B1 and related SINEs in mammalian genomes.
Although B1 and Alu were the first discovered Short Interspersed Elements (SINEs), the studies of these genomic repeats were mostly limited to mice and humans and little data on their presence in other animals were available. Here we report the presence of these SINEs in a wide range of rodents (in all 15 tested families) as well as primates and tree-shrews and their absence in other mammals. Distribution pattern of these SINEs in mammals supports close relationship between rodents and primates as well as tree-shrews. Sequence analysis of these elements, apparently descending from cellular 7SL RNA indicates their rearrangements such as dimerization (Alu), quasi-dimerization (B1), acquiring a tRNA-related unit (B1-dID), extended deletions, etc., preceding their active expansion in the genomes. The revealed common pattern of microenvironment of some rearrangement hot spots in SINEs (internal duplications and deletions) suggests involvement of short direct repeats in the mechanism of such rearrangements. This hypothesis allows us to explain short rearrangements in these and other short retroposons.
Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, 32 Vavilov St., 119991, Moscow, Russia.
Nikita S
NS
Vassetzky
Oleg A
OA
Ten
Dmitri A
DA
Kramerov
D000818:Animals; D001483:Base Sequence; D003001:Cloning, Molecular; D004247:DNA / Q000737:chemistry / Q000235:genetics; D019143:Evolution, Molecular; D018628:Gene Dosage; D014644:Genetic Variation; D016678:Genome; D006801:Humans; D008322:Mammals / Q000235:genetics*; D008969:Molecular Sequence Data; D010802:Phylogeny; D011323:Primates / Q000235:genetics; D020733:RNA, Small Cytoplasmic / Q000235:genetics; D012377:Rodentia / Q000235:genetics; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D012689:Sequence Homology, Nucleic Acid; D020086:Short Interspersed Nucleotide Elements / Q000235:genetics*; D018271:Signal Recognition Particle / Q000235:genetics; D014418:Tupaiidae / Q000235:genetics
C115990:7SL RNA; D020733:RNA, Small Cytoplasmic; D018271:Signal Recognition Particle; D004247:DNA