background: the phylogenetic location of chinese spirometra sparganum isolates remains unclear. the aim of this study was to explore the phylogenetic location of the spirometra sparganum isolates from china. methods: the 28s ribosomal dna (rdna) d1 sequences of 14 spirometra sparganum isolates collected from thirteen locations in china were analyzed by using neighbor-joining (nj), maximum parsi...

We have determined the complete nucleotide sequence of Xenopus laevis 28S rDNA (4110 bp). In order to locate evolutionarily conserved regions within rDNA, we compared the Xenopus 28S sequence to homologous rDNA sequences from yeast, Physarum, and E. coli. Numerous regions of sequence homology are dispersed throughout the entire length of rDNA from all four organisms. These conserved regions hav...

Eco-RI-A fragments of the human ribosomal RNA gene family from two types of tissue and three individuals were cloned in lambda vectors and compared by restriction enzyme digestion and electron microscopy. The EcoRI fragment A contains (i) 0.2 kb of the 3' end of the 18S rDNA, (ii) 2.5 kb of internal transcribed spacer and the 5.8S rDNA, and (iii) 4.6 kb of the 28S rDNA gene. All of the six clon...

PURPOSE Repetitive ribosomal DNA (rDNA) genes are GC-rich clusters in the human genome. The aim of the study was to determine the methylation status of two rDNA subunits, the 18S and 28S genes, in ovarian tumors and to correlate methylation levels with clinicopathologic features in a cohort of ovarian cancer patients. EXPERIMENTAL DESIGN 18S and 28S rDNA methylation was examined by quantitati...

sequence data of a recent coi barcoding study on fish from the nayband national park in the persian gulf showed relatively high sequence divergence among nominal gerres filamentosus specimens. the sequences grouped into two clusters, signaling the possible existence of cryptic species. the clustering pattern was corroborated by results of 16s rdna sequencing. we investigated the hypothesis that...

A new species, Descolea quercina, is described and illustrated from Northern parts of Khyber Pakhtunkhwa, Pakistan. It is characterized by medium to large basidiomata, squamose to squamose-granulose hygrophanous pileus, and limoniform, verrucose basidiospores with partly concrescent verrucae. Phylogenetic analyses of nuc rDNA region encompassing the internal transcribed spacers 1 and 2 along wi...

BACKGROUND The phylogenetic location of Chinese Spirometra sparganum isolates remains unclear. The aim of this study was to explore the phylogenetic location of the Spirometra sparganum isolates from China. METHODS The 28S ribosomal DNA (rDNA) D1 sequences of 14 Spirometra sparganum isolates collected from thirteen locations in China were analyzed by using Neighbor-Joining (NJ), maximum parsi...

We obtained two different clones (16 kb and 13 kb) of B. mori rDNA with intron sequence within the 28S-rRNA coding region. The sequence surrounding the intron was found to be highly conserved as indicated in several eukaryotes (Tetrahymena, Drosophila and Xenopus). The 28S rRNA-coding sequence of 16 kb and 13 kb clone was interrupted at precisely the same sites as those where the D. melanogaste...