridization (FISH). Comparative GTG- and CBG-banding suggested that the interspecific variation may be due to rearrangements such as pericentric inversions, centromere repositioning, and heterochromatin variation. We report two new karyotypes for T. s. setosus and describe for the first time the banding patterns of the two Trinomys species.

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.

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