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Nf CR1, the first non‐LTR retrotransposon characterized in the Australian lungfish genome, Neoceratodus forsteri , shows similarities to CR1‐like elements
Author(s) -
Sirijovski Nickolche,
Woolnough Catherine,
Rock Jennifer,
Joss Jean M. P.
Publication year - 2004
Publication title -
journal of experimental zoology part b: molecular and developmental evolution
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.823
H-Index - 63
eISSN - 1552-5015
pISSN - 1552-5007
DOI - 10.1002/jez.b.21022
Subject(s) - lungfish , retrotransposon , genome , biology , genetics , human genome , interspersed repeat , repeated sequence , dna , gene , evolutionary biology , transposable element , fish <actinopterygii> , fishery
The genomes of lungfish, together with those of some urodele amphibians, are the largest of all vertebrate genomes. It has been assumed that the bulk of the DNA making up these large genomes has been derived from repeat elements, like the noncoding DNA of those genomes that have been sequenced (e.g., human). In an attempt to characterize repeat sequences in the lungfish genome, we have isolated, by restriction enzyme digestion of genomic DNA, sequences of a repeat element in Neoceratodus forsteri , the most primitive of the living lungfishes. The fragments sequenced from the Eco RI and Bgl II digests were used to perform genome walking PCR in order to obtain the full sequence of the repeat element. This element shares homology with the non‐LTR (LINE) element, Chicken Repeat 1 (CR1), described for several vertebrates and some invertebrates; we have called it N. forsteri CR1 ( Nf CR1). Nf CR1 shares all the domains of other CR1 elements but it also has several unique features that suggest it may no longer be active in the lungfish genome. It occurs in both full‐length and 5′‐truncated versions and in its present “inactive” form represents ∼0.05% of the lungfish genome. J. Exp. Zool. (Mol. Dev. Evol.) 304B:1–10, 2005 . © 2005 Wiley‐Liss, Inc.