5-Methylcytosine-Rich Heterochromatin in Reptiles

2019 ◽  
Vol 157 (1-2) ◽  
pp. 53-64 ◽  
Author(s):  
Michael Schmid ◽  
Claus Steinlein ◽  
Alina M. Reiter ◽  
Michail Rovatsos ◽  
Marie Altmanová ◽  
...  
Keyword(s):  
Indirect Immunofluorescence ◽  
Sex Chromosomes ◽  
Dna Sequences ◽  
Experimental Approach ◽  
Constitutive Heterochromatin ◽  
Banding Patterns ◽  
Turtle Species ◽  
C Banding ◽  
Species Specific ◽  
Chromosome Regions

An experimental approach using monoclonal anti-5-methylcytosine antibodies and indirect immunofluorescence was elaborated for detecting 5-methylcytosine-rich chromosome regions in reptilian chromosomes. This technique was applied to conventionally prepared mitotic metaphases of 2 turtle species and 12 squamate species from 8 families. The hypermethylation patterns were compared with C-banding patterns obtained by conventional banding techniques. The hypermethylated DNA sequences are species-specific and are located in constitutive heterochromatin. They are highly reproducible and often found in centromeric, pericentromeric, and interstitial positions of the chromosomes. Heterochromatic regions in differentiated sex chromosomes are particularly hypermethylated.

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 Chromosome Banding in Amphibia. XXXIII. Demonstration of 5-Methylcytosine-Rich Heterochromatin in Anura

2016 ◽  
Vol 148 (1) ◽  
pp. 35-43
Author(s):  
Michael Schmid ◽  
Claus Steinlein
Keyword(s):  
Dna Sequences ◽  
Nucleolus Organizer ◽  
Major Influence ◽  
Banding Patterns ◽  
Nucleolus Organizer Regions ◽  
Experimental Parameters ◽  
Species Specific ◽  
Antibody Labeling ◽  
Chromosome Regions

An experimental approach using monoclonal anti-5-methylcytosine (5-MeC) antibodies and indirect immunofluorescence was elaborated for detecting 5-MeC-rich chromosome regions in anuran chromosomes. This technique was applied to mitotic metaphases of 6 neotropical frog species belonging to 6 genera and 4 families. The hypermethylation patterns were compared with a variety of banding patterns obtained by conventional banding techniques. The hypermethylated DNA sequences are species-specific and located exclusively in constitutive heterochromatin. They are found in centromeric, pericentromeric, telomeric, and interstitial positions of the chromosomes and adjacent to nucleolus organizer regions. 5-MeC-rich DNA sequences can be embedded both in AT- and GC-rich repetitive DNA. The experimental parameters that have major influence on the reproducibility and quality of the anti-5-MeC antibody labeling are discussed.

Demonstration of 5-Methylcytosine-Rich DNA Sequences in Chiroptera

2017 ◽  
Vol 152 (1) ◽  
pp. 38-45 ◽  
Author(s):  
Michael Schmid ◽  
Claus Steinlein ◽  
Christian Lomb ◽  
Marianne Volleth
Keyword(s):  
Chromosome Number ◽  
Repetitive Dna ◽  
Dna Sequences ◽  
Constitutive Heterochromatin ◽  
Metaphase Chromosomes ◽  
Valuable Data ◽  
Species Specific ◽  
Antibody Labeling ◽  
Chromosome Segments ◽  
Chromosome Regions

5-Methylcytosine-rich heterochromatic regions were demonstrated in metaphase chromosomes of 5 species of Chiroptera by indirect immunofluorescence using a monoclonal anti-5-methylcytosine antibody. These species belong to 4 genera and 2 families and are characterized by divergent karyotypes. One species (Glauconycteris beatrix) has an extremely low diploid chromosome number of 2n = 22 with only meta- to submetacentric elements and remarkably large amounts of constitutive heterochromatin located in the centromeric and pericentromeric regions of all chromosome pairs. Two species (G. beatrix and Neoromicia cf. guineensis) possess X-autosome translocations. In all species, the hypermethylated chromosome segments correspond to constitutive heterochromatin, and the numbers and positions of hypermethylated chromosome segments in the karyotypes are constant and species-specific. In some species (Pipistrellus hesperidus, Neoromicia cf. somalicus), there are several smaller chromosome pairs in which the bright anti-5-methylcytosine antibody labeling is not restricted to constitutively heterochromatic regions but is observed along the whole lengths of these chromosomes. The nature of these additional hypermethylated regions is discussed. The analysis of 5-methylcytosine-rich chromosome regions elucidates valuable data for chiropteran cytogenetics and reflects the high pace of evolution of the repetitive DNA fraction in their genomes.

