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.

scholarly journals Xenopus Cytogenetics and Chromosomal Evolution

2015 ◽  
Vol 145 (3-4) ◽  
pp. 192-200 ◽  
Author(s):  
Vladimir Krylov ◽  
Tereza Tlapakova
Keyword(s):  
Developmental Biology ◽  
Genetic Linkage ◽  
Chromosome Banding ◽  
Chromosomal Evolution ◽  
Model Organisms ◽  
Gene Localization ◽  
Physical Maps ◽  
Gene Position ◽  
Tightly Coupled

The genus Xenopus represents important model organisms in the field of developmental biology and chromosomal evolution. Developmental processes are tightly coupled with the analysis of gene function via genetic linkage and mapping. Cytogenetic techniques such as chromosome banding or FISH are essential tools for the determination of gene position and subsequently for the construction of linkage and physical maps. Here, we present a summary of key achievements in X. tropicalis and X. laevis cytogenetics with emphasis on the gene localization to chromosomes. The second part of this review is focused on the chromosomal evolution regarding both above-mentioned species. With respect to methodology, hybridization techniques such as FISH and chromosome-specific painting FISH are highlighted.

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.

Rye C-banding patterns and meiotic stability of hexaploid triticale (× Triticosecale) selections differing in kernel shriveling

Genome ◽  
1990 ◽  
Vol 33 (5) ◽  
pp. 686-689 ◽  
Author(s):  
Charles M. Papa ◽  
R. Morris ◽  
J. W. Schmidt
Keyword(s):  
Secale Cereale ◽  
Chromosome Banding ◽  
Agronomic Performance ◽  
Hexaploid Triticale ◽  
Kernel Development ◽  
Banding Patterns ◽  
C Banding ◽  
Meiotic Stability ◽  
Metaphase I

Two winter hexaploid triticale populations derived from the same cross were selected on the basis of grain appearance and agronomic performance. The five lines from 84LT402 showed more kernel shriveling than the four lines from 84LT401. The derived lines were analyzed for aneuploid frequencies, rye chromosome banding patterns, and meiotic stability to detect associations with kernel development. The aneuploid frequencies were 16% in 84LT401 and 18% in 84LT402. C-banding showed that both selection groups had all the rye chromosomes except 2R. The two groups had similar telomeric patterns but differed in the long-arm interstitial patterns of 4R and 5R. Compared with lines from 84LT402, those from 84LT401 had significantly fewer univalents and rod bivalents, and more paired arms at metaphase I; fewer laggards and bridges at anaphase I; and a higher frequency of normal tetrads. There were no significant differences among lines within each group for any meiotic character. Since there were no differences within or between groups in telomeric banding patterns, the differences in kernel shriveling and meiotic stability might be due to genotypic factors and (or) differences in the interstitial patterns of 4R and 5R. By selecting plump grains, lines with improved kernel characteristics along with improved meiotic stability are obtainable.Key words: triticale, meiotic stability, C-banding, Secale cereale, heterochromatin.

Karyotype, C-banding, and Ag-NOR analysis in Diplodus bellottii (Sparidae, Perciforms). Intra-individual polymorphism involving heterochromatic regions

Genome ◽  
1993 ◽  
Vol 36 (4) ◽  
pp. 672-675 ◽  
Author(s):  
A. Amores ◽  
G. Martinez ◽  
J. Reina ◽  
M. C. Alvarez
Keyword(s):  
Karyotype Evolution ◽  
Karyotype Analysis ◽  
Centric Fusion ◽  
Active Regions ◽  
Chromosome Polymorphism ◽  
Terminal Position ◽  
C Banding ◽  
Metacentric Pair ◽  
Pericentric Inversions ◽  
Nucleolus Organizers

A karyotype analysis was carried out in nine specimens of the Sparid species Diplodus bellottii using conventional staining, as well as C-banding and Ag-NOR banding techniques, showing, respectively, 2n = 46 and fundamental number (FN) = 54, and scarce heterochromatic areas irregularly distributed and up to four NOR active regions that were C positive. When compared with the karyotypes of other related species, one centric fusion giving rise to a large metacentric pair and several pericentric inversions seem to have been involved in the karyotype evolution. An intra-individual polymorphism was detected in one specimen, resulting in two karyotypic forms in roughly identical proportion, owing to a larger C-band by the NOR regions, appearing either in a terminal position of the short arms of pair 2 or in telomeric position of pair 3. These findings suggest that the extra heterochromatic segment responsible for the heteromorphism apparently only involves associated heterochromatin and not the NORs themselves. This C-positive block seems to have eventually been transferred between heterologous NOR chromosomes by a somatic event, facilitated by the physical proximity of NOR pairs in the nucleolus.Key words: Sparidae, karyotype, heterochromatin, nucleolus organizers, chromosome polymorphism.

