title: Isolation and characterization of genomic retrotransposon sequences from octoploid strawberry (Fragaria x ananassa Duch.).
abstract: Strawberry (Fragaria spp.) is a kind of herbaceous perennial plant that propagates vegetatively. The conserved domains of reverse transcriptase (RT) genes of Ty1-copia and Ty3-gypsy groups of LTR retrotransposons were amplified from the cultivated strawberry (Fragaria x ananassa Duch.). Sequence analysis of clones demonstrated that 5 of 19 Ty1-copia group unique sequences and 2 of 10 Ty3-gypsy unique sequences in F. x ananassa genome possessed either stop codon or frameshift. Ty1-copia group sequences are highly heterogeneous (divergence ranged from 1 to 69.8%), but the Ty3-gypsy group sequences are less (divergence ranged from 1 to 10%). Southern dot blot hybridization result suggested that both of the LTR retrotransposons are present in the genome of cultivated strawberry with high copy number (Ty1-copia group 2,875 Ty3-gypsy group 348). RT-PCR amplification from total RNA, which was extracted from leaves of micropropagated strawberry plants, did not yield either of the RT fragments. This is the first report on the presence of RT sequences of Ty1-copia and Ty3-gypsy group retrotransposons in F. x ananassa genome.
authors.affiliation: College of Horticulture, Shenyang Agricultural University, Shenyang, PR China.
authors.forename: Yue
authors.initials: Y
authors.lastname: Ma
authors.forename: Haiyue
authors.initials: H
authors.lastname: Sun
authors.forename: Guiling
authors.initials: G
authors.lastname: Zhao
authors.forename: Hongyan
authors.initials: H
authors.lastname: Dai
authors.forename: Xiuyan
authors.initials: X
authors.lastname: Gao
authors.forename: He
authors.initials: H
authors.lastname: Li
authors.forename: Zhihong
authors.initials: Z
authors.lastname: Zhang
mesh_terms: D000595:Amino Acid Sequence; D015139:Blotting, Southern; D031985:Fragaria / Q000145:classification / Q000235:genetics*; D018745:Genome, Plant / Q000235:genetics; D008969:Molecular Sequence Data; D010802:Phylogeny; D012194:RNA-Directed DNA Polymerase / Q000235:genetics; D018626:Retroelements / Q000235:genetics*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid
chemical_list: D018626:Retroelements; D012194:RNA-Directed DNA Polymerase