CHROMOSOMES AND DNA OF MICROTUS II. CONFIRMATION OF DELETION OF CONSTITUTIVE HETEROCHROMATIN IN M. AGRESTIS CELLS IN VITRO

1977 ◽  
Vol 19 (3) ◽  
pp. 537-541 ◽  
Author(s):  
J. E. K. Cooper
Keyword(s):  
Somatic Cell ◽  
Cell Line ◽  
Cell Lines ◽  
X Chromosome ◽  
Sex Chromosomes ◽  
Constitutive Heterochromatin ◽  
The Other ◽  
Microtus Agrestis ◽  
C Banding

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.

G and/or C-bands in plant chromosomes?

1984 ◽  
Vol 71 (1) ◽  
pp. 111-120
Author(s):  
I. Schubert ◽  
R. Rieger ◽  
P. Dobel
Keyword(s):  
Constitutive Heterochromatin ◽  
Giemsa Staining ◽  
Giemsa Banding ◽  
Base Pairs ◽  
Banding Patterns ◽  
C Banding ◽  
Plant Chromosomes ◽  
Nucleolus Organizing Region ◽  
Similarities And Differences ◽  
Simple Sequence

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.

Identification of the somatic chromosomes of Psathyrostachys fragilis (Poaceae)

1984 ◽  
Vol 26 (4) ◽  
pp. 430-435 ◽  
Author(s):  
I. Linde-Laursen ◽  
R. von Bothmer
Keyword(s):  
Silver Nitrate ◽  
Banding Pattern ◽  
Constitutive Heterochromatin ◽  
Differential Staining ◽  
Feulgen Staining ◽  
Banding Patterns ◽  
C Banding ◽  
Nucleolar Organizers ◽  
Silver Nitrate Staining ◽  
C And N

The karyotype of the outbreeding P. fragilis (2n = 2x = 14) was investigated by Feulgen staining and by C-, N-, and Ag-banding techniques. The complement consisted of 14 large chromosomes, 8 metacentrics and 6 satellite (SAT) chromosomes, probably among the longest within the Poaceae. Two SAT-chromosome pairs carried small, and one pair carried minute, polymorphic, completely heterochromatic satellites. Each chromosome could be referred to one of the seven chromosome pairs by its C-banding pattern. The patterns comprised from zero to three conspicuous, but not large bands per chromosome resulting in an overall low content of constitutive heterochromatin (<4%). The C-banded karyotype of P. fragilis differed from any previously reported in the Triticeae. Six of seven chromosome pairs were polymorphic either for C-banding patterns or satellite size (or for both). N-banding gave no differential staining of chromosomes. Silver nitrate staining established that the nucleolar organizers had different nucleolus-forming capacities. The presence of the small and minute satellites was more consistently demonstrated after C- and N-banding than after Feulgen staining.Key words: Triticeae, Poaceae, karyotype, C-, N-, and Ag-banding.

On sex determination in the Turkish desert woodlouse Hemilepistus elongatus (Crustacea, Isopoda, Oniscidea): searching for sex chromosomes and for sex-specific differences in simple DNA repeats

Genome ◽  
1996 ◽  
Vol 39 (4) ◽  
pp. 818-821 ◽  
Author(s):  
G. Röder ◽  
K. E. Linsenmair ◽  
I. Nanda ◽  
M. Schmid
Keyword(s):  
Chromosome Number ◽  
Sex Determination ◽  
Sex Chromosomes ◽  
Genomic Dna ◽  
Constitutive Heterochromatin ◽  
Dna Repeats ◽  
Male And Female ◽  
General Morphology ◽  
C Banding ◽  
Heteromorphic Sex Chromosomes

The karyotype of male and female Hemilepistus elongatus was investigated by means of C-banding. The diploid chromosome number in both sexes is 2n = 50. By scrutinizing general morphology and localization of the constitutive heterochromatin, no heteromorphic sex chromosomes were found. All chromosome pairs in males are well paired during diakinesis. Hybridization of genomic DNA with (GACA)4 and (GATA)4 oligonucleotides revealed no sex-specific patterns. Key words : karyotype, C-banding, sex determination, simple DNA-repeats, Isopoda.

