scholarly journals Karyotypic diversity between allopatric populations of the group Hoplias malabaricus (Characiformes: Erythrinidae): evolutionary and biogeographic considerations

2010 ◽  
Vol 8 (2) ◽  
pp. 361-368 ◽  
Author(s):  
Daniel Rodrigues Blanco ◽  
Roberto Laridondo Lui ◽  
Luiz Antonio Carlos Bertollo ◽  
Vladimir Pavan Margarido ◽  
Orlando Moreira Filho

Three populations of the group Hoplias malabaricus from the hydrographic basins of the São Francisco, Araguaia/Tocantins and Xingu Rivers in Brazil were analyzed using classic cytogenetic methods (Giemsa staining, C-banding and Ag-NORs) and molecular methods (fluorescent in situ hybridization with 18S rDNA, 5S rDNA and 5SHindIII satellite DNA probes). The chromosome markers allowed the characterization of these populations as belonging to karyomorph A and the detection of inter-population divergences. These differences likely stem from different evolutionary histories resulting from geographic isolation between populations associated to the dispersive mode of these organisms, reinforcing genetic diversity in the group Hoplias malabaricus.

Genome ◽  
1999 ◽  
Vol 42 (5) ◽  
pp. 1008-1012 ◽  
Author(s):  
F Fontana ◽  
M Lanfredi ◽  
M Chicca ◽  
L Congiu ◽  
J Tagliavini ◽  
...  

The genes for 28S and 5S rDNA were physically mapped on the chromosomes of two sturgeon species, the sterlet (Acipenser ruthenus, 2n = 118 ± 4) and the Adriatic sturgeon (Acipenser naccarii, 2n = 248 ± 4) by fluorescent in situ hybridization. In the sterlet, the 28S rDNA was located on six chromosomes, four of which actively transcribed, while in the Adriatic sturgeon the 28S rDNA was located on a chromosome number ranging from 10 to 12, eight of which actively transcribed. The 5S rDNA was physically mapped on two chromosomes in the sterlet and on four in the Adriatic sturgeon. A more detailed characterization of the latter karyotype was obtained during this study. All these data are discussed in connection with the ploidy relationships among sturgeon species.Key words: karyotype, ploidy, FISH, 28S and 5S rDNA.


2021 ◽  
Vol 19 (4) ◽  
Author(s):  
Leandro Ranucci ◽  
Carlos A. Fernandes ◽  
Luciana A. Borin-Carvalho ◽  
Isabel C. Martins-Santos ◽  
Ana L. B. de Portela-Castro

ABSTRACT Moenkhausia is a highly specious genus among the Characidae, composed of 96 valid species. Only twelve species have a known karyotype. Thus, here are presented the first cytogenetic data of two allopatric populations of Moenkhausia bonita and one of M. forestii, both belonging to the upper Paraná River basin (PR) with discussion on the evolutionary and cytotaxonomic aspects of the genus. The two species presented 2n = 50 chromosomes but different karyotype formulas and occurrence of 1-2 B chromosomes. These elements are small metacentrics in M. bonita and small acrocentrics in M. forestii. In both species, B chromosomes were euchromatic. Ag-NOR sites were found in pair 3 (metacentric), coinciding with fluorescent in situ hybridization (FISH) by the 18S rDNA probe in both species. However, the species differed in terms of the number and position of 5S rDNA sites. Heterochromatic blocks, mapped in M. bonita showed the least amount of heterochromatin in the terminal and pericentromeric regions, while the M. forestii karyotype revealed a greater amount of interstitial heterochromatic blocks. The karyotype distinctions between the two species, including the morphology of B chromosomes, may contribute as a reference in the taxonomic studies in this group.


