C-Banding and Nucleolar Organizer Regions of Sphoeroides greeleyi (Tetraodontidae, Tetraodontiformes)

Caryologia ◽  
2002 ◽  
Vol 55 (2) ◽  
pp. 171-174 ◽  
Author(s):  
Mario Jorge Ignacio Brum ◽  
Liliane Cristine Gomes Mota
Keyword(s):  
Nucleolar Organizer ◽  
Nucleolar Organizer Regions ◽  
C Banding

scholarly journals Cytogenetical analyses in three fish species of the genus Pimelodus(Siluriformes: Pimelodidae) from rio São Francisco: considerations about the karyotypical evolution in the genus

2005 ◽  
Vol 3 (2) ◽  
pp. 285-290 ◽  
Author(s):  
Caroline Garcia ◽  
Orlando Moreira Filho
Keyword(s):  
Chromosome Pair ◽  
Chromosomal Rearrangements ◽  
Nucleolar Organizer ◽  
Differential Staining ◽  
Nucleolar Organizer Regions ◽  
C Banding ◽  
Heteromorphic Sex Chromosomes ◽  
Chromosomal Markers ◽  
Staining Techniques ◽  
Species Specific

Karyotypes and other chromosomal markers were investigated in three species of the catfish genus Pimelodus, namely P. fur, P. maculatus and Pimelodus sp., from municipality of Três Marias, Minas Gerais, Brazil, using differential staining techniques (C-banding, Silver nitrate and CMA3 staining). The diploid chromosome number was 2n = 56 in P. maculatus and Pimelodus sp., while in P. fur 2n = 54. The karyotype of P. fur consisted in 32M + 8SM + 6ST + 8A with fundamental number (NF) of 100, that of P. maculatus 32M + 12SM + 12A with NF = 112, and that of Pimelodus sp. had 32M + 12Sm + 6ST + 6A with NF = 106.The nucleolar organizer regions (NORs) in all three species were invariably detected in telomeres of longer arm of the 20th chromosome pair. These sites were also positive after CMA3 and C-banding. No heteromorphic sex chromosomes were detected and C-banding pattern was species specific. Inferences about the karyotype differentiation in Pimelodus and putative chromosomal rearrangements are hypohesized.

Chromosomal analysis of the leptodactylids Pleurodema diplolistris and Physalaemus nattereri (Amphibia, Anura)

2006 ◽  
Vol 27 (4) ◽  
pp. 481-489 ◽  
Author(s):  
Luciana B. Lourenço ◽  
Josiane A.A. Nascimento ◽  
Gilda V. Andrade ◽  
Denise C. Rossa-Feres ◽  
Shirlei M. Recco-Pimentel
Keyword(s):  
Nucleolar Organizer ◽  
The Other ◽  
Chromosomal Analysis ◽  
Nucleolar Organizer Regions ◽  
Chromosome 11 ◽  
Similar Morphology ◽  
C Banding ◽  
Heterochromatic Block

Abstract Detailed characterizations of the karyotypes of the Brazilian leptodactylid frogs Pleurodema diplolistris, the only species of Pleurodema not studied cytogenetically so far, and Physalaemus nattereri, a species in the Ph. biligonigerus group, are presented. Both karyotypes had 2n = 22 and their chromosomes had a very similar morphology, except for pair 11, which was metacentric in Pl. diplolistris and telocentric in Ph. nattereri. The localization of nucleolar organizer regions (NORs) and heterochromatic bands allowed the differentiation of chromosomes that were morphologically indistinguishable between these species, such as pairs 1, 3 and 10, which showed interstitial C-bands in Ph. nattereri, and pair 8, that had an NOR and an adjacent C-band in Pl. diplolistris. Pair 8 also has NOR-bearing chromosomes in many other Pleurodema species. However, in these species, the NOR is located proximal to the centromere on the short arm, while in Pl. diplolistris it occurred distally on the long arm, a condition that may be considered a derived state. In Ph. nattereri, the NOR occurred on chromosome 11 and differed from the other species of the Ph. biligonigerus group. In contrast, C-banding revealed a heterochromatic block near the centromere on the short arm of pair 3, a characteristic common to all members of this group of Physalaemus.

C-banding pattern and nucleolar organizer regions of Cynoglossus semilaevis Gunther, 1873*

2006 ◽  
Vol 16 (7) ◽  
pp. 769-772
Author(s):  
Wu Di ◽  
Zhang Shicui ◽  
ZHUANG Zhimeng ◽  
Pang Qiuxiang ◽  
Wang Changliu ◽  
...  
Keyword(s):  
Banding Pattern ◽  
Nucleolar Organizer ◽  
Cynoglossus Semilaevis ◽  
Nucleolar Organizer Regions ◽  
C Banding

Extensive multivalent pairing occurs in male lake trout meiosis

Genome ◽  
1990 ◽  
Vol 33 (2) ◽  
pp. 219-224 ◽  
Author(s):  
Jane E. Disney ◽  
James E. Wright Jr.
Keyword(s):  
Silver Staining ◽  
Lake Trout ◽  
Nucleolar Organizer ◽  
Salvelinus Namaycush ◽  
Nucleolar Organizer Regions ◽  
Robertsonian Fusion ◽  
C Banding

Extensive multivalent pairing was observed in the tetraploid derivative lake trout (Salvelinus namaycush). In conjunction with previously reported hybrid splake (brook × lake) trout data, this result supports a meiotic model to explain the phenomenon of pseudolinkage. In addition, C-banding of mitotic and meiotic lake trout chromosomes revealed an intraindividual polymorphism for a Robertsonian fusion. Silver staining of lake trout chromosomes showed that the chromosomes with active nucleolar organizer regions located proximal to a centromere were not involved in the fusion event.Key words: lake trout, mitosis, C-banding, nucleolar organizer regions, intraindividual Robertsonian polymorphism, meiosis.