The Hypermethylated Regions in Avian Chromosomes

2017 ◽  
Vol 151 (4) ◽  
pp. 216-227 ◽  
Author(s):  
Michael Schmid ◽  
Claus Steinlein
Keyword(s):  
Sex Chromosomes ◽  
Sex Chromosome ◽  
Bird Species ◽  
Evolutionary Process ◽  
General Rule ◽  
Centromeric Heterochromatin ◽  
Comparative Cytogenetics ◽  
Species Specific ◽  
Chromosome Segments ◽  
Chromosome Regions

Chromosomal locations and amounts of 5-methylcytosine-rich chromosome regions were detected in the karyotypes of 13 bird species by indirect immunofluorescence using a monoclonal anti-5-methylcytosine antibody. These species belong to 7 orders and 10 families of modern (Neognathae) and primitive (Palaeognathae) birds and are characterized by macro- and microchromosomes as well as ZW sex chromosomes. In all 13 species, the hypermethylated chromosome segments are confined to constitutive heterochromatin. The chromosomal locations of hypermethylated DNA regions in the karyotypes are constant and species-specific. There is no general rule with regard to the distribution of these hypermethylated chromosome regions in the genomes of birds. In most instances, hypermethylated segments are located in the centromeric regions of chromosomes, but in the sex chromosomes, these can also be found in telomeric and interstitial postitions. In most of the species studied, the centromeric heterochromatin in many, if not all, of the microchromosomes is hypermethylated. However, in one species, the only detectable hypermethylated heterochromatic regions are located in one pair of macroautosomes and in the Z sex chromosome, but none of the microchromosomes contains visible quantities of 5-methylcytosine. The analysis of 5-methylcytosine-rich chromosome regions can be very helpful for the comparative cytogenetics of closely related species or subspecies. It also reflects the dynamic evolutionary process operating in the highly repetitive DNA of eukaryotic chromosomes.

Oligonucleotide fingerprinting reveals various probe-dependent levels of informativeness in chickpea (Cicer arietinum)

Genome ◽  
1992 ◽  
Vol 35 (3) ◽  
pp. 436-442 ◽  
Author(s):  
Kurt Weising ◽  
Dieter Kaemmer ◽  
Franz Weigand ◽  
Jörg T. Epplen ◽  
Gunter Kahl
Keyword(s):  
Cicer Arietinum ◽  
Dna Sequences ◽  
Repetitive Sequences ◽  
Banding Patterns ◽  
Simple Repetitive Sequences ◽  
Leguminous Crop ◽  
Oligonucleotide Fingerprinting ◽  
Species Specific ◽  
Synthetic Oligonucleotides ◽  
Different Levels

Synthetic oligonucleotides complementary to simple repetitive DNA sequences were used to detect inter- and intra-specific polymorphisms in a leguminous crop plant (chickpea, Cicer arietinum) and its wild relatives. All the investigated repetitive motifs [(GACA)4, (GATA)4, (GTG)5, (CA)8, (TCC)5, (GGAT)4, and (AGTTT)4] were abundantly present and polymorphic in the chickpea genome. Different probes revealed different levels of variability. Whereas species-specific banding patterns were obtained with the (GTG)5 probe, other probes revealed differences between accessions, or even individuals. The somatic multilocus patterns were stable for all probes.Key words: genetic polymorphism, simple repetitive sequences, DNA fingerprinting, synthetic oligonucleotide probes.

Differentiation of four taxa of the Anopheles balabacensis complex using H-banding patterns in the sex chromosomes

1984 ◽  
Vol 26 (4) ◽  
pp. 425-429 ◽  
Author(s):  
S. Wibowo ◽  
V. Baimai ◽  
R. G. Andre
Keyword(s):  
Sex Chromosomes ◽  
Species Differences ◽  
Constitutive Heterochromatin ◽  
Staining Technique ◽  
Hoechst 33258 ◽  
Metaphase Chromosomes ◽  
Banding Patterns ◽  
Morphological Studies ◽  
Anopheles Balabacensis ◽  
Distinct Taxon

Analyses of metaphase chromosomes of four taxa of the Anopheles balabacensis complex (A. dirus A, B, and C, and A. takasagoensis) using the Hoechst 33258 staining technique have revealed remarkable differences in the fluorescence banding patterns of the sex chromosomes. These result from changes in the amount and distribution of constitutive heterochromatin. This evidence supports the results from cross-mating experiments and from morphological studies which indicate that three of these taxa, A. takasagoensis, dirus A, and dirus B, are sibling species. Differences in H-staining patterns of the sex chromosomes of a dirus colony from Kanchanaburi suggest that it too is a genetically distinct taxon, provisionally designated as dirus C, within the A. balabacensis complex.Key words: Anopheles, H-banding, heterochromatin, sex chromosomes.

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