Genome ◽  
1995 ◽  
Vol 38 (6) ◽  
pp. 1061-1069 ◽  
Author(s):  
A. Cuadrado ◽  
N. Jouve ◽  
C. Ceoloni

The molecular characterization of heterochromatin in six lines of rye has been performed using fluorescence in situ hybridization (FISH). The highly repetitive rye DNA sequences pSc 119.2, pSc74, and pSc34, and the probes pTa71 and pSc794 containing the 25S–5.8S–18S rDNA (NOR) and the 5S rDNA multigene families, respectively, were used. This allowed the individual identification of all seven rye chromosomes and most chromosome arms in all lines. All varieties showed similar but not identical patterns. A standard in situ hybridization map was constructed following the nomenclature system recommended for C-bands. All FISH sites observed appeared to correspond well with C-band locations, but not all C-banding sites coincided with hybridization sites of the repetitive DNA probes used. Quantitative and qualitative differences between different varieties were found for in situ hybridization response at corresponding sites. Variation between plants and even between homologous chromosomes of the same plant was found in open-pollinated lines. In inbred lines, the in situ pattern of the homologues was practically identical and no variation between plants was detected. The observed quantitative and qualitative differences are consistent with a corresponding variation for C-bands detected both within and between cultivars.Key words: fluorescence in situ hybridization, repetitive DNA, rye, Secale cereale, polymorphism.


Caryologia ◽  
2008 ◽  
Vol 61 (4) ◽  
pp. 411-416 ◽  
Author(s):  
Costa Fabiane R. ◽  
Telma N. S. Pereira ◽  
George L. Hodnett ◽  
Messias G. Pereira ◽  
David M. Stelly

2019 ◽  
Author(s):  
Meriam HADJ AMOR ◽  
Sarra Dimassi ◽  
Hanen Hannachi ◽  
Amel Taj ◽  
Adnene Mlika ◽  
...  

Abstract Background: While Miller-Dieker syndrome critical region deletions are well known delineated anomalies, submicroscopic duplications in this region have recently emerged as a new distinctive syndrome. So far, only few cases have been described overlapping 17p13.3 duplications. Methods: In this study, we report on clinical and cytogenetic characterization of two new cases involving 17p13.3 and 3p26 chromosomal regions in two sisters with familial history of lissencephaly. Fluorescent In Situ Hybridization and array Comparative Genomic Hybridization were performed. Results: A deletion including the critical region of the Miller-Dieker syndrome of at least 2,9 Mb and a duplication of at least 3,6 Mb on the short arm of chromosome 3 were highlighted in one case. The opposite rearrangements, duplication 17p13.3 and deletion 3p were seen in the second case. This double chromosome aberration is the result of an adjacent 1:1 meiotic segregation of a maternal reciprocal translocation t(3;17)(p26.2;p13.3). Conclusions: 17p13.3 and 3p26 deletions have a clear range of phenotypic features while duplications still have uncertain clinical significance. However, we could suggest that regardless of the type of the rearrangement, the gene dosage and interactions of CNTN4, CNTN6 and CHL1 in the 3p26 and PAFAH1B1, YWHAE in 17p13.3 could result in different clinical spectrums.


2020 ◽  
Vol 14 (2) ◽  
pp. 231-242
Author(s):  
Caio Augusto Gomes Goes ◽  
Sandro Natal Daniel ◽  
Lucas Henrique Piva ◽  
George Shigueki Yasui ◽  
Roberto Ferreira Artoni ◽  
...  

Astyanax Baird et Girard, 1854, is one of the largest genera in the family Characidae and comprises 177 valid species. This genus has been the focus of cytogenetic studies primarily owing to the presence of B chromosomes and high karyotypic diversity among different populations. The intense genetic variability in Astyanax is one of the factors responsible for the occurrence of species complexes, which are groups (1) with certain difficulties in establishing common genetic pools or (2) belonging to different cryptic species. To evaluate cytogenetic marker inheritance and the possibility of the identification of these hybrids, this study aimed to describe cytogenetic hybrids from three strains of species of the genera Astyanax and Hyphessobrycon Eigenmann, 1908. A. lacustris Lütken, 1875, A. schubarti Britski, 1964, A. fasciatus Cuvier, 1819, and H. anisitsi Eigenmann, 1907 were used to generate three hybrid lineages. The diploid number, heterochromatin sites, and ribosomal genes (18S and 5S rDNA) of the parental strains and the hybrids were analyzed. The results indicated that the three hybrid lineages had cytogenetic markers of both parents, presenting Mendelian inheritance. However, differences in distribution of heterochromatic blocks were observed between the hybrids and the parent strains. Our results allowed the identification of the hybrid strains based on the cytogenetic markers applied, reinforcing the efficiency of cytogenetic markers as tools for identification and indicating that such events may increase the karyotypic diversity in the genera Astyanax and Hyphessobrycon.


