Reference population database for 24 STR loci of selected provinces of Argentina.

BACKGROUND: Argentinean population is the result of admixture between South Amerindians, Europeans and to a lesser degree, Africans. Since the advent of forensic molecular genetics, the construction of local reference databases became mandatory. Aiming to further extend the technical quality reference database of Argentina, we present herein the allele frequencies for 24 autosomal STRs, including D22S1045, and SE33 (not previously reported for Argentina in STRidER). CONCLUSIONS: Genotypes of 6454 unrelated individuals (3761 males and 2694 females) from 13 out of 23 provinces were analysed. Forensic parameters were calculated for each marker. The observed heterozygosity ranged from 0.661 (TPOX) to 0.941 (SE33). The locus SE33 was revealed to be the most informative marker showing the highest values for PIC (0.955), GD (0.952), TPI (8.455) and PE (0.879). On the other hand, TPOX turned out to be the least informative marker: PIC (0.618), GD (0.669), and PE (0.371). The high number of analyzed individuals allowed detecting low frequency alleles and microvariants in CSF1PO; D16S539 and D21S11 D18S51; PENTA D; PENTA E and at locus D6S1043. METHODS AND RESULTS: This study is the most extensive for Argentina and complements the already reported information concerning the autosomal STRs commonly used in forensic identification. The results were submitted passing STRidER quality control standards (QC), receiving the reference number STR000327 v.2.

Social injustice unveiled by genetic analysis: Argentina as a case study.

BACKGROUND: The population of the American countries is genetically heterogeneous, whose genesis result from of recent admixture events. In this process, the transoceanic European component displaced the original inhabitants of the continent. AIM: To investigate whether socially differentiated cohorts exhibit underlying ancestry components within an urban admixed population, two cohorts of individuals inhabiting Argentina were studied. One cohort included genetically unrelated individuals involved in voluntary paternity testing while the other included sexual or blood-crime suspects. MATERIALS & METHODS: We analyzed over 2500 unrelated individuals: four Native American maternal lineage mtDNA markers in 1024 samples, five Y chromosome haplogroups in 658 male samples, 24 autosomal ancestry informative markers (AIMs) in 205 samples, and 15 autosomal short tandem repeats (STRs) in 1557 samples; countrywide and divided by regions. RESULTS: While our results confirm a tricontinental ethnic contribution to both cohorts, their proportions showed statistically significant differences, with a higher proportion of Native American ancestry in the cohort linked to violent crimes compared to those in paternity testing. This hallmark was observed with all the marker sets used and at various levels of analysis. DISCUSSION: Since paternity tests are costly, socio-economic differences might help to interpret our observations. The effect of discrimination against descendants of Native American minorities, and exposure to violent social environments, might link marginal groups to criminality. CONCLUSION: Our findings underscore the relevance of proper social management since only by improving living conditions, reducing discrimination, promoting education, and providing job opportunities will it be possible to attain equality in a heterogeneous society. Genetic markers proved to be highly informative in unveiling unexpected social differences.

Development of a nested real time PCR/high resolution melting assay for human T-cell lymphotropic viruses types 1 and 2 (HTLV-1 and 2) identification.

HTLV-1 and HTLV-2 are present in different high-risk populations, such as sexual workers and injecting drug users (IDUs). HTLV-1 is endemic in areas of Middle East, Southern Japan and Latin America, whereas HTLV-2 infection is endemic among some Native Americans and some Central African tribes. The pathogenic consequences and clinical manifestations of these two viruses differ significantly, demanding an adequate identification; therefore, proper diagnosis of HTLV-1 and 2 infection is crucial. To get a final diagnosis of HTLV-1 or 2 infection, it is recommended that positive serologic samples should be confirmed by PCR assays or western blot (WB) analysis. Thus, the aim of this study was to develop and implement a simple reaction for the rapid identification of HTLV-1 and 2. Nested real-time PCR technique followed by high resolution melting was performed based on the tax/rex sequences of HTLV-1 (M2) and HTLV-2 (MoT) cell lines perfectly discriminating between HTLV-1 from HTLV-2, by distinct melting curve profiles. The sensitivity assay of this method revealed that at least 1 viral copy of HTLV-1 or 1·5 viral copy of HTLV-2 could be amplified. Later, this method was validated using 200 blood samples from corpses. In agreement with previous epidemiological, the HTLV-1 and 2 prevalence was 1·5% (CI 95%: 0·31-4·3) and 0·5% (CI 95%: 0·013-2·75), respectively. The strategy proposed herein has some advantages over other PCR-based tests because it not only reduces considerably time and the costs of the total diagnosis but also allows detection and discrimination of HTLV-1 and 2 in the same reaction.

