细粒棘球绦虫烯醇酶（EgEnolase）基因的克隆和序列分析

目的细粒棘球绦虫烯醇酶基因（EgEnolase）的克隆和所编码的蛋白质的结构、功能以及应用前景分析。方法利用美国国家生物技术信息中心（NCBI,http：//www.ncbi.nlm.nih.gov/）的在线分析工具BLASTx和瑞士生物信息学研究所的蛋白分析专家系统（ExPaSy,http：//ca.expasy.org/）,以及CBS Prediction Servers提供的蛋白序列在线分析工具,结合Vector NTI suite生物信息学分析软件,从GenBank中细粒棘球绦虫的表达序列标签（EST）数据库中发现烯醇酶的5’端和3’端的EST序列,根据预测的编码区两端序列设计引物,从细粒棘球绦虫青海绵羊分离株中用多聚酶链式反应（PCR）方法扩增其基因组序列,PCR产物克隆到T载体,测序并分析序列中的内含子,以内含子两侧序列的合并序列为引物,采用不对称PCR方法去除其中的内含子序列,预测编码蛋白的结构和功能特征,并分析其应用前景。结果细粒棘球绦虫青海绵羊株烯醇酶基因的基因组序列长为1449bp,含有两个长度分别为78bp和69bp的小内含子。该基因编码433个氨基酸;预测其氨基酸序列中含有一段跨膜区（aa104-124）,N端在膜外,C端在膜内,恰好分为两个不同的功能域,膜内区是执行酶催化功能的主体,Swiss-Model模建的3D结构显示,膜内区由α螺旋和β折叠相间排列形成桶样结构,底物结合位点、催化中心、Mg2＋结合位点等关键位点在空间上紧密靠近,位于桶形结构的中心。该蛋白还有一个潜在的核定位序列aa190-199。该蛋白含有多个T、B细胞表位,且膜外的aa49-57和膜内的aa228-236兼性的T、B细胞表位,线性B细胞表位aa206-213中包含了催化位点Glu210。结论细粒棘球绦虫烯醇酶可能是一个位于虫体皮层表膜具有较好的免疫诊断和疫苗应用前景的膜蛋白,同时还可能进入细胞核调节基因表达。     

福建畲族17个染色体短串联重复序列基因座遗传多态性

目的:调查Y染色体17个短串联重复序列(Y-STR)基因座的多态性及其单倍型在福建畲族人群的分布情况.方法:应用AmpFlSTR(@)YfilerTM荧光标记复合扩增系统,对福建畲族152名无关男性个体血液样本进行17个Y-STR位点的复合扩增,应用ABI PRISM 310遗传分析仪对扩增产物进行检测分析.结果:DYS456、DYS389 Ⅰ、DYS390、DYS389Ⅱ、DYS458、DYS19、DYS385a\b、DYS393、DYS391、DYS439、DYS635、DYS392、Y-GATA-H4、DYS437、DYS438、DYS448各位点遗传多样性(gene diversity,GD值)分布在0.419 6～0.944 7之间.17个Y-STR位点共同构成的单倍型150种,其单倍型多样性为0.999 825 7.结论:福建畲族17个Y-STR位点具有丰富的遗传多样性,可为父权鉴定和父系进化研究提供有价值的遗传学资料.     

人类白细胞抗原A和C座位基因重组二个家系分析

目的 探讨2个家系人类白细胞抗原(human leukocyte antigen,HLA)座位的重组情况.方法 采用聚合酶链反应-序列特异寡核苷酸探针技术检测2个家系成员HLA-A、-C、-B、-DRB1和-DQB1位点,应用测序分型方法进行HLA高分辨基因分型,然后通过家系遗传分析确定HLA基因重组相关位点,检测短串联重复序列位点确定其家系成员亲权关系.结果 2个家系HLA单倍型的重组发生在HLA-A和C位点之间,家系调查显示1例为父源、1例为母源HLA单倍型发生了交换后遗传给子代,短串联重复序列结果证实2个家系成员内具有高度的亲权关系.结论 发现了2个中国汉族人群HLA-A和C基因座位间的基因重组家系,为深入研究HLA的重组机制提供了基础.     

