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...

Nearly 800 nucleotides from the 5' terminus of the 28S ribosomal gene of Paracoccidioides brasiliensis were sequenced, and a 14-base DNA probe specific for this species was identified. Hybridization results showed that the probe identified P. brasiliensis ribosomal DNA in a panel of ribosomal DNAs representing a total of 48 species of fungi.

Paratylenchus shenzhenensis n. sp. was collected from the rhizosphere soil of Anthurium andraeanum in Shenzhen, Guangdong Province, China. The new species is characterized by having a female with a small body (249-302 μm), well developed stylet (17-21 μm), rounded head with four submedian lobes and lip-region with a slight depression at the oral area, small post-vulval uterine sac with a few ve...

BACKGROUND Metagenetic analyses, which amplify and sequence target marker DNA regions from environmental samples, are increasingly employed to assess the biodiversity of communities of small organisms. Using this approach, our understanding of microbial diversity has expanded greatly. In contrast, only a few studies using this approach to characterize metazoan diversity have been reported, desp...

Species identification using DNA sequences is the basis for DNA taxonomy. In this study, we sequenced the ribosomal large-subunit RNA gene sequences (3,037-3,061 bp) in length of 13 Chinese Theileria stocks that were infective to cattle and sheep. The complete 28S rRNA gene is relatively difficult to amplify and its conserved region is not important for phylogenetic study. Therefore, we selecte...

Mouse-human somatic cell hybrids that lose (segregate) human chromosomes produce only mouse 28S ribosomal RNA even when they retain copies of the human chromosomes that contain the genes for 28S ribosomal RNA. In contrast, mouse-human hybrid cells that segregate mouse chromosomes produce only human 28S ribosomal RNA even when they have retained copies of mouse chromosomes that contain the 28S r...

We have analyzed multiple recombinant DNA clones containing ribosomal RNA repeat units of the silkmoth, Bombyx mori. In combination with genomic DNA blots, analysis of these clones indicated that the rDNA repeat of B. mori is 10.8 kilobase pair in length and tandemly repeated in the genome, as reported by Manning et al. (18). However, contrary to that report, approximately 12% of the rDNA cistr...

We have amplified and sequenced the 5.8S and 28S ribosomal DNA genes and intergenic regions of Paracoccidioides brasiliensis, strain Pb01. Using primers specifically designed for both ribosomal DNA regions, we were able to discriminate between P. brasiliensis and other human pathogenic fungi by PCR. The use of this molecular marker could be important for paracoccidiodomycosis diagnosis and ecol...

An RNA-ribosomal DNA complex can be isolated from ovaries of Xenopus laevis incubated in vitro during the amplification stage. A part of the RNA present in the complex is resistent to RNase but becomes completely sensitive after heat denaturation, a treatment that also allows the separation of the RNA from the DNA. The size of the RNA-ribosomal DNA complex is strongly reduced after treatment wi...