Demand for larger Y-STR reference databases in ethnic melting-pot countries: Argentina as a test case.

The Y chromosome behaves as a single locus. Its genetic information is useful in forensic casework, deficiency kinship testing, and population genetics studies. Continuous increases of loci number within commercial kits forced modification of worldwide reference databases. In Pan American countries, like Argentina, diverse parental ethnic groups contributed to the extant admixed urban populations. We report 509 additional haplotypes of 23 Y-STRs from donors inhabiting urban areas of six Argentinean provinces: Buenos Aires, Santiago del Estero, Santa Cruz, Rio Negro, Santa Fe, and Formosa. To better understand the demographic landscape of the admixed urban paternal lineages, structural analysis was performed using published data from other Argentinean provinces. AMOVA by Rst distance and inferred haplogroups by two predictive online software methods based on haplotypes yielded complementary results with respect to detected population structure, probably due to the different proportions of the Native American Q3-M3 haplogroup in the studied samples. This situation, which is common to most North, Meso, and South American countries, underscores the need for the additional step of typing specific SNPs for haplogroup diagnosis. We propose organizing Y-STR haplotype reference databases according to the most frequent haplogroups detected in a given admixed population.

Historical records under the genetic evidence: "Chiriguano" tribe genesis as a test case.

Historical records suggest that Chiriguano tribe is the result of a genetic admixture event. The process involved the arrival of Guaraní tribesmen descending from Amazonian region of Brazil along with groups of Arawak origin that inhabited the foothill plains of Bolivia. Later they arrived in Argentina at the beginning of the twentieth century. Aiming to test the historical records, we analysed a set of 46 samples collected at San Ramon de la Nueva Orán, Province of Salta, Argentina. A wide set of uni- and biparentally transmitted genetic markers were analysed, including 23 autosomal STRs; 46 AIM-DIPs and 24 AIM-SNPs all located at diverse autosomal chromosome locations; 23 Y-STRs and the entire mtDNA D-Loop sequence. Ancestry informative markers allowed for the detection of a strong Native American component in the genomes (> 94%), while all mtDNA haplotypes showed Native American characteristic motives, and 93% of Y-haplotypes belonged to the Q1a3a Y-haplogroup. The analysis of mitochondrial haplotypes and Y chromosome, although they did not match other populations, revealed a relationship between the Chiriguano and other groups of Guaraní and Arawak origin inhabiting Brazil and Bolivia, confirming, at least in part, the historical records describing the origins of Chiriguano tribal settlements in northwestern Argentina.

Increased prevalence of human herpesvirus type 8 (HHV-8) genome among blood donors from North-Western Argentina.

The prevalence of HHV-8 infection varies widely in South American populations, displaying geographical variations in its distribution. The heterogeneous genetic contributions provided by the transatlantic parental populations that modified the Native American genomes may explain this epidemiological observation. Aiming to determine the prevalence of HHV-8 genome among healthy South American blood donors and its potential association with genetic ancestry, 772 individuals were screened by a highly sensitive PCR protocol and ancestry was assessed in 414 samples. HHV-8 DNA was significantly more prevalent among North-western Argentines than among those from the metropolitan region (P = 0.001) and Bolivians (P = 0.0008), but no differences were found when compared with Peruvians and Paraguayans. Although significant differences were observed in the ancestry components of the studied populations, no association was found in the genetic admixture between HHV-8 [+] and HHV-8 [-] samples from the same place. These results support the hypothesis of the existence of geographical factors related to HHV-8 prevalence which could be explained by the presence of specific risk factors, cultural characteristics or behaviors, probably related to contaminated saliva and/or sexual transmission. The presence of HHV-8 in South American blood units available for transfusion and an increased risk of infection in some provinces of North-western Argentina represent a hazard for immunosuppressed recipients. J. Med. Virol. 89:518-527, 2017. © 2016 Wiley Periodicals, Inc.

