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To explore the genetic diversity of Asarum sieboldii this study developed SSR markers based on transcriptome sequencing results and five populations of A.sieboldii from different regions were used as samples for genetic diversity assessment using software such as GenALEx 6.5, NTSYS 2.1, and Structure 2.3.4. The results showed that 16 SSR markers with high polymorphism and good repeatability were selected from the A.sieboldii transcriptome. Primers designed based on the flanking sequences of these markers successfully amplified 56 polymorphic fragments from 150 individual samples of the five A.sieboldii populations. On average, each primer amplified 3.5 polymorphic fragments, ranging from 2 to 8. The mean values of expected heterozygosity(H_e), Shannon's diversity index(I), Nei's gene diversity index(H), and the polymorphic information content(PIC) were 0.172, 0.281, 0.429, and 0.382, respectively. The mean population differentiation coefficient(F_(ST)) was 0.588, consistent with the analysis of molecular variance(AMOVA) results, which indicated greater genetic variation among A.sieboldii populations(69%) than that within populations(31%). The percentage of polymorphic loci(PPL) ranged from highest to lowest as SNJ>LN>SY>SZ>TB. Principal coordinate analysis(PCoA) and UPGMA clustering analysis further revealed genetic clustering of A.sieboldii individuals based on their geographical distribution, consistent with the results of the structure clustering analysis. In summary, the SSR markers developed from the transcriptome effectively assessed the genetic differentiation and population structure of natural A.sieboldii populations, revealing a relatively low genetic diversity in A.sieboldii, with genetic variation primarily observed at the population level and a correlation between population differentiation and geographic distance.
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Humanos , Variación Genética , Asarum , Transcriptoma/genética , Repeticiones de Microsatélite/genética , FilogeniaRESUMEN
Objective:To explore genetic relationship and population structure of Turpinia arguta in six locations of Jiangxi province by inter-simple sequence repeat （ISSR） molecular marker technique， and to provide theoretical basis for the protection and utilization of this medicinal material resource. Method:A total of 22 samples from six locations in four counties in Jiangxi province were collected， and genomic DNA was extracted by kit method. Polymerase chain reaction （PCR） amplification was performed using sixty-four universal ISSR molecular marker primers， and the products were detected with polyacrylamide gel electrophoresis （PAGE）. NTsys 2.10e software was selected to calculate the genetic similarity coefficient by unweighted pair group method with arithmetic mean （UPGMA） and cluster analysis. Population genetic structure was analyzed by Structure 2.1 software. Result:A total of forty-eight ISSR primers were amplified to obtain the product， the percent of polymorphic bands ranged from 45.45% to 100%. UPGMA cluster analysis showed that these plant individuals could not be clustered according to their respective executive locations. Analysis of population genetic structure showed that 22 samples of T. arguta could be divided into three populations. Conclusion:There is gene exchange among the populations of T. arguta in Jiangxi province， and it can affect the genetic structure of germplasm resources from different geographical sources.
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Objective To describe the genetic structure of populations in different areas of China,and explore the effects of different strategies to control the confounding factors of the genetic structure in cohort studies.Methods By using the genome-wide association study (GWAS) on data of 4 500 samples from 10 areas of the China Kadoorie Biobank (CKB),we performed principal components analysis to extract the fast and second principal components of the samples for the component two-dimensional diagram generation,and then compared them with the source of sample area to analyze the characteristics of genetic structure of the samples from different areas of China.Based on the CKB cohort data,a simulation data set with cluster sample characteristics such as genetic structure differences and extensive kinship was generated;and the effects of different analysis strategies including traditional analysis scheme and mixed linear model on the inflation factor (λ) were evaluated.Results There were significant genetic structure differences in different areas of China.Distribution of the principal components of the population genetic structure was basically consistent with the geographical distribution of the project area.The first principal component corresponds to the latitude of different areas,and the second principal component corresponds to the longitude of different areas.The generated simulation data showed high false positive rate (λ =1.16),even if the principal components of the genetic structure was adjusted or the area specific subgroup analysis was performed,λ could not be effectively controlled (λ ＞ 1.05);while,by using a mixed linear model adjusting for the kinship matrix,λ was effectively controlled regardless of whether the genetic structure principal component was further adjusted (λ =0.99).Conclusions There were large differences in genetic structure among populations in different areas of China.In molecular epidemiology studies,bias caused by population genetic structure needs to be carefully treated.For large cohort data with complex genetic structure and extensive kinship,it is necessary to use a mixed linear model for association analysis.
