Micro and macro geographical analysis of Y-chromosome lineages in South Iberia.

In this study, we intend to identify the evolutionary footprints of the South Iberian population focusing on the Berber and Arab influence, which has received little attention in the literature. Analysis of the Y-chromosome variation represents a convenient way to assess the genetic contribution of North African populations to the present-day South Iberian genetic pool and could help to reconstruct other demographic events that could have influenced on that region. A total of 26 Y-SNPs and 17 Y-STRs were genotyped in 144 samples from 26 different districts of South Iberia in order to assess the male genetic composition and the level of substructure of male lineages in this area. To obtain a more comprehensive picture of the genetic structure of the South Iberian region as a whole, our data were compared with published data on neighboring populations. Our analyses allow us to confirm the specific impact of the Arab and Berber expansion and dominion of the Peninsula. Nevertheless, our results suggest that this influence is not bigger in Andalusia than in other Iberian populations.

Admixture and genetic relationships of Mexican Mestizos regarding Latin American and Caribbean populations based on 13 CODIS-STRs.

Short tandem repeats (STRs) of the combined DNA index system (CODIS) are probably the most employed markers for human identification purposes. STR databases generated to interpret DNA profiles are also helpful for anthropological purposes. In this work, we report admixture, population structure, and genetic relationships of Mexican Mestizos with respect to Latin American and Caribbean populations based on 13 CODIS-STRs. In addition, new STR population data were included from Tijuana, Baja California (Northwest, Mexico), which represents an interesting case of elevated genetic flow as a bordering city with the USA. Inter-population analyses included CODIS-STR data from 11 Mexican Mestizo, 12 Latin American and four Caribbean populations, in addition to European, Amerindian, and African genetic pools as ancestral references. We report allele frequencies and statistical parameters of forensic interest (PD, PE, Het, PIC, typical PI), for 15 STRs in Tijuana, Baja California. This Mexican border city was peculiar by the increase of African ancestry, and by presenting three STRs in Hardy-Weinberg disequilibrium, probably explained by recurrent gene flow. The Amerindian ancestry in Central and Southeast of Mexico was the greatest in Latin America (50.9-68.6%), only comparable with the North of Central America and Ecuador (48.8-56.4%), whereas the European ancestry was prevalent in South America (66.7-75%). The African ancestry in Mexico was the smallest (2.2-6.3%) in Latin America (≥ 2.6%), particularly regarding Brazil (21%), Honduras (62%), and the Caribbean (43.2-65.2%). CODIS-STRs allowed detecting significant population structure in Latin America based on greater presence of European, Amerindian, and African ancestries in Central/South America, Mexican Mestizos, and the Caribbean, respectively.

Y-chromosomal DNA analysis in French male lineages.

French population, despite of its crucial geographic location for repopulation movements of Europe across time, it has been insufficiently characterized at the genetic level, especially for Y-chromosomal DNA variation. In order to make a genetic structure characterization, we have analyzed the Y-chromosome diversity of 558 male individuals, scattered along 7 different French regions: Alsace (Strasbourg), Auvergne (Clermont-Ferrand), Bretagne (Rennes), Île-de-France (Paris), Midi-Pyrénées (Toulouse), Nord-Pas-de-Calais (Lille) and Provence-Alpes-Côte d'Azur (Marseille). A total of 17 Y-chromosome STRs and 27 Y-chromosome SNPs were genotyped for each individual. Even though we find that most of the individual populations in France were not differentiated from each other, Bretagne population shows population substructure, an important fact to be considered when establishing general population databases.

Terena Amerindian group autosomal STR data: comparison studies with other Brazilian populations.

Allele frequencies for the high polymorphic short tandem repeats (STR) loci PentaE, PentaD, D18S51, D21S11, TH01, D3S1358, FGA, D16S539, D7820, D13S317, vWA and D81179 were analysed in an native Amerindian population from Mato Grosso do Sul state named Terena. Deviations from Hardy-Weinberg expectations were evaluated and the results showed no differences from equilibrium in all loci. The combined power of discrimination and the combined power of exclusion for the 12 tested STR loci were 0.99999999 and 0.999999 respectively. The Terena population data were compared to other from 11 Brazilian populations (Amazônia, Pernambuco, Mato Grosso do Sul, São Paulo, Rio Grande do Sul, Alagoas, Sergipe, Rio Grande do Norte, Santa Catarina, Rondônia and Rio de Janeiro) representing the major Brazilian geographic regions. The F(ST) comparative analysis showed no significant differences between all those populations except when comparing Terena with the remained ones.

Genetic polymorphism of 15 STR loci in central western Colombia.

Fifteen autosomal short tandem repeat (STR) loci were analyzed using the AmpFISTR Identifiler PCR Amplification Kit in 1944 samples of healthy unrelated individuals, born in the regions of Caldas, Quindio and Risaralda, Colombia. Allele frequencies and statistical parameters of forensic interest are presented for all markers (D8S1179, D21S11, D7S820, CSF1PO, D3S1358, THO1, D13S317, D16S539, D2S1338, D19S433, vWA, TPOX, D18S51, D5S818 and FGA). All loci of the pooled data were in agreement with Hardy-Weinberg equilibrium, after Bonferroni correction. Comparisons with neighboring Latin American populations and Andalucia (Spain) revealed significant differences in allele distributions. Genetic data presented in this study can be used for routine forensic applications in the region.