Role of HLA-DP and HLA-DQ on the clearance of hepatitis B virus and the risk of chronic infection in a multiethnic population.

BACKGROUND & AIMS: HBV infection exhibits geographical variation in its distribution in South America. While HBV rates are low in central Argentina, the north-western region exhibits intermediate HBV rates. Unfortunately, the reasons that could explain this difference are still unknown. METHODS: A total of 1440 Argentines were recruited and grouped into HBV patients, HBV-resolved individuals and healthy controls. Genetic ancestry was assessed by analysis of biparental lineages and ancestry autosomal typing. SNPs of HLA-DPA1 (rs3077), HLA-DPB1 (rs9277542), HLA-DQB1 (rs2856718) and HLA-DQB2 (rs7453920) were determined, and HBV genotyping was performed by phylogenetic analysis in HBV patients. RESULTS: Native American ancestry prevailed in the north-western region when compared with central Argentina (P<.0001). However, no differences were observed among the three groups of each region. The distribution of HBV genotypes revealed significant differences (P<.0001). Three SNPs (rs3077, rs9277542 and rs7453920) showed a significant association with protection against chronic HBV and viral clearance in both regions. The remaining SNP showed a significant association with susceptibility to chronic HBV. The frequency rates of rs3077-T, related to protection against chronic HBV and viral clearance, were lower in north-western Argentina when compared with central Argentina. The same uneven frequency rates were observed for SNP rs9277542. CONCLUSIONS: This is the first study addressing the associations between the HLA-DP and HLA-DQ loci and the protection against chronic HBV and viral clearance in a multiethnic South American population. The uneven distribution of HLA-DP and HLA-DQ supports the HBV epidemiological differences observed in these two regions of Argentina with dissimilar ancestry genetic background.

Potential forensic use of a 33 X-InDel panel in the Argentinean population.

Polymorphic genetic markers located on the X chromosome might become a complement in particular forensic identification when the biological kinship are deficient. We analyzed forensic statistical parameters of 33 X-chromosome InDel polymorphisms in a sample of 320 individuals from Argentina. The X-chromosome InDel polymorphism (X-InDel) panel was amplified in a single multiplex PCR reaction. Hardy-Weinberg Equilibrium was determined in the female cohort, whereas the male cohort was used to calculate linkage disequilibrium (LD) tested by an extension of Fisher's exact test, D', and Chi-square values. Regarding LD, 15 markers were organized and grouped into six blocks containing two or three linked loci each, namely block I (MID356-MID357), block II (MID448804-MID3703-MID218), block III (MID3705-MID3706-MID304737), block IV (MID197147-MID3754), block V (MID3664-MID284601-MID103547), and block VI (MID3763-MID3728). The haplotype diversity was higher than 0.99 in all cases. Blocks III and VI showed the highest match probability in the studied population, whereas block II showed the lowest. The accumulated power of discrimination was 99.9999991 % in women and 99.9992925 % in men. The mean exclusion chance in trios and duos were 99.9891736 and 99.6099391 %, respectively. Since 15 markers are associated as haplotypic blocks, for a conservative treatment of the data, statistical evaluation should consider their haplotypic frequencies and the remaining 18 markers can be evaluated as independent loci.

Development of a quantitation approach for total human and male DNA based on real time PCR followed by high resolution melting analysis.

We developed and validated a total human DNA quantitation technique that simultaneously allows male DNA detection. This assay, called Amel-Y, is a duplex Real Time PCR followed by HRM (high resolution melting) analysis using the intercalating dye SYTO9. Amel-Y duplex produces two amplicons, one for the amelogenin gene (106/112 bp, female/male) and another (84 bp) corresponding to human Y chromosome-specific fragment to detect male DNA. After HRM analysis, two melting peaks differing in 5.3°C-5.5°C are detected if both male and female DNA are present and only one if only female DNA is present. For specificity assessment, the inclusion of high concentrations of bacterial and fungal DNA in the quantitation reactions allowed discarding species cross-reactivity. A set of crime scene evidence from forensic casework has been quantified with commercial kits and compared with Amel-Y duplex. Our method detected male DNA from a concentration of 18 pg/µL and supports autosomal/Y DNA detection ratio up to 200:1. A limitation of the technique is its inability to quantify male and female donnors in a mixed sample. The Amel-Y duplex demonstrated to be an efficient system for quantifying total human DNA being a specific, rapid, sensitive, and cost-effective method suitable for mixed DNA samples and applicable to any field where human DNA quantification is required, such as molecular diagnosis, population genetics, and forensic identification.

