Analysis of genetic polymorphisms and a novel tri-allelic cloning sequence for the D13S317 locus among an ethnic Han Chinese population / 中华医学遗传学杂志

OBJECTIVE@#To study the genetic polymorphisms of short-tandem repeats (STR) for the D13S317 locus among an ethnic Han Chinese population and verify a novel tri-allelic pattern identified for the locus.@*METHODS@#A total of 378 paternity test cases from Guangdong Forensic Authentication Institute from October 17, 2017 to December 28, 2017 were selected as the study subjects. A GlobalFilerTM Express kit was used for the STR genotyping. Samples suspected for having a novel tri-allelic pattern were verified with a PowerPlex 21 kit. Potential variant of the primer-binding region and flanking sequences underlying the tri-allelic pattern was excluded by molecular cloning and sequencing.@*RESULTS@#Six alleles were detected for the D13S317 locus, with the characteristic distribution frequencies being 8 (29.1%), 9 (13.1%), 10 (15.21%), 11 (24.21%), 12 (13.89%) and 13 (3.44%), respectively. In one of the families, the D13S317 locus of the proband was suspected to harbor a triband allele (8, 9, 10). A re-test has confirmed the result of initial test. Molecular cloning and sequencing analysis of the D13S317 locus in the proband and his daughter has failed to find allelic variants in the primer-binding region and flanking sequence, which has confirmed the novel tri-allelic pattern for the locus.@*CONCLUSION@#A novel type 2 tri-allelic pattern (8, 9, 10) at the D13S317 locus has been identified among the ethnic Han Chinese population. The pattern has not been transmitted to the female offspring, and has been included in the international STRBase database for the first time.

Application of Familial Y-STR Haplotype Mismatch Tolerance in Genealogy Inference / 法医学杂志

OBJECTIVES@#To provide a guideline for genealogy inference and family lineage investigation through a study of the mismatch tolerance distribution of Y-STR loci in Chinese Han male lineage.@*METHODS@#Three Han lineages with clear genetic relationships were selected. YFiler Platinum PCR amplification Kit was used to obtain the typing data of 35 Y-STR loci in male samples. The variation of Y-STR haplotypes in generation inheritance and the mismatch tolerance at 1-7 kinship levels were statistically analyzed.@*RESULTS@#Mutations in Y-STR were family-specific with different mutation loci and numbers of mutation in different lineages. Among all the mutations, 66.03% were observed on rapidly and fast mutating loci. At 1-7 kinship levels, the number of mismatch tolerance ranged from 0 to 5 on all 35 Y-STR loci, with a maximum step size of 6. On medium and slow mutant loci, the number of mismatch tolerance ranged from 0 to 2, with a maximum step size of 3; on rapidly and fast mutant loci, the number of mismatch tolerance ranged from 0 to 3, with a maximum step size of 6.@*CONCLUSIONS@#Combined use of SNP genealogy inference and Y-STR lineage investigation, both 0 and multiple mismatch tolerance need to be considered. Family lineage with 0-3 mismatch tolerance on all 35 Y-STR loci and 0-1 mismatch tolerance on medium and slow loci can be prioritized for screening. When the number of mismatch tolerance is eligible, family lineages with long steps should be carefully excluded. Meanwhile, adding fast mutant loci should also be handled with caution.

Assessment of genotyping markers in the molecular characterization of a population of clinical isolates of Fusarium in Colombia / Evaluación de marcadores de genotipificación en la caracterización molecular de una población de aislamientos clínicos de Fusarium en Colombia

Introduction: Fusarium is a very heterogeneous group of fungi, difficult to classify, with a wide range of living styles, acting as saprophytes, parasites of plants, or pathogens for humans and animals. Prevalence of clinical fusariosis and lack of effective treatments have increased the interest in the precise diagnosis, which implies a molecular characterization of Fusarium populations. Objective: We compared different genotyping markers in their assessment of the genetic variability and molecular identification of clinical isolates of Fusarium. Materials and methods: We evaluated the performance of the fingerprinting produced by two random primers: M13, which amplifies a minisatellite sequence, and (GACA)4, which corresponds to a simple repetitive DNA sequence. Using the Hunter Gaston Discriminatory Index (HGDI), an analysis of molecular variance (AMOVA), and a Mantel test, the resolution of these markers was compared to the reference sequencing-based and PCR genotyping methods. Results: The highest HGDI value was associated with the M13 marker followed by (GACA)4. AMOVA and the Mantel tests supported a strong correlation between the M13 classification and the reference method given by the partial sequencing of the transcription elongation factor 1-alpha (TEF1-α) and rDNA 28S. Conclusion: The strong correlation between the M13 classification and the sequencing-based reference together with its higher resolution demonstrates its adequacy for the characterization of Fusarium populations.

