Chromosomal evolution and biogeography of collared lemmings (Dicrostonyx) in the eastern and High Arctic of Canada

1993 ◽  
Vol 71 (8) ◽  
pp. 1481-1493 ◽  
Author(s):  
Oksana A. Borowik ◽  
Mark D. Engstrom
Keyword(s):  
Sex Chromosome ◽  
Chromosomal Evolution ◽  
High Arctic ◽  
Chromosomal Variation ◽  
Robertsonian Fusion ◽  
Banding Patterns ◽  
Dicrostonyx Groenlandicus ◽  
Chromosomal Differentiation ◽  
Chromosomal Data ◽  
Primitive State

Chromosomal variation was examined in 10 populations of Dicrostonyx in the eastern and High Arctic of Canada to determine the extent and nature of chromosomal variation and to examine chromosomal differentiation within and among species and subspecies. Chromosomal data are presented for two species of collared lemmings, D. hudsonius and D. groenlandicus, including D. g. groenlandicus, D. g. clarus, and D. g. lentus. Standard, G-banded, and C-banded karyotypes revealed variation among populations of D. groenlandicus due to Robertsonian fusions and the addition of B chromosomes. G-banding revealed complete homologous banding patterns of autosomal arms between D. groenlandicus and D. hudsonius; however, sex chromosome constitution differed between the two species. Dicrostonyx groenlandicus possesses a neo-XY, formed by a Robertsonian fusion of the sex chromosomes and a pair of autosomes. The neo-XY does not occur in D. hudsonius, and this absence appears to be the primitive state for the genus.

scholarly journals Chromosomal banding patterns in acute nonlymphocytic leukemia

Blood ◽  
1976 ◽  
Vol 47 (5) ◽  
pp. 705-721 ◽  
Author(s):  
JD Rowley ◽  
D Potter
Keyword(s):  
Sex Chromosome ◽  
Chromosomal Abnormalities ◽  
Normal Karyotype ◽  
Chromosomal Evolution ◽  
Structural Rearrangement ◽  
Myelogenous Leukemia ◽  
Acute Nonlymphocytic Leukemia ◽  
Banding Patterns ◽  
Chromosomal Banding ◽  
Balanced Translocations

Bone marrow chromosomes obtained from 50 of 55 consecutive adult patients with acute nonlymphocytic leukemia were analyzed with quinacrine fluorescence. Twenty-five patients showed a normal karyotype and 25 an abnormal karyotype on the initial samples available for analysis. Among the 25 patients with abnormalities, the marrow cells contained 48 chromosomes in one case, 47 in two, 46 in ten, 45 in nine, 43 in two, and 42 chromosomes in one case. Seven of the ten patients with 46 chromosomes had abnormalities, primarily balanced translocations, that were not detected with the standard Giemsa stains. The analysis of all of the data available revealed the presence of nonrandom chromosome changes such as the addition of No. 8, the loss of No. 7, and a gain or loss of one No. 21. the most frequent structural rearrangement was the translocation between the long arm of No. 8 and No. 21, which may also be associated with the loss of a sex chromosome. Chromosomal abnormalities decreased or disappeared during remission; the same abnormality recurred in relapse. Chemotherapy did not appear to produce a stable clone of aberrant cells. Evolution of the karyotype occurred in eight patients, in five of whom an additional No. 8 was observed. This pattern of chromosomal evolution in patients with acute leukemia was very similar to that observed in patients with chronic myelogenous leukemia in the blast phase.

scholarly journals Sequential Steps of Chromosomal Differentiation in Atlantic Surgeonfishes: Evolutionary Inferences

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Paulo Roberto Antunes de Mello Affonso ◽  
Maria Aparecida Fernandes ◽  
Josivanda Santos Almeida ◽  
Wagner Franco Molina
Keyword(s):  
Molecular Phylogeny ◽  
Nucleolar Organizer ◽  
Chromosomal Evolution ◽  
Nucleolar Organizer Regions ◽  
Similar Distribution ◽  
Noncoding Sequences ◽  
Pericentric Inversions ◽  
Chromosomal Differentiation ◽  
Chromosomal Data

Surgeonfishes are a species-rich group and a major biomass on coral reefs. Three species are commonly found throughout South Atlantic,Acanthurus bahianus,A. chirurgus, andA. coeruleus. In this paper, we present the first cytogenetic data of these species, revealing a sequential chromosomal diversification.A. coeruleuswas characterized by a relatively conserved karyotype evolved by pericentric inversions of some pairs (2n=48, 2sm + 4st + 42a). In contrast, the karyotypes ofA. bahianus(2n=36) andA. chirurgus(2n=34) were highly differentiated by the presence of six large metacentric pairs inA. bahianus(12m + 2sm + 4st + 18a) andA. chirurgus(12m + 2sm + 4st +1 6a) probably derived by chromosomal fusions that corroborate their closer relationship. A discerniblein tandemfusion represents an autapomorphic character toA. chirurgus. In spite of macrostructure variation, single nucleolar organizer regions (NORs) on short arms of a subtelocentric pair and similar distribution of C-bands were observed in the three species. Overlapping of chromosomal data with molecular phylogeny indicated pericentric inversions which took place nearly at 19 Ma while centric fusions are as recent as 5 Ma. A physical mapping of coding and noncoding sequences inAcanthuruscould clarify the role of additional rearrangements during their chromosomal evolution.

