Genetic variation and relationships at six VNTR loci in two distinct sample populations in Brazil

Background: The Brazilian population has been the focus of intensive genetic study due to admixture characteristics whereas there are few reports on the variability of VNTR loci in Brazil.

Primary objective: The aim of this study was to analyse genetic parameters in sample populations from two geographically distant regions: São Luís City, in Maranhão State and Campinas City, in São Paulo State. We investigated if distinct colonization influences could produce detectable differences in genetic background.

Subject and methods: DNA samples from peripheral drained blood were obtained from unrelated individuals who underwent paternity testing. Allelic variation in six VNTR loci (D2S44, D4S139, D5S110, D8S358, D10S28 and D17S79) was evaluated. The results were compared to reference databases available for general Latin-derived European and African–American populations as well as for other Brazilian groups.

Results: This study reveals that forensic population parameters did not show differences among regions, although we detected admixture values varying between the south-east and north-east of Brazil.

Conclusions: Differences between the two samples are probably due to different admixture proportions of European- and African-derived alleles in each region; both populations are in Hardy–Weinberg equilibrium. In addition, the allelic frequency for all loci, in both populations, can be used as database for forensic purposes.     

Genetic variation at three VNTR loci in three tribal populations of Orissa,India

BACKGROUND: The variable number of tandem repeats (VNTR) loci are robust, simple and rapid tools for genetic characterization of both individuals and populations. This paper presents data on the distribution of three VNTRs (APOB, YNZ22 and D1S80) in three tribal populations (Gadaba, Kuvi-Khond and Paroja) of the Koraput district of Orissa, India with a view to enlarge our understanding of molecular genetic diversity among these tribes and the usage of these VNTRs in anthropogenetic studies. SUBJECTS AND METHODS: Three tribal populations were genotyped for APOB, YNZ22 and D1S80 loci using the polymerase chain reaction (PCR) technique. Gadaba are an Austro-Asiatic tribe while Kuvi-Khond and Paroja are Dravidian tribes. All samples were collected, with consent, from unrelated individuals. RESULTS: The observed allelic variation in these tribes is comparable with many Indian populations, but they showed significant overall and inter-population variability within the region. Allele *24 was the most common allele at the D1S80 locus in all populations, with Gadabas having the highest frequency (50%) followed by Paroja (32%) and Kuvi-Khond (23%). Gadabas also showed a higher frequency of allele *19 (13%) and *31 (9%) compared to other Indian and European populations. In the Apo B system, allele *37 was the most common in all three populations, with Gadabas having the highest frequency (39%) followed by Paroja (24%) and Kuvi-Khond (21%). This allele is present in high frequencies in other Indian (except Gonds) and European populations. Alleles *33 (17%), *35 (20%) and *45 (12%) were also common in the Gadabas, but Kuvi-Khond showed higher frequencies of *31(10%), *35(13%) and the larger allele *49(16%). Paroja, on the other hand, had higher frequencies of *31 (14%), *33 (17%) and *45 (13%). Allele *49 was also present in Paroja (10%) but was absent in the Gadaba. For the YNZ22 system, allele *4 was the most common in Kuvi-Khond (25%) and Paroja (21.4%), and allele *2 was the predominant allele in the Gadaba (33%). However allele *4 still occurs at relatively high frequency in Gadaba (27%). Allele *2 also occurs at relatively high frequency in Kuvi-Khond (20%) and intermediate frequency in Paroja (11%). Average heterozygosity was relatively low for Gadaba (0.7597 +/- 0.0191) and high for Kuvi-Khond (0.8618 +/- 0.0149) and Paroja (0.8512 +/- 0.0190), perhaps a reflection of effective population size and limitations to mating. The level of gene differentiation is, however, low (3-4%) for the three systems studied in these tribal populations and in data compiled from previous studies from the region. CONCLUSIONS: The VNTRs are polymorphic in the tribal populations studied and there is extensive allelic variation. Gadabas are isolated but Kuvi-Khond and Paroja show clear affinities with the Gonds, a major tribal group of Central India. Overall, allele frequency distribution, heterozygosity and genetic diversity analysis show that genetic diversity observed is socially, linguistically and geographically structured in this region.     

