CONSTITUTIVE HETEROCHROMATIN OF INDIAN MUNTJAC CHROMOSOMES REVEALED BY DNASE TREATMENT AND A C-BANDING TECHNIQUE

1974 ◽  
Vol 16 (2) ◽  
pp. 273-280 ◽  
Author(s):  
H. Kato ◽  
K. Tsuchiya ◽  
T. H. Yosida
Keyword(s):  
Secondary Constriction ◽  
Constitutive Heterochromatin ◽  
Banding Technique ◽  
Size Difference ◽  
Indian Muntjac ◽  
C Banding ◽  
Dnase Treatment ◽  
Muntiacus Muntjak ◽  
Secondary Constrictions ◽  
Constriction Region

A karyotype of a female Indian muntjac, Muntiacus muntjak vaginalis, was described. The karyotype was unique in that No. 1 and No. 3 homologous pairs were heteromorphic with respect to the size of their secondary constrictions. In these pairs, one of the homologs always had a longer secondary constriction than that on the corresponding homolog. Heterochromatin in the secondary constriction region was visualized with difficulty by a C-banding technique, but was demonstrated clearly by a DNase treatment followed by Giemsa staining, which also revealed the size difference of the secondary constriction. Centromeric constitutive heterochromatin of No. 1 chromosome was also found to differ in size between the homologs. On the basis of the heteromorphic character of No. 3 chromosome, or an X-autosome complex, it was possible to confirm autoradiographically that X-inactivation had occurred at random.

scholarly journals Locations of 18S and 28S ribosomal genes on the chromosomes of the Indian muntjac.

1975 ◽  
Vol 64 (1) ◽  
pp. 251-254 ◽  
Author(s):  
M L Pardue ◽  
T C Hsu
Keyword(s):  
In Situ Hybridization ◽  
Ribosomal Rna ◽  
Secondary Constriction ◽  
Ribosomal Genes ◽  
Metaphase Chromosomes ◽  
Indian Muntjac ◽  
Secondary Constrictions

The locations of genes coding for 18S and 28S ribosomal RNA have been mapped on metaphase chromosomes of the Indian muntjac M. muntjak by in situ hybridization with (3H)rRNA from the toad X. laevis. The results show that, in the muntjac, rDNA clusters are associated with the prominent secondary constrictions on the X and the Y1 chromos. In addition a cluster of rDNA is found near the tip of one arm on the longest pair of autosomes. The autosomal cluster of rDNAs usually does not express as a secondary constriction at metaphase.

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.

scholarly journals Hypermethylated Chromosome Regions in Nine Fish Species with Heteromorphic Sex Chromosomes

2015 ◽  
Vol 147 (2-3) ◽  
pp. 169-178 ◽  
Author(s):  
Michael Schmid ◽  
Claus Steinlein ◽  
Cassia F. Yano ◽  
Marcelo B. Cioffi
Keyword(s):  
Sex Chromosomes ◽  
Constitutive Heterochromatin ◽  
Banding Technique ◽  
Comparative Cytogenetics ◽  
Closely Related Species ◽  
Valuable Data ◽  
C Banding ◽  
Heteromorphic Sex Chromosomes ◽  
Species Specific ◽  
Chromosome Regions

Sites and amounts of 5-methylcytosine (5-MeC)-rich chromosome regions were detected in the karyotypes of 9 Brazilian species of Characiformes fishes by indirect immunofluorescence using a monoclonal anti-5-MeC antibody. These species, belonging to the genera Leporinus, Triportheus and Hoplias, are characterized by highly differentiated and heteromorphic ZW and XY sex chromosomes. In all species, the hypermethylated regions are confined to constitutive heterochromatin. The number and chromosome locations of hypermethylated heterochromatic regions in the karyotypes are constant and species-specific. Generally, heterochromatic regions that are darkly stained by the C-banding technique are distinctly hypermethylated, but several of the brightly fluorescing hypermethylated regions merely exhibit moderate or faint C-banding. The ZW and XY sex chromosomes of all 9 analyzed species also show species-specific heterochromatin hypermethylation patterns. The analysis of 5-MeC-rich chromosome regions contributes valuable data for comparative cytogenetics of closely related species and highlights the dynamic process of differentiation operating in the repetitive DNA fraction of sex chromosomes.

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.