Introducción. Fusarium es un grupo heterogéneo de hongos, difícil de clasificar y con una amplia gama de estilos de vida, que actúa como saprófito, parásito de plantas o patógeno de humanos y animales. La prevalencia de la fusariosis clínica y la falta de tratamientos han incrementado el interés en su diagnóstico preciso, lo que conlleva la caracterización molecular de las poblaciones. Objetivo. Comparar marcadores de genotipificación en la evaluación de la variabilidad genética e identificación de aislamientos clínicos de Fusarium. Materiales y métodos. Se evaluó la huella genética producida por dos cebadores aleatorios: M13, que amplifica una secuencia minisatélite, y (GACA)4, que corresponde a una secuencia repetitiva de ADN. Utilizando el índice discriminatorio de Hunter Gaston (HGDI), el análisis de varianza molecular (AMOVA) y una prueba de Mantel, se comparó la resolución de estos marcadores con métodos de genotipificación basados en secuenciación y PCR. Resultados. El mayor HGDI se asoció con el marcador M13, seguido de (GACA)4. Las pruebas AMOVA y Mantel mostraron correlación entre las clasificaciones obtenidas con M13 y la referencia basada en la secuenciación parcial del factor de elongación de transcripción 1-alfa (TEF1-α) y el ADNr 28S. Conclusión. La fuerte correlación entre la clasificación obtenida con M13 y el método de referencia, así como su alta resolución, demuestran su idoneidad para la caracterización de poblaciones de Fusarium.

Genetic diversity analysis of forty-three insertion/deletion loci for forensic individual identification in Han Chinese from Beijing based on a novel panel / 浙江大学学报（英文版）（B辑：生物医学和生物技术）

Due to the virtues of no stutter peaks, low rates of mutation, and short amplicon sizes, insertion/deletion (InDel) polymorphism is an indispensable tool for analyzing degraded DNA samples from crime scenes for human identifications (Wang et al., 2021). Herein, a self-developed panel of 43 InDel loci constructed previously by our group was utilized to evaluate the genetic diversities and explore the genetic background of the Han Chinese from Beijing (HCB) including 301 random healthy individuals. The lengths of amplicons at 43 InDel loci in this panel ranged from 87 to 199 bp, which indicated that the panel could be used as an effective tool to utilize highly degraded DNA samples for human identity testing. The loci in this panel were validated and performed well for forensic degraded DNA samples (Jin et al., 2021). The combined discrimination power (PD) and combined probability of exclusion (PE) values in this panel indicated that the 43 InDel loci could be used as the candidate markers in personal identification and parentage testing of HCB. In addition, population genetic relationships between the HCB and 26 reference populations from five continents based on 19 overlapped InDel loci were displayed by constructing a phylogenetic tree, principal component analysis (PCA), and population genetic structure analysis. The results illustrated that the HCB had closer genetic relationships with the Han populations from Chinese different regions.

Analysis of Genetic Polymorphism and Population Genetic Structure of 57 Autosomal InDel Loci in Beichuan Qiang Population / 法医学杂志

OBJECTIVES@#To investigate the genetic information of 57 autosomal InDel loci (A-InDels) included in AGCU InDel 60 fluorescence detection kit in the Beichuan Qiang population of Sichuan Province and evaluate its application value in forensic medicine.@*METHODS@#A total of 200 unrelated healthy individuals from Beichuan Qiang population of Sichuan Province were typing detected by AGCU InDel 60 fluorescence detection kit. Allele frequencies and population genetic parameters of the 57 A-InDels were statistically analyzed and compared with the available data of 26 populations.@*RESULTS@#After Bonferroni correction, there was no linkage disequilibrium between the 57 A-InDels, and all loci were in Hardy-Weinberg equilibrium. Except for rs66595817 and rs72085595, the minor allele frequencies of 55 A-InDels were above 0.3. PIC ranged from 0.298 3 to 0.375 0, CDP was 1-2.974 8×10-24, CPEduo was 0.999 062 660, and CPEtrio was 0.999 999 999. The calculation of the genetic distance showed that Beichuan Qiang population had the closest genetic distances with Beijing Han and South China Han populations, but far away from African populations.@*CONCLUSIONS@#The 57 A-InDels in AGCU InDel 60 fluorescence detection kit have a good genetic polymorphism in Beichuan Qiang population of Sichuan Province, which can be used as effective supplemental for individual identification and paternity identification in forensic medicine.