Allele sharing at six VNTR loci and genetic distances among three ethnically defined human populations

Because of their high degree of polymorphisms, the variable number of tandem repeat (VNTR) loci have become extremely useful in studies involving gene mapping, determination of identity and relatedness of individuals, and evolutionary relationships among populations. However, there are some concerns regarding whether or not the patterns of such genetic variation can be studied by the classical population models that are developed for studying genetic variation at blood groups and protein loci, since VNTR alleles detected by molecular size may not always be identical by descent. Although theoretical and empirical studies demonstrate that this concern is overstated, this study provides further support of the application of the traditional mutation-drift models to predict the pattern of intra- and inter-populational variation at VNTR loci. By comparing genetic variation at six VNTR loci with that at 16 blood groups and protein loci in three ethnically defined populations, we show that the patterns of variability at these two sets of loci are in general parallel to each other. Shared VNTR alleles among populations are generally more frequent than the ones which are not present in every population; the proportion of shared alleles among populations increases with increasing genetic similarity of populations; and the number of VNTR alleles is positively correlated with gene diversity at these loci. All of these observations are in agreement with the prediction of the mutation-drift models, particularly when the possibility of forward-backward mutations are taken into account. This parallelism of genetic variation at VNTR loci and blood groups/protein loci further asserts the potential of using such hypervariable loci for microevoltionary studies, where closely related populations may exhibit considerably less allele frequency differences at the classical blood group and protein loci. © 1992 Wiley-Liss, Inc.     

Genetic variation at three VNTR loci (D1S80, APOB, and D17S5) in two tribal populations of Andhra Pradesh, India

This study reports the genetic variation at three variable number of tandem repeat (VNTR) loci (APOB, D17S5 and D1S80) in two tribes (Thoti and Kolam) of Andhra Pradesh, India. Kolams constitute 1% of the total scheduled tribal population of Andhra Pradesh, while Thoti is a numerically small tribe. All three genetic loci were genotyped using the polymerase chain reaction (PCR) technique and were polymorphic in both populations. At the D1S80 locus, both populations showed higher frequencies of allele *31 (9-14%) than other Indian populations. In the APOB system, Thoti showed a very high frequency of allele *37 (54%) and for D17S5 system allele *4 was the most common in Thoti (32%) and allele *2 in Kolam (28%). Both tribes differed statistically significantly from other tribal populations of the region. The level of gene differentiation was low (GST = 0.038) for Indian tribal populations. The allele frequency distribution, heterozygosity and genetic diversity analysis shows that the observed genetic variation is socially and geographically structured.     

Genetic variation at 15 polymorphic, autosomal, short tandem repeat loci of two Hungarian populations in Transylvania, Romania

Aim

To determine allele distribution and genetic parameters for two populations living in the Romanian region of Transylvania: Hungarians from Cluj and Szeklers from Covasna county, and to compare the results between the two populations and with other Hungarian and Romanian populations.

Methods

Allele frequencies for 15 autosomal STR loci (D8S1179, D21S11, D7S820, CSF1PO, D3S1358, TH01, D13S317, D16S539, D2S1338, D19S433, VWA, TPOX, D18S51, D5S818, and FGA), several forensic parameters, and paternity parameters were determined for Szekler Hungarians of Covasna county (CV-Sze, n = 278) and non-Szekler Transylvanian Hungarians, who were represented by Hungarians from Cluj county (CJ-Hu, n = 146).

Results

Average expected heterozygosity was above 70%. The combined power of discrimination and combined power of exclusion values were high. All tested loci were in agreement with Hardy-Weinberg equilibrium, with the exception of the CSF1PO locus for Covasna county. Pairwise population comparison tests and exact population differentiation tests showed no significant differences between the CJ-Hu and CV-Sze populations, and the CV-Sze group showed greater differences from other Romanian populations than did the CJ-Hu group.

