TITLE

Secondary loss of a cis-spliced intron during the divergence of Giardia intestinalis assemblages

AUTHOR(S)
Ryoma Kamikawa; Yuji Inagaki; Tetsuo Hashimoto
PUB. DATE
July 2014
SOURCE
BMC Research Notes;2014, Vol. 7 Issue 1, p2
SOURCE TYPE
Academic Journal
DOC. TYPE
Article
ABSTRACT
Background Giardia intestinalis is a parasitic unicellular eukaryote with a highly reduced genome, in which only six cis-spliced and four trans-spliced introns have been discovered. However, we anticipate that more cis- and trans-spliced introns likely remain unidentified in genes encoding hypothetical proteins that occupy ca. 2/3 of all of the open reading frames (ORFs) in the Giardia genome. Consequently, comprehensive surveys of introns in ORFs for hypothetical proteins are critical for better understanding of the intron evolution in this organism. Results In this study, we identified two novel cis-spliced introns in the draft genome data of G. intestinalis strain WB, by surveying the conserved sequence motifs shared amongst the previously known introns. G. intestinalis strains can be divided into phylogenetically distinct assemblages A-H, and all the introns identified in past studies are shared among the published genome data from strains WB, DH, GS, and P15 representing assemblages A1, A2, B, and E, respectively. Nevertheless one of the two novel introns identified in this study was found to be absent in strain P15. Conclusion By considering the organismal relationship among G. intestinalis assemblages A1, A2, B, and E, one of the two introns identified in this study has highly likely been lost after the divergence of the assemblages. On the basis of a sequence comparison between the intronbearing loci in WB, DH, and GS genomes and the homologous but intron-free locus in P15 genome, we propose that the loss of this particular intron was mediated by integration of the DNA fragment reverse-transcribed from mature mRNAs.
ACCESSION #
97130455

 

Related Articles

  • Computational Identification of Four Spliceosomal snRNAs from the Deep-Branching Eukaryote Giardia intestinalis. Chen, Xiaowei Sylvia; White, W. Timothy J.; Collins, Lesley J.; Penny, David // PLoS ONE;2008, Vol. 3 Issue 8, p1 

    RNAs processing other RNAs is very general in eukaryotes, but is not clear to what extent it is ancestral to eukaryotes. Here we focus on pre-mRNA splicing, one of the most important RNA-processing mechanisms in eukaryotes. In most eukaryotes splicing is predominantly catalysed by the major...

  • GENOME EVOLUTION: Introns branch out. Alfred, Jane // Nature Reviews Genetics;Apr2002, Vol. 3 Issue 4, p236 

    Discusses research being done on a spliceosomal intron in Giardia lamblia. Reference to a study by Nixon et al; Origins of eukaryotic introns.

  • Evaluating the evolution of G. lamblia based on the small nucleolar RNAs identified from Archaea and unicellular eukaryotes. Man Teng; Gai-Ping Zhang; Zhao-Rong Lun; Hui Zhou; Liang-Hu Qu // Parasitology Research;Jun2009, Vol. 104 Issue 6, p1543 

    Abstract  The evolutionary position of Giardia lamblia has been challenged in recent years. Comparison of the snoRNAs identified from Archaea and unicellular eukaryotes shows that G. lamblia snoRNAs are more similar in most respects to the counterparts identified from Dictyostelium...

  • Giardia: Not so special, after all? Knight, Jonathan // Nature;5/20/2004, Vol. 429 Issue 6989, p236 

    Discusses the confusion on the role of Giardia intestinalis in the evolution of life. Hypothesis of scientists on the development of mitochondria by eukaryotes; Role of a prokaryotic cellular parasite that could process oxygen in the development; Question on the evolutionary position of the...

  • Interactions between Giardia duodenalis Sm proteins and their association with spliceosomal snRNAs. Gómez, Vanessa; Wasserman, Moisés // Parasitology Research;Feb2017, Vol. 116 Issue 2, p617 

    Giardia duodenalis is a parasite that colonises the intestines of humans and other vertebrates, causing diarrhoea and poor nutrient absorption. G. duodenalis is sometimes considered an early diverging eukaryote, and its genome exhibits simplified molecular machinery for many cellular processes,...

  • Parasite With Minimalist Genome May Offer Clues To Metabolism. Kingman, Sharon // BioWorld International;10/3/2007, Vol. 12 Issue 40, p1 

    The article reports on the claim of Staffan Svärd, an associate professor at Uppsala University in Sweden, that a newly available genome sequence of the intestinal parasite Giardia lamblia could lead to alternative therapies for treating the diarrhea it causes, as well as better understanding...

  • Giardia: A Missing Link between Prokaryotes and Eukaryotes. Kabnick, Karen S.; Peattie, Debra A. // American Scientist;Jan/Feb91, Vol. 79 Issue 1, p34 

    Analyzes the intestinal parasite Giardia lamblia as a representative of the first line of descent from prokaryotic to eukaryotic cells. Information on prokaryotes and eukaryotes; Emergence of the first eukaryote; Findings suggesting Giardia as the missing link.

  • Live Imaging of Mitosomes and Hydrogenosomes by HaloTag Technology. Martincov�, Eva; Voleman, Lubo�; Najdrov�, Vladim�ra; De Napoli, Maximiliano; Eshar, Shiri; Gualdron, Melisa; Hopp, Christine S.; Sanin, David E.; Tembo, Dumizulu L.; Van Tyne, Daria; Walker, Dawn; Marcincikov�, Michaela; Tachezy, Jan; Dole�al, Pavel // PLoS ONE;Apr2012, Vol. 7 Issue 4, p1 

    Hydrogenosomes and mitosomes represent remarkable mitochondrial adaptations in the anaerobic parasitic protists such as Trichomonas vaginalis and Giardia intestinalis, respectively. In order to provide a tool to study these organelles in the live cells, the HaloTag was fused to G. intestinalis...

  • Live Imaging of Mitosomes and Hydrogenosomes by HaloTag Technology. Martincová, Eva; Voleman, Luboš; Najdrová, Vladimíra; De Napoli, Maximiliano; Eshar, Shiri; Gualdron, Melisa; Hopp, Christine S.; Sanin, David E.; Tembo, Dumizulu L.; Van Tyne, Daria; Walker, Dawn; Marcinčiková, Michaela; Tachezy, Jan; Doležal, Pavel // PLoS ONE;Apr2012, Vol. 7 Issue 4, p1 

    Hydrogenosomes and mitosomes represent remarkable mitochondrial adaptations in the anaerobic parasitic protists such as Trichomonas vaginalis and Giardia intestinalis, respectively. In order to provide a tool to study these organelles in the live cells, the HaloTag was fused to G. intestinalis...

Share

Read the Article

Courtesy of THE LIBRARY OF VIRGINIA

Sorry, but this item is not currently available from your library.

Try another library?
Sign out of this library

Other Topics