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 ◽  
...  

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.

Genes ◽  
2020 ◽  
Vol 11 (11) ◽  
pp. 1366
Author(s):  
Geize Aparecida Deon ◽  
Larissa Glugoski ◽  
Marcelo Ricardo Vicari ◽  
Viviane Nogaroto ◽  
Francisco de Menezes Cavalcante Sassi ◽  
...  

Harttia comprises an armored catfish genus endemic to the Neotropical region, including 27 valid species with low dispersion rates that are restricted to small distribution areas. Cytogenetics data point to a wide chromosomal diversity in this genus due to changes that occurred in isolated populations, with chromosomal fusions and fissions explaining the 2n number variation. In addition, different multiple sex chromosome systems and rDNA loci location are also found in some species. However, several Harttia species and populations remain to be investigated. In this study, Harttia intermontana and two still undescribed species, morphologically identified as Harttia sp. 1 and Harttia sp. 2, were cytogenetically analyzed. Harttia intermontana has 2n = 52 and 2n = 53 chromosomes, while Harttia sp. 1 has 2n = 56 and 2n = 57 chromosomes in females and males, respectively, thus highlighting the occurrence of an XX/XY1Y2 multiple sex chromosome system in both species. Harttia sp. 2 presents 2n = 62 chromosomes for both females and males, with fission events explaining its karyotype diversification. Chromosomal locations of the rDNA sites were also quite different among species, reinforcing that extensive rearrangements had occurred in their karyotype evolution. Comparative genomic hybridization (CGH) experiments among some Harttia species evidenced a shared content of the XY1Y2 sex chromosomes in three of them, thus pointing towards their common origin. Therefore, the comparative analysis among all Harttia species cytogenetically studied thus far allowed us to provide an evolutionary scenario related to the speciation process of this fish group.


1975 ◽  
Vol 28 (1) ◽  
pp. 89 ◽  
Author(s):  
Max Kinga ◽  
Dennis King

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.


Caryologia ◽  
2001 ◽  
Vol 54 (3) ◽  
pp. 217-226 ◽  
Author(s):  
Carolina Elena Viña Bertolotto ◽  
Miguel Trefaut Rodrigues ◽  
Yatiyo Yonenaga-Yassuda

Blood ◽  
1976 ◽  
Vol 47 (5) ◽  
pp. 705-721 ◽  
Author(s):  
JD Rowley ◽  
D Potter

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.


2011 ◽  
Vol 9 (1) ◽  
pp. 201-208 ◽  
Author(s):  
Vanessa Paes da Cruz ◽  
Cristiane Kioko Shimabukuro-Dias ◽  
Claudio Oliveira ◽  
Fausto Foresti

Cytogenetic analysis of Potamotrygon aff. motoro and P. falkneri indicated the occurrence of an X1X1X2X2/X1X2 Y multiple sex chromosome system in both species, with 2n = 66 chromosomes for females and 2n = 65 chromosomes for males. The nucleolus organizer regions (NORs) identified using Ag-NOR technique showed that both species have multiple Ag-NORs (5 to 7 chromosomes stained). C-banding technique indicated the presence of heterochromatic blocks in the centromeric regions of almost all chromosomes in both species. Through this study there was evidence of heterogeneity in the karyotypes, which suggests that chromosomal rearrangements such as inversions and/or translocations occurred during the chromosomal evolution in two species of this genus.


2017 ◽  
Vol 153 (2) ◽  
pp. 96-104 ◽  
Author(s):  
Patrik F. Viana ◽  
Tariq Ezaz ◽  
Leandro Marajó ◽  
Milena Ferreira ◽  
Jansen Zuanon ◽  
...  

The genus Colomesus is the sole representative of the family Tetraodontidae in the Amazon region. Here, Colomesus asellus was analyzed using conventional and molecular cytogenetic protocols. Its diploid chromosome number is 2n = 46 with 12 meta-, 10 submeta-, 16 subtelo-, and 8 acrocentric chromosomes and a fundamental number of FN = 84. An XX/XY sex chromosome system was identified. Mapping of 18S rDNA correlated with the nucleolus organizer regions (Ag-NORs) in the short arms of the 2 X chromosomes in females and in the Y chromosome in males. C-banding revealed heterochromatin in the centromeric regions of all chromosomes, except for pair 3. Prominent sex chromosome-specific heterochromatin amplification was observed, covering the short arms of the Y chromosome almost entirely. FISH with telomeric and tropomyosin (tpm1) sequences, respectively, revealed terminal signals in all chromosomes. The analysis of extended DNA fibers confirmed the colocalization and the interspersed pattern of the telomeric and tpm1 sequences. Thus, this study highlights the remarkable evolutionary dynamism presented by the Amazonian puffer fish regarding the differentiation of a heteromorphic XY sex chromosome system and a particular sex-specific amplification of rDNA sites. This is the first record of such an association in the Tetraodontidae family.