Application of SifaInDel 45plex System in the Han and Mongolian Populations / 法医学杂志

OBJECTIVES@#To investigate the genetic polymorphism of InDel loci in SifalnDel 45plex system in the Han population in Jiangsu Province and the Mongolian population in Inner Mongolia, and to evaluate the effectiveness of the system in forensic medicine.@*METHODS@#SifaInDel 45plex system was used for genotyping in blood samples of 398 unrelated individuals from the above two populations, and allele frequencies and population genetic parameters of the two populations were calculated respectively. Eight intercontinental populations in the gnomAD database were used as reference populations. The genetic distances between the two studied populations and eight reference populations were calculated based on the allele frequencies of 27 autosomal-InDels (A-InDels). The phylogenetic trees and multidimensional scaling (MDS) analysis diagrams were constructed accordingly.@*RESULTS@#Among two studied populations, the 27 A-InDels and 16 X-InDels showed no linkage disequilibrium between each other and the allele frequency distributions were in Hardy-Weinberg equilibrium. The CDP of the 27 A-InDels in two studied populations were all higher than 0.999 999 999 9, and the CPEtrio were all less than 0.999 9. The CDP of the 16 X-InDels in Han in Jiangsu and Mongolian in Inner Mongolia female and male samples were 0.999 997 962, 0.999 998 389, and 0.999 818 940, 0.999 856 063, respectively. The CMECtrio were all less than 0.999 9. The results of population genetics showed that the Jiangsu Han nationality, Inner Mongolia Mongolian nationality and East Asian population clustered into one branch, showing closer genetic relationship. The other 7 intercontinental populations clustered into another group. And the above 3 populations displayed distant genetic relationships with the other 7 intercontinental populations.@*CONCLUSIONS@#The InDels in the SifaInDel 45plex system have good genetic polymorphism in the two studied populations, which can be used for forensic individual identification or as an effective complement for paternity identification, and to distinguish different intercontinental populations.

Optimization and Developmental Validation of 38-plex InDel Panel for Ancestry Inference / 法医学杂志

OBJECTIVES@#The previously established 38-plex InDel system was optimized and its performance was validated according to the Scientific Working Group on DNA Analysis Method (SWGDAM) application guidelines. The ancestry inference accuracy of individuals from East Asian, European, African and mixed populations was verified.@*METHODS@#DNA standard sample 9947A was used as the template to establish the optimal amplification conditions by adjusting primer balance, Mg2+ final concentration and optimizing PCR thermal cycle parameters and amplification volume. The allelic dropout, nonspecific amplification and whether the origin of the inferred samples matched the known information were compared to evaluate the performance of this system.@*RESULTS@#The optimal dosage of this system was 0.125-2 ng DNA template. The results of InDel typing were accurate, the amplification equilibrium was good, and the species specificity was good. This system showed certain tolerance to DNA samples including the inhibitor such as hemoglobin (≤80 μmol/L), indigo (≤40 mmol/L), calcium ion (≤1.0 mmol/L), and humic acid (≤90 ng/μL). The system enabled the direct amplification of DNA from saliva and blood on filter paper, and the results of ethnic inference were accurate. The system successfully detected the mixed DNA sample from two individuals. The test results of the system for common biological materials in practical cases were accurate.@*CONCLUSIONS@#The results of the 38-plex InDel system are accurate and reliable, and the performance of the system meets the requirement of the SWGDAM guidelines. This system can accurately differentiate the ancestry origins of individuals from African, European, East Asian, and Eurasian populations and can be implemented in forensic practice.

Genetic polymorphisms of 21 non-combined of DNA index system short tandem repeat loci in Hainan Li population / 中华医学遗传学杂志

OBJECTIVE@#To investigate the genetic polymorphisms of 21 non-combined DNA index system short tandem repeat (STR) loci in Hainan Li population.@*METHODS@#DNA samples from 339 unrelated healthy individuals of Li population from Hainan Province were extracted and amplified with fluorescence labeled multiplex PCR system. PCR products were electrophoresed on an ABI3130 Genetic Analyzer following the manufacturer's instructions. Allele designation was performed with a GeneMapper ID-X by comparison with the allele ladder provided by the corresponding kit.@*RESULTS@#A total of 173 alleles and 489 genotypes were observed for the 21 STR loci, respectively. The frequencies of alleles and genotypes were 0.0010-0.5434 and 0.0020-0.3274, respectively. The heterozygosity varied from 0.639 to 0.833. Discrimination power (DP) was 0.803-0.948, power of exclusion for trio-paternity was 0.416-0.584, power of exclusion for duo-paternity was 0.140-0.238, the polymorphism information content(PIC) was 0.57-0.81, respectively. The total discrimination power (TDP), cumulative probability of exclusion for trio-paternity testing(CPE-trio) and cumulative probability of exclusion for duo-paternity testing (CPE-duo) were 0.999 999 999 999 99, 0.999 999 883 211 752, and 0.987 266, respectively.@*CONCLUSION@#The 21 STR loci are highly polymorphic and informative in the studied population and can be employed as supplementary loci in duo-paternity testing or cases with variant circumstances.

