Population genetic studies in three Chinese minorities

Genetic markers in the Tuvan population of Todja, Siberia

Todja is a secluded region of northern Tuva-situated in the Sayany Mountains, Siberia. The aboriginal population of Todja is Tuvan. A total of 128 healthy Tuvans living in Todja were typed for HLA-A, -B and -C antigens and several plasma and erythrocyte protein polymorphisms (Hp, Tf, Gc, ESD, ACP, PGM1, PGD and ADA). The observed frequencies of all 8 blood protein and HLA genotypes were in agreement with Hardy-Weinberg expectations. The most frequent HLA antigens in Todjans are A2 (0.36), A3 (0.24), A9 (0.50), B15 (0.34) and B40 (0.50). HLA haplotypes A2B5, A2B40, A9B15 and A9B40 are most common in this population. The observed frequencies of protein polymorphisms and HLA antigens and haplotypes in Todjans are similar to those of other Mongoloid populations. A comparison of HLA frequencies currently observed in Todjans with those obtained 20 years ago at the same locality showed minor changes attributable to the effect of migration.

Genetic origins of the Japanese: a partial support for the dual structure hypothesis

Based on the morphological characteristics of the skull and teeth, Hanihara ([1991] Japan Review 2:1-33) proposed the "dual structure model" for the formation of modern Japanese populations. We examine this model by dividing it into two independent hypotheses: 1) the Upper Paleolithic population of Japan that gave rise to the Neolithic Jomon people was of southeast Asian origin, and 2) modern Ainu and Ryukyuan (Okinawa) populations are direct descendants of the Jomon people, while Hondo (Main Island)-Japanese are mainly derived from the migrants from the northeast Asian continent after the Aeneolithic Yayoi period. Our aim is to examine the extent to which the model is supported by genetic evidence from modern populations, particularly from Japan and other Asian areas. Based on genetic distance analyses using data from up to 25 "classic" genetic markers, we find first that the three Japanese populations including Ainu and Ryukyuan clearly belong to a northeast Asian cluster group. This negates the first hypothesis of the model. Then, we find that Ainu and Ryukyuans share a group contrasting with Hondo-Japanese and Korean, supporting the second hypothesis of the model. Based on these results, we propose a modified version of the dual structure model which may explain the genetic, morphological, and archaeological evidence concerning the formation of modern Japanese populations.

Origin of the Koreans: a population genetic study

A population genetic study was undertaken to investigate the origin of Koreans. Thirteen polymorphic and 7 monomorphic blood genetic markers (serum proteins and red cell enzymes) were studied in a group of 437 Koreans. Genetic distance analyses by both cluster and principal components models were performed between Koreans and eight other populations (Koreans in China, Japanese, Han Chinese, Mongolians, Zhuangs, Malays, Javanese, and Soviet Asians) on the basis of 47 alleles controlled by 15 polymorphic loci. A more detailed analysis using 65 alleles at 19 polymorphic loci was performed on six populations. Both analyses demonstrated genetic evidence of the origin of Koreans from the central Asian Mongolians. Further, the Koreans are more closely related to the Japanese and quite distant from the Chinese. The above evidence of the origin of Koreans fits well with the ethnohistoric account of the origin of Koreans and the Korean language. The minority Koreans in China also maintained their genetic identity.

Genetic studies among the Nagas and Hmars of eastern India

A total of 148 Nagas (65 urban and 83 rural) and 81 Hmars from northeastern India were tested for 15 blood genetic markers. Both the Nagas and Hmars lacked haemoglobin variants and G6PD deficiency and had a high frequency of PGDC. This may be attributed to selective pressures operating at these loci. Genetic distance estimates using 41 alleles at 11 polymorphic loci showed appreciable heterogeneity between the urban and rural Nagas that were in line with the differences in gene frequencies. Considerable genetic admixture of the urban Nagas from the Hmar and other neighbouring populations is evident. The Nagas were found to be quite distant from the mainland Han Chinese and Malays as well as from the Bengalis and Oraons. However, they appear to be related to the Hmar and Lepcha. Evidence supporting the ethnohistoric origin of the Nagas from China or the South Seas is lacking.