Analysis of locus D9S1120 and its genetic admixture correlation in seven argentina native american ethnic groups.

OBJECTIVE: Genetic data have complemented archaeological and linguistic investigations for understanding the peopling of the Americas. Aiming to investigate the Native South American genetic background in Argentina, seven Amerindian and one urban population were selected. The analysis focused on locus D9S1120 due to its potential anthropological information about Native American origins. METHODS: The sample set included 603 individuals belonging to nine isolated Argentinean aboriginal communities from seven tribes (N = 296), 100 individuals living in Buenos Aires city, and three potentially parental population references samples (N = 207). We computed allele and genotype frequency distributions, genetic distances, and pairwise differences among and within them. Admixture proportion was determined by means of typing 13 autosomal short tandem repeats plus D9S1120 in all populations, and comparing the data with those from three parental groups including Native American, European and Sub Saharan West African. RESULTS: The Native American-specific allele 9RA was found at an average frequency of 0.26 in aboriginal groups. Statistically significant differences were observed among the Native American groups when compared with the Buenos Aires urban population using analysis of molecular variance (AMOVA) (Fst = 0.05669; P < 0.0001). Admixture analysis denoted different results between the cohorts of Amerindian samples displaying the specific 9RA allele, compared with those lacking it. A linear correlation was established between positive 9RA and Native American ancestry. CONCLUSIONS: Autosomal-based genetic admixture showed that the studied communities have considerable European and Native America contributions. Our results concerning D9S1120 further contribute to a better understanding of the admixture process between Sub Saharan African, Native American, and European individuals that shaped the genetic background of Argentinean extant population.

Influence of ethnicity on the distribution of genetic polymorphisms associated with risk of chronic liver disease in South American populations.

BACKGROUND: The global burden of chronic liver disease is rising. Besides environmental, behavioral, viral and metabolic factors, genetic polymorphisms in patatin-like phospholipase-3 (PNPLA3) and vitamin D receptor (VDR) genes have been related to the development of chronic liver disease and progression towards liver cancer. Although their prevalence differs remarkably among ethnic groups, the frequency of these polymorphisms in South American populations -whose genetic background is highly admixed- has been poorly studied. Hence, the aim of this study was to characterize polymorphisms related to chronic liver disease and their association with the genetic ancestry of South American populations. RESULTS: DNA samples from 258 healthy unrelated male volunteers were analyzed. The frequencies of G and C alleles of rs738409 polymorphism (PNPLA3 gene) were 74 % and 26 %, respectively; whereas the bAt (CCA) haplotype (VDR gene) was observed in 32.5 % of the samples. The GG genotype of PNPLA3 rs738409 and the bAt (CCA) haplotype -associated with an increased risk of chronic liver disease and progression towards liver cancer- were significantly more frequent among samples exhibiting maternal and paternal Native American haplogroups (63.7 % and 64.6 %), intermediate among admixed samples (45.1 % and 44.9 %; p = 0.03) and the lowest for Non-native American ancestry (30.1 % and 29.6 %; p = 0.001 and p = 0.0008). CONCLUSIONS: These results suggest that individuals with Native American ancestry might have a high risk of chronic liver disorders and cancer. Furthermore, these data not only support the molecular evaluation of ancestry in multi-ethnic population studies, but also suggest that the characterization of these variants in South American populations may be useful for establishing public health policies aimed at high risk ethnic communities.

Analysis of D216H polymorphism in Argentinean patients with primary dystonia.

The D216H polymorphism (rs1801968) in TOR1A has been suggested as a risk factor for developing primary dystonia in German subjects not carrying the deletion c.904-906delGAG (∆GAG). However, this association could not be confirmed in other populations with different ethnic backgrounds. The purpose of this study is to evaluate the D216H polymorphism in an Argentinean cohort of 40 patients with primary dystonia and 200 unrelated control subjects. The authors could observe a significantly higher frequency of the H216 variant in dystonic patients lacking ∆GAG as compared with controls.

Detection of a novel 16.3 variant allele at locus DYS533 in R1b males inhabiting southern South America: A 19-nucleotide insertion explains its origin based on Sanger sequencing results.