Genetic polymorphism of 23 autosomal STR loci in Han population from Yuncheng, Shanxi Province / 中南大学学报(医学版)

OBJECTIVES@#Due to the genetic feature of high diversity than other DNA markers, short tandem repeat (STR) plays key roles in forensic, anthropology, and population genetics. Newly introduced multiple STR kit is more valuable because of the greatly improved discriminatory power with the increase in the number of STR loci. The genetic polymorphic data are essential for the application and research in specific population. This study aims to investigate the genetic polymorphism of Han population residing in Yuncheng district, Shanxi Province, to evaluate the application of 23 STR loci in forensic personal identification and paternity test, and to explore the genetic relationship of Han population between Yuncheng and other populations.@*METHODS@#A total of 23 STR loci were amplified from 525 healthy unrelated individuals from the Han nationality in Yuncheng, Shanxi Province using the AGCU EX25 amplification kit. The products were detected and separated by ABI 3500 Genetic Analyzer. Alleles were genotyped by GeneMapper ID (Version 3.2) software, and corresponding frequencies and forensic parameters were calculated. We calculated the genetic distance and plotted the neighboring-joining tree with other 13 population.@*RESULTS@#The allele frequency of the 23 STRs ranged from 0.0010 to 0.5090. No deviation from Hardy-Weinberg equilibrium (@*CONCLUSIONS@#These 23 STRs are highly genetic polymorphic and informative in the Han population of Yuncheng, Shanxi Province, which can provide basic data for forensic personal identification, paternity testing, and population genetic research.

SNP Panel Analysis of Ancestry Inference in East Asian Populations / 法医学杂志

Objective To develop an SNP Panel for East Asian population, which has a high individual identification rate and the capability of ancestry analysis. Methods The 55 SNP Panel by Professor KIDD of Yale University and the 128 SNP Panel by Professor SELDIN of Davis School of California University, 170 SNP Panel in total was used as the basis and its test data in the East Asian population was collected. The genetic parameters of SNP loci were calculated and combined with the results of heatmap analysis to screen SNP loci suitable for East Asian population. Some Tibetan and Han samples were tested. The possibility of using the SNP loci in ancestry inference was analyzed by means of STRUCTURE analysis, principal component analysis and heatmap analysis. Results A Panel with 45 SNPs （45 SNP Panel） was screened out, and the average genetic parameters of each SNP were better than 170 SNP Panel, with the same ancestry analysis and inference ability. Conclusion In terms of ancestry inference information, the 45 SNP Panel can completely replace the 170 SNP Panel and achieve the same ancestry analysis and inference ability. In genetic parameters, 45 SNP Panel is better than 170 SNP Panel in the East Asian population, which shows its important potential forensic application value.

Performance Verification of SeqType® P52 Human Ancestry Identification SNP Detection Kit / 法医学杂志

Objective To evaluate the discrimination efficiency of the SeqType® P52 Human Ancestry Identification SNP Detection Kit based on a high-throughput sequencing platform in five Chinese ethnic groups. Methods Using the SeqType® P52 Human Ancestry Identification SNP Detection Kit based on a high-throughput sequencing platform, a total of 350 samples from Han, Tibetan, Mongolian, Uygur, and Yi populations in China were detected and population cluster analysis was performed. Results The effective sequencing depth of a single site in a single sample was ≥720×, and the average report rate was 96%. The mean values of allele frequency differences between the Tibetan, Mongolian, Uygur, Yi and Han population were 0.20, 0.05, 0.24 and 0.11, respectively. Using Structure 2.3.4 software under K=5 mode, independent ancestral component in Han, Tibetan and Uygur could be detected, which was consistent with the result observed from the principal component analysis （PCA）. For the Yi population, two thirds of them had relatively independent ancestral component close to the Tibetan population and one third were similar to the Uygur population. The Mongolian population had similar ancestral origin component with Han population. Conclusion The composite detection system with 52 screened ancestry-informative SNP sites has been established in this study, which can effectively analyze the composition and individual genetic components of populations from Han, Tibetan and Uygur. The ability to discriminate among Han, Mongolian and Yi needs to be further improved. The SeqType® P52 Human Ancestry Identification SNP Detection Kit can be used to infer the origin of an individual's ancestors in some forensic DNA cases.