Constitutive heterochromatin DNA polymorphisms in diploid Medicago sativa ssp. falcata

Genome ◽  
1999 ◽  
Vol 42 (5) ◽  
pp. 930-935 ◽  
Author(s):  
G R Bauchan ◽  
M A Hossain
Keyword(s):  
Medicago Sativa ◽  
Banding Pattern ◽  
Constitutive Heterochromatin ◽  
Nucleolar Organizer ◽  
Dna Polymorphisms ◽  
Banding Technique ◽  
Chromosome 3 ◽  
Nucleolar Organizer Regions ◽  
First Report ◽  
C Banding

A Giemsa C-banding technique was used to study the amount and location of constitutive heterochromatin in diploid (2n = 2x = 16) Medicago sativa ssp. falcata (L.) Arcangeli. Most accessions had the standard C-banding pattern with centromeric bands on all the chromosomes and a prominent heterochromatic band at the nucleolar organizer regions (NOR) of the satellited (SAT) chromosomes. However, we observed in various accessions that constitutive heterochromatic C-bands can exist at the telomeric ends of all the chromosomes. Interstitial bands occurred on the short arms of all chromosomes except for chromosome 3 and on the long arms of chromosomes 1, 2, 3, and 6, only. Rearranged chromosomes such as isochromosomes have been observed for the short arms of chromosomes 2 and 6. This is the first report on the existence of C-banding polymorphisms and the detection of putative isochromsomes in the chromosomes of diploid ssp. falcata which could have contributed to the variation observed in cultivated alfalfa.Key words: alfalfa, C-bands, chromosome, isochromosome.

Heterochromatin organization in the nucleus of Indian muntjac (Muntiacus muntjak)

1986 ◽  
Vol 28 (4) ◽  
pp. 628-630 ◽  
Author(s):  
Ram S. Verma ◽  
Jessey P. Jacob ◽  
Arvind Babu
Keyword(s):  
Restriction Endonuclease ◽  
Y Chromosome ◽  
X Chromosome ◽  
General Pattern ◽  
Banding Technique ◽  
Chromosome Y ◽  
Heterochromatic Segment ◽  
Indian Muntjac ◽  
Muntiacus Muntjak

The heterochromatin in Indian muntjac (Muntiacus muntjak) is located at the periphery of primary constrictions of all the chromosomes. The X chromosome contains significantly larger amounts of heterochromatin than the rest of the complement by C-banding technique. However, the small portion of C-band region was found to be resistant by restriction endonuclease HaeIII (5′… GG ↓ CC … 3′) and was clearly visible on the nucleus. Therefore, the position of this large heterochromatic segment is examined at somatic metaphases. The distribution of the heterochromatin of the X chromosome observed in Indian muntjac is contrary to the general pattern observed in other species, i.e., the chromosomes consisting greater amount of heterochromatin are located more peripherally than those with lesser amount. However, the smaller Y chromosome (Y1) is frequently found at the periphery. The present findings suggest that the role of heterochromatin organization in the nucleus vary between different heterochromatic segments of the same species and vary from species to species.Key words: heterochromatin, chromosome, nucleus, metaphase, Muntiacus muntjak.

scholarly journals Distribuição diferencial da heterocromatina constitutiva em duas espécies da aranha marrom: Loxosceles intermedia e L. laeta (Araneae, Sicariidae) da região metropolitana de Curitiba, PR (Brasil)

2002 ◽  
Vol 31 ◽  
Author(s):  
ROXANE WIRSCHUM SILVA ◽  
DÉBORA DO ROCIO KLISIOWICZ ◽  
DORALICE MARIA CELLA ◽  
OLDEMIR CARLOS MANGILI ◽  
IVES JOSÉ SBALQUEIRO
Keyword(s):  
Metropolitan Area ◽  
Constitutive Heterochromatin ◽  
Sex Chromosome ◽  
The Other ◽  
Banding Technique ◽  
C Banding ◽  
Sex Chromosome System ◽  
Males And Females ◽  
First Time ◽  
Détermination Sexuelle