Conclusion

Hungarians from Cluj show greater genetic heterogeneity than Szeklers from Covasna. The loci tested are suitable for studying micro-differentiation between these two populations, and between these populations and other populations in Hungary and Romania.Since its introduction 25 years ago, DNA fingerprint analysis has become a major tool in diagnosing and treating disease, forensic identification, taxonomy, phylogenetics, and other applications (1,2). Microsatellites, also called simple sequence repeats or short tandem repeats (STR), are among the most polymorphic DNA markers. These sequences of 2-6 basepairs are easily amplified by polymerase chain reaction (PCR) and show widespread and uniform distribution throughout the genome. They show a high level of polymorphism, which is relatively stable (3). These properties of STR loci make them suitable for numerous genetic, forensic, and medical applications.According to the 2002 census in Romania (4), 19.6% of the residents of the Transylvania region belong to the Hungarian ethnic group, with most of them living in the Szekler (Székely) counties of Covasna and Harghita. Earlier genetic studies have suggested that ancient Hungarians and Szekler Hungarians separated from each other more than 1000 years ago. Some centuries ago, the two Szekler groups separated from each other, which affected the genetic structure of these groups (5). In the last decade, genetic parameters for the Szekler population (HR-Sze) and Csángó population (HR-Csn) from Harghita have been published (6), but no population study has been conducted on Szekler communities from Covasna and other, non-Szekler Hungarians, from Transylvania.This study sheds light on the genetic makeup of Hungarian communities from Transylvania by determining CODIS STR allele frequencies, as well as forensic and paternity data for the Szekler Hungarians of Covasna county (CV-Sze) and non-Szekler Hungarians of Cluj county (CJ-Hu).Using allele frequencies, we carried out pairwise comparisons and differentiation tests to test the following hypotheses:1. There is significant genetic distance between the non-Szekler Hungarians (CJ-Hu) and the Szekler populations (HR-Sze and CV-Sze), which indicates genetic isolation of the two Szekler groups from the other Hungarian communities living in Transylvania.2. There is significant genetic distance between the two Szekler populations (HR-Sze and CV-Sze), which reveals genetic isolation of the Szekler communities.3. There is a positive correlation between geographical distance and genetic distance when ethnic Hungarian populations in this study are compared with other ethnic Romanian populations.4. As a result of population migration and ethnic cross-breeding, non-Szekler Hungarians in this study show greater genetic heterogeneity than do Szekler Hungarians.     

Genetic variation at fibrinogen loci and plasma fibrinogen levels.

In view of the controversy regarding genetic variation at the fibrinogen loci and plasma fibrinogen levels, we have analysed DNA polymorphisms at the alpha (TaqI), beta (BclI and HaeIII), and gamma (KpnI/SacI) fibrinogen loci in 247 subjects whose plasma fibrinogen was determined by clotting and nephelometric assays. Strong linkage disequilibrium was found between the alpha/TaqI and gamma/KpnI/SacI markers and between the beta/BclI and beta/HaeIII markers. A lesser association was found between the alpha/TaqI and beta/BclI loci, beta/BclI and gamma/KpnI/SacI markers, alpha/TaqI and beta/HaeIII markers, and the gamma/KpnI/SacI and beta/HaeIII markers. This is consistent with the known physical order of these loci and suggests a relative excess of recombination in the alpha/gamma to beta interval. Plasma fibrinogen levels, by either assay method, when corrected or uncorrected for age, sex, and smoking habit, did not show any statistically significant associations with the four fibrinogen polymorphisms examined at the alpha, beta, and gamma fibrinogen loci either singly or when analysed as a haplotype.     

Genetic variation and evolutionary stability of the FMR1 CGG repeat in six closed human populations

In an attempt to understand the allelic diversity and mutability of the human FMR1 CGG repeat, we have analyzed the AGG substructure of this locus within six genetically-closed populations (Mbuti pygmy, Baka pygmy, R. surui, Karitiana, Mayan, and Hutterite). Most alleles (61/92 or 66%) possessed two AGG interspersions occurring with a periodicity of one AGG every nine or ten CGG repeats, indicating that this pattern is highly conserved in all human populations. Significant differences in allele distribution were observed among the populations for rare variants possessing fewer or more AGG interruptions than the canonical FMR1 CGG repeat sequence. Comparisons of expected heterozygosity of the FMR1 CGG repeat locus with 30 other microsatellite loci, demonstrated remarkably similar levels of polymorphism within each population, suggesting that most FMR1 CGG repeat alleles mutate at rates indistinguishable from other microsatellite loci. A single allele (1 out of 92) was identified with a large uninterrupted tract of pure repeats (42 pure CGG triplets). Retrospective pedigree analysis indicated that this allele had been transmitted unstably. Although such alleles mutate rapidly and likely represent evolving premutations, our analysis suggests that in spite of the estimated frequency of their occurrence, these unstable alleles do not significantly alter the expected heterozygosity of the FMR1 CGG repeat in the human population. © 1996 Wiley-Liss, Inc.     

NGS-based typings for 7 HLA loci in two populations from Barra Mansa,RJ, Brazil

We investigated HLA class I (HLA-A, -B, and -C) and class II (HLA-DRB1, -DQB1, -DPA1, and -DPB1) alleles by NGS-based typing among 478 Brazilian individuals from two populations in the Barra Mansa city based on their self-declared skin color (Caucasian, N = 405, AFND-ID: 3729; Black, N = 73, AFND-ID: 3731) to calculate allelic and haplotypic frequencies, plus linkage disequilibrium. No locus deviated from Hardy-Weinberg equilibrium. Both populations shared the most frequent allele on HLA-A, -C, -DPA1, and -DPB1. Genotype and frequency data are available in the Allele Frequencies Net Database.     