PLoS ONE ◽  
2021 ◽  
Vol 16 (10) ◽  
pp. e0258474
Author(s):  
Vergiana dos Santos Paixão ◽  
Pablo Suárez ◽  
Willam Oliveira da Silva ◽  
Lena Geise ◽  
Malcolm Andrew Ferguson-Smith ◽  
...  

Rhipidomys (Sigmodontinae, Thomasomyini) has 25 recognized species, with a wide distribution ranging from eastern Panama to northern Argentina. Cytogenetic data has been described for 13 species with 12 of them having 2n = 44 with a high level of autosomal fundamental number (FN) variation, ranging from 46 to 80, assigned to pericentric inversions. The species are grouped in groups with low FN (46–52) and high FN (72–80). In this work the karyotypes of Rhipidomys emiliae (2n = 44, FN = 50) and Rhipidomys mastacalis (2n = 44, FN = 74), were studied by classical cytogenetics and by fluorescence in situ hybridization using telomeric and whole chromosome probes (chromosome painting) of Hylaeamys megacephalus (HME). Chromosome painting revealed homology between 36 segments of REM and 37 of RMA. We tested the hypothesis that pericentric inversions are the predominant chromosomal rearrangements responsible for karyotypic divergence between these species, as proposed in literature. Our results show that the genomic diversification between the karyotypes of the two species resulted from translocations, centromeric repositioning and pericentric inversions. The chromosomal evolution in Rhipidomys was associated with karyotypical orthoselection. The HME probes revealed that seven syntenic probably ancestral blocks for Sigmodontinae are present in Rhipidomys. An additional syntenic block described here is suggested as part of the subfamily ancestral karyotype. We also define five synapomorphies that can be used as chromosomal signatures for Rhipidomys.


2021 ◽  
Vol 12 ◽  
Author(s):  
Renata Luiza Rosa de Moraes ◽  
Francisco de Menezes Cavalcante Sassi ◽  
Luiz Antonio Carlos Bertollo ◽  
Manoela Maria Ferreira Marinho ◽  
Patrik Ferreira Viana ◽  
...  

Miniature fishes have always been a challenge for cytogenetic studies due to the difficulty in obtaining chromosomal preparations, making them virtually unexplored. An example of this scenario relies on members of the family Lebiasinidae which include miniature to medium-sized, poorly known species, until very recently. The present study is part of undergoing major cytogenetic advances seeking to elucidate the evolutionary history of lebiasinids. Aiming to examine the karyotype diversification more deeply in Pyrrhulina, here we combined classical and molecular cytogenetic analyses, including Giemsa staining, C-banding, repetitive DNA mapping, comparative genomic hybridization (CGH), and whole chromosome painting (WCP) to perform the first analyses in five Pyrrhulina species (Pyrrhulina aff. marilynae, Pyrrhulina sp., P. obermulleri, P. marilynae and Pyrrhulina cf. laeta). The diploid number (2n) ranged from 40 to 42 chromosomes among all analyzed species, but P. marilynae is strikingly differentiated by having 2n = 32 chromosomes and a karyotype composed of large meta/submetacentric chromosomes, whose plesiomorphic status is discussed. The distribution of microsatellites does not markedly differ among species, but the number and position of the rDNA sites underwent significant changes among them. Interspecific comparative genome hybridization (CGH) found a moderate divergence in the repetitive DNA content among the species’ genomes. Noteworthy, the WCP reinforced our previous hypothesis on the origin of the X1X2Y multiple sex chromosome system in P. semifasciata. In summary, our data suggest that the karyotype differentiation in Pyrrhulina has been driven by major structural rearrangements, accompanied by high dynamics of repetitive DNAs.


Blood ◽  
1976 ◽  
Vol 47 (5) ◽  
pp. 705-721 ◽  
Author(s):  
JD Rowley ◽  
D Potter

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.


Sign in / Sign up

Export Citation Format

Share Document