Rinaldo Wellerson Pereira, Simone Silva dos Santos, Sérgio Danilo Junho Pena
Published: March 14, 2006
Genet. Mol. Res. 5 (1) : 63-71

Cite this Article:
R.Wellerson Pereira, S.Silva dos Santos, S.Danilo Jun Pena (2006). A novel polymorphic Alu insertion embedded in a LINE 1 retrotransposon in the human X chromosome (DXS225): identification and worldwide population study. Genet. Mol. Res. 5(1): 63-71.

About the Authors
Rinaldo Wellerson Pereira, Simone Silva dos Santos, Sérgio Danilo Junho Pena

Corresponding author
S.D.J. Pena
E-mail: spena@dcc.ufmg.br

ABSTRACT

We describe a novel polymorphic Alu insertion (DXS225) on the human X chromosome (Xq21.3) embedded into an L1 retrotransposon. The DXS225 polymorphism was genotyped in 684 males from the CEPH Human Genome Diversity Panel. This insertion was found in all regions of the globe, suggesting that it took place before modern humans spread from Africa ca. 100,000 years ago. However, only one Amerindian population (Karitiana) showed this insertion allele, which may have been introduced by European admixture. Thus, it appears likely that the Alu insertion was absent from pre-Columbian America. Analysis of molecular variance worldwide demonstrated that 92.2% of the genetic variance was concentrated within populations. DXS225 is flanked by two microsatellites (DXS8114 and DXS1002), which are 86 kb apart and are in very strong linkage disequilibrium. The combination of a unique event polymorphism on the X chromosome in linkage disequilibrium with two rapidly evolving microsatellites should provide a useful tool for studies of human evolution.

Key words: Polymorphism, Alu, X chromosome, CEPH panel, Human population genetics.