Based upon the three experimentally derived models of E. coli 23S rRNA (1-3) and partial model for yeast 26S (4), which was deduced by homology to coli, we a secondary structure Xenopus laevis 28S rRNA. This is first complete presented eukaryotic Compensatory base changes support general validity our offer help resolve correct in regions where they are different from one another. Eukaryotic rDNA longer than prokaryotic virtue introns, expansion segments transcribed spacers, all discussed...

We have determined the complete nucleotide sequence of Xenopus laevie 28S rDNA (4110 bp). In order to locate evolutionarily conserved regions within rDNA, we compared homologous sequences from yeast, Physarum . and E. coli Numerous homology are dispersed throughout entire length all four organisms. These a higher A+T base composition than remainder rDNA. The has nine major areas inserted when 23S total these inserts in is 83Z G+C, generally responsible for high (66Z) G+C content as whole....

Sites of DNA synthesis initiation have been detected at the nucleotide level in a yeast origin bidirectional replication with use point mapping. The ARS1 Saccharomyces cerevisiae showed transition from discontinuous to continuous an 18-base pair region (nucleotides 828 845) within element B1 toward B2, adjacent binding site for recognition complex, putative initiator protein.

Nascent strand sequencing (NS-seq) is used to discover DNA replication origins genome-wide, allowing identification of features for their specification. NS-seq depends on the ability lambda exonuclease (λ-exo) efficiently digest parental while leaving RNA-primer protected nascent strands intact. We genomics and biochemical approaches determine if λ-exo digests all sequences equally. report that does not G-quadruplex (G4) structures in a plasmid. Moreover, digestion nonreplicating genomic...

Ribosomal protein L1 from the prokaryote Escherichia coli has been shown to form a specific complex with 26S ribosomal RNA eukaryote Dictyostelium discoideum. The segment of rRNA protected ribonuclease digestion by and corresponding region in rDNA were investigated nucleotide sequence analysis, an analogous section Xenopus laevis was identified. When L1-specific segments eukaryotic compared those prokaryotic rRNA, striking similarities both primary secondary structure apparent. These...

Using a combination of RNA sequencing and construction cDNA clones followed by DNA sequencing, we have determined the primary nucleotide sequence U3 snRNA in Xenopuslaevis Xenopus borealis This molecule has length 219 nucleotides. Alignment sequences with from other organisms reveals three evolutionarily conserved blocks. We probed secondary structure intact nuclei using single-strand specific chemical reagents; primer extension was used to map positions modification. The blocks fall within...

Germline-restricted DNA has evolved in diverse animal taxa and is found several vertebrate clades, nematodes, flies. In these lineages, either portions of chromosomes or entire are eliminated from somatic cells early development, restricting the genome to germline. Little known about why germline-restricted evolved, especially flies, which 3 families, Chironomidae, Cecidomyiidae, Sciaridae, carry (GRCs). We conducted a genomic analysis GRCs fungus gnat Bradysia ( Sciara ) coprophila...

Two independent two-dimensional (2D) gel methods were used to map an origin of replication that is developmentally regulated by the steroid hormone ecdysone, namely for DNA puff amplification in fungus fly Sciara coprophila. Initiation was found occur within a small region no larger than 6 kb use neutral/neutral 2D method. Neutral/alkaline analyses support results gels and further define approximately 1-kb area where majority initiates. This first example multicellular eukaryotes has been...

ABSTRACT Oxford Nanopore Technologies’ nanopore sequencing device, the MinION, holds promise of ultra-long DNA fragments >100kb. An obstacle to realizing this is delivering molecules nanopores. We present our progress in developing cost-effective ways overcome and resulting MinION data, including multiple reads

Recent studies on the 2′-O-methylation and pseudouridylation of U6 small nuclear RNA (snRNA) hypothesize that these posttranscriptional modifications might occur in nucleolus. In this report, we present direct evidence for nucleolar localization snRNA analyze kinetics after injection vitro transcribed fluorescein-labeled transcripts into Xenopus laevis oocytes. contrast to U3 (snoRNA) which developed strong labeling over 4 h maintained signals through 24 h, localized nucleoli immediately...