We typed 1541 Y-STR haplotypes from reference samples along forensic casework investigations. In three haplotypes, we detected a variant allele designed as 16.3 at locus DYS533. This was confirmed by amplification using two commercial kits. Sanger sequencing revealing a novel motif corresponding to [TATC]12 repeats with a 19-bp insertion in the flanking upstream region. We propose its origin as an insertion at - 9.1 upstream of the repeat motifs. We searched other local databases and found this allele in various geographical areas of Argentina and neighbouring countries. The haplotypes share a common core of 10 Y-STRs (DYS389-I/13; DYS389-II/30; DYS19/14; DYS481/22; DYS438/12; DYS437/16; DYS635/23; DYS392/13; DYS393/13; GATA H4/11) and belong to the R1b haplogroup. This 16.3 allele is restricted to southern South America, which allows us to propose a local and relatively recent origin. The sequence described herein constitutes a novelty that could be considered in future criteria for the nomenclature of STRs based on massively parallel sequencing.

Use of genetic tools to assess predation on reintroduced howler monkeys (Alouatta caraya) in Northeastern Argentina.

Despite strong support from the media, the reintroduction of animals into natural environments does not always achieve its goal. Alouatta caraya is the primate species facing the greatest hunting pressure due to the illegal pet trade in Argentina. Confiscations of this species are common, as is the voluntary surrender of animals by owners no longer able or willing to care for them. These animals ultimately arrive at rehabilitation centers and, in many cases, are released into natural environments that may differ from the original sites where they were captured. Until recently, the lack of genetic analysis of the individuals involved led to biased relocation decisions. We followed the reintroduction of 12 A. caraya individuals in a protected area (Isla Palacio, Misiones, Argentina). The presence of potential predators such as pumas (Puma concolor) and jaguars (Panthera onca) in this area was confirmed by camera traps, footprints and feces. After the disappearance of four A. caraya at the reintroduction site, we investigated the applicability of genetic assignment tests based on genotypic data to accurately identify predated individuals. Genetic analyses allowed us to determine the predator species (P. onca) and to identify the predated individuals as two of the reintroduced animals. This procedure is promising for identifying the remains of predated individuals, and can contribute to the design of reintroduction policies based on scientific evidence.

Molecular analysis of congenital goitres with hypothyroidism caused by defective thyroglobulin synthesis. Identification of a novel c.7006C>T [p.R2317X] mutation and expression of minigenes containing nonsense mutations in exon 7.

BACKGROUND: Thyroglobulin (TG) deficiency is an autosomal-recessive disorder that results in thyroid dyshormonogenesis. A number of distinct mutations have been identified as causing human hypothyroid goitre. OBJECTIVES: The purpose of this study was to identify and characterize new mutations in the TG gene in an attempt to increase the understanding of the genetic mechanism responsible for this disorder. A total of six patients from four nonconsanguineous families with marked impairment of TG synthesis were studied. METHODS: Single-strand conformation polymorphism (SSCP) analysis, sequencing of DNA, genotyping, expression of chimeric minigenes and bioinformatic analysis were performed. RESULTS: Four different inactivating TG mutations were identified: one novel mutation (c.7006C>T [p.R2317X]) and three previously reported (c.886C>T [p.R277X], c.6701C>A [p.A2215D] and c.6725G>A [p.R2223H]). Consequently, one patient carried a compound heterozygous for p.R2223H/p.R2317X mutations; two brothers showed a homozygous p.A2215D substitution and the remaining three patients, from two families with typical phenotype, had a single p.R277X mutated allele. We also showed functional evidences that premature stop codons inserted at different positions in exon 7, which disrupt exonic splicing enhancer (ESE) sequences, do not interfere with exon definition and processing. CONCLUSIONS: In this study, we have identified a novel nonsense mutation p.R2317X in the acetylcholinesterase homology domain of TG. We have also observed that nonsense mutations do not interfere with the pre-mRNA splicing of exon 7. The results are in accordance with previous observations confirming the genetic heterogeneity of TG defects.

Genetic assignment of illegally trafficked neotropical primates and implications for reintroduction programs.

