RESUMO
Previous studies of four populations revealed that a hypervariable short tandem repeat (iSTR) in intron 7 of the human complement factor I (CFI) gene on chromosome 4q was unique, with 17 possible East Asian-specific group H alleles observed at relatively high frequencies. To develop a deeper anthropological and forensic understanding of iSTR, 1161 additional individuals from 11 Asian populations were investigated. Group H alleles of iSTR and c.1217A allele of a SNP in exon 11 of the CFI gene were associated with each other and were almost entirely confined to East Asian populations. Han Chinese in Changsha, southern China, showed the highest frequency for East Asian-specific group H alleles (0.201) among 15 populations. Group H alleles were observed to decrease gradually from south to north in 11 East Asian populations. This expansion of group H alleles provides evidence that southern China and Southeast Asia are a hotspot of Asian diversity and a genetic reservoir of Asians after they entered East Asia. The expected heterozygosity values of iSTR ranged from 0.927 in Thais to 0.874 in Oroqens, higher than those of an STR in the fibrinogen alpha chain (FGA) gene on chromosome 4q. Thus, iSTR is a useful marker for anthropological and forensic genetics.
Assuntos
Povo Asiático/genética , Fator I do Complemento/genética , Antropologia Forense/métodos , Repetições de Microssatélites/genética , Polimorfismo Genético , Alelos , Éxons/genética , Ásia Oriental , Variação Genética , Genética Populacional , Humanos , Íntrons/genética , Reação em Cadeia da PolimeraseRESUMO
In this study, five single nucleotide polymorphisms (SNPs) in the ABCC4, FBN1, CEP152, ZNF804B, and GALNT11 genes were investigated to assess allele frequencies in 14 different populations by a novel pentaplex PCR method. All SNPs were polymorphic in East Asians, whereas mutant alleles were absent or rare in non-East Asians. The frequencies of a mutant allele in FBN1 (rs140598) showed a north-south downward cline in East Asia, whereas those of a mutant allele in ZNF804B (rs1916830) were relatively uniform in East Asia. The highest frequencies of mutant alleles in ABCC4 (rs3765534), CEP152 (rs2289178), and GALNT11 (rs3778922) were observed in Okinawa. The mutant allele in GALNT11 was found only in Far-East Asian populations: the frequencies were about 0.153 in Okinawa, 0.076 in the main island of Japan, and 0.017-0.004 in Korea. These five East Asian- and Japanese-specific SNPs would be useful markers for forensic individualization, in particular, as ancestry-informative markers.
Assuntos
Frequência do Gene/genética , Genética Populacional , Polimorfismo de Nucleotídeo Único/genética , Ásia Oriental/etnologia , Genótipo , Humanos , N-Acetilgalactosaminiltransferases/genéticaRESUMO
Human HERC1 is one of six HERC proteins and may play an important role in intracellular membrane trafficking. The human HERC1 gene is suggested to have been affected by local positive selection. To assess the global frequency distributions of coding and non-coding single nucleotide polymorphisms (SNPs) in the HERC1 gene, we developed a new simultaneous genotyping method for four SNPs, and applied this method to investigate 1213 individuals from 12 global populations. The results confirmed remarked differences in the allele and haplotype frequencies between East Asian and non-East Asian populations. One of the three common haplotypes observed was found to be characteristic of East Asians, who showed a relatively uniform distribution of haplotypes. Information on haplotypes would be useful for testing the function of polymorphisms in the HERC1 gene. This is the first study to investigate the distribution of HERC1 polymorphisms in various populations.
Assuntos
Fatores de Troca do Nucleotídeo Guanina/genética , Haplótipos , Polimorfismo de Nucleotídeo Único , Grupos Populacionais/genética , Algoritmos , Animais , Feminino , Frequência do Gene , Humanos , Masculino , Pan troglodytes/genética , Reação em Cadeia da Polimerase/métodos , Ubiquitina-Proteína LigasesRESUMO
Isoelectric focusing has revealed that human complement factor I (CFI) is controlled by two polymorphic alleles, CFI(*)A and CFI(*)B, and a few rare variant alleles. In this study the molecular basis of the CFI polymorphism was investigated in 174 Japanese. The CFI(*)A was divided into two suballeles, CFI(*)As (R201S) and CFI(*)Ah (R406H). CFI(*)Aj, a rare variant allele originating from CFI(*)Ah, had an additional mutation (R502L). The distribution of these three mutations and two registered SNPs was investigated in a total of 2,471 individuals in 20 populations from various areas, and six haplotypes were observed. Haplotype H3, which is characterized by CFI(*)As, was found only in Far East populations: the frequencies were about 0.03 in the main island of Japan and lower than 0.01 in Okinawa and Korea. Haplotype H5, characterized by CFI(*)Ah, prevailed almost exclusively in East Asians and was observed at the highest frequencies in southern Chinese Han and Thais. CFI(*)Ah must have arisen in a southeastern part of Asia and thereafter have spread to neighboring populations.
Assuntos
Fator I do Complemento/genética , Haplótipos/genética , Mutação/genética , Polimorfismo de Nucleotídeo Único/genética , Alelos , Genética Populacional , Humanos , JapãoRESUMO
Asians as well as Europeans have light skin, for which no genes to date are known to be responsible. A mutation, Ala481Thr (c.G1559A), in the oculocutaneous albinism type II (OCA2) gene has approximately 70% function of the wild type allele in melanogenesis. In this study, the distribution of the mutation was investigated in a total of 2,615 individuals in 20 populations from various areas. OCA2 481Thr prevailed almost exclusively in a northeastern part of Asia. The allele frequency was highest in Buryat (0.24) in Mongolia and showed a north-south downward geographical gradient. These findings suggest that OCA2 481Thr arose in a region of low ultraviolet radiation and thereafter spread to neighboring populations.
Assuntos
Povo Asiático/genética , Proteínas de Membrana Transportadoras/genética , Pigmentação da Pele/genética , Alanina/química , Alanina/genética , Alelos , Frequência do Gene , Genótipo , Humanos , População/genética , Treonina/química , Treonina/genética , Raios UltravioletaRESUMO
Upper and lower incisors of 400 Jat Sihks (200 of each sex) have been measured for their length and breadth to assess any possible sexual dimorphism. However, the difference between the two sexes has been observed to be insignificant.