16 STR data of a Greek population.

Allele frequencies for 16 STR loci (D8S1179, D21S11, D7S820, CSF1PO, D3S1358, TH01, D13S317, D16S539, D2S1338, D19S433, vWA, TPOX, D18S51, D5S818, FGA, and SE33) were calculated for a sample of 300 unrelated individuals from Greece. No deviations from Hardy-Weinberg equilibrium were observed for all loci. The combined power of discrimination (PD) and the combined power of exclusion (PE) for the 16 tested STR loci were 0.999999999 and 0.999999816, respectively. Population comparisons were carried out and low genetic distances were found between our data and those previously published for other neighbouring European populations.

Genetic data of 10 X-STRs in a Spanish population sample.

In this work, we present population genetic data of 10 X-chromosome STRs (DXS8378, DXS9898, DXS8377, HPRTB, GATA172D05, DXS7423, DXS6809, DXS7132, DXS101 and DXS6789) obtained from sample of 145 unrelated female individuals belonging to Valencia (Spain), a region located in the east of the Iberian Peninsula. All the markers studied present high genetic diversities, similar to those previously reported in other European population samples. No deviations from Hardy-Weinberg equilibrium were observed, with the exception of DXS101 locus. Allele frequencies and parameters of forensic interest for each X-STR were calculated. High mean exclusion chance and power of discrimination values were obtained by combining these 10 X-linked markers. Population comparisons (exact test of population differentiation; pairwise genetic distances) were carried out and low genetic distances were found between our sample and those from other Spanish or European regions.

Analysis of artificially degraded DNA using STRs and SNPs--results of a collaborative European (EDNAP) exercise.

Recently, there has been much debate about what kinds of genetic markers should be implemented as new core loci that constitute national DNA databases. The choices lie between conventional STRs, ranging in size from 100 to 450 bp; mini-STRs, with amplicon sizes less than 200 bp; and single nucleotide polymorphisms (SNPs). There is general agreement by the European DNA Profiling Group (EDNAP) and the European Network of Forensic Science Institutes (ENFSI) that the reason to implement new markers is to increase the chance of amplifying highly degraded DNA rather than to increase the discriminating power of the current techniques. A collaborative study between nine European and US laboratories was organised under the auspices of EDNAP. Each laboratory was supplied with a SNP multiplex kit (Foren-SNPs) provided by the Forensic Science Service, two mini-STR kits provided by the National Institute of Standards and Technology (NIST) and a set of degraded DNA stains (blood and saliva). Laboratories tested all three multiplex kits, along with their own existing DNA profiling technique, on the same sets of degraded samples. Results were collated and analysed and, in general, mini-STR systems were shown to be the most effective. Accordingly, the EDNAP and ENFSI working groups have recommended that existing STR loci are reengineered to provide smaller amplicons, and the adoption of three new European core loci has been agreed.

Mutation rates at Y chromosome specific microsatellites.

A collaborative work was carried out by the Spanish and Portuguese ISFG Working Group (GEP-ISFG) to estimate Y-STR mutation rates. Seventeen Y chromosome STR loci (DYS19, DYS385, DYS389I and II, DYS390, DYS391, DYS392, DYS393, DYS437, DYS438, DYS439, DYS460, DYS461, DYS635 [GATA C4], GATA H4, and GATA A10) were analyzed in a sample of 3,026 father/son pairs. Among 27,029 allele transfers, 54 mutations were observed, with an overall mutation rate across the 17 loci of 1.998 x 10(-3) (95% CI, 1.501 x 10(-3) to 2.606 x 10(-3)). With just one exception, all of the mutations were single-step, and they were observed only once per gametogenesis. Repeat gains were more frequent than losses, longer alleles were found to be more mutable, and the mutation rate seemed to increase with the father's age. Hum Mutat 26(6), 520-528, 2005. (c) 2005 Wiley-Liss, Inc.

Análisis microgeográfico de linajes paternos y maternos en el noroeste de la península ibérica / Microgeographic patterns of paternal and maternal lineages in the North West of Iberia

Se ha analizado el efecto del muestreo y la subestructuración poblacional en la estima de frecuencias haplotípicas de cromosoma Y y ADN mitocondrial en las poblaciones de Galicia y Cantabria (NO España).En Galicia se encontraron diferencias significativas en las frecuencias de haplogrupos de SNPs entre una muestra de población general y otra de pequeños núcleos rurales, observándose sin embargo una gran homogeneidad tanto en linajes maternos como paternos. Por el contrario, la población cántabra presenta una marcada subestructura genética tanto en el cromosoma Y como en el ADNmt. En este trabajo analizamos las implicaciones forenses y antropológicas de estos resultados (AU)

Data for nine autosomal STRs markers (CSF1PO, D13S31, D16S539, D7S820, F13A01, FESFPS, TH01, vWA, TPOX) from Venezuela.

Allele frequencies for nine autosomal STRs loci were obtained from individuals from a sample of unrelated individuