Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
6
pubmed:dateCreated
2005-5-12
pubmed:abstractText
In kinetoplastids, Euglena, and four metazoan phyla, trans-splicing has been described as a mechanism for the generation of mature messenger RNAs (mRNAs): 5'-ends of precursor mRNAs are replaced by a short spliced leader (SL) exon from a small SL RNA. Although the full phylogenetic range is unknown, trans-splicing has not been found in vertebrates, insects, plants, or yeast. In animal groups where it does occur, i.e., nematodes, cnidarians, platyhelminths, and primitive chordates, SL RNAs do not show sequence relatedness across phyla. The apparently sporadic phylogenetic distribution and the lack of SL RNA homology have led to opposing hypotheses on its evolution, involving either an ancient origin followed by loss in multiple lineages or independent acquisition in several taxa. Here we present evidence for the occurrence of trans-splicing in bdelloid rotifers (Bdelloidea, Rotifera). A common 23-nt sequence, representing the SL exon-diagnostic of SL RNA-mediated trans-splicing-was found at the 5'-end of at least 50%-65% of mRNAs from Adineta ricciae and Philodina sp. The trans-splicing pattern in bdelloid rotifers can be unusually complex, as observed in transcripts from a heat shock protein gene, hsp82-1, where the SL exon was spliced to three alternative positions. Bdelloid rotifer SL RNAs were found to be 105 or 106 nt long and comprised the SL sequence, a conserved splice donor site and an intron containing a putative spliceosome-binding motif. Intriguingly, some similarity of rotifer SL RNA sequence and predicted secondary structure was seen to that of the predominant SL1 RNA of nematodes, although it is unlikely that this demonstrates homology. In addition, sequence corresponding to the rotifer SL exon was found at the 5'-end of a number of full-length complementary DNA (cDNA) clones in a rice (Oryza sativa) database. None of these cDNAs gave a close match with homologous plant genes, suggesting that a small but significant portion of the rice expressed sequence tag database represents sequences derived from rotifers. In summary, the description of SL-mediated trans-splicing in Rotifera extends its representation to at least five metazoan phyla, making it increasingly probable that this is a phylogenetically widespread and therefore ancient phenomenon.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jun
pubmed:issn
0737-4038
pubmed:author
pubmed:issnType
Print
pubmed:volume
22
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1482-9
pubmed:dateRevised
2010-11-18
pubmed:meshHeading
pubmed-meshheading:15788744-Animals, pubmed-meshheading:15788744-Base Sequence, pubmed-meshheading:15788744-Biological Evolution, pubmed-meshheading:15788744-DNA, Complementary, pubmed-meshheading:15788744-Evolution, Molecular, pubmed-meshheading:15788744-Exons, pubmed-meshheading:15788744-Genes, Plant, pubmed-meshheading:15788744-Genome, Plant, pubmed-meshheading:15788744-Models, Genetic, pubmed-meshheading:15788744-Molecular Sequence Data, pubmed-meshheading:15788744-Nucleic Acid Conformation, pubmed-meshheading:15788744-Oryza sativa, pubmed-meshheading:15788744-Phylogeny, pubmed-meshheading:15788744-RNA, Spliced Leader, pubmed-meshheading:15788744-RNA Precursors, pubmed-meshheading:15788744-RNA Splicing, pubmed-meshheading:15788744-Rotifera, pubmed-meshheading:15788744-Sequence Homology, Nucleic Acid, pubmed-meshheading:15788744-Spliceosomes, pubmed-meshheading:15788744-Trans-Splicing
pubmed:year
2005
pubmed:articleTitle
Spliced leader RNA-mediated trans-splicing in phylum Rotifera.
pubmed:affiliation
Institute of Biotechnology, University of Cambridge, Cambridge, United Kingdom.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't