Mitochondrial DNA Polymorphism in Zhejiang She Population Based on Next Generation Sequencing / 法医学杂志

Objective To study the genetic polymorphism of whole mitochondrial DNA （mtDNA） genomes in She population in Zhejiang and to explore the maternal genetic structure of the She population. Methods Whole mtDNA genomes of 231 unrelated individuals from She population in Zhejiang Province were sequenced. The number of mutations and population genetics parameters such as, the haplotype diversity （HD）, discrimination power （DP）, and random match probabilities （RMP） were analyzed. The mtDNA haplogroups of Zhejiang She population were classified, and the maternal genetic relationships between She and nine other Chinese populations were estimated. Results In 231 Zhejiang She samples, 8 507 mutations （702 types） were observed and the samples were classified into 94 haplogroups. The HD, DP and RMP values were 0.998 6, 0.994 2 and 0.005 8, respectively. The lowest genetic differentiation degree （Fst=0.006 89） was detected between Zhejiang She population and southern Han population. Principal component analysis （PCA） and median-joining network analysis showed that the genetic distance of Zhejiang She population with Guangxi Yao, Yunnan Dai and Southern Han populations was relatively close, but the population still had some unique genetic characteristics. Conclusion The whole mtDNA genomes are highly polymorphic in Zhejiang She population. The Zhejiang She population contains complex and diverse genetic components and has a relatively close maternal genetic relationship with Guangxi Yao, Yunnan Dai and Southern Han populations. Meanwhile, Zhejiang She population has kept its unique maternal genetic components.

Population genetics of three threatened catfish species in heterogeneous environments of the Cauca River, Colombia

Neotropical catfishes Ageneiosus pardalis, Pimelodus grosskopfii and Sorubim cuspicaudus are migratory fishes of commercial importance that exhibit decreasing populations due to overfishing and other anthropic interventions. This study used species-specific microsatellite loci to test the hypothesis that threatened fish populations show genetic vulnerability signs and are genetically structured in the middle and lower sections of the Cauca River. The studied species exhibit genetic diversity levels higher than the average values reported for Neotropical Siluriformes; however, they seem to have suffered recent bottlenecks and they present significant endogamy levels that are higher for the critically endangered catfish P. grosskopfii. Furthermore, both Ageneiosus pardalis and S. cuspicaudus are each formed by one genetic group, while Pimelodus grosskopfii comprises two coexisting genetic groups. The information obtained in this study is useful for the decision making in management plans that are appropriate for the sustainability of these three species populations within the proposal for the expansion of the hydroelectric development and other anthropic activities.(AU)

Los bagres Neotropicales Ageneiosus pardalis, Pimelodus grosskopfii y Sorubim cuspicaudus, son peces migratorios de importancia comercial cuyas poblaciones han disminuido debido a la sobrepesca y otras intervenciones antrópicas. En este trabajo, se utilizaron loci microsatélites especie-específicos para contrastar la hipótesis de que las poblaciones de peces amenazadas muestran señales de vulnerabilidad genética y están genéticamente estructuradas en los sectores medio y bajo del río Cauca. Las especies estudiadas exhiben niveles de diversidad genética superiores a los promedios reportados para Siluriformes Neotropicales; sin embargo, parecen haber sufrido cuellos de botella recientes y presentan niveles significativos de endogamia que son más altos para el bagre en peligro crítico, P. grosskopfii. Además, Ageneiosus pardalis y S. cuspicaudus están conformados cada uno por un solo grupo genético, mientras que Pimelodus grosskopfii comprende dos grupos genéticos que coexisten. La información obtenida en este estudio es útil para la toma de decisiones en planes de manejo que sean adecuados para la sostenibilidad de las poblaciones de estas tres especies de bagre dentro de las propuestas para la expansión de desarrollo hidroeléctrico y otras actividades antrópicas.(AU)

Development of microsatellite loci and population genetics of the catfish Pimelodus yuma (Siluriformes: Pimelodidae)

Pimelodus yuma (formerly Pimelodus blochii) is a freshwater fish, endemic to the Colombian Magdalena-Cauca and Caribbean basins that experiences habitat disturbances resulting from anthropogenic activities. Due to the lack of information about the population genetics of this species, this study developed 14 species-specific microsatellite loci to assess the genetic diversity and population structure of samples from the lower section of the Cauca River. The studied species showed genetic diversity levels higher than the average values reported for Neotropical Siluriformes and significant inbreeding levels as was described for some congeners. Furthermore, P. yuma comprises two coexisting genetic groups that exhibit gene flow along the lower section of the Cauca River. This information constitutes a baseline for future monitoring of the genetic diversity and population structure in an anthropic influenced sector of the Magdalena-Cauca basin.(AU)

