Characterization and modification of heterochromatin in four species of the immigrans species group of Drosophila

1986 ◽  
Vol 28 (3) ◽  
pp. 340-347 ◽  
Author(s):  
J. P. Gupta ◽  
Arun Kumar

The distribution of constitutive heterochromatin in mitotic chromosomes of four species (viz., Drosophila quadrilineata de Meijere, D. immigrans Sturtevant, D. pulaua Wheeler, and D. kohkoa Wheeler) was studied using C-banding and fluorescence staining techniques. The results of this study had revealed that the heterochromatic segments detected by C-banding in the species under study were found to coincide precisely with the areas giving bright fluorescence with the two fluorochromes, Hoechst 33258 and quinacrine. This suggested the presence of A–T rich base pairs in their heterochromatin. These studies further revealed that the modification of heterochromatin caused due to the additions or deletions in particular had also played a very significant role during the differentiation of these species.Key words: heterochromatin modification, immigrans species group, Drosophila.

1984 ◽  
Vol 71 (1) ◽  
pp. 111-120
Author(s):  
I. Schubert ◽  
R. Rieger ◽  
P. Dobel

Similarities and differences become evident from comparisons of centromeric and non-centromeric banding patterns in plant and animal chromosomes. Similar to C and G-banding in animals (at least most of the reptiles, birds and mammals), centromeric and nucleolus-organizing region bands as well as interstitially and/or terminally located non-centromeric bands may occur in plants, depending on the kind and strength of pretreatment procedures. The last group of bands may sometimes be subdivided into broad regularly occurring ‘marker’ bands and thinner bands of more variable appearance. Non-centromeric bands in plants often correspond to blocks of constitutive heterochromatin that are rich in simple sequence DNA and sometimes show polymorphism; they thus resemble C-bands. However, most of these bands contain late-replicating DNA. Also they are sometimes rich A X T base-pairs, closely adjacent to each other and positionally identical to Feulgen+ and Q+ bands, thus being comparable to mammalian G-bands. Although banding that is reverse to the non-centromeric bands after Giemsa staining is still uncertain in plants, reverse banding patterns can be obtained with Feulgen or with pairs of A X T versus G X C-specific fluorochromes. It is therefore concluded that not all of the plant Giemsa banding patterns correspond to C-banding of mammalian chromosomes. Before the degree of homology between different Giemsa banding patterns in plants and G and/or C-bands in mammals is finally elucidated, the use of the neutral term ‘Giemsa band’, specified by position (e.g. centromeric, proximal, interstitial, terminal), is suggested to avoid confusion.


1976 ◽  
Vol 18 (3) ◽  
pp. 513-518 ◽  
Author(s):  
M. Manolache ◽  
W. M. Ross ◽  
M. Schmid

The chromosomes of the domestic dog (Beagle) were investigated by several different staining techniques. G-banding, Q-banding, and the bis-benzimidazol derivative Hoechst 33258, make possible the identification of all 39 chromosome pairs. Constitutive heterochromatin (C-bands) was present on a few chromosomes as distinctive, large stained areas; on the other autosomes there was little or no heterochromatin detectable.


1983 ◽  
Vol 25 (1) ◽  
pp. 72-75
Author(s):  
Liming Shi ◽  
T. C. Hsu ◽  
Sen Pathak

The X chromosome and all autosomes of the cockroach Blaberus discoidalis (2n = 37, XO) contain large segments of constitutive heterochromatin (C-bands). From spermatogonial metaphases, the C-bands are found to be located in the middle of most chromosomes, including the X. The C-bands show bright fluorescence when stained with Hoechst 33258. In pachytene, autosomal heterochromatin can be easily identified in acetic orcein squash preparations as condensed segments. In the same preparations the X chromosome exhibits a "closed" appearance with a lightly stained middle loop and two heavily stained terminal segments which lie side-by-side as if they are paired. In C-banded preparations, an opposite reaction is found, i.e., the loop is heavily stained while the tips are lightly stained. In Hoechst 33258 preparations, the loop is brightly fluorescent while the tips are less brightly stained. Thus, in pachytene of conventional orcein preparations the heteropyknotic behavior between euchromatin and heterochromatin of the X chromosome is the reverse of the usual staining pattern; instead of condensed heterochromatin and decondensed euchromatin, euchromatin is condensed whereas heterochromatin is decondensed. The "paired" euchromatic tips may suggest autologous homology between the original X and the original Y which might have been translocated onto the X in the course of karyological evolution.