广西毛南族17个Y染色体短串联重复序列基因座遗传多态性

目的:调查17个Y染色体短串联重复序列(Y-STR)基因座及其单倍型在广西毛南族人群中的分布情况.方法:应用AmpFlSTR YfilerTM荧光标记复合扩增系统,对毛南族208名无关男性个体血样进行17个Y-STR位点的复合扩增,用ABI PRISM310遗传分析仪对扩增产物进行检测分析.结果:DYS456、 DYS389Ⅰ、 DYS390、 DYS389Ⅱ、 DYS458、 DYS19、 DYS385a＼b、 DYS393、 DYS391、 DYS439、 DYS635、 DYS392、 Y-GATA-H4、 DYS437、 DYS438、 DYS448各位点遗传多样性(GD值)分布在0 5852～0 9770之间.17个Y-STR位点共同构成的单倍型205种,其单倍型多样性为0 999785.广西毛南族与其他群体的Y-STR位点等位基因分布差异具有统计学意义.结论:广西毛南族17个Y-STR位点具有丰富的遗传多样性,可为父权鉴定和父系进化研究提供有价值的遗传学资料.     

额敏县158例肝包虫手术患者调查

棘球蚴病俗称包虫病,是因棘球绦虫的幼虫寄生于人体组织而引起的人兽共患性寄生虫病,分布于全世界广大的畜牧地区,在人与动物之间传播.在我国多流行于西北和西南牧区.目前已确认的棘球绦虫有4种,即细粒棘球绦虫、多房棘球绦虫、伏氏棘球绦虫及少节棘球绦虫.在我国主要为细粒棘球蚴病和泡型棘球蚴病.据调查,人肝包虫的感染率在3.1~31.5%,忠病率在0.5~5.0%[1]仅新疆每年因患包虫病接受手术者达2000人次以上.已成为农牧民因病致贫和因病反贫的主要原因.严重危害人类的健康.现将我县2004年至2009年158例肝包虫手术患者作如下分析:     

西藏昌都藏族mtDNA高变Ⅰ和高变Ⅱ区序列多态性分析

目的 探讨藏族人群线粒体DNA(mitochondrial DNA,mtDNA)控制区的两个高变区(hypervariable region,HVR)Ⅰ、Ⅱ的多态性.方法 采用PCR扩增和末端标记荧光循环测序的方法,对97名西藏昌都地区藏族无关个体进行了序列分析.结果 共观察到111个变异位点,序列变异包括了碱基的转换、颠换、插入、缺失等各种类型.其中,在HVR Ⅰ区(nt16024-nt16365)内观察到68个变异位点,92种单倍型,基因多样性h值为0.9985;在HVRⅡ区(nt73-nt340)内观察到43变异位点,91种单倍型,基因多样性h值为0.9882;随机匹配概率在HVRⅠ和HVRⅡ区P值分别为0.0120和0.0118;联合两个高变区序列,可观察到97种不同的单倍型,随机匹配概率P值为0.0103.结论 昌都藏族与其他群体比较有其独特的mtDNA序列遗传特点,与亚洲其他人种及白人有明显差异.mtDNA序列多态性在群体遗传学调查及法医学个体识别方面有广泛的应用前景.     

广西黑衣壮族17个Y-STR位点遗传多态性

目的　调查17个Y染色体短串联重复序列(Y-STR) 基因座及其单倍型在广西黑衣壮族人群中的分布情况。方法　应用AmpFlSTR? Yfiler?荧光标记复合扩增系统,对黑衣壮族184名无关男性个体血样进行17个Y-STR位点的复合扩增,用ABI PRISM 310遗传分析仪对扩增产物进行检测分析。结果　DYS456、DYS389Ⅰ、DYS390、DYS389Ⅱ、DYS458、DYS19、DYS385a\b、DYS393、DYS391、DYS439、DYS635、DYS392、Y-GATA-H4、DYS437、DYS438、DYS448各位点遗传多样性(GD 值) 分布在0. 4910～0.9727之间。17个Y-STR 位点共同构成的单倍型180种,其单倍型多样性为0.99976。广西黑衣壮族与其他群体的Y-STR位点等位基因分布差异具有统计学意义。结论　广西黑衣壮族17个Y-STR位点具有丰富的遗传多样性,可为父权鉴定和父系进化研究提供有价值的遗传学资料。     