The black and gold howler monkey (Alouatta caraya) is a neotropical primate threatened by habitat loss and capture for illegal trade in Argentina. Using multilocus microsatellite genotypes from 178 A. caraya individuals sampled from 15 localities in Argentina, we built a genotype reference database (GRDB). Bayesian assignment methods applied to the GRDB allowed us to correctly re-assign 73% of individuals to their true location of origin and 93.3% to their cluster of origin. We used the GRDB to assign 22 confiscated individuals (17 of which were reintroduced), and 3 corpses to both localities and clusters of origin. We assigned with a probability >70% the locality of origin of 14 individuals and the cluster of origin of 21. We found that most of the confiscated individuals were assigned to one cluster (F-Ch-C) and two localities included in the GRDB, suggesting that trafficked A. caraya primarily originated in this area. Our results reveal that only 4 of 17 reintroduced individuals were released in sites corresponding to their cluster of origin. Our findings illustrate the applicability of genotype databases for inferring hotspots of illegal capture and for guiding future reintroduction efforts, both of which are essential elements of species protection and recovery programs.

Genetic diversity and phylogeographic analysis of human herpesvirus type 8 (HHV-8) in two distant regions of Argentina: Association with the genetic ancestry of the population.

BACKGROUND: The genetic diversity of persistent infectious agents, such as HHV-8, correlates closely with the migration of modern humans out of East Africa which makes them useful to trace human migrations. However, there is scarce data about the evolutionary history of HHV-8 particularly in multiethnic Latin American populations. OBJECTIVES: The aims of this study were to characterize the genetic diversity and the phylogeography of HHV-8 in two distant geographic regions of Argentina, and to establish potential associations with pathogenic conditions and the genetic ancestry of the population. STUDY DESIGN: A total of 101 HIV-1 infected subjects, 93 Kaposi's Sarcoma (KS) patients and 411 blood donors were recruited in the metropolitan (MET) and north-western regions of Argentina (NWA). HHV-8 DNA was detected by ORF-26 PCR in whole blood, saliva and FFPE tissues. Then, ORF-26 and ORF-K1 were analyzed for subtype assignment. Mitochondrial DNA and Y chromosome haplogroups, as well as autosomal ancestry markers were evaluated in samples in which subtypes could be assigned. Phylogeographic analysis was performed in the ORF-K1 sequences from this study combined with 388 GenBank sequences. RESULTS: HHV-8 was detected in 50.7%, 59.2% and 8% of samples from HIV-1 infected subjects, KS patients and blood donors, respectively. ORF-K1 phylogenetic analyses showed that subtypes A (A1-A5), B1, C (C1-C3) and F were present in 46.9%, 6.25%, 43.75% and 3.1% of cases, respectively. Analyses of ORF-26 fragment revealed that 81.95% of strains were subtypes A/C followed by J, B2, R, and K. The prevalence of subtype J was more commonly observed among KS patients when compared to the other groups. Among KS patients, subtype A/C was more commonly detected in MET whereas subtype J was the most frequent in NWA. Subtypes A/C was significantly associated with Native American maternal haplogroups (p = 0.004), whereas subtype J was related to non-Native American haplogroups (p < 0.0001). Sub-Saharan Africa, Europe and Latin America were the most probable locations from where HHV-8 was introduced to Argentina. CONCLUSIONS: These results give evidence of the geographic circulation of HHV-8 in Argentina, suggest the association of ORF-26 subtype J with KS development and provide new insights about its relationship with ancient and modern human migrations and identify the possible origins of this virus in Argentina.

Genetic structure of Mataco-Guaycurú speakers from Argentina and the extent of their genetic admixture with neighbouring urban populations.

Argentina hosts more than 30 Native American groups, who are widely distributed throughout the country. Mataco-Guaycurú speakers settled in the ecoregion of Gran Chaco and represent 26.7% of the extant aboriginal population of the country. To further investigate the genetic attributes of these speakers, we focused our attention on four aboriginal groups, namely, Wichí, Toba, Pilagá and Mocoví, belonging to the Mataco-Guaycurú linguistic group. Our main goal was to evaluate the interrelationships among the groups and the relationships of these groups with admixed urban populations and to assess correspondences between molecular analysis and historical information. A total of 890 samples (282 Native Americans and 608 inhabitants of admixed urban areas) were analysed. Genetic information was gathered from 15 autosomal STRs, 17 Y-STRs, entire mtDNA control region sequences, 24 AIM-SNPs and 46 AIM-DIPs. Native American signatures were detected in 97.9% of mtDNA lineages, 89.1% of Y-haplotypes and 90.3% to 96.9% of autosomal markers. Wichí exhibited the genetic composition with the largest Native American contribution among the groups and a weak signal of gene flow. This work provides extended genetic information of potential interest in the fields of molecular anthropology and forensic genetics.