2018 ◽  
Vol 154 (1) ◽  
pp. 37-44 ◽  
Author(s):  
Beata Grzywacz ◽  
Haruki Tatsuta ◽  
Kei-ichiro Shikata ◽  
Elżbieta Warchałowska-Śliwa

In the present paper, karyotypes of 7 Japanese Podismini species, Anapodisma beybienkoi, Fruhstorferiola okinawaensis, Parapodisma caelestis, P. mikado, P. setouchiensis, P. tenryuensis, and Sinopodisma punctata (2n♂ = 21, all acrocentric), are described and compared on the basis of conventional (C-banding, DAPI/CMA3-staining, Ag-NOR) and molecular (FISH with 18S rDNA and telomeric probes) cytogenetic staining methods. This is the first study to report karyotypes of A. beybienkoi and P. caelestis. Differential staining techniques showed karyotypic diversity in these species. The number of 18S rDNA signals ranged from 2 to 6, and the signals were located on the autosomes or sex chromosomes. In all species, clusters of rDNA coincided with Ag-NORs. Telomeric signals occurred at the chromosome ends at the pachytene stage and seldom at other stages of meiosis. Paracentromeric and some distal and interstitial blocks of constitutive heterochromatin were detected in the chromosomes of Anapodisma, Fruhstorferiola, and Parapodisma species. Staining with DAPI and CMA3 revealed 2 groups of heterochromatin composition. In addition, intraspecific differences in the number of rDNA clusters and C-bands were observed within Parapodisma species. Based on the evidence of cytogenetic characteristics, the monophyly of Tonkinacridina cannot be supported.


Genome ◽  
1991 ◽  
Vol 34 (4) ◽  
pp. 631-637 ◽  
Author(s):  
D. G. Bedo

Mitotic and meiotic chromosomes of the Old World screwworm fly, Chrysomya bezziana, were studied using C-banding and quinacrine and counterstain-enhanced fluorescence techniques. The five autosomes in the karyotype are evenly graded in size, with somewhat variable arm ratios. Distinguishing all autosomes on these features alone can be difficult. C-banding produces small centromeric bands in the autosomes, whereas the much longer X and Y chromosomes have extensive dark C-band blocks with intermediate background staining. Most bright fluorescence occurs in the sex chromosomes, particularly the X chromosome, which has remarkable banding detail. Band resolution is greatly increased in mitotic metaphase cells from embryos. Quinacrine staining of mitotic chromosomes produces bright fluorescence at the centromere regions of chromosomes 2, 3, and 4, assisting in their identification. Meiotic chromosomes have distinctly reduced brightness and resolution of fluorescent bands and show marked chromatid asynapsis in the brighter regions of the sex chromosomes. Fluorochromes staining A∙T-rich DNA (quanacrine and 4,6-diamidino-2-phenylindole (DAPI)) produce bright staining in a large proportion of the sex chromosomes. By contrast chromomycin, which binds preferentially to G∙C-rich DNA, stains a much smaller proportion of the sex chromosomes than expected from reciprocal staining. Together with the asynapsis data this indicates that much of the heterochromatin in the sex chromosomes has unusual structural properties.Key words: Chrysomya bezziana, screwworm, karyotype, C-banding, fluorescence, heterochromatin.


1984 ◽  
Vol 26 (5) ◽  
pp. 564-568 ◽  
Author(s):  
Orlando Moreira-Filho ◽  
Luiz Antonio Carlos Bertollo ◽  
Pedro Manoel Galetti Jr.

Nucleolar organizer regions (NORs) were studied in mitotic chromosomes of four species of fish of family Parodontidae: Parodon tortuosus, Apareiodon affinis, Apareiodon ibitiensis, and Apareiodon piracicabae. All four species exhibited only a single nucleolar chromosome pair in their karyotypes. Intraspecific differences were observed in the size of these chromosomes; however, these were not very clear for A. affinis and A. piracicabae, Apareiodon piracicabae exhibited two clearly visible NORs in each of the nucleolar chromosomes, which was the only configuration practically found in this species. This trait therefore predominates in a homozygous condition in the population investigated. Regions of constitutive heterochromatin adjacent to the two NORs were detected. Possible mechanisms that may have originated the two NORs are discussed.Key words: nucleolar organizing regions, fish.