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.

Role of heterochromatin during preferential 9q;22q translocation in chronic myelogenous leukemia

1986 ◽  
Vol 28 (6) ◽  
pp. 998-1002 ◽  
Author(s):  
Ram S. Verma ◽  
Jorge Rodriguez ◽  
Arvind Babu ◽  
Sundari Chemitiganti ◽  
Morton Coleman ◽  
...  
Keyword(s):  
Chronic Myelogenous Leukemia ◽  
Secondary Constriction ◽  
Constitutive Heterochromatin ◽  
Influencing Factor ◽  
Chromosome 9 ◽  
Myelogenous Leukemia ◽  
Distamycin A ◽  
C Banding ◽  
Pericentric Inversions

The secondary constriction region (h) of human chromosome 9 was evaluated in 55 chronic myelogenous leukemia (CML) patients with respect to its size and position. Each case was examined by C-banding and distamycin A–4,6-diamidino-2-phenylindole techniques for the expression of the h regions. When one h region of chromosome 9 was larger, it was more frequently involved in the reciprocal translocation with chromosome 22. In addition, there was a higher incidence of pericentric inversions in the h regions in the translocated chromosome 9 when compared with normal homologues. The role of the constitutive heterochromatin of chromosome 9 as a possible influencing factor during 9q;22q translocation in CML is suggested.Key words: chromosomes 9 and 22, leukemia C-banding, DA–DAPI technique, heterochromatin.

Cytogenetics of Alismatales s.s.: chromosomal evolution and C-banding

2009 ◽  
Vol 280 (1-2) ◽  
pp. 119-131 ◽  
Author(s):  
L. L. Feitoza ◽  
L. P. Felix ◽  
A. A. J. F. Castro ◽  
R. Carvalho
Keyword(s):  
Chromosomal Evolution ◽  
C Banding

Karyotypic and chromosome banding studies of the potato tuber moth, Phthorimaea operculella (Zeller) (Lepidoptera, Gelechiidae)

1984 ◽  
Vol 26 (2) ◽  
pp. 141-145 ◽  
Author(s):  
D. G. Bedo
Keyword(s):  
Silver Staining ◽  
Chromosome Banding ◽  
Phthorimaea Operculella ◽  
Holocentric Chromosomes ◽  
Potato Tuber Moth ◽  
Considerable Variability ◽  
Fluorescent Staining ◽  
Hoechst 33258 ◽  
Metaphase Chromosomes ◽  
C Banding

The karyotype of Phthorimaea operculella is similar in both sexes and consists of 29 chromosome pairs. These are of similar size with gradual intergradation except for one pair which is significantly longer. C-banding and fluorescent staining with quinacrine and Hoechst 33258 failed to induce bands in metaphase chromosomes while silver staining clearly showed active nucleoli in all stages except metaphase. The banding results are compared with the few reports available on banding of holocentric chromosomes. It is concluded that considerable variability exists in the heterochromatic structure of holocentric chromosomes.Key words: Lepidoptera, moth, karyotype, C-banding.

Chromosomal Evolution in the Diplodactylinae (Gekkonidae, Reptilia) .2. Chromosomal Variability Between New Caledonian Species

1990 ◽  
Vol 38 (2) ◽  
pp. 219 ◽  
Author(s):  
M King ◽  
G Mengden
Keyword(s):  
New Zealand ◽  
Chromosomal Evolution ◽  
Pericentric Inversions ◽  
Chromosomal Variability

The karotypes of six species of New Caledonian gekkos from the genera Rhacodactylus and Bavayia are described. The chromosomes of R. auriculatus, R. sarasinorum and B. sauvagei share a highly derived biarmed 2n=38 karyomorph, which is common to species from both New Zealand and Australia and is believed to be a relic from a previous Gondwanaland distribution. In contrast, R. leachianus, B. crassicollis and B. montana have karyotypes further modified from this karyomorph by a series of presumed pericentric inversions. This chromosomal repatterning appears to have been associated with the speciation of this complex. A chromosomal perspective on Kluge's (1987) recent reclassification of the Diplodactylinae is also provided and discussed.

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