辽宁回族、锡伯族群体11个Y染色体短串联重复序列基因座遗传多态性及遗传关系的分析

目的 调查辽宁地区回族、锡伯族群体11个Y染色体短串联重复序列(Y-chromosomal shorttandem repeat,Y-STR)基因座及单倍型的遗传多态性,探讨其群体遗传学及法医学应用价值.方法 应用Powerplex Y System荧光标记复合扩增系统检测204名回族、280名锡伯族无关男性个体血样的11个Y-STR基因座,用AB1310遗传分析仪进行基因分型,计算等位基因和单倍型频率,并结合已公开发表的国内其他15个群体相应基因座的遗传学资料,分析其遗传距离和聚类关系.结果 回族个体中共检出187种单倍型,单倍型频率多样性0.9990,基因多样性(gene diversity,GD)值在0.4783(DYS437)-0.9679(DYS385a/b);锡伯族个体中共检出237种单倍型,单倍型频率多样性0.9984,基因多样性GD值在0.3618(DYS391)-0.9686(DYS385a/b)之间.遗传距离分析结果显示,回族和锡伯族的遗传距离最小(0.0257),与彝族遗传距离最大(0.1046);锡伯族与朝鲜族遗传距离最大(0.0978).聚类分析与系统发生树结果一致,17个群体大致分为3类.结论 11个Y-SIR基因座在回族、锡伯族群体中具有较好的遗传多态性,适用于该地区的法医学应用.与其他民族群体Y-SIR单倍型数据的研究对了解他们的起源、迁移以及相互关系有重要意义.     

中国四个少数民族九个Y-STR位点基因频率和单倍型研究

目的 通过对中国满族、维吾尔族、壮族、柯尔克孜族4个少数民族群体共117个男性样本9个Y-STR位点的多态性分析，得到其相关位点的多态信息。方法 对所有样本的9个Y-STR位点进行PCR扩增，产物在ABI PRISM^TM377 DNA Sequencer上进行电泳，结果用Genotyper2．0软件进行分型。计算基因频率、多样性、遗传距离。结果在这9个位点上满族有43个等位基因，32种单倍型；维吾尔族43个等位基因，33种单倍型；柯尔克孜族有31个等位基因，15种单倍型；壮族有34个等位基因，23种单倍型。其中满族和维吾尔族的遗传距离最小，仅为0．02530。而柯尔克孜族和壮族的遗传距离最大，达到了0．34590。结论 4个民族均有较高的单倍型多样性。研究不同民族群体的遗传多样性对了解他们的起源、迁移以及相互关系有重要的意义。     

两个X连锁少汗性外胚层发育不良家系的基因突变分析

目的 对两个X连锁隐性遗传少汗性外胚层发育不良(X-linked hypohidrotic ectodermal dysplasia,XLHED)家系进行ED1基因突变分析,为罹患家庭提供遗传咨询及产前诊断.方法 综合应用序列分析及多重连接依赖性探针扩增方法,对两个家系的先证者进行ED1基因突变分析,并针对检测到的突变位点对女性成员进行检测.采集家系1胎儿的羊水细胞进行产前诊断,包括致病突变位点的分析、ED1基因内4个短串联重复序列(short tandem repeat,STR)位点的单倍型连锁分析、性别鉴定及核型分析.结果 家系1先证者缺失ED1基因第1外显子及下游2个STR位点DXS8269,DXS1422区域,其余外显子序列分析未见异常,其女儿为该缺失突变的携带者;结合连锁分析、性别鉴定及核型分析结果,家系1胎儿为男性非ED1基因缺失突变携带者,胎儿足月分娩后随访,为健康个体.家系2先证者经序列分析检测到ED1基因第3外显子c.463C＞T(R155C)错义突变,母亲为c.463C＞T(R155C)杂合突变携带者.结论 ED1基因第1外显子区域缺失和错义突变R155C是导致2个少汗性外胚层发育不全家系患者临床表型的主要原因,ED1基因的突变检测结合单倍型分析,能准确地对该类家系提供产前诊断.     