scholarly journals Chromosomal banding patterns in acute nonlymphocytic leukemia

Blood ◽  
1976 ◽  
Vol 47 (5) ◽  
pp. 705-721 ◽  
Author(s):  
JD Rowley ◽  
D Potter
Keyword(s):  
Sex Chromosome ◽  
Chromosomal Abnormalities ◽  
Normal Karyotype ◽  
Chromosomal Evolution ◽  
Structural Rearrangement ◽  
Myelogenous Leukemia ◽  
Acute Nonlymphocytic Leukemia ◽  
Banding Patterns ◽  
Chromosomal Banding ◽  
Balanced Translocations

Abstract Bone marrow chromosomes obtained from 50 of 55 consecutive adult patients with acute nonlymphocytic leukemia were analyzed with quinacrine fluorescence. Twenty-five patients showed a normal karyotype and 25 an abnormal karyotype on the initial samples available for analysis. Among the 25 patients with abnormalities, the marrow cells contained 48 chromosomes in one case, 47 in two, 46 in ten, 45 in nine, 43 in two, and 42 chromosomes in one case. Seven of the ten patients with 46 chromosomes had abnormalities, primarily balanced translocations, that were not detected with the standard Giemsa stains. The analysis of all of the data available revealed the presence of nonrandom chromosome changes such as the addition of No. 8, the loss of No. 7, and a gain or loss of one No. 21. the most frequent structural rearrangement was the translocation between the long arm of No. 8 and No. 21, which may also be associated with the loss of a sex chromosome. Chromosomal abnormalities decreased or disappeared during remission; the same abnormality recurred in relapse. Chemotherapy did not appear to produce a stable clone of aberrant cells. Evolution of the karyotype occurred in eight patients, in five of whom an additional No. 8 was observed. This pattern of chromosomal evolution in patients with acute leukemia was very similar to that observed in patients with chronic myelogenous leukemia in the blast phase.

scholarly journals Chromosomal Evolution and Evolutionary Relationships of Lebiasina Species (Characiformes, Lebiasinidae)

2019 ◽  
Vol 20 (12) ◽  
pp. 2944 ◽  
Author(s):  
Sassi ◽  
Oliveira ◽  
Bertollo ◽  
Nirchio ◽  
Hatanaka ◽  
...  
Keyword(s):  
Sex Chromosome ◽  
Distribution Patterns ◽  
Chromosomal Evolution ◽  
Evolutionary Relationships ◽  
Comparative Genomic ◽  
Banding Patterns ◽  
Rdna Sites ◽  
Sex Chromosome System ◽  
High Level ◽  
Chromosomal Sequences

We present the first cytogenetic data for Lebiasina bimaculata and L. melanoguttata with the aim of (1) investigating evolutionary events within Lebiasina and their relationships with other Lebiasinidae genera and (2) checking the evolutionary relationships between Lebiasinidae and Ctenoluciidae. Both species have a diploid number 2n = 36 with similar karyotypes and microsatellite distribution patterns but present contrasting C-positive heterochromatin and CMA3+ banding patterns. The remarkable interstitial series of C-positive heterochromatin occurring in L. melanoguttata is absent in L. bimaculata. Accordingly, L. bimaculata shows the ribosomal DNA sites as the only GC-rich (CMA3+) regions, while L. melanoguttata shows evidence of a clear intercalated CMA3+ banding pattern. In addition, the multiple 5S and 18S rDNA sites in L. melanogutatta contrast with single sites present in L. bimaculata. Comparative genomic hybridization (CGH) experiments also revealed a high level of genomic differentiation between both species. A polymorphic state of a conspicuous C-positive, CMA3+, and (CGG)n band was found only to occur in L. bimaculata females, and its possible relationship with a nascent sex chromosome system is discussed. Whole chromosome painting (WCP) and CGH experiments indicate that the Lebiasina species examined and Boulengerella maculata share similar chromosomal sequences, thus supporting the relatedness between them and the evolutionary relationships between the Lebiasinidae and Ctenoluciidae families.

scholarly journals Chromosomal Differentiation in Genetically Isolated Populations of the Marsh-Specialist Crocidura suaveolens (Mammalia: Soricidae)

