Elsevier

Legal Medicine

Volume 17, Issue 1, January 2015, Pages 52-55
Legal Medicine

Brief Communication
Investigation of Japanese-specific alleles: Most are of Jomon lineage

https://doi.org/10.1016/j.legalmed.2014.08.006Get rights and content

Highlights

  • Three SNPs suggested the existence of Japanese-specific alleles on autosomes.

  • Further study identified a total of 67 (nearly) Japanese-specific alleles.

  • DNA samples from Jomon skeletons were also investigated.

  • Most of those alleles were suggested to have originated from the Jomon lineage.

  • These alleles would be useful as ancestry-informative markers.

Abstract

Japanese-specific alleles are expected to be powerful markers for the differentiation of the Japanese from other people. In this study, three single nucleotide polymorphisms (SNPs) in the GALNT11, H19, and PLA2G12A genes were analyzed in 2396 DNA samples from 25 global populations, and the derived alleles suggested that Japanese-specific alleles exist on autosomes. To identify new Japanese-specific alleles, candidate SNPs obtained from the HapMap database were investigated using 875 DNA samples from nine populations. A total of 67 (nearly) Japanese-specific derived alleles were observed. Of them, 57 showed higher frequencies in the Ryukyuans, living in the southernmost part of the Japanese Archipelago, than in the Wajins living in mainland Japan, and 43 were also present in Koreans at low frequencies. Jomon skeletons excavated from Hokkaido, the northernmost island of Japan, showed higher frequencies of the three derived alleles in the GALNT11, H19, and PLA2G12A genes than the Ryukyuans, suggesting that most of the 57 derived alleles observed at the high frequencies in the Ryukyuans originated from the Jomon lineage. These novel markers will be useful in the field of forensics.

Introduction

The focus of a recent field in forensic genetics has been on the differentiation of individuals using ancestry-informative markers (AIMs) [1], [2], [3]. Genetic markers with a geographically restricted distribution, or with marked differences in allele frequency between two regions, are useful to infer the ancestry of an individual and population to which an individual belongs, and to understand human migration and expansion in anthropology. Japanese-specific alleles are expected to be powerful for the characterization of a forensic sample as being of Japanese origin. Y chromosomal haplogroups C1 and D2 have been observed only in the Japanese Archipelago in large-scale investigations [4], [5]. In particular, haplogroup D2 was found at a frequency as high as 0.55 in the Ryukyuans, the Japanese in Okinawa, the southernmost part of the Japanese Archipelago, and 0.85 in the Ainu, the aboriginal people of Hokkaido, the northernmost part of the Japanese Archipelago. The Wajins, the mainland Japanese, had frequencies of 0.26–0.38 [6]. However, these two haplogroups were also observed in Koreans at low frequencies [6], [7], and haplogroup D2 was found in Chinese at a lower frequency [7]. Mitochondrial haplogroup M7a was not restricted to Japanese and Koreans, but showed higher frequencies in Japan than in mainlanders of East Asia [8], [9]. Thus, they can be regarded as fairly Japanese-specific. On autosomes, only a few Japanese-specific single nucleotide polymorphisms (SNPs) have been found to date. We previously reported that a derived allele of a SNP (rs3778922) in the GALNT11 gene was observed at frequencies of 0.076–0.153 in the Wajins and Ryukyuans, and 0.004–0.017 in two Korean populations [10]. A derived allele (rs76162918) of the H19 gene showed frequencies of 0.068–0.088 in four Wajin populations and 0–0.005 in two Korean populations [11]. These alleles were not found in several mainland populations of East Asia. They are not entirely Japanese-specific, but can be regarded as such because of the clearly low frequencies in the Korean populations. The HapMap database suggests the existence of a Japanese-specific allele (rs2285715) in the PLA2G12A gene, which is adjacent to the CFI gene with a nearly Japanese-specific allele [12]. In this study, we analyzed the frequencies of these three SNPs in the GALNT11, H19, and PLA2G12A genes in 25 global populations and Jomon skeletons, and investigated SNPs on autosomes to search for new Japanese-specific markers on autosomes, possibly permitting the differentiation between Japanese and mainlanders of East Asia.

Section snippets

Materials and methods

For the three SNPs of GALNT11, H19, and PLA2G12A, a total of 2,396 unrelated individuals from 25 populations were investigated (Table 1). The geographical locations of 22 South and East Asian populations are shown in Fig. 1. To identify new Japanese-specific alleles, a total of 874 individuals from nine populations were investigated. Fifty-four DNA samples extracted from Jomon skeletons excavated from archaeological sites in Hokkaido [13] were also investigated. Simultaneous typing of the three

Typing of three SNPs

Fig. 2 shows the electrophoretic pattern of products obtained by the triplex APLP method. The nucleotide substitutions were clearly and unambiguously detected as bands with different sizes. Table 1 shows the frequencies of derived alleles of the three SNPs. The observed distribution was in good agreement with the Hardy–Weinberg law. The derived alleles of GALNT11 and PLA2G12A were restricted to the Japanese and Korean populations, suggestive of being nearly Japanese-specific. The H19 derived

Discussion

To explain the origins of modern Japanese, three main models have been proposed based on morphological studies. The transformation model claims that modern Japanese evolved solely from Jomon people, who spread to the Japanese Archipelago more than 15,000 years ago and developed the Jomon culture of hunter-gatherers. The replacement model contends that modern Japanese evolved solely from Yayoi people, who migrated to the Japanese Archipelago through the Korean Peninsula with wet rice agriculture

Acknowledgements

We would like to thank Prof. Naruya Saitou, National Institute of Genetics for his providing us with some Chinese DNA samples. This study was supported in part by Grants-in-Aid for Scientific Research (23590849 and 26460878 to IY and 264440257 to NA) from the Japan Society for the Promotion of Science, Japan.

References (21)

There are more references available in the full text version of this article.

Cited by (7)

  • Japaneseplex: A forensic SNP assay for identification of Japanese people using Japanese-specific alleles

    2018, Legal Medicine
    Citation Excerpt :

    This study was approved by the Ethics Committee of the Faculty of Medicine, Tottori University. SNPs were selected from a total of 124 SNPs with an entirely or nearly Japanese-specific allele, consisting of 67 previously published [15] and 57 new additional SNPs, as shown in Supplementary Table S1, where different measures of ancestry informativeness: the absolute allele frequency differences (δ), F statistics (FST), and informativeness for assignment (In) [18], were calculated between Koreans in Seoul and JP-Tottori. In was calculated using log2 instead of the natural logarithm [19], and multiplication by 0.6931 could convert the In values into results by the natural logarithm.

  • Genotyping of the c.1423C>T (p.P475S) polymorphism in the ADAMTS13 gene by APLP and HRM assays: Northeastern Asian origin of the mutant

    2016, Legal Medicine
    Citation Excerpt :

    The Japanese population on Okinawa, also known as Ryukyuans, is ethnically different from main island Japanese, called Wajin. Ryukyuans are more influenced by the Jomon lineage [17,18]. The second and third highest frequencies were observed in Oroqen (0.0802) and Evenki (0.0702), ethnic minorities living in northeastern parts of China.

View all citing articles on Scopus
View full text