Molecular identification of Echinococcus species from eastern and southern Qinghai, China, based on the mitochondrial cox1 gene

The Qinghai-Tibetan Plateau (QTP, in western China), which is the largest and highest plateau on Earth, is a highly epidemic region for Echinococcus spp. We collected 70 Echinococcus samples from humans, dogs, sheep, yaks, plateau pikas, and voles in eastern and southern Qinghai and genotyped them using the mitochondrial DNA marker cytochrome oxidase subunit I gene and maximum parsimony and Bayesian reconstruction methods. Based on the 792-bp sequence matrix, we recorded 124 variable sites, of which, 115 were parsimony-informative. Thirty-four haplotypes (H1-H34) were detected, of which H1-H15, H16-H17, and H18-H34 belonged to Echinococcus shiquicus, Echinococcus multilocularis, and Echinococcus granulosus, respectively. Within 26 human isolates, three were identified as E. multilocularis and 23 were E. granulosus. We also detected a dual infection case in a dog with E. multilocularis and E. granulosus. The intraspecific haplotype (Hd ± SD) and nucleotide (Nd ± SD) diversity of E. shiquicus (0.947 ± 0.021; 0.00441 ± 0.00062) was higher than that for E. granulosus (0.896 ± 0.038; 0.00221 ± 0.00031) and E. multilocularis (0.286 ± 0.196; 0.00036 ± 0.00025). Moreover, the haplotype network of E. shiquicus showed a radial feature rather than a divergent feature in a previous study, indicating this species in the QTP has also evolved with bottleneck effects.     

Conserved extended haplotypes discriminate HLA-DR3-homozygous Basque patients with type 1 diabetes mellitus and celiac disease

The major susceptibility locus for type 1 diabetes mellitus (T1D) maps to the human lymphocyte antigen (HLA) class II region in the major histocompatibility complex on chromosome 6p21. In southern European populations, like the Basques, the greatest risk to T1D is associated with DR3 homo- and heterozygosity and is comparable to that of DR3/DR4, the highest risk genotype in northern European populations. Celiac disease (CD) is another DR3-associated autoimmune disorder showing certain overlap with T1D that has been explained by the involvement of common genetic determinants, a situation more frequent in DR3-rich populations, like the Basques. As both T1D- and CD-associated HLA alleles are part of conserved extended haplotypes (CEH), we compared DR3-homozygous T1D and CD patients to determine whether CEHs were equally distributed between both disorders or there was a differential contribution of different haplotypes. We observed a very pronounced distribution bias (P<10(-5)) of the two major DR3 CEHs, with DR3-B18 predominating in T1D and DR3-B8 in CD. Additionally, high-density single nucleotide polymorphism (SNP) analysis of the complete CEH [A*30-B*18-MICA*4-F1C30-DRB1*0301-DQB1*0201-DPB1*0202] revealed extraordinary conservation throughout the 4.9 Mbp analyzed supporting the existence of additional diabetogenic variants (other than HLA-DRB1*0301-DQB1*0201), conserved within the DR3-B18 CEH (but not in other DR3 haplotypes) that could explain its enhanced diabetogenicity.     