scholarly journals Cytogenetic analysis of the neotropical spider Nephilengys cruentata (Araneomorphae, tetragnathidae): standard staining, NORs, C-bands and base-specific fluorochromes

2005 ◽  
Vol 65 (2) ◽  
pp. 193-202 ◽  
Author(s):  
D. Araújo ◽  
D. M. Cella ◽  
A. D. Brescovit
Keyword(s):  
Sex Determination ◽  
Banding Pattern ◽  
Constitutive Heterochromatin ◽  
Repetitive Sequences ◽  
Nucleolar Organizer ◽  
Pericentromeric Region ◽  
Banding Technique ◽  
Nucleolar Organizer Regions ◽  
Fluorochrome Staining ◽  
C Banding

The aim of this work is to characterize Nephilengys cruentata in relation to the diploid number, chromosome morphology, type of sex determination chromosome system, chromosomes bearing the Nucleolar Organizer Regions (NORs), C-banding pattern, and AT or GC repetitive sequences. The chromosome preparations were submitted to standard staining (Giemsa), NOR silver impregnation, C-banding technique, and base-specific fluorochrome staining. The analysis of the cells showed 2n = 24 and 2n = 26 chromosomes in the embryos, and 2n = 26 in the ovarian cells, being all the chromosomes acrocentric. The long arm of the pairs 1, 2 and 3 showed an extensive negative heteropycnotic area when the mitotic metaphases were stained with Giemsa. The sexual chromosomes did not show differential characteristics that allowed to distinguish them from the other chromosomes of the complement. Considering the diploid numbers found in N. cruentata and the prevalence of X1X2 sex determination chromosome system in Tetragnathidae, N. cruentata seems to possess 2n = 24 = 22 + X1X2 in the males, and 2n = 26 = 22 + X1X1X2X2 in the females. The pairs 1, 2 and 3 showed NORs which are coincident with the negative heteropycnotic patterns. Using the C-banding technique, the pericentromeric region of the chromosomes revealed small quantity or even absence of constitutive heterochromatin, differing of the C-banding pattern described in other species of spiders. In N. cruentata the fluorochromes DAPI/DA, DAPI/MM and CMA3/DA revealed that the constitutive heterochromatin is rich in AT bases and the NORs possess repetitive sequences of GC bases.

Cytotaxonomic studies of Encarsia Förster (Hymenoptera: Aphelinidae)

1999 ◽  
Vol 89 (3) ◽  
pp. 209-215 ◽  
Author(s):  
F. Baldanza ◽  
L. Gaudio ◽  
G. Viggiani
Keyword(s):  
Chromosome Number ◽  
Cryptic Species ◽  
Silver Staining ◽  
Nucleolar Organizer ◽  
Nucleolar Organizer Regions ◽  
Economic Interest ◽  
C Banding ◽  
Cytogenetic Studies ◽  
Karyological Data ◽  
Karyotype Differentiation

AbstractA cytotaxonomic study was carried out on 13 species of Encarsia Förster, known to parasitize aleyrodids and diaspidids. The chromosomes varied greatly both in number and morphology, with E. protransvena Viggiani having the lowest chromosome number (2n = 6) and E. asterobemisiae Viggiani & Mazzone the highest (2n = 20). The most common chromosome number was 2n = 10. C-banding, G-banding and silver staining for nucleolar organizer regions (NOR) provided the possibility of distinguishing between karyotypes with the same chromosome number and morphology and to identify all the pairs of homologues in a diploid set for advanced cytogenetic studies. The karyotype of Coccophagus lycimnia (Walker) was also examined. The chromosome data suggested that in Encarsia, karyotype differentiation has mainly occurred through a series of centric fusions, although other rearrangements may also have been significant. The importance of karyological data in systematic studies and in the identification of biotypes and cryptic species of economic interest is outlined.

scholarly journals Karyotype, constitutive heterochromatin and nucleolar organizer regions (NORs) in Belosacris coccineipes (Acrididae-Leptysminae)

2000 ◽  
Vol 23 (3) ◽  
pp. 575-579 ◽  
Author(s):  
Vilma Loreto ◽  
Maria José de Souza
Keyword(s):  
Sex Determination ◽  
Silver Nitrate ◽  
X Chromosome ◽  
Silver Staining ◽  
Constitutive Heterochromatin ◽  
Nucleolar Organizer ◽  
Nucleolar Organizer Regions ◽  
C Banding ◽  
Nucleolar Organizers ◽  
Silver Nitrate Staining

Several techniques including C-banding, fluorochromes and silver staining were used to obtain information about heterochromatin patterns in the grasshopper B. coccineipes. Conventional staining showed a karyotype with 2n = 23 chromosomes in males and 2n = 24 in females, as well as XO:XX sex determination and acrotelocentric chromosomes. The medium-sized X chromosome was heteropycnotic positive at the beginning of prophase I and negative in metaphase I. C-banding revealed heterochromatic blocks in the pericentromeric regions of all chromosomes. Silver nitrate staining in this species showed three small bivalents (S9-S11) as nucleolar organizers with NORs located in the pericentromeric regions. CMA3-positive blocks were seen in pericentromeric regions of pairs M6, S9, S10 and S11. Sequential staining with CMA3/AgNO3 revealed homology between the CMA3-positive bands and NORs of the bivalents S9, S10 and S11. The CMA3-positive block of the bivalent M6 could represent a latent secondary NOR. The results obtained permit us to distinguish two categories of the constitutive heterochromatin in B. coccineipes.

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