Ribosomal RNA precursors and mature 28S ribosomal RNA from HeLa cells display a highly reproducible secondary structure of hairpin loops after they are spread and examined in an electron microscope. This structure was used to map the linear arrangement of these molecules. Partial digestion with 3'-exonuclease from ascites cell nuclei established that the 28S RNA region is located at the 5'-end ...

Cytogenetic analyses of the location of 18S and 5S ribosomal DNAs, and the base composition of B chromosomes of Iheringichthys labrosus from Tibagi River, Paraná, Brazil, are provided. AgNORs were observed in the terminal position on the long arm of a subtelocentric chromosome pair. CMA3-positive staining was observed in some chromosomes, which besides being associated with NORs, were all DAPI-...

Initiation factor eIF-3 from rat liver forms a binary complex with the small ribosomal subunit. Within this complex, 18S ribosomal RNA can be cross-linked to the 66 000 dalton subunit of eIF-3 by treating the complex with a short bifunctional reagent, diepoxybutane, with a distance of 4A between the reactive groups. In binary complexes containing eIF-3 premodified with the heterobifunctional re...

Cryptosporidium oocysts were found in 43 out of 77 calves from two farms in Iwate Prefecture and nine farms on Tanegashima Island, Kagoshima Prefecture, Japan. The DNA fragments of 18S ribosomal RNA (18S rRNA) gene were amplified by a nested PCR from 43 oocyst-positive as well as one oocyst-negative samples. All of them were precisely identified as C. parvum by analyzing the nucleotide sequence...

When studying the altered expression of genes associated with cartilage regeneration by quantitative real-time RT-PCR (RT-qPCR), reference genes with highly stable expression during different stages of chondrocyte developmental are necessary to normalize gene expression accurately. Until now, no reports evaluating expression changes of commonly used reference genes in rabbit articular cartilage...

In Europe, most reported human cases of babesiosis have been attributed, without strong molecular evidence, to infection with the bovine parasite Babesia divergens. We investigated the first known human cases of babesiosis in Italy and Austria, which occurred in two asplenic men. The complete 18S ribosomal RNA (18S rRNA) gene was amplified from specimens of their whole blood by polymerase chain...

The primary structure of rabbit 18S ribosomal RNA was determined by nucleotide sequence analysis of the RNA directly. The rabbit rRNA was specifically cleaved with T1 ribonuclease, as well as with E. coli RNase H using a Pst 1 DNA linker to generate a specific set of overlapping fragments spanning the entire length of the molecule. Both intact and fragmented 18S rRNA were end-labeled with [32P]...

In situ hybridization of 18S-5.8S-25S rDNA probes labeled with biotin or rhodamine and 5S rDNA probes labeled with digoxigenin was used to locate rDNA sites on root-tip metaphase chromosomes of Citrus sinensis L. (2n = 2x = 18), Poncirus trifoliata L. Raf. (2n = 2x = 18), and Citrus x Poncirus hybrids (2n = 2x = 18). Counterstaining with the fluorochromes chromomycin A3 and DAPI uniquely identi...

Quantitative RT-PCR analysis. The following primers were used to amplify β-casein cDNA and 18S rRNA sequences: forward primer of the β-casein gene 5'-GCT CAG GCT CAA ACC ATC TC-3' and reverse primer 5'-TGT GGA AGG AAG GGT GCT AC-3'; forward primer of the 18S rRNA gene 5’-TCGGAACTGAGGCCATGATT-3’ and reverse primer 5’CCTCCGACTTTCGTTCTTGATT-3’. Fragments of β-casein gene and 18S rRNA were amplifie...

Truncated mouse ribosomal DNA (rDNA) genes were stably incorporated into rat HTC-5 cells by DNA-mediated cell transfection techniques. The mouse rDNA genes were accurately transcribed in these rat cells indicating that there is no absolute species specificity of rDNA transcription between mouse and rat. No more than 170 nucleotides of the 5' nontranscribed spacer was required for the accurate i...