Additional factor in some HLA DR3/DQ2 haplotypes confers a fourfold increased genetic risk of celiac disease

Although HLA-DQ genes are the major celiac disease (CD) susceptibility genes, results from Finnish families suggest that not all DQ2-encoding haplotypes confer equal susceptibility to CD, implying the effect of other gene(s) in the HLA region. The aim of the present work was to extend and confirm the aforementioned results in a southern European population ( Italian) and to better localize the additional risk factor/s. The association of nine loci spanning the HLA region from DR to HFE, 4.5-Mb telomeric of HLA-A, was tested. The analysis was performed by comparing marker frequencies in DR3-DQ2 haplotypes transmitted and non-transmitted to the affected offspring in 156 Italian CD families selected for having at least one DR3-positive parent. The same analysis was performed independently in 101 Finnish CD families selected with the same criteria. Three alleles, MICA-A5.1, MICB-CA24 and MIB-350, all characteristic of the B8-DR3 extended haplotype, showed a significantly increased frequency in DR3 transmitted haplotypes in the Italian families. DR3 haplotypes carrying the combination of these alleles conferred an approximate fourfold increased CD risk. B8-DR3 transmitted haplotypes were significantly more conserved telomerically down to the MIC-Class I region. Similar results were seen in the Finnish families. The major conclusion that holds true in both populations is that, while DQ2 is an absolute requirement for the development of CD, the presence of an additional genetic factor within the MIC-Class I region confers an approximate 4-fold increased risk of the disease.     

Specific detection of Echinococcus spp. from the Tibetan fox (Vulpes ferrilata) and the red fox (V. vulpes) using copro-DNA PCR analysis

There are three Echinococcus species, Echinococcus granulosus, E. multilocularis, and E. shiquicus, which are distributed on the vast area of pastureland on the eastern Tibetan plateau in China. Tibetan foxes (Vulpes ferrilata) have been determined to be the main wild definitive host of E. multilocularis and E. shiquicus, but little information is available on the prevalence of these two parasites in Tibetan foxes. Consequently, the copro-prevalence of these parasites in foxes from the eastern Tibetan plateau was evaluated in this study. For each copro-DNA sample extracted from fox feces, a 133-bp segment of EgG1 Hae III was used to screen for infection with E. granulosus. Multiplex nested polymerase chain reaction (PCR) analysis was used to target an 874-bp segment of the mitochondrial COI gene to distinguish E. multilocularis and E. shiquicus. Among 184 fecal samples, 120 were from Tibetan foxes and six from red foxes (Vulpes vulpes). Of the fecal samples from Tibetan foxes, 74 (giving a copro-prevalence of 62?%) showed the presence of Echinococcus spp.: 23 (19?%) were found to contain E. multilocularis, 32 (27?%) E. shiquicus, and 19 (16?%) showed mixed infection with both E. multilocularis and E. shiquicus. Two fecal samples from red foxes were found to be infected with E. multilocularis. No fox feces were found to be infected with E. granulosus. Tests on zinc finger protein genes and a 105-bp fragment of the Sry gene found no significant difference in the prevalence of the two parasites between sexes. The efficiency of our multiplex nested PCR methods were compared with previous polymerase chain reaction-based restriction fragment length polymorphism (PCR-RFLP) methods and some problems associated with the copro-PCR were discussed.     

RECOMBINATION FRACTIONS IN THE HLA SYSTEM BASED ON THE DATA SET ‘PROVINCES FRANÇAISES’: INDICATIONS OF HAPLOTYPE-SPECIFIC RECOMBINATION RATES

In the large genetic survey ‘Provinces Françaises’ the recombination fractions in the HLA system have been estimated by a family analysis programme (FAP). A total of 1332 families were analysed and in general the findings were in agreement with recombination fractions reported previously. The maternal recombination rates were on average 1.8 times higher than the corresponding ones for males. The comparison of the recombination fractions with the corresponding physical distances suggests the existence of hot spots of recombination. The analysis did not show deviations from expected values for HLA-A and B alleles on HLA-A/B recombinant haplotypes. However, analysis of HLA-B/DR recombinant haplotypes showed a skewed distribution of B and DR alleles. The significance of the findings is difficult to evaluate as all results are estimated numbers and frequencies but a manual analysis of the recombinant families confirmed the observations. HLA-B/DR recombinant haplotypes carried often HLA-DR3 and DR11 whereas DR2 and DR7 were more rarely present on recombinant haplotypes. DR4 had an increased incidence on BF/DR recombinant haplotypes but not on A/B or B/BF recombinant haplotypes. Some of the haplotypes with the strongest linkage disequilibria as A1, B8, DR3 and A3, B7, DR2 seem to be less frequently involved in recombinations than other haplotypes. Variations of recombination rates depending on certain alleles or haplotypes might partially explain the conservation of some haplotypes or part of haplotypes in Caucasoids.     