内蒙古地IX四个民族九个X短串联重复序列位点的多态性研究

目的 研究内蒙古地区蒙古族、鄂温克族、鄂伦春族、达斡尔族民族X染色体遗传结构及其变化规律,了解9个位点的法医学、群体遗传学应用价值及4个民族间的亲属关系.方法 以9个X短串联重复序列(short tandem repeats, X-STR)位点(DXS6789,DXS101,DXS8378,DXS7132,DXS7133,DXS7423,DXS6804,DXS6799和HPRTB)作为遗传标记,通过等位基因频率、杂合度、多态信息量等遗传学指标,以及不同群体之间的差异性比较、遗传距离分析和聚类分析,调查内蒙古地区4个主要少数民族群体遗传结构及其变化规律.结果 这9个位点在民族间分布具有不同特点,多数具有中等程度多态性,可作为法医学和人类遗传学分析标记.遗传距离和聚类分析显示蒙古族与西安汉族、鄂伦春族与达斡尔族之间具有较近的遗传关系,该结果接近实际语系关系、文化特点及历史记载.结论 研究表明,这9个X-STR位点不仅可用于法医人类学,同时也可用于群体种系关系的研究.     

中国朝鲜族六个基因座遗传多态性

目的 了解中国朝鲜族群体中6个X染色体短串联重复序列(short tandem repeat,X-STR)基因座DXS7132、DXS6854、DXS6769、DXS9898、DXS8378和GATA31E08在中国朝鲜族群体中的遗传多态性.方法 用PCR扩增、变性聚丙烯酰胺凝胶电泳和银染方法对6个X-STR基因座进行检测.结果 6个基因座中分别检出8个、6个、8个、8个、5个和lO个等位基因,6个基因座基因型频率分布(女性个体)均符合Hardy-Weinberg平衡(P>0.05);观测杂合度均大于0.4660、多态信息含量均大于0.5293、女性个人识别力均大干0.7737、男性个人识别力均大于0.6107,男性单倍型多样性为0.9993.结论 6个基因座均具有较高的遗传多态性,是较理想的遗传标记系统.为中国朝鲜族起源的研究和朝鲜族群体的亲子鉴定和个人识别提供了宝贵的基础资料.     

广西毛南族6个短串联重复序列的遗传多态性

目的 调查广西毛南族人群6个短串联重复序列的群体遗传分布资料,探讨7个民族的遗传关系.方法 应用荧光标记STR基因扫描技术分析200名广西毛南族无关个体.以遗传距离和系统发生树来分析7个民族间的遗传关系.结果 6个STR基因座平均观察杂合度0.7825,平均多态信息总量分别为0.7324,累积个体识别力达0.99999951,累积非父排除率达0.994575.鄂伦春族、东乡族、锡伯族3个民族聚为一支,金秀瑶族、融水苗族、罗城仫佬族、毛南族4个少数民族聚成另一支.结论 D3S1358的等位基因16、D5S818的等位基因11、D7S820的等位基因11、D13S317的等位基因8、vWA的等位基因14、FGA的等位基因22可能是广西毛南族群体中相应STR基因座最原始的等位基因.广西毛南族的6个STR基因座属高度遗传多态性标记,广西毛南族与罗城仫佬族的遗传关系最近,其次分别为融水苗族、金秀瑶族、锡伯族、东乡族、鄂伦春族.     

Genetic relationships of the populations in eastern India.

The genetic relationships for four sets of populations in eastern India have been studied by using gene frequency data available in the literature. The Caucasoid populations in Assam and West Bengal are genetically close but different from the Mongoloid populations in the neighbourhood. The genetic distance analysis shows that the Mongoloid populations in Assam and West Bengal cluster according to their states of residence, indicating a correlation between genetic and geographical distances.     

