Shaping and reshaping of salmonid genomes by amplification of tRNA-derived retroposons during evolution.
Three families of tRNA-derived repeated retroposons in the genomes of salmonid species have been isolated and characterized. These three families differ in sequence, but all are derived from a tRNA(Lys) or from a tRNA species structurally related to tRNA(Lys). The salmon Sma I family is present in the genomes of two species of the genus Oncorhynchus but not in other species, including five other species of the same genus. The charr Fok I family is present only in four species and subspecies of the genus Salvelinus. The third family, the salmonid Hpa I family, appears to be present in all salmonid species but is not present in species that are not members of the Salmonidae. Thus, the genome of proto-Salmonidae was originally shaped by amplification and dispersion of the salmonid Hpa I family and then reshaped by amplification of the Sma I and Fok I families in the more recently evolved species of salmon and charr, respectively. We speculate that amplification and dispersion of retroposons may have played a role in salmonid speciation.
Kido
Y
Y
Institute of Biological Sciences, University of Tsukuba, Ibaraki, Japan.
Aono
M
M
Yamaki
T
T
Matsumoto
K
K
Murata
S
S
Saneyoshi
M
M
Okada
N
N
D000818:Animals; D001483:Base Sequence; D005075:Biological Evolution; D004251:DNA Transposable Elements; D005784:Gene Amplification; D008969:Molecular Sequence Data; D005810:Multigene Family; D009690:Nucleic Acid Conformation; D012343:RNA, Transfer / Q000235:genetics*; D012357:RNA, Transfer, Lys / Q000235:genetics*; D012487:Salmonidae / Q000235:genetics*; D012689:Sequence Homology, Nucleic Acid; D013045:Species Specificity
D004251:DNA Transposable Elements; D012357:RNA, Transfer, Lys; D012343:RNA, Transfer