HLA-DR and -DQ genotypes of celiac disease patients serologically typed to be non-DR3 or non-DR5/7.

The susceptibility to develop celiac disease (CD) seems to be primarily associated to a particular HLA-DQ alpha/beta heterodimer encoded by the DQA1*0501 and DQB1*0201 alleles, in cis position on the DR3-DQ2 haplotype or in trans position by DR5-DQ7/DR7-DQ2 heterozygotes. However, exceptional patients exist who are neither DR3 nor DR5/DR7, particularly among Southern European populations. We therefore examined the DRB1, DQA1, and DQB1 alleles of 13 Spanish CD patients who were serologically typed to be neither DR3 nor DR5/DR7. Five patients were found to carry the DQA1*0501 and DQB1*0201 alleles either in cis or in trans position, three of them had previously been serologically mistyped. However, two of these patients carried DQA1*0501 and DQB1*0201 on haplotypes other than DR3 or DR5 in combination with DR7. One of the latter patients carried an unusual DR4-DQ2 haplotype, while another had an unusual DR8-DQ2 haplotype. Four of the remaining eight patients carried DR4-DQ8 haplotypes. Taken together, our findings provide further evidence that the DQ alpha/beta heterodimer encoded by the DQA1*0501 and the DQB1*0201 alleles confers the primary HLA-associated susceptibility to develop CD. However, our studies also corroborate that a second (and "weaker") HLA-associated CD susceptibility gene may be present on some DR4-carrying haplotypes.     

HLA-DR, DQ genotypes of celiac disease patients and healthy subjects from the West of Ireland

Celiac disease (CD) has one of the strongest class II HLA associations of any human illness. We used DNA-RFLP typing to study the class II HLA genotypes of celiac disease patients from the West of Ireland, the geographic area with the highest rate of celiac disease in the world. We confirmed the high frequency of HLA-DR3 in this population, and we were also able to demonstrate the additional risk of developing celiac disease imparted by HLA-DR7. This was done by clearly distinguishing DR7, DQ2 haplotypes from DR7, DQ9 haplotypes, and by "subtraction analysis" of haplotype frequencies. As reported in other populations, most of the patients without DR3 were heterozygous for DR7 and DR11 or 12 (DR5), or had DR4. We used PCR-RFLP and direct sequencing of amplified DNA to examine HLA-DR4 subtypes. The frequency of HLA-DR4 was markedly decreased in patients compared with controls (p=0.000001) and there was a significant alteration of DR4 subtypes of the patients compared with controls (p=0.0227). Moreover, all of the CD patients (5 of 5) with DR4 had a haplotype associated with the DQB1*0302 allele compared with only 11 of 23 control subjects with DR4. Our results in this population with exceptionally high risk of CD strongly support the DQ heterodimer hypothesis and suggest that the recently described sequence difference between the DQB1*02 alleles of DR3 and DR7 may contribute to a synergistic increased risk when these haplotypes are inherited together. In addition, our findings suggest a role for HLA-DQ in DR4-associated CD.     

