The geographic mosaic of Ecuadorian Y-chromosome ancestry.

Ecuadorians originated from a complex mixture of Native American indigenous people with Europeans and Africans. We analyzed Y-chromosome STRs (Y-STRs) in a sample of 415 Ecuadorians (145 using the AmpFlSTR® Yfiler™ system [Life Technologies, USA] and 270 using the PowerPlex®Y23 system [Promega Corp., USA]; hereafter Yfiler and PPY23, respectively) representing three main ecological continental regions of the country, namely Amazon rainforest, Andes, and Pacific coast. Diversity values are high in the three regions, and the PPY23 exhibits higher discrimination power than the Yfiler set. While summary statistics, AMOVA, and RST distances show low to moderate levels of population stratification, inferred ancestry derived from Y-STRs reveal clear patterns of geographic variation. The major ancestry in Ecuadorian males is European (61%), followed by an important Native American component (34%); whereas the African ancestry (5%) is mainly concentrated in the Northwest corner of the country. We conclude that classical procedures for measuring population stratification do not have the desirable sensitivity. Statistical inference of ancestry from Y-STRS is a satisfactory alternative for revealing patterns of spatial variation that would pass unnoticed when using popular statistical summary indices.

Analysis of uni and bi-parental markers in mixture samples: Lessons from the 22nd GHEP-ISFG Intercomparison Exercise.

Since 1992, the Spanish and Portuguese-Speaking Working Group of the ISFG (GHEP-ISFG) has been organizing annual Intercomparison Exercises (IEs) coordinated by the Quality Service at the National Institute of Toxicology and Forensic Sciences (INTCF) from Madrid, aiming to provide proficiency tests for forensic DNA laboratories. Each annual exercise comprises a Basic (recently accredited under ISO/IEC 17043: 2010) and an Advanced Level, both including a kinship and a forensic module. Here, we show the results for both autosomal and sex-chromosomal STRs, and for mitochondrial DNA (mtDNA) in two samples included in the forensic modules, namely a mixture 2:1 (v/v) saliva/blood (M4) and a mixture 4:1 (v/v) saliva/semen (M8) out of the five items provided in the 2014 GHEP-ISFG IE. Discrepancies, other than typos or nomenclature errors (over the total allele calls), represented 6.5% (M4) and 4.7% (M8) for autosomal STRs, 15.4% (M4) and 7.8% (M8) for X-STRs, and 1.2% (M4) and 0.0% (M8) for Y-STRs. Drop-out and drop-in alleles were the main cause of errors, with laboratories using different criteria regarding inclusion of minor peaks and stutter bands. Commonly used commercial kits yielded different results for a micro-variant detected at locus D12S391. In addition, the analysis of electropherograms revealed that the proportions of the contributors detected in the mixtures varied among the participants. In regards to mtDNA analysis, besides important discrepancies in reporting heteroplasmies, there was no agreement for the results of sample M4. Thus, while some laboratories documented a single control region haplotype, a few reported unexpected profiles (suggesting contamination problems). For M8, most laboratories detected only the haplotype corresponding to the saliva. Although the GHEP-ISFG has already a large experience in IEs, the present multi-centric study revealed challenges that still exist related to DNA mixtures interpretation. Overall, the results emphasize the need for further research and training actions in order to improve the analysis of mixtures among the forensic practitioners.

Immunological status of isolated lymphoid follicles after intestinal transplantation.

Intestinal transplantation (ITx) faces the challenge of grafting a high immunogenic organ, which is certainly one of the major obstacles for intestinal allograft acceptance. The allograft has to guarantee the proper functioning of the mucosal immune machinery under immunosuppressive conditions. Recently, it has been elucidated that isolated lymphoid follicles (ILFs) are an indispensable part of mucosal immunity to maintain IgA synthesis and consequently to control commensal microflora. No data about these follicular structures in the setting of ITx are available so far. Therefore, we addressed the question whether constitution, integrity and function of allograft ILFs are disturbed by immunosuppressive regimen. We compared allograft ILFs from terminal ileum of transplant patients with ILFs from nontransplant patients via flow cytometry, quantitative real-time polymerase chain reaction and immunohistochemistry. We found that host leukocytes rapidly repopulate allograft ILFs and that maintenance immunosuppressive regimen, tacrolimus and corticosteroids, does not affect their cellular integrity and function. However, allograft ILFs revealed a higher maturation state than control samples and IgA positive plasma cells were increased in number in allograft mucosa. Our results open the path for a better understanding of allograft mucosal immunity.

Análisis de polimorfismos ligados a enfermedad cardiovascular en población general de Buenos Aires / Analysis of the polymorphism linked to cardiovascular disease in a general population from Buenos Aires

Atherosclerotic cardiovascular disease (CVD) is a major health problem around the world. The development of CVD is a complex process, and evidence demonstrates that family history is associated with CVD. The most common forms of CVD are believed to be multifactorial and to result from many genes, each with a small effect working alone or in combination with modifier genes or environmental factors. A large number of candidate gene associatin studies have been conducted for myocardial infarction and atherosclerotic CVD. Variants of the ACE, AGT, AGTR1, APOA5, APOE, CYP11B2, eNOS, FII, FVL, MTHFR, PA11, and genes in general population of Buenos Aires have been examined in the present study; allele frequency, genotype frequency and Hardy Weinberg equilibrium were analyzed in all cases.

Análisis de STRs de cromosoma X: su utilidad en casos de filiación / Analysis of X-Chromosome markers: utility in paternity identification

Analysis of X-chromosome markers is being increasingly used in special paternity cases. Here, we present a complex case composed of mother, child and three sibs of the decaesed alleged father. Exlcusion of the alleged biological relationships between child and the alleged group could be confirmed by typing a set of 10 X-chromosome STRs (short tandem repeat) in addition to the 17 autosomal STRs routinely analyzed, proving that analyses of these X-chromosome STRs is a useful supplementary tool in special situations of disputed paternity.

Nueva variante en el polimorfismo del intrón 4 de la enzima Oxido Nítrico Sintasa endotelial (eNOS) / A new variant of the polymorphism in the fourth intron from the endothelial nitric oxide synthase enzyme

Nitric oxide (NO) derived from endothelial Nitric Oxide Synthase enzyme (eNOS) is an important mediator of the vascular function. Various polymorphisms have been described for the eNOS gene that has effects on its expression. One of the most studied markers in the eNOS gen is located in the fourth intron and is characterized by the presence of a variable number of tandemly repeated sequence of 27 base pairs. In this work we report the existence and the sequence of a new variant for these polymorphism and we hypothestize its potential role in the regulation of NO productition by eNOS.

Bases de datos de STRs en Argentina: consideraciones para su utilización en casos forenses y de paternidad / STRs (Short Tandem Repeats) database in Argentina: considerations for its employement in forensic cases and paternity

The employmento fo genetic markers to study paternity and criminalistics requires the development of a database with allelic frequencies that allows an statistic evaluation of the results obtained. With the objective to determine if in Argentina could be possible to use a general database for forensic detrminations, we analyze the results of the typing of 15 Short Tandem Repeats (STRs) markers, used at present by the international scientific community in studies related to paternity and criminalistic. The results obtained in this study are described and discussed

Bases de datos de STRs en Argentina: consideraciones para su utilización en casos forenses y de paternidad / STRs (Short Tandem Repeats) database in Argentina: considerations for its employement in forensic cases and paternity

The employmento fo genetic markers to study paternity and criminalistics requires the development of a database with allelic frequencies that allows an statistic evaluation of the results obtained. With the objective to determine if in Argentina could be possible to use a general database for forensic detrminations, we analyze the results of the typing of 15 Short Tandem Repeats (STRs) markers, used at present by the international scientific community in studies related to paternity and criminalistic. The results obtained in this study are described and discussed

Polimorfismo del ADN mitocondrial en una población indígena del noroeste argentino / Genetic plymorphism of mitochondrial DNA in a closed native population geographically located in northern Argentina

This study was undertaken to evaluate the genetic polymorphism of mitochondrial DNA in a closed native population geographically located in Northern Argentina

Diferncias en los loci DYS389I y DYS389II producidas por una mutación en el locus DYS389I. Cálculo de la probabilidad de paternidad en un caso forense de abuelismo / Differences of loci DYs389I and DYS389II produced by a mutation in locus DYS389I and a calculation of the probability of paternity in a forensic case of ancestry

Presentamos un caso de filiación en el que un varón reclama la paternidad de un hombre fallecido cuyos rstos han sido cremados. Los abuelos paternos alegados también han fallecido, sólo se dispone de los restos biológicos del abuelo paterno para realizar la comparación con el Titular, no existiendo otros familiares del Padre Alegado que puedan ser analizados

Polimorfismo del ADN mitocondrial en una población indígena del noroeste argentino / Genetic plymorphism of mitochondrial DNA in a closed native population geographically located in northern Argentina

This study was undertaken to evaluate the genetic polymorphism of mitochondrial DNA in a closed native population geographically located in Northern Argentina

Diferncias en los loci DYS389I y DYS389II producidas por una mutación en el locus DYS389I. Cálculo de la probabilidad de paternidad en un caso forense de abuelismo / Differences of loci DYs389I and DYS389II produced by a mutation in locus DYS389I and a calculation of the probability of paternity in a forensic case of ancestry

Presentamos un caso de filiación en el que un varón reclama la paternidad de un hombre fallecido cuyos rstos han sido cremados. Los abuelos paternos alegados también han fallecido, sólo se dispone de los restos biológicos del abuelo paterno para realizar la comparación con el Titular, no existiendo otros familiares del Padre Alegado que puedan ser analizados