Dispersion and insertion polymorphism in two small subfamilies of recently amplified human Alu repeats

Mark A. Batzer, Lawrence Livermore National Laboratory
Carol M. Rubin, University of California, Davis
Utha Hellmann-Blumberg, University of California, Davis
Michelle Alegria-Hartman, Lawrence Livermore National Laboratory
Esther P. Leeflang, University of California, Davis
Joshua D. Stern, University of California, Davis
Hernan A. Bazan, University Medical Center New Orleans
Tamim H. Shaikh, University Medical Center New Orleans
Prescott L. Deininger, University Medical Center New Orleans
Carl W. Schmid, University of California, Davis


Newly isolated members of two recently propagated (young) Alu subfamilies were examined for sequence diversity and insertion polymorphism in primate genomes. The smaller subfamily (termed HS-2) is comprised of approximately 5 to 25 members, while the larger (termed Sb2) includes approximately 125 to 600 members. Individual members of these Alu subfamilies share distinguishing sets of diagnostic mutations, are well-conserved relative to each other, and have expanded in the human lineage. At least one member from each subfamily is known to be polymorphic in humans. Three newly characterized HS-2 Alu family members as well as three Sb2 Alu repeats are monomorphic (fixed) in humans. The existence of a number of Alu subfamilies that have amplified in parallel within the human genome provides compelling evidence for the simultaneous activity of multiple dispersed Alu source genes. © 1995 Academic Press Limited.