Biogeography of Triatoma sanguisuga (Hemiptera: Reduviidae) on two barrier islands off the coast of Georgia, United States

Thirty-three Triatoma sanguisuga (LeConte) adults and nymphs were collected during June and July 2009, at five sites on Cumberland Island and two sites on Sapelo Island, Georgia, to assess genetic diversity within and between sites. All but three specimens were found in a peridomestic habitat. The entire length (699 bp) of the cytochrome oxidase II mitochondrial gene was sequenced for each specimen. Twelve haplotypes were identified, nine from Cumberland Island and three from Sapelo Island. No haplotypes were shared between the two islands, indicating there is limited or no movement of gene flow between the islands. Phylogenetic relationships among the haplotypes were determined using both neighbor-joining and maximum parsimony analyses. The phylogenetic trees from both analyses were similar, with no distinct clades on either tree devoted to haplotypes from a single island. A haplotype network structure was determined using nested clade analysis, which produced two haplotype networks, one containing only specimens found on Cumberland Island. The second network included specimens from both islands, with the ancestral haplotype from Sapelo Island. This pilot study is the first to highlight triatomine populations in the southeastern United States using the cytochrome oxidase II mitochondrial gene, and indicates strong population structuring along the Georgia Coast.     

High-risk genotypes HLA-DR3-DQ2/DR3-DQ2 and DR3-DQ2/DR4-DQ8 in co-occurrence of type 1 diabetes and celiac disease

Shared susceptibility alleles in the HLA region contribute to the co-existence of type 1 diabetes (T1D) and celiac disease (CD). The aim of our study was to identify HLA genotype variations that influence co-occurrence of T1D and CD (T1D?+?CD) and the order of their onset. Totally 244 patients, 67 with T1D, 68 with CD and 69 with T1D?+?CD, (split into “T1D first” and “CD first”), were analyzed. Control group consisted of 130 healthy unrelated individuals. Two-tailed Fisher’s exact test was used for statistical analysis. The genetic background of Slovenian CD patients resembled more northern than southern European populations with DR3-DQ2/DR3-DQ2 (odds ratio [OR]?=?19.68) conferring the highest risk. The T1D?+?CD was associated with DR3-DQ2/DR3-DQ2 (OR?=?45.53) and even more with DR3-DQ2/DR4-DQ8 (OR?=?93.76). DR3-DQ2/DR7-DQ2 played a neutral role in susceptibility for T1D?+?CD. The order of the onset of T1D or CD in patients with co-occurring diseases was not influenced by HLA risk genotype profile. DR3-DQ2/DR3-DQ2 was associated with an increased risk for developing CD in patients with T1D, whereas patients with CD carrying DR3-DQ2/DR4-DQ8 were at higher risk for developing T1D. In addition to other genetic factors including HLA class I alleles present on DR3-DQ2 extended haplotype, the second extended haplotype may moderate the risk for T1D?+?CD conferred by DR3-DQ2. Our results suggested that individuals carrying high-risk genotypes DR3-DQ2/DR3-DQ2 or DR3-DQ2/DR4-DQ8 would more likely develop both T1D and CD than either disease alone.     

Origins and genetic features of the Okhotsk people,revealed by ancient mitochondrial DNA analysis

In order to investigate the phylogenetic status of the Okhotsk people that were distributed in northern and eastern Hokkaido as well as southern Sakhalin during the fifth to the thirteenth centuries, DNA was carefully extracted from human bone and tooth remains excavated from archaeological sites. The hypervariable region 1 sequences of the mitochondrial DNA (mtDNA) control region were successfully amplified and 16 mtDNA haplotypes were identified from 37 individuals of the Okhotsk people. Of the 16 haplotypes found, 6 were unique to the Okhotsk people, whereas the other 10 were shared by northeastern Asian people that are currently distributed around Sakhalin and downstream of the Amur River. The phylogenetic relationships inferred from mtDNA sequences showed that the Okhotsk people were more closely related to the Nivkhi and Ulchi people among populations of northeastern Asia. In addition, the Okhotsk people had a relatively closer genetic affinity with the Ainu people of Hokkaido, and were likely intermediates of gene flow from the northeastern Asian people to the Ainu people. These findings support the hypothesis that the Okhotsk culture joined the Satsumon culture (direct descendants of the Jomon people) resulting in the Ainu culture, as suggested by previous archaeological and anthropological studies.