MBE Advance Access published online on September 14, 2005
Molecular Biology and Evolution,
Evidence for Recent Positive Selection at the Human AIM1 Locus in a European Population
Mikiko Soejima 1, Hidenori Tachida 2, Takafumi Ishida 3, Akinori Sano 1, and Yoshiro Koda 1*
1 Department of Forensic Medicine and Human Genetics, Kurume University School of Medicine, Kurume 830-0011, Japan
2 Department of Biology, Faculty of Sciences, Kyushu University, Fukuoka 810-8560, Japan
3 Department of Biological Sciences, Graduate School of Science, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-0033 Japan
* To whom correspondence should be addressed.
Yoshiro Koda, E-mail: ykoda@med.kurume-u.ac.jp
Two missense polymorphisms (E272K and L374F) of the AIM1 locus, encoding a melanocyte differentiation antigen, were shown to have a clear association with human ethnicities. These two nonpathogenic SNPs may be associated with human pigmentation variation. In this study, we investigated sequence variation in the coding region and exon-flanking sequence and found low genetic variation only in subjects of European descent. All four statistical tests applied to the 7.55-kb region surrounding the L374F polymorphism detected statistically significant deviations from selective neutrality in Europeans. In addition, haplotype analysis revealed that one haplotype carrying 374F was overrepresented in this population, and the low rate of variation, with some features of selective sweeps, was shown to be statistically significant. These results suggest that positive selection recently has been acting or has acted on at least this region of the melanogenic gene and that an advantageous haplotype spread rapidly in Europe.
Keywords: AIM1; directional selection; pigmentation.
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