Genes ◽  
2020 ◽  
Vol 11 (3) ◽  
pp. 270 ◽  
Author(s):  
Francisca Garcia ◽  
Luis Biedma ◽  
Javier Calzada ◽  
Jacinto Román ◽  
Alberto Lozano ◽  
...  
Keyword(s):  
Iberian Peninsula ◽  
Habitat Specialization ◽  
Evolutionary Significance ◽  
Chromosomal Variation ◽  
Gulf Of Cadiz ◽  
Habitat Specialist ◽  
Isolated Populations ◽  
Distributional Range ◽  
Gulf Of Cádiz ◽  
Chromosomal Differentiation

The genus Crocidura represents a remarkable model for the study of chromosome evolution. This is the case of the lesser white-toothed shrew (Crocidura suaveolens), a representative of the Palearctic group. Although continuously distributed from Siberia to Central Europe, C. suaveolens is a rare, habitat-specialist species in the southwesternmost limit of its distributional range, in the Gulf of Cádiz (Iberian Peninsula). In this area, C. suaveolens is restricted to genetically isolated populations associated to the tidal marches of five rivers (Guadiana, Piedras, Odiel, Tinto and Guadalquivir). This particular distributional range provides a unique opportunity to investigate whether genetic differentiation and habitat specialization was accompanied by chromosomal variation. In this context, the main objective of this study was to determinate the chromosomal characteristics of the habitat-specialist C. suaveolens in Southwestern Iberia, as a way to understand the evolutionary history of this species in the Iberian Peninsula. A total of 41 individuals from six different populations across the Gulf of Cádiz were collected and cytogenetically characterized. We detected four different karyotypes, with diploid numbers (2n) ranging from 2n = 40 to 2n = 43. Two of them (2n = 41 and 2n = 43) were characterized by the presence of B-chromosomes. The analysis of karyotype distribution across lineages and populations revealed an association between mtDNA population divergence and chromosomal differentiation. C. suaveolens populations in the Gulf of Cádiz provide a rare example of true karyotypic polymorphism potentially associated to genetic isolation and habitat specialization in which to investigate the evolutionary significance of chromosomal variation in mammals and their contribution to phenotypic and ecological divergence.

Karyotypes of Leptarrhena and Tanakaea (Saxifragaceae)

1984 ◽  
Vol 62 (4) ◽  
pp. 671-673 ◽  
Author(s):  
Douglas E. Soltis
Keyword(s):  
Chromosome Number ◽  
Chromosome Numbers ◽  
Chromosomal Evolution ◽  
Conservative Nature ◽  
Chromosomal Data ◽  
Base Chromosome Number ◽  
Flavonoid Chemistry

In an attempt to clarify subtribal relationships in tribe Saxifrageae, chromosome numbers and karyotypes were determined for the two species comprising subtribe Leptarrheninae: Leptarrhena pyrolifolia and Tanakaea radicans. In both species 2n = 14, a common chromosome number throughout Saxifrageae. The two species have distinctive karyotypes that appear to differ in the centromeric positions of three pairs of chromosomes. These findings, in conjunction with earlier studies, demonstrate that genera of Saxifrageae often differ karyotypically. Leptarrhena exhibits considerable karyotypic similarity to genera of subtribe Saxifraginae characterized by a base chromosome number of x = 7. Chromosomal data, therefore, do not clearly differentiate subtribes Saxifraginae and Leptarrheninae. This observation is in agreement with evidence from paly-nology and flavonoid chemistry. Karyotypic studies continue to demonstrate the conservative nature of chromosomal evolution in tribe Saxifrageae.

scholarly journals Chromosomal Evolution in the Lizard Genus Varanus (Reptilia)

1975 ◽  
Vol 28 (1) ◽  
pp. 89 ◽  
Author(s):  
Max Kinga ◽  
Dennis King
Keyword(s):  
Chromosome Number ◽  
Pericentric Inversion ◽  
Sex Chromosome ◽  
Chromosomal Rearrangements ◽  
Chromosomal Evolution ◽  
Size Groups ◽  
Sex Chromosome System

The karyotypes have been determined of 16 of the 32 species of the genus Varanus, including animals from Africa, Israel, Malaya and Australia. A constant chromosome number of 2n = 40 was observed. The karyotype is divided into eight pairs of large chromosomes and 12 pairs of microchromosomes. A series of chromosomal rearrangements have become established in both size groups of the karyotype and are restricted to centromere shifts, probably caused by pericentric inversion. Species could be placed in one of six distinct karyotype groups which are differentiated by these rearrangements and whose grouping does not always correspond with the current taxonomy. An unusual sex chromosome system of the ZZjZW type was present in a number of the species examined.

Chromosomal variation in social voles: a Robertsonian fusion in Günther’s vole

2012 ◽  
Vol 58 (3) ◽  
pp. 255-265 ◽  
Author(s):  
Jan Zima ◽  
Atilla Arslan ◽  
Petr Benda ◽  
Miloš Macholán ◽  
Boris Kryštufek
Keyword(s):  
Chromosomal Variation ◽  
Robertsonian Fusion
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