title: A retrotransposon of the non-long terminal repeat class from the human blood fluke Schistosoma mansoni. Similarities to the chicken-repeat-1-like elements of vertebrates.
abstract: The genomes of representative species of fishes, amphibians, and reptiles contain non-long-terminal-repeat (non-LTR) retrotransposons showing strong sequence identity to the chicken repeat 1 (CR1) non-LTR retrotransposon from birds. These nonavian retroelements have been termed CR1-like elements. We have isolated sequences of a non-LTR retrotransposon from the human blood fluke Schistosoma mansoni. These schistosome sequences, which we have termed the SR1 family of non-LTR retrotransposons, contain regions of deduced amino acids characteristic of the CR1-like elements. SR1 elements possess atypical 3' termini consisting of the tandem repeat (AACCATTTG)2 which are similar in structure to the imperfect tandem repeat of the 3' termini of CR1. There are at least 200 copies of SR1 interspersed through the genome of S. mansoni. The structural and amino acid sequence similarities of SR1 with members of the CR1-like elements suggest that the SR1 family belongs to the CR1-like category of non-LTR retrotransposons. Although other non-LTR retrotransposons have been described in invertebrates, this is the first CR1-like element reported from a nonvertebrate taxon, suggesting that the phylogenetic distribution of CR1-like retrotransposons is not restricted to vertebrates.
authors.affiliation: Molecular Parasitology Unit, Queensland Institute of Medical Research, Australia.
authors.forename: A C
authors.initials: AC
authors.lastname: Drew
authors.forename: P J
authors.initials: PJ
authors.lastname: Brindley
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D001717:Birds / Q000235:genetics; D001769:Blood / Q000469:parasitology*; D002645:Chickens / Q000235:genetics*; D017124:Conserved Sequence; D015247:Deoxyribonuclease HindIII / Q000235:genetics / Q000378:metabolism; D005260:Female; D016678:Genome; D015801:Helminth Proteins / Q000235:genetics*; D006801:Humans; D008297:Male; D008969:Molecular Sequence Data; D016366:Open Reading Frames; D012194:RNA-Directed DNA Polymerase / Q000235:genetics; D012091:Repetitive Sequences, Nucleic Acid; D018626:Retroelements / Q000235:genetics*; D012550:Schistosoma mansoni / Q000235:genetics*; D014714:Vertebrates / Q000235:genetics
chemical_list: D015801:Helminth Proteins; D018626:Retroelements; C107019:SR1 protein, Schistosoma mansoni; D012194:RNA-Directed DNA Polymerase; D015247:Deoxyribonuclease HindIII