2018 ◽  
Vol 12 (3) ◽  
pp. 285-298 ◽  
Author(s):  
Ivanny Coelho da Fonseca ◽  
Luan Aércio Melo Maciel ◽  
Frank Raynner Vasconcelos Ribeiro ◽  
Luís Reginaldo Ribeiro Rodrigues

The genus Pimelodus LaCépède, 1803 comprises 35 formally recognized species distributed along the major neotropical river basins. Despite conservatism in diploid number with 2n=56, an intense variation of chromosomal morphology (karyotypic formula) has been documented in Pimelodus species. In the present study, we analyzed karyotypes of 20 specimens, identified as Pimelodusblochii Valenciennes, 1840 and collected from the lower courses of the Tapajós, Amazonas and Trombetas Rivers. The karyotypes were characterized by Giemsa conventional staining, C-banding, silver staining (Ag-NOR) and fluorescent in situ hybridization (FISH) with 5S and 18S rDNA probes. The karyotypes showed 2n=56 chromosomes in fish from the Tapajós River. In contrast, fish from the Amazonas and Trombetas Rivers had 2n=58. The nucleolus organizing regions were labeled on the short arm of an acrocentric chromosome as demonstrated by silver staining and FISH. Signals for 18S and 5S rDNA were co-localized on one chromosome pair. Our results demonstrate karyotypic divergence between Tapajós and Amazonas-Trombetas populations of P.blochii, interpreted as supporting the existence of a species complex in this taxon.


2009 ◽  
Vol 55 (11) ◽  
pp. 1250-1260 ◽  
Author(s):  
Gregor Kölsch ◽  
Corinna Matz-Grund ◽  
Bo V. Pedersen

Intracellular bacterial symbionts are known from various insect groups, particularly from those feeding on unbalanced diets, where the bacteria provide essential nutrients to the host. In the case of reed beetles (Coleoptera: Chrysomelidae, Donaciinae), however, the endosymbionts appear to be associated with specialized “glands” that secrete a material used for the beetles’ unusual water-tight cocoon. These glands were discovered over a century ago, but the bacteria they contain have yet to be characterized and placed in a phylogenetic context. Here, we describe the ultrastructure of two endosymbiotic species (“ Candidatus Macropleicola appendiculatae” and “ Candidatus Macropleicola muticae”) that reside in cells of the Malpighian tubules of the reed beetle species Macroplea appendiculata and Macroplea mutica , respectively. Fluorescent in situ hybridization using oligonucleotides targeting the 16S rRNA gene specific to Macroplea symbionts verified the localization of the symbionts in these organs. Phylogenetic analysis of 16S rRNA placed “Candidatus Macropleicola” in a clade of typically endosymbiotic Enterobacteriaceae (γ-proteobacteria). Finally, we discuss the evidence available for the hypothesis that the beetle larvae use a secretion produced by the bacteria for the formation of an underwater cocoon.


2009 ◽  
Vol 52 (4) ◽  
pp. 893-899
Author(s):  
Aline Dias Brandão ◽  
Lyderson Facio Viccini ◽  
Shirlei Maria Recco-Pimentel

Since previous cytogenetic reports of Aloysia have only described the meiotic behavior and chromosomal number of some species, the aim of this work was to provide detailed cytogenetic description of Aloysia virgata that would contribute to the understanding of the taxonomical organization of the Verbenaceae. Aloysia virgata had a karyotype with 2n = 36 metacentric chromosomes, all with similar size. The large amount of heterochromatin seen after Giemsa staining was confirmed by C-banding. Four nucleolar organizer regions (NORs) were detected with an rDNA 45S probe in two homologous pairs and two sites of 5S rDNA located on one chromosomal pair were detected by fluorescence in situ hybridization. The interphase nucleus was classified as semi-reticulate. Meiotic analysis showed a normal chromosomal behavior, with 18 bivalents in some parts of prophase I and in metaphase I. The number of chromosomes, NORs and 5S rDNA segments did not exclude a possible polyploid origin.


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