Blood genetic markers in the Chinese of two eastern provinces

A total of 205 Han Chinese from two eastern provinces (155 from Fujien and 50 from Hopeh) were tested for the distribution of six blood groups--A1A2BO, MN, Rhesus (CcDEe), Lewisa, Kell (Kk) and Fya--four serum proteins--albumin and haptoglobin types; transferrin and group-specific component subtypes--haemoglobin, and twelve red cell enzyme systems--glucose-6-phosphate dehydrogenase, 6-phosphogluconate dehydrogenase, lactate and malate dehydrogenases; acid phosphatase, esterate-D, glyoxalase I, adenylate kinase, glucose-phosphate isomerase, phosphoglucomutase (locus 2), and superoxide dismutase types; and phosphoglucomutase (locus 1) subtypes. The frequencies of blood groups were more or less within the reported frequencies in the Chinese. However the frequency of le was much lower in the present series. The Chinese are characterized by low p1, Ro, k, le, and a high Fya in general. P2 was lacking in the Chinese. There were some differences in the blood group frequencies in the two provinces. The frequencies of Hp alleles; Tf and Gc subtypes show characteristic mongoloid features with high Hp1, TfD, and GcIF. The frequency of TFC2 was higher in the Fujien province than that in Hopeh. At the hemoglobin locus only one Hb AD was detected, while the frequency of the beta-thalassemia trait was 0.03. No red cell G6PD deficiency or variant was detected. The distribution of red cell enzymes showed Mongoloid characteristics with low PGDC, AK2, ESD1, GLO1, and higher pa. PGM1 subtypes also had Mongoloid characteristics with lower PGM2+ and higher PGM2-. The phenotypic distribution of all the fifteen polymorphic loci was at Hardy-Weinberg equilibrium in both the Chinese populations.

Study of five haemogenetic markers (Gc, C3, Bf, Ag, and GALT) in six Indonesian populations and in 12 subgroups of Balinese

In various ethnic groups of the Indonesian archipelago and of Bali, the polymorphisms of the serum proteins Gc globulin (vitamin D-binding protein), C3 (complement component 3), Bf (complement factor B), Ag x,y (lipoprotein allotypes), and of the red cell enzyme system GALT (galactose-1P-uridyltransferase) were analysed. Among the studied proteins, the Gc system was the most informative one for the anthropologist. Besides considerable differences of frequencies of the common alleles Gc*1F, Gc*1S and Gc*2, a number of rare alleles (1A1, 1A3, 1A8, 1A9, 1A12, 1C2, 1C21, 1C24, and 2C8) and some new ones (1C28, 1C29, 1C30, 2C9) were observed. The presence of Gc*1A1 demonstrates the relationship to the Australo-Melanesian populations, but Mongolian variants (1A3, 1A8, 1A9, 1C2) were also encountered. Within the C3 system a very high frequency of the C3*S allele was observed in all populations. The rare alleles C3*F0.55, C3S1, and C3*S0.5 were observed in some groups. A new allele (C3*F0.35) was detected in a Chinese individual and in a nobleman from Bali. The frequency of the Bf*F allele was rather low in general, and the Bf*S0.7 allele was found in three Indonesian individuals only. The Ag*(x) frequencies were rather high, as it is known for Asiatic populations. Variability among subgroups was not very pronounced. The GALT*2 allele (Duarte variant of the enzyme) was observed very rarely; however, it was present in several populations. Enzyme activities could not be determined, and therefore we cannot tell whether the galactosaemia gene (GALT*0) was present or not.

Diversity of some gene frequencies in European and Asian populations. IV. Genetic population structure assessed by the variogram

Isolation-by-distance models of population structure predict an exponential decrease of genetic relatedness with distance. Under the Kimura-Weiss (1964) model the plots of gene frequency variance versus distance (variograms), computed at various loci, are expected to have equal slope and reach a common asymptote. The gene frequency distributions at eight loci in 192 European and Asian populations have been summarized by variograms. On the average, the Kimura-Weiss model seems to describe adequately allele frequency change up to 900 km, but gradients are apparent at greater distances for most markers studied. These patterns may result form either differential selection or long-range gene flow; however, the extensive clinal variation observed for glyoxalase, esterase D and 6-PGD cannot be entirely accounted for by the Neolithic radiation of early farmers in the Middle East and Europe.

Polymorphisms of Pi, Hp, ADA and AK in Mongolian, Korean and Zhuang populations of China

Three minority ethnic groups from China, Mongolian, Koreans, and Zhuangs were studied for the genetic markers AK, ADA, Hp, and Pi. AK was monomorphic in Koreans and Zhuangs. Significant differences were observed in the Hp system between Mongolians and Zhuangs.

Genetic studies in Atacameño Indians: serum protein and red cell-enzyme polymorphisms

Phenotype and gene frequencies among Atacameño Indians are presented for nine serum protein polymorphisms (Hp, Gc with subtypes, Tf with subtypes, Amy, C3, Bf, PLG) and nine red-cell-enzyme polymorphisms (AcP, PGM1 with subtypes, AK, ADA, 6-PGD, GPT, EsD, GLO). Four systems--Tf, Amy, AK, ADA were found to be monomorphic. In the PGM1 subtypes an extremely high frequency of PGM1a3 could be observed. In two samples a new Gc mutant was identified and classified as Gc1A26. In the EsD system an unusual phenotype was detected in one sample.