title: Structure and variability of recently inserted Alu family members.
abstract: The HS subfamily of Alu sequences is comprised of a group of nearly identical members. Individual subfamily members share 97.7% nucleotide identity with each other and 98.9% nucleotide identity with the HS consensus sequence. Individual subfamily members are on the average 2.8 million years old, and were probably derived from a single source 'master' gene sometime after the human/great ape divergence. The recent Alu family member insertions provide a better image of the structure of Alu retroposons before they have had the opportunity to change significantly. All of the HS subfamily members are flanked by perfect direct repeats as a result of insertion at staggered nicks. The 'master' gene from which the HS subfamily members were derived had an oligo-dA rich tail at least 40 bases long. The 'master' gene is very rich in CpG dinucleotides, but nucleotide substitutions within subfamily members accumulated in a random manner typical for Alu sequence with CpG substitutions occurring 9.2 fold faster than non-CpG substitutions.
authors.affiliation: Department of Biochemistry and Molecular Biology, Louisiana State University Medical Center, New Orleans 70112.
authors.forename: M A
authors.initials: MA
authors.lastname: Batzer
authors.forename: G E
authors.initials: GE
authors.lastname: Kilroy
authors.forename: P E
authors.initials: PE
authors.lastname: Richard
authors.forename: T H
authors.initials: TH
authors.lastname: Shaikh
authors.forename: T D
authors.initials: TD
authors.lastname: Desselle
authors.forename: C L
authors.initials: CL
authors.lastname: Hoppens
authors.forename: P L
authors.initials: PL
authors.lastname: Deininger
mesh_terms: D001483:Base Sequence; D005075:Biological Evolution; D016384:Consensus Sequence; D004251:DNA Transposable Elements; D014644:Genetic Variation; D015894:Genome, Human; D006801:Humans; D008969:Molecular Sequence Data; D012091:Repetitive Sequences, Nucleic Acid; D012689:Sequence Homology, Nucleic Acid; D013045:Species Specificity
chemical_list: D004251:DNA Transposable Elements