Genetic variation observed at two tetrameric short tandem repeat loci on chromosome 12 (D12S66 and D12S67) among five distinct ethnic groups of India: detection of two new alleles

Objective : The present investigation reports the genetic variation observed at two tetrameric short tandem repeat (STR) loci on chromosome 12 (D12S66 and D12S67) among five anthropologically distinct population groups of India. Subjects and methods : A total of 277 random, normal and healthy volunteers were investigated for the D12S66 locus, and 236 for the locus D12S67, from five ethnic groups of India. Two of these belong to the state of Maharashtra in western India (Konkanastha Brahmins and Marathas) and three from the state of Kerala in South India (Nairs, Ezhavas and Muslims). DNA was extracted from peripheral blood samples, amplified by duplex polymerase chain reaction (PCR) and electrophoresed on 6% denaturing urea (7 M) gel electrophoresis. The analysis was performed on ALF Express DNA sequencer (Amersham Pharmacia Biotech) using Fragment Manager software. Statistical analysis was done by using Arlequin ver. 1.1. Results : At D12S66 locus, a total of nine alleles (8-17 repeats) and 27 genotypes were detected with an observed heterozygosity ranging from 0.55 to 0.91. At the D12S67 locus, nine alleles (36-44 repeats) and 33 genotypes were observed with a heterozygosity ranging from 0.74 to 0.89. Both the loci displayed high Power of Discrimination (PD) which ranged from 0.81 to 0.91 and Polymorphic Information Content (PIC) ranging from 0.68 to 0.84. At D12S66, two alleles were detected for the first time in these population groups which were not reported earlier. The level of gene differentiation ( G ST value, 0.02) was moderate at these two loci, indicating a close relationship among the population groups. Conclusions : From this investigation, it is concluded that both the tetrameric loci are highly polymorphic and informative, and can be used for the characterization of the Indian population groups in addition to other well-studied STR loci.     

Genetic variation observed at two tetrameric short tandem repeat loci on chromosome 12 (D12S66 and D12S67) among five distinct ethnic groups of India: detection of two new alleles

OBJECTIVE: The present investigation reports the genetic variation observed at two tetrameric short tandem repeat (STR) loci on chromosome 12 (D12S66 and D12S67) among five anthropologically distinct population groups of India. SUBJECTS AND METHODS: A total of 277 random, normal and healthy volunteers were investigated for the D12S66 locus, and 236 for the locus D12S67, from five ethnic groups of India. Two of these belong to the state of Maharashtra in western India (Konkanastha Brahmins and Marathas) and three from the state of Kerala in South India (Nairs, Ezhavas and Muslims). DNA was extracted from peripheral blood samples, amplified by duplex polymerase chain reaction (PCR) and electrophoresed on 6% denaturing urea (7 M) gel electrophoresis. The analysis was performed on ALF Express DNA sequencer (Amersham Pharmacia Biotech) using Fragment Manager software. Statistical analysis was done by using Arlequin ver. 1.1. RESULTS: At D12S66 locus, a total of nine alleles (8-17 repeats) and 27 genotypes were detected with an observed heterozygosity ranging from 0.55 to 0.91. At the D12S67 locus, nine alleles (36-44 repeats) and 33 genotypes were observed with a heterozygosity ranging from 0.74 to 0.89. Both the loci displayed high Power of Discrimination (PD) which ranged from 0.81 to 0.91 and Polymorphic Information Content (PIC) ranging from 0.68 to 0.84. At D12S66, two alleles were detected for the first time in these population groups which were not reported earlier. The level of gene differentiation (G(ST) value, 0.02) was moderate at these two loci, indicating a close relationship among the population groups. CONCLUSIONS: From this investigation, it is concluded that both the tetrameric loci are highly polymorphic and informative, and can be used for the characterization of the Indian population groups in addition to other well-studied STR loci.     

Genetic variation in populations of kennedya yellow mosaic tymovirus

Summary Kennedya yellow mosaic tymovirus (KYMV) occurs along the eastern Australian seaboard in the perennial legumesDesmodium triflorum andD. scorpiurus in the north, andKennedya rubicunda in the south. The genetic variation of more than 100 isolates of KYMV, most of them from the north, has been studied using an RNA hybrid mismatch polymorphism (RHMP) method. The method clearly separated the isolates into two groups; all the northernDesmodium isolates formed one group and all theKennedya isolates from the south another. These sub-populations were themselves variable and theDesmodium population alone was more variable than that of the related turnip yellow mosaic tymovirus in the Kosciusko alpine area.     