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Objective To describe the genetic structure of populations in different areas of China,and explore the effects of different strategies to control the confounding factors of the genetic structure in cohort studies.Methods By using the genome-wide association study (GWAS) on data of 4 500 samples from 10 areas of the China Kadoorie Biobank (CKB),we performed principal components analysis to extract the fast and second principal components of the samples for the component two-dimensional diagram generation,and then compared them with the source of sample area to analyze the characteristics of genetic structure of the samples from different areas of China.Based on the CKB cohort data,a simulation data set with cluster sample characteristics such as genetic structure differences and extensive kinship was generated;and the effects of different analysis strategies including traditional analysis scheme and mixed linear model on the inflation factor (λ) were evaluated.Results There were significant genetic structure differences in different areas of China.Distribution of the principal components of the population genetic structure was basically consistent with the geographical distribution of the project area.The first principal component corresponds to the latitude of different areas,and the second principal component corresponds to the longitude of different areas.The generated simulation data showed high false positive rate (λ =1.16),even if the principal components of the genetic structure was adjusted or the area specific subgroup analysis was performed,λ could not be effectively controlled (λ ＞ 1.05);while,by using a mixed linear model adjusting for the kinship matrix,λ was effectively controlled regardless of whether the genetic structure principal component was further adjusted (λ =0.99).Conclusions There were large differences in genetic structure among populations in different areas of China.In molecular epidemiology studies,bias caused by population genetic structure needs to be carefully treated.For large cohort data with complex genetic structure and extensive kinship,it is necessary to use a mixed linear model for association analysis.
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The genus Tripterygium is an immune suppressor in the Chinese traditional medicines. Due to the habitat destruction and anthropogenic over-exploitation, the wild genus Tripterygium plants have decreased dramatically in recent years or even been endangered. It is critical to evaluate and protect genus Tripterygium wild resource. In this research, simple sequence repeat (SSR) molecular markers were applied to the investigation of the genetic diversity and genetic structure of 28 populations for genus Tripterygium (396 samples from 9 provinces in China). We found a high level of genetic diversity (percentage of polymorphic loci PPL=77.29%, Shannon's information index I=0.639 4; Nei's expected heterozygosity H=0.359 9) and high genetic differentiation among the populations (gene flow Nm=0.228 7). Based on Nei's genetic distance, the phylogenic tree of populations was constructed and 28 populations were divided into 6 clusters according to STRUCTURE clustering analysis. T. hypoglaucumwas was mainly divided into 3 clusters, including Sichuan, Yunnan and GuizhouChongqing. T. regelii was separated to cluster 4, while T. wilfordii was divided into two clusters:the transition type LQ and NY were divided into cluster 5, and the others were in cluster 6. These results provide a theory basis for the conservation of wild resource, research of genetic polymorphism and molecular marker for assisted breeding of genus Tripterygium.
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Objective Selecting Tibetan ancestry informative SNPs base on high-altitude adaptation genes of Tibetan. Methods We developed a multiplex assay constituted of 87 SNPs located on EPAS1 and EGLN1 genes based on Agena Mas-sARRAY? genotyping system. 183 samples from Tibet plateau were genotyped. The genotypes of 2504 samples from 26 populations were downloaded from the 1000 genomes. Genetic frequency and population structure were analyzed and compared between Tibetan population and worldwide populations. Results SNPs that have distinctive distribution between Tibetan and other populations could be used as Tibetan AISNPs (Ancestry informative SNPs). We selected 23 SNPs has a separated principal genetic component in STRUCTURE result. Conclusion These 23 AISNPs we selected could be combined into ancestry informative SNP panels to improve the resolution of ancestry inference in East Asian, and provide clues for cases of biological material ancestry inference.
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The genetic structure of small-scale landscape groups of Oncomelania hupensis in Songzi City ,Hubei Province was identify in this study .O .hupensis snails were collected from 10 habitats in Songzi City ,of which 6 polymorphic microsat-ellite DNA loci (T6-17 ,P101 ,D11 ,B14 ,T4-33 ,and C22) were carried out with GeneScan .The number of alleles (Na) ,het-erozygosity (H) ,fixation index (FST) of snails in each group ,genetic distance between groups ,and the polymorphic informa-tion content (PIC) were calculated .Cluster analysis was then carried out based on genetic distance ,and hierarchical AMOVA calculation was conducted .By certified the shells of snails ,10 groups were divided into light and ribbed shell (including shallow rib and deep rib) .There were 141 alleles in total detection on 10 populations and 20-34 alleles in each locus ,which were detec-ted for 23 .5 on average .The average number of alleles in 6 loci was 1 .575 and the number of alleles in each locus was uneven , showing large numerical differences ranged from 0 .445 to 3 .060 .The average observed heterozygosity (Ho) ranged from 0 .438 ue between paired populations was from -0 .015 64 to 0 .252 47 ,and the polymorphic information content in the population ranged from 0 .528 -0 .857 ,showing a high polymorphism .Hierarchical AMOVA calculations showed that inter-individual variation of the snails occupied 88 .4% of the total variations .Cluster analysis revealed that the three ribbed shell population in Munu Kou Village ,Hengti Village and Yixing Village first clustered to the three light shell population in Mashizizu Village , Mingzhu Village and Tuqiao Village ,then clustered to the light shell population in Tuanshan Village and Jiama Cao Village with the two shallow rib population in Desheng Village and Tianmu He Village .Under the different landscape environment of Songzi Area ,there were different shells presenting on the morphology of O .hupensis .Although there was a rich diversity on O .hupensis of Songzi City ,the genetic differences mostly present in individuals .Different groups didn’t show the significant genetic differentiation among the different shell morphology of O .hupensis .