Pimelodus yuma (anteriormente Pimelodus blochii) es un pez dulceacuícola endémico de las cuencas colombianas Magdalena-Cauca y Caribe que experimenta alteraciones del hábitat como resultado de actividades antropogénicas. Debido a la falta de información sobre la genética poblacional de esta especie, este estudio desarrolló 14 loci microsatélites especie-específicos para evaluar la diversidad genética y la estructura poblacional de muestras de la sección baja del río Cauca. La especie estudiada mostró niveles de diversidad genética más altos que los valores promedio reportados para Siluriformes neotropicales y niveles de endogamia significativos como se describió para algunos congéneres. Además, P. yuma comprende dos grupos genéticos coexistentes que exhiben flujo de genes a lo largo de la sección baja del río Cauca. Esta información constituye una línea base para futuros monitoreos de la diversidad genética y la estructura poblacional en un sector de influencia antrópica de la cuenca Magdalena-Cauca.(AU)

Development of microsatellite loci and population genetics in the bumblebee catfish species Pseudopimelodus atricaudus and Pseudopimelodus magnus (Siluriformes: Pseudopimelodidae)

The Neotropical freshwater catfish Pseudopimelodus atricaudus and Pseudopimelodus magnus are two recently discovered species endemic to the Colombian Magdalena-Cauca River basin. In this study, a set of 13 microsatellite loci were developed by using next generation sequence technology to assess the genetic diversity and population structure in P. atricaudus and test for cross-species amplification in P. magnus. Both species exhibited high genetic diversity (P. atricaudus: Na: 9.000 - 9.769 alleles/locus, Ho: 0.760 - 0.804, HE: 0.804 - 0.840; P. magnus: Na: 12.8 - 5.4 alleles/locus, Ho: 0.638 - 0.683, HE: 0.747 - 0.755) compared to the mean levels of genetic diversity reported for Neotropical Siluriformes, and lack of genetic differentiation among sampling sites within the Cauca River (P. atricaudus: F'ST=0.013 - 0.017, P > 0.05, D'est= -0.004 - 0.023, P > 0.05; P. magnus: F'ST= 0.031, P= 0.055; D'est= 0.045, P= 0.058). This work is the first insight on the diversity and the population genetics of species of the family Pseudopimelodidae and provides a framework to further population genetic and conservation analyses needed in this poorly studied family at the microevolutionary level.(AU)

Los bagres neotropicales Pseudopimelodus atricaudus y Pseudopimelodus magnus son dos especies recientemente descubiertas, endémicas de la cuenca Magdalena-Cauca en Colombia. En este estudio, se desarrollaron 13 loci microsatélites usando tecnología de secuenciación de próxima generación para evaluar la diversidad genética y la estructura poblacional de P. atricaudus y evaluar su amplificación cruzada en P. magnus. Ambas especies exhibieron altos valores de diversidad genética (P. atricaudus: Na: 9.000 - 9.769 alelos/locus, HO: 0.760 - 0.804, HE: 0.804 - 0.840; P. magnus: Na: 12.8 - 5.4 alelos/locus, HO: 0.638 - 0.683, HE: 0.747 - 0.755) comparados con los valores promedios de diversidad genética reportados para Siluriformes neotropicales, y ausencia de estructura genética entre los sitios analizados (P. atricaudus: F'ST= 0.013 - 0.017, P > 0.05, D'est= -0.004 - 0.023, P > 0.05; P. magnus: F'ST= 0.031, P= 0.055; D'est= 0.045, P= 0.058). Este trabajo representa la primera aproximación a la diversidad y genética poblacional de especies de la familia Pseudopimelodidae y proporciona un marco de referencia para futuros estudios genético-poblacionales y de conservación, requeridos en esta familia de bagres poco estudiada en el nivel microevolutivo.(AU)

Transferability of heterologous primers in Brycon falcatus

The genus Bryconcomprises fish species of significant socioeconomic and biological importance in Brazil. Despite that, the genetic knowledge about these species is scarce, especially regardingBrycon falcatus. Thus, the objective of this study was to evaluate the transferability of heterologous microsatellite primers inB. falcatus for the first time. Heterologous primers obtained from B. opalinus, B. hilarii, B. insignis, B. orbignyanus, B. amazonicus, Prochilodus argenteus, Prochilodus lineatus, Piaractus mesopotamicus, and Colossoma macropomum were evaluated. The primers that showed the best amplification patterns were applied to a sample of 22 individuals and the genetic parameters were calculated. Nine primers displayed satisfactory cross-amplification withB. falcatus: BoM5 (Brycon opalinus); Bh8, Bh13 and Bh16 (B. hilarii); Borg59 (B. orbignyanus); Bag22 (B. amazonicus); Par12 and Par80 (P. argenteus), and Cm1A8 (C. macropomum). The genetic parameters (number of alleles, effective alleles, allele richness, and expected and observed heterozygosity) and the polymorphic information content (PIC) confirmed the viability of these primers for population genetics analyses. Our study demonstrates the potential of transferability of microsatellite markers from related species and even different genera to B. falcatus, providing usefull tools for future population genetic studies in this species. (AU)

