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PMID: 12034842 Published · ppublish English Journal Article Research Support, Non-U.S. Gov't Research Support, U.S. Gov't, Non-P.H.S.

A novel family of mobile genetic elements is limited to the germline genome in Tetrahymena thermophila.

Nucleic acids research ·Vol. 30 ·No. 11 ·2002-06-01 ·Pages 2524-37

Wuitschick JD, Gershan JA, Lochowicz AJ, Li S, Karrer KM

Abstract

In the ciliated protozoan Tetrahymena thermophila, extensive DNA elimination is associated with differentiation of the somatic macronucleus from the germline micronucleus. This study describes the isolation and complete characterization of Tlr elements, a family of approximately 30 micronuclear DNA sequences that are efficiently eliminated from the developing macronucleus. The data indicate that Tlr elements are comprised of an approximately 22 kb internal region flanked by complex and variable termini. The Tlr internal region is highly conserved among family members and contains 15 open reading frames, some of which resemble genes encoded by transposons and viruses. The Tlr termini appear to be long inverted repeats consisting of (i) a variable region containing multiple direct repeats which differ in number and sequence from element to element and (ii) a conserved terminal 47 bp sequence. Taken together, these results suggest that Tlr elements comprise a novel family of mobile genetic elements that are confined to the Tetrahymena germline genome. Possible mechanisms of developmentally programmed Tlr elimination are discussed.

MeSH Terms
Amino Acid Sequence Animals Base Composition Base Sequence Blotting, Southern Cell Nucleus/genetics Conserved Sequence/genetics DNA Transposable Elements/genetics DNA, Protozoan/genetics Genome, Protozoan Genomic Library Germ Cells/cytology,metabolism Germ-Line Mutation/genetics Molecular Sequence Data Multigene Family/genetics Open Reading Frames/genetics Protozoan Proteins/chemistry,genetics Repetitive Sequences, Nucleic Acid/genetics Sequence Alignment Tetrahymena thermophila/chemistry,cytology,genetics
Chemicals
DNA Transposable Elements DNA, Protozoan Protozoan Proteins
Authors & Affiliations
5 authors, click to expand affiliations / ORCID
Wuitschick Jeffrey D
Department of Biology, Marquette University, Milwaukee, WI 53201-1881, USA.
Gershan Jill A
Lochowicz Andrew J
Li Shuqiang
Karrer Kathleen M
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Article Info
Journal
Nucleic acids research
Abbr.
Nucleic Acids Res
ISSN
1362-4962
DOI
10.1093/nar/30.11.2524
Published
2002-06-01
Pages
2524-37
Language
English
Region
England
NLM ID
0411011
PMCID
PMC117186
Subset
IM
Databases
GENBANK
AF451860, AF451861, AF451862, AF451863, AF451864, AF451865, AF451866, AF451867, AF451868, AF451869, AF451870
External Links
PubMed source DOI: 10.1093/nar/30.11.2524 PMC Full Text View journal details
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