Genetic variation in two field populations and a laboratory colony of Glossina pallidipes (Diptera: Glossinidae)

Glossina pallidipes Austen from Lambwe and Nguruman in Kenya and a laboratory colony, originating from flies collected at Lambwe, were compared for 12 enzyme-gene systems using polyacrylamide gel electrophoresis. In the Nguruman, Lambwe, and colony flies, mean heterozygosities were 9.1, 15.3, and 16.5%, and polymorphism was observed in 3, 4, and 5 loci, respectively. Significant differences in number of gene products were observed between Nguruman and Lambwe flies at three loci, between Nguruman and colony flies at four loci, and between Lambwe and colony flies at two loci. Evidence is presented indicating that the locus for phosphoglucomutase is on the X chromosome, whereas loci for octanol dehydrogenase, malate dehydrogenase, phosphoglucose isomerase, and a thoracic esterase (Esterase-1) are autosomal.     

Analysis of the copulatory courtship songs of Lutzomyia longipalpis in six populations from Brazil

The sand fly Lutzomyia longipalpis Lutz & Neiva (Diptera: Psychodidae: Phlebotominae), the main vector of Leishmania infantum in the Americas, is believed to be a species complex, although the status of different Brazilian populations is still somewhat unclear. Preliminary analysis of the acoustic signals that are produced during copulation by L. longipalpis males has suggested the existence of three sibling species in Brazil. In the current report, we analyze in more detail a number of parameters of the copulatory courtship songs of L. longipalpis males from four allopatric populations from different parts of the country (Marajó Island, Natal, Jacobina, and Lapinha Cave) and from two sympatric populations from the locality of Sobral, where two types of males can be differentiated by the number of pale spots (one or two pairs) found on the abdomen. We show that males from the localities of Natal, Marajó, and Sobral (two-spot morph) have very similar songs composed of successive bursts, which are modulated in frequency and amplitude. No significant differences were found in the song parameters of these three populations. In contrast, one-spot males from Sobral and males from Jacobina and Lapinha produce songs that are made of pulses but with distinct patterns for each population and significant differences in all song parameters studied. The results suggest that the L. longipalpis complex in Brazil is composed of four sibling species and that the differences in song patterns between the populations are consistent with the level of divergence found in the period gene.     

A summary statistic approach to sequence variation in noncoding regions of six schizophrenia-associated gene loci

In order to explore the role of noncoding variants in the genetics of schizophrenia, we sequenced 27 kb of noncoding DNA from the gene loci RAC-alpha serine/threonine-protein kinase (AKT1), brain-derived neurotrophic factor (BDNF), dopamine receptor-3 (DRD3), dystrobrevin binding protein-1 (DTNBP1), neuregulin-1 (NRG1) and regulator of G-protein signaling-4 (RGS4) in 37 schizophrenia patients and 25 healthy controls. To compare the allele frequency spectrum between the two samples, we separately computed Tajima's D-value for each sample. The results showed a smaller Tajima's D-value in the case sample, pointing to an excess of rare variants as compared to the control sample. When randomly permuting the affection status of sequenced individuals, we observed a stronger decrease of Tajima's D in 2400 out of 100,000 permutations, corresponding to a P-value of 0.024 in a one-sided test. Thus, rare variants are significantly enriched in the schizophrenia sample, indicating the existence of disease-related sequence alterations. When categorizing the sequenced fragments according to their level of human-rodent conservation or according to their gene locus, we observed a wide range of diversity parameter estimates. Rare variants were enriched in conserved regions as compared to nonconserved regions in both samples. Nevertheless, rare variants remained more common among patients, suggesting an increased number of variants under purifying selection in this sample. Finally, we performed a heuristic search for the subset of gene loci, which jointly produces the strongest difference between controls and cases. This showed a more prominent role of variants from the loci AKT1, BDNF and RGS4. Taken together, our approach provides promising strategy to investigate the genetics of schizophrenia and related phenotypes.     

中国朝鲜族六个Y染色体短串联重复基因座遗传多态性的研究

目的 检测吉林延边地区朝鲜族人群6个Y染色体短串联重复(Y-short tandem repeat,Y-STR)基因座DYS441、DYS442、DYS443、DYS444、DYS445和DYS446的遗传多态性,以获取相应的遗传多态性数据.方法 应用PCR扩增、变性聚丙烯酰胺凝胶电泳和银染法对205名延边地区朝鲜族男性个体的6个Y-STR基因座进行检测和分析.结果 在6个基因位点中,分别检出了8、7、7、5、6和9个等位基因,基因多样性分布为0.5302～0.7897.共发现151种单倍型,单倍型基因多样性为0.9938.结论 6个Y-STR基因座在延边地区朝鲜族群体中均呈现较强的遗传多态性,因此是较为理想的遗传标记系统,在父系遗传关系确定和中国朝鲜族起源研究等方面具有较高的应用价值.