Caries and genetic variability of streptococcus mutans / Caries y variabilidad genética de streptococcus mutans

In the last two decades, the increase in population genetics studies has contributed to elucidating important questions about the evolution of the pathogenesis of bacteria of clinical interest. The objective of this study is to revise and update the knowledge of the last fifteen years regarding the genetic variability of Streptococcus mutans and their association with dental caries. Streptococcus mutans, one of the most widely distributed bacteria in the world, are heavily associated with this condition. This research shows the results of numerous studies carried out in various countries that, using molecular and biochemical methods, revealed associations between different serotypes and caries activity. In addition, it is reported that the population genetics structure of Streptococcus mutans in Argentina is highly recombinant, which reflects the largest waves of human immigration that occurred in the 19th and 20th centuries. On the other hand, demographic analysis suggests that these bacteria experienced a population expansion that coincided with the beginning of agricultural development.

En las últimas dos décadas el incremento de los estudios de genética de poblaciones ha contribuido a dilucidar cuestiones importantes sobre la evolución de la patogénesis de bacterias de interés clínico. El objetivo de este trabajo es realizar una actualización sobre los conocimientos de los últimos quince años referidos a la variabilidad genética de Streptococcus mutans y su relación con la caries dental. Streptococcus mutans, de amplia distribución mundial, es una de las bacterias más fuertemente asociada a dicha enfermedad. En este trabajo se muestran resultados de numerosos estudios realizados en diferentes países que utilizando métodos moleculares y bioquímicos revelaron asociaciones entre diferentes serotipos y la actividad de caries. Además, se reporta que la estructura genética poblacional de Streptococcus mutans de Argentina es de alto nivel recombinante, lo que reflejaría las grandes oleadas inmigratorias humanas ocurridas en los siglos 19thy 20th. Por otra parte, los análisis demográficos sugieren que esta bacteria experimentó una expansión poblacional coincidente con el comienzo del desarrollo de la agricultura

Polimorfismo +405G> C del gen del factor de crecimiento de endotelio vascular en población cubana / Vascular Endothelial Growth Factor gene +405G> C polymorphism in the Cuban population

Introducción: El factor de crecimiento endotelial vascular (VEGF) es una proteína involucrada en la proliferación y migración celular del endotelio vascular, en cuyo gen se ha reportado el polimorfismo +405G>C. Se reconoce que no existen reportes genéticos poblacionales de esta variante en Cuba, que permitan caracterizar los perfiles inmunogenéticos a nivel molecular, para su aplicación en estudios de asociación alélica. Objetivo: Describir las frecuencias génicas y genotípicas del polimorfismo VEGF (+405 G>C) en la población cubana. Material y Métodos: Se realizó un estudio observacional, descriptivo, transversal, entre octubre de 2017 y marzo de 2018 en 162 neonatos cubanos, de ambos sexos y sanos, para el pesquisaje neonatal de enfermedades metabólicas, cuyas muestras biológicas se conservaban en el banco de ADN del Centro Nacional de Genética Médica. La caracterización molecular de los genotipos fue realizada mediante un PCR-ARMS. Se utilizó el software GENEPOP 4.4 y el paquete estadístico STATISTICA 8.0 para los cálculos de las frecuencias génicas y genotípicas. Resultados: La población no se ajustó al modelo de equilibrio de Hardy Weinberg para el gen evaluado. Las frecuencias génicas estimadas para el polimorfismo VEGF (+405 G>C) fueron de 0,33 para el alelo G y de 0,67 para el alelo C. El cálculo de las frecuencias genotípicas resultó en 0,14, 0,37 y 0,49, para las variantes GG, GC y CC, respectivamente. Conclusiones: Las frecuencias alélicas VEGF.C fueron superiores a la del alelo VEGF.G, siendo el genotipo VEGF.GG el de menor representación en el conjunto estudiado(AU)

