@article{SchmidSteinlein2016, author = {Schmid, Michael and Steinlein, Claus}, title = {Chromosome Banding in Amphibia. XXXIII. Demonstration of 5-Methylcytosine-Rich Heterochromatin in Anura}, series = {Cytogenetic and Genome Research}, volume = {148}, journal = {Cytogenetic and Genome Research}, number = {1}, issn = {1424-8581}, doi = {10.1159/000446141}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-199022}, pages = {35-43}, year = {2016}, abstract = {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.}, language = {en} } @article{SchmidSteinleinLombetal.2016, author = {Schmid, Michael and Steinlein, Claus and Lomb, Christian and Sperling, Karl and Neitzel, Heidemarie}, title = {5-Methylcytosine-Rich Heterochromatin in the Indian Muntjac}, series = {Cytogenetic and Genome Research}, volume = {147}, journal = {Cytogenetic and Genome Research}, number = {4}, issn = {1424-8581}, doi = {10.1159/000444431}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-196701}, pages = {240-246}, year = {2016}, abstract = {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.}, language = {en} } @article{SchmidSteinleinYanoetal.2016, author = {Schmid, Michael and Steinlein, Claus and Yano, Cassia F. and Cioffi, Marcelo B.}, title = {Hypermethylated Chromosome Regions in Nine Fish Species with Heteromorphic Sex Chromosomes}, series = {Cytogenetic and Genome Research}, volume = {147}, journal = {Cytogenetic and Genome Research}, number = {2-3}, issn = {1424-8581}, doi = {10.1159/000444067}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-196710}, pages = {169-178}, year = {2016}, abstract = {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.}, language = {en} }