TY - JOUR A1 - Schmid, Michael A1 - Steinlein, Claus T1 - Chromosome Banding in Amphibia. XXXIII. Demonstration of 5-Methylcytosine-Rich Heterochromatin in Anura JF - Cytogenetic and Genome Research N2 - 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. KW - Anura KW - heterochromatin KW - hypermethylated DNA KW - immunofluorescence KW - 5-Methylcytosine Y1 - 2016 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-199022 SN - 1424-8581 SN - 1424-859X N1 - This publication is with permission of the rights owner freely accessible due to an Alliance licence and a national licence (funded by the DFG, German Research Foundation) respectively. VL - 148 IS - 1 ER - TY - JOUR A1 - Schmid, Michael A1 - Steinlein, Claus T1 - Chromosome Banding in Amphibia. XXXIV. Intrachromosomal Telomeric DNA Sequences in Anura JF - Cytogenetic and Genome Research N2 - The mitotic chromosomes of 4 anuran species were examined by various classical banding techniques and by fluorescence in situ hybridization using a (TTAGGG)\(_n\) repeat. Large intrachromosomal telomeric sequences (ITSs) were demonstrated in differing numbers and chromosome locations. A detailed comparison of the present results with numerous published and unpublished data allowed a consistent classification of the various categories of large ITSs present in the genomes of anurans and other vertebrates. The classification takes into consideration the total numbers of large ITSs in the karyotypes, their chromosomal locations and their specific distribution patterns. A new category of large ITSs was recognized to exist in anuran species. It consists of large clusters of ITSs located in euchromatic chromosome segments, which is in clear contrast to the large ITSs in heterochromatic chromosome regions known in vertebrates. The origin of the different categories of large ITSs in heterochromatic and euchromatic chromosome regions, their mode of distribution in the karyotypes and evolutionary fixation in the genomes, as well as their cytological detection are discussed. KW - heterochromatin KW - intrachromosomal telomeric sequences KW - Anura KW - euchromatin KW - evolutionary fixation Y1 - 2016 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-196693 SN - 1424-8581 SN - 1424-859X N1 - This publication is with permission of the rights owner freely accessible due to an Alliance licence and a national licence (funded by the DFG, German Research Foundation) respectively. VL - 148 IS - 2-3 ER - TY - JOUR A1 - Schmid, Michael A1 - Steinlein, Claus A1 - Lomb, Christian A1 - Sperling, Karl A1 - Neitzel, Heidemarie T1 - 5-Methylcytosine-Rich Heterochromatin in the Indian Muntjac JF - Cytogenetic and Genome Research N2 - Two 5-methylcytosine (5-MeC)-rich heterochromatic regions were demonstrated in metaphase chromosomes of the Indian muntjac by indirect immunofluorescence using a monoclonal anti-5-MeC antibody. The metaphases were obtained from diploid and triploid cell lines. A major region is located in the ‘neck' of the 3;X fusion chromosome and can be detected after denaturation of the chromosomal DNA with UV-light irradiation for 1 h. It is located exactly at the border of the X chromosome and the translocated autosome 3. A minor region is found in the centromeric region of the free autosome 3 after denaturing the chromosomal DNA for 3 h or longer. The structure and possible function of the major hypermethylated region as barrier against spreading of the X-inactivation process into the autosome 3 is discussed. KW - heterochromatin KW - immunofluorescence KW - Indian muntjac KW - 5-Methylcytosine Y1 - 2016 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-196701 SN - 1424-8581 SN - 1424-859X N1 - This publication is with permission of the rights owner freely accessible due to an Alliance licence and a national licence (funded by the DFG, German Research Foundation) respectively. VL - 147 IS - 4 ER - TY - JOUR A1 - Schmid, Michael A1 - Steinlein, Claus A1 - Yano, Cassia F. A1 - Cioffi, Marcelo B. T1 - Hypermethylated Chromosome Regions in Nine Fish Species with Heteromorphic Sex Chromosomes JF - Cytogenetic and Genome Research N2 - 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. KW - heterochromatin KW - heteromorphic sex chromosomes KW - hypermethylation KW - immunofluorescence KW - 5-Methylcytosine KW - fish Y1 - 2016 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-196710 SN - 1424-8581 SN - 1424-859X N1 - This publication is with permission of the rights owner freely accessible due to an Alliance licence and a national licence (funded by the DFG, German Research Foundation) respectively. VL - 147 IS - 2-3 ER -