Recurrence of the p.R277X/p.R1511X compound heterozygous mutation in the thyroglobulin gene in unrelated families with congenital goiter and hypothyroidism: haplotype analysis using intragenic thyroglobulin polymorphisms.

Thyroglobulin (TG) functions as the matrix for thyroid hormone synthesis. Thirty-five different loss-of-function mutations in the TG gene have been reported. These mutations are transmitted in an autosomal recessive mode. The objective of this study is to analyze the recurrence of the p.R277X/p.R1511X compound heterozygous mutation in the TG gene in two unrelated families (one Argentinian and another Brazilian) with congenital hypothyroidism, goiter and impairment of TG synthesis. The first and last exon of the TG gene, the exons where previously mutations and single nucleotide polymorphisms (SNPs) were detected, as well as the TG promoter, were analyzed by automatic sequencing in one affected member of the each family. Four microsatellite markers localized in introns 10, 27, 29 and 30 of the TG gene, one insertion/deletion intragenic polymorphism and 15 exonic SNPs were used for haplotype analysis. A p.R277X/p.R1511 compound heterozygous mutation in the TG gene was found in two members of an Argentinian family. The same mutations had been also reported previously in two members of a Brazilian family. We constructed mutation-associated haplotypes by genotyping members of the two families. Our results suggest that the cosegregating haplotype is different in each one of these families. Different haplotypes segregated with the p.R277X and p.R1511 mutations demonstrating the absence of a founder effect for these mutations between Argentinian and Brazilian populations. However, haplotyping of Argentinian patients showed the possibility that the p.R277X alleles might be derived from a common ancestral chromosome.

Genetic structure in the southernmost populations of black-and-gold howler monkeys (Alouatta caraya) and its conservation implications.

Black-and-gold howler monkeys Alouatta caraya, are arboreal primates, inhabitants of Neotropical forests, highly susceptible to the yellow fever virus, considered early 'sentinels' of outbreaks, and thus, of major epidemiological importance. Currently, anthropogenic habitat loss and modifications threatens their survival. Habitat modification can prevent, reduce or change dispersal behavior, which, in turn, may influence patterns of gene flow. We explored past and contemporary levels of genetic diversity, elucidated genetic structure and identified its possible drivers, in ten populations (n = 138) located in the southernmost distribution range of the species in South America, in Argentina and Paraguay. Overall, genetic variability was moderate (ten microsatellites: 3.16 ± 0.18 alleles per locus, allelic richness of 2.93 ± 0.81, 0.443±0.025 unbiased expected heterozygosity; 22 haplotypes of 491-bp mitochondrial Control Region, haplotypic diversity of 0.930 ± 0.11, and nucleotide diversity of0.01± 0.007). Significant evidence of inbreeding was found in a population that was, later, decimated by yellow fever. Population-based gene flow measures (FST = 0.13; θST = 018), hierarchical analysis of molecular variance and Bayesian clustering methods revealed significant genetic structure, grouping individuals into four clusters. Shared haplotypes and lack of mitochondrial differentiation (non-significant θST) among some populations seem to support the hypothesis of historical dispersal via riparian forests. Current resistance analyses revealed a significant role of landscape features in modeling contemporary gene flow: continuous forest and riparian forests could promote genetic exchange, whereas disturbed forests or crop/grassland fields may restrict it. Estimates of effective population size allow anticipating that the studied populations will lose 75% of heterozygosity in less than 50 generations. Our findings suggest that anthropogenic modifications on native forests, increasingly ongoing in Northeastern Argentina, Southern Paraguay and Southeastern Brazil, might prevent the dispersal of howlers, leading to population isolation. To ensure long-term viability and maintain genetic connectivity of A. caraya remnant populations, we recommend preserving and restoring habitat continuity. To conserve the species genetic pool, as well, the four genetic clusters identified here should be considered separate Management Units and given high conservation priority. In light of our findings and considering complementary non-genetic information, we suggest upgrading the international conservation status of A. caraya to "Vulnerable".