As aranhas do gênero Loxosceles são pequenas, apresentam distribuição cosmopolita, hábitos noturnos e não agressivos. Na região metropolitana de Curitiba, são encontradas duas espécies de aranha marrom: L. intermedia e L. laeta. A primeira é a mais abundante e responsável, nos últimos anos, por inúmeros acidentes denominados de Loxoscelismo. O presente trabalho tem como objetivo estudar citogeneticamente estas aranhas, através de técnicas de coloração comum (Giemsa) e de bandeamento C, em células prémeióticas, meióticas e embrionárias. Exemplares foram coletados em domicílios ou fornecidos pelo Laboratório Interdisciplinar de Pesquisa em Animais Peçonhentos (LIPAPE). As preparações citológicas foram obtidas a partir de testículos de aranhas adultas ou de células embrionárias. Os dados mostram que as duas espécies são cariotipicamente similares e caracterizam-se por apresentar um número diplóide diferenciado entre os sexos: 2n=23 nos machos e 24 nas fêmeas. Esta diferença é devida ao sistema cromossômico de determinação sexual múltiplo, do tipo X1X2Y (machos) e X1X1X2X2 (fêmeas). A aplicação da técnica de bandeamento C revelou que em L. intermedia poucos cromossomos apresentam banda pericentromérica, incluindo os sexuais, X1 e X2, ao passo que em L. laeta, diferentemente, todos os cromossomos do genoma apresentaram bandas pericentroméricas conspícuas. Em ambas as espécies, o cromossomo Y mostrou-se quase que totalmente heterocromático. Este tipo de bandeamento, além de ser inédito em Loxosceles, revelou ser uma importante característica na diferenciação cariotípica entre L. intermedia e L. laeta. ABSTRACT The genus Loxosceles includes cosmopolitan small spiders, which have nocturnal and non-agressive habits. Two species of brown spiders are found in the metropolitan area of Curitiba: L. intermedia and L. laeta. The first one is more abundant, and responsible for many accidents (Loxoscelism). The aim of this study is to analyze cytogenetically these spiders, through conventional (Giemsa) and c-banding techniques in pre-meiotic, meiotic and embrionary cells. The specimens were collected in houses or kindly provided by Laboratório Interdisciplinar de Pesquisa em Animais Peçonhentos (LIPAPE). Cytological preparations were obtained from embrionic cells or from testis of adult specimens. The data showed that both species are karyotipically similar, and had different diploid numbers in males and females (2n=23 and 2n=24, respectively). This difference is the result of a multiple sex chromosome system (X1X2Y/ X1X1X2X2). The use of c-banding technique revealed that a few chromosomes of L. intermedia showed pericentromeric blocks of constitutive heterochromatin, including gonosomes X1 and X2. On the other hand, all the chromosomes of L. laeta showed conspicuous pericentromeric C-positive segments. In both species, the Y chromosome revealed to be almost tottaly heterochromatic. This study described the result of the use of c-banding technique for the first time in Loxosceles, which revealed an important karyotypical distintion between L. intermedia and L. laeta. RÉSUMÉ Les araignées du genre Loxosceles sont petites, présentent une distribution cosmopolite, ont des habits nocturnes et ne sont pas agressives. Dans la region métropolitaine de Curitiba, on y trouve deux espèces de l’araignée marron: L. intermedia et L. laeta. La premiere c’est la plus abondante et responsable, dans les dernières années par des nombreux accidents connus sous le nom de loxoscelisme. Le but de cet article est celui d’étudier la cytogénétique de ces araignées, par moyen des colorants ordinaires dont le Giemsa et par le technique du bandage C en utilisant des cellules C, des cellules pré-meyotiques, meyotiques et embryonnaires. Des échantillons ont été soit obtenues dans des maisons particulières, soit fournies par le Laboratório Interdisciplinar de Pesquisa em Animais Peçonhentos (LIPAPE), et les préparations cytologiques obtenues des testicules des adultes ou des cellules embryonnaires. Les résultats montrent que les deux espèces sont similaires du point de vue caryotype et se caractérisent par avoir un numéro diploíde différencié entre les sexes : 2n=23 dans les mâles et 24 dans les femelles. Cette différence dans le numéro diploïde est due ao système chromosomique de détermination sexuelle – multiple du type X1X2Y (mâles)/X1X1X2X2 (femelles). L’utilisation du bandage C a montré que chez L. intermedia pas beaucoup de chromosomes présentent la bande pericentrométrique, y compris les sexuels X1 et X2. Par contre, chez L. laeta, tous les chromosomes du génome présentent des bandes pericentrométriques visibles. Dans toutes les deux, le chromosome Y s’est montré presque hétérochromatique. Cet type de bandage, en plus d’inédite chez Loxosceles, s’est montré aussi important dans la séparation caryotypique entre L. intermedia et L. laeta.

scholarly journals Chromosomal analyses in Megalonema platanum (Siluriformes: Pimelodidae), an endangered species from South American rivers

2011 ◽  
Vol 9 (1) ◽  
pp. 177-182 ◽  
Author(s):  
Rafael Augusto de Carvalho ◽  
Sebástian Sanchez ◽  
Ana Claudia Swarça ◽  
Alberto Sergio Fenocchio ◽  
Isabel C. Martins-Santos ◽  
...  
Keyword(s):  
Diploid Number ◽  
Secondary Constriction ◽  
Centromeric Heterochromatin ◽  
Large Chromosome ◽  
South American ◽  
Terminal Position ◽  
Chromosomal Data ◽  
First Time ◽  
Secondary Constrictions ◽  
Submetacentric Pair

This study presents chromosomal data of Megalonema platanum from rio Tibagi, Paraná, Brazil and from rio Paraná, Argentina. The diploid number was equal 54 with karyotype composition of 24m+16sm+2st+12a in both populations. The AgNOR sites were detected in the terminal position of a submetacentric pair of the two analyzed populations, coinciding with secondary constrictions on the short arm of pair 15. CMA3 and FISH with 18S rDNA probe displayed fluorescent signals that correspond to the AgNOR sites and secondary constriction. The presence of a small acrocentric supernumerary chromosome can be observed in M. platanum from rio Tibagi, with centromeric heterochromatin. Others heterochromatic blocks were evidenced in the terminal position of some chromosome and one metacentric large chromosome pair, probably the first pair, showed an interstitial heterochromatin. In the population of the rio Paraná were still observed heterochromatic blocks in both ends in some chromosomes. This work brings for the first time cytogenetic date of M. platanum, which is a very rare species in the rio Paraná basin and may be endangered.

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