1986 ◽  
Vol 28 (4) ◽  
pp. 536-539 ◽  
Author(s):  
Axel J. J. Dietrich

It is well known that there is a strong influence of fixation, i.e., acetic methanol versus formaldehyde, on the chromosome morphology at stages of the first meiotic division. In this study the influence of both these types of fixation on the morphology of mitotic chromosomes was examined in human lymphocytes. After methanol – acetic acid (3:1) fixation, the chromosomes show the "classical" condensed shape in which it is not always possible to recognize the two sister chromatids. These chromosomes are accessible to the conventional G-, R-, and C-banding techniques. After formaldehyde fixation at a relatively high pH, the chromosomes are thinner and longer (two to six times) when compared with chromosomes following methanol – acetic acid fixation. They show a scaffold-like morphology, sometimes with a halo of thin material around it. In all cases the two sister chromatids could be recognized. This chromosome structure could be easily stained with silver, Giemsa, 4,6-diamino-2-phenyl-indole (DAPI), and fluorescein isocyanate isomere 1 (FITC). The results obtained following these stainings gave no indication to any specific chemical composition of a probable central scaffold. The scaffold-like structures were not accessible to G-, R-, or C-banding techniques. The only effect observed following these banding techniques was the disappearance of the halo of thin material around the central scaffold-like structure.Key words: chromosome structure, fixation influence, human lymphocytes.


2005 ◽  
Vol 3 (2) ◽  
pp. 285-290 ◽  
Author(s):  
Caroline Garcia ◽  
Orlando Moreira Filho

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.


1977 ◽  
Vol 19 (3) ◽  
pp. 537-541 ◽  
Author(s):  
J. E. K. Cooper

The distribution of constitutive heterochromatin has been examined by C-banding in two somatic cell lines, grown in vitro, from a female Microtus agrestis. One line retains one intact X chromosome together with the short arm of the other X chromosome, while the other cell line retains only the short arm of one X chromosome. Thus, each cell line has lost substantial amounts of heterochromatin from the sex chromosomes, but this material has been deleted from the cells, and not translocated to other chromosomes. Nonetheless, both cell lines continue to propagate well in vitro.


Zootaxa ◽  
2021 ◽  
Vol 4949 (2) ◽  
pp. 261-288
Author(s):  
L. LEE GRISMER ◽  
PETER GEISSLER ◽  
THY NEANG ◽  
TIMO HARTMANN ◽  
PHILIPP WAGNER ◽  
...  

The integrated results of maximum likelihood (ML) and Bayesian inference (BI) analyses, principal component analyses (PCA), and a multiple factor analysis (MFA) recover a new, widely allopatric species of the Cyrtodactylus intermedius species group. Cyrtodactylus kulenensis sp. nov is endemic to the Phnom Kulen sandstone massif of the Phnom Kulen National Park, Siem Reap Province, in the lowlands of northwestern Cambodia. A phylogenetic analysis from a short read (275 base pairs) of the mitochondrial gene NADH dehydrogenase subunit 2 (ND2) from C. kulenensis sp. nov. was aligned with 1449 base pairs from all other species in the intermedius group.  The analysis recovered C. kulenensis sp. nov. as the sister species to a lineage composed of populations from the widely separated hilly regions of Sa Keao and Sakaerat in eastern Thailand. Multivariate (PCA, DAPC, and MFA) and univariate analyses (ANOVA) using combinations of meristic (scale counts), mensural (morphometric), and categorical (color pattern and morphology) characters from 52 specimens encompassing all species of the intermedius group clearly demonstrate C. kulenensis sp. nov. is significantly different and discretely diagnosable from all other species in the intermedius group. This new discovery further highlights the herpetological diversity and high levels of range-restricted endemism in basin-habitat-island landscapes throughout Indochina and the continued need for field work in the landscapes that remain unsurveyed. 


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