Introduction: The vascular endothelial growth factor (VEGF) is a protein involved in the proliferation and cell migration of the vascular endothelium. In its gene, +405G>C Polymorphism has been reported. There are no population genetic reports of this variant in Cuba that allow the characterization of immunogenetic profiles at a molecular level for its application to allelic association studies. Objectives: To describe the genic and genotypic frequencies of the VEGF (+405 G>C) polymorphism in the Cuban population. Material and Methods: A descriptive cross-sectional observational study was carried out from October 2017 to March 2018 in 162 Cuban healthy newborns of both sexes for the neonatal screening for metabolic diseases, whose biological samples were conserved in the DNA bank of the National Center for Medical Genetics. The molecular characterization of the genotypes was carried out using a PCR-ARMS. The GENEPOP 4.4 software and the statistical software package STATISTICA 8.0 were used for the analysis of genic and genotypic frequencies. Results: The population did not adjust to the Hardy-Weinberg equilibrium model for the gene evaluated. The estimated gene frequencies of VEGF +405 G> C polymorphism were 0.33 for the G allele and 0.67 for the C allele. The calculation of the genotypic frequencies resulted in 0.14, 0.37 and 0.49, for the variants GG, GC and CC, respectively. Conclusions: The allelic frequencies of VEGF.C were higher than the frequencies of the VEGF.G allele, being the VEGF GG the least represented genotype in the group studied(AU)

Genetic diversity and genetic structure evaluation of cultivated Chinese wolfberry (Lycium barbarum) based on microsatellite population genetics / 中国中药杂志

A total of 178 Chinese wolfberry individuals from 17 populations were detected by 7 pairs of SSR primers to evaluate genetic diversity and structure, using software GenALEx 6.5,NTSYS,STRUCTURE, the effects of cultivation on genetic diversity and structure were clarified aiming to find the strategies for genetic management and sustainable use. The results showed that the genetic diversity of cultivated Chinese wolfberry was low. The average number of alleles N_A, expected heterozygosity H_E, observed heterozygosity H_O, and Shannon's information index H' was 3.9, 0.443 7, 0.556 6, 0.788 1, respectively. STRUCTURE, UPGMA clustering and PCA test indicated that Chinese wolfberry varieties were severely intermixed but no differentiation among varieties. Mantel test showed no significant correlation between genetic distance and geographic distance. AMOVA analysis showed that genetic variation mainly occurred among individuals within the population(84.58%, P<0.001), and there was almost no genetic differentiation between varieties(3.63%, P<0.001) and between populations(11.79%, P<0.001). The cultivation has caused a significant decline in the genetic diversity of Chinese wolfberry, which may cause inbreeding decline. New germplasm resources should be sought from the wild to improve the existing cultivars. On the other hand, there are obvious homogenization and germplasm intermixing between cultivated varieties and populations. Meanwhile, Chinese wolfberry cultivars should be purified and prevented from flowing into the wild population, in case of causing pollution of the wild germplasm.

Development of a small panel of SNPs to infer ancestry in Chileans that distinguishes Aymara and Mapuche components

BACKGROUND: Current South American populations trace their origins mainly to three continental ancestries, i.e. European, Amerindian and African. Individual variation in relative proportions of each of these ancestries may be confounded with socio-economic factors due to population stratification. Therefore, ancestry is a potential confounder variable that should be considered in epidemiologic studies and in public health plans. However, there are few studies that have assessed the ancestry of the current admixed Chilean population. This is partly due to the high cost of genome-scale technologies commonly used to estimate ancestry. In this study we have designed a small panel of SNPs to accurately assess ancestry in the largest sampling to date of the Chilean mestizo population (n = 3349) from eight cities. Our panel is also able to distinguish between the two main Amerindian components of Chileans: Aymara from the north and Mapuche from the south. RESULTS: A panel of 150 ancestry-informative markers (AIMs) of SNP type was selected to maximize ancestry informativeness and genome coverage. Of these, 147 were successfully genotyped by KASPar assays in 2843 samples, with an average missing rate of 0.012, and a 0.95 concordance with microarray data. The ancestries estimated with the panel of AIMs had relative high correlations (0.88 for European, 0.91 for Amerindian, 0.70 for Aymara, and 0.68 for Mapuche components) with those obtained with AXIOM LAT1 array. The country's average ancestry was 0.53 ± 0.14 European, 0.04 ± 0.04 African, and 0.42 ± 0.14 Amerindian, disaggregated into 0.18 ± 0.15 Aymara and 0.25 ± 0.13 Mapuche. However, Mapuche ancestry was highest in the south (40.03%) and Aymara in the north (35.61%) as expected from the historical location of these ethnic groups. We make our results available through an online app and demonstrate how it can be used to adjust for ancestry when testing association between incidence of a disease and nongenetic risk factors. CONCLUSIONS: We have conducted the most extensive sampling, across many different cities, of current Chilean population. Ancestry varied significantly by latitude and human development. The panel of AIMs is available to the community for estimating ancestry at low cost in Chileans and other populations with similar ancestry.