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Multilocus sequence typing MLST with high solution sensitivity and specificity is widely used to study the population genetic structure of pathogen by amplification and sequencing of the housekeeping genes. MLST also provides more evidence and plays an important role in parasite research. This paper reviews the principle and method of MLST and its applica-tion on population genetic structure analysis of parasites.
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La mezcla entre individuos nativos y múltiples colonos ha dejado como resultado la actual configuración de las poblaciones humanas, lo cual puede conllevar a estructura genética, fenómeno apreciable al observar diferencias en las frecuencias alélicas y genotípicas de las poblaciones de una región geográfica respecto a otra. El análisis de estas poblaciones se ha enfocado en la identificación y cuantificación del grado de mezcla, herramienta útil en la comprobación mediante la asociación de marcadores polimórficos involucrados en el desarrollo de enfermedades. Un obstáculo en la identificación de variantes genéticas asociadas a enfermedades, es la comparación de casos y controles procedentes de poblaciones con diferentes antecedentes genéticos. En este sentido, es importante establecer el grado de estructura genética en las poblaciones debido a la distribución diferencial de los polimorfismos asociados a una enfermedad de interés...
The current configuration of human populations is due to the mix of native individuals and many colonizers; it can entail genetic structure, a phenomenon appreciable to observe differences in allele and genotype frequencies of populations of a geographic region over another. This analysis has focused on the identification and quantification of the degree of mixing, useful tool for checking through association of polymorphic markers involved in the development of diseases. One obstacle in identifying genetic variants associated with diseases is the comparison of cases and controls from populations with different genetic backgrounds. In the opposite sense, it is important to establish the degree of genetic structure in populations due to the differential distribution of alleles of polymorphisms associated with a disease of interest...
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Colombia , Enfermedad , GenéticaRESUMEN
The objective of this research was to study the population genetic structure of four herds of Mediterranean buffaloes in Brazil. It was used pedigree data from 6,588 buffaloes of Mediterranean breed born from 1980 to 2002. Of the total number of animals studied, 60.5, 15.3 and 2.1% had a pedigree in the first, second and third ascendancy, respectively. The effective number of herds that provided breeding males was 1.60 for parents, 1.16 for grandparents and 1.00 for great-grandparents. There were 923 founder animals and only 71 effective founders. The effective number of ancestors explaining the genetic variability of the population was 71 and only 30 ancestors accounted for 50% of the genetic variability of the population. The average relatedness coefficient (AR) between individuals and inbreeding (F) of the population were estimated at 0.37 and 0.34% respectively. The average estimate of generation interval was 8.71±2.85 years. The variability of the current population is the result of a few ancestors, who are mostly also founders showing that the population was developed from a narrow genetic base which characterizes the occurrence of founder effect.
O objetivo deste trabalho foi estudar a estrutura genética populacional de bubalinos da raça Mediterrâneo, em quatros rebanhos, no Brasil. Foram utilizados dados de pedigree de 6.588 bubalinos da raça Mediterrâneo nascidos no período de 1980 a 2002. Do total de animais estudados, 60,5; 15,3 e 2,1% possuíam pedigree na primeira, segunda e terceira ascendência, respectivamente. O número efetivo de rebanhos que forneceram machos reprodutores foi de 1,60 para pais; 1,16 para avôs e 1,00 para bisavôs. O número de animais fundadores foi 923 e o número efetivo de fundadores foi apenas 71. O número efetivo de ancestrais que explicaram a variabilidade genética da população foi de 71 e somente 30 ancestrais explicaram 50% da variabilidade genética da população. Os coeficientes médios de relação (CR) entre os indivíduos da população e de endogamia (F) foram estimados em 0,37 e 0,34%, respectivamente. A estimativa média do intervalo de gerações foi de 8,71±2,85 anos. A variabilidade da população atual é fruto da contribuição de poucos ancestrais, que são, na sua maioria, também fundadores, evidenciando que a população se desenvolveu a partir de uma base genética estreita, o que caracteriza a ocorrência do efeito fundador.
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Red snappers (Lutjanus purpureus in Brazil and Lutjanus campechanus in USA and Gulf of Mexico) are both under clear effect of overfishing. Because of their high morphological similarity it has already been suggested that they could possibly be considered as a single species. To investigate the degree of similarity and the genetic structure of red snapper populations we constructed a common dataset of partial D-loop mtDNA sequences of L. purpureus from Brazil (Amapá, Pará and Maranhão) and L. campechanus from the Atlantic coast of the USA (Florida, Louisiana and Mississippi). Phylogenetic and population genetic analyses surprisingly depicted high similarity between L. campechanus and L. purpureus, compatible with the hypothesis of a single species of red snapper for the Western Atlantic Ocean. These preliminary but very curious findings open an important discussion regarding the legislation involved on the capture of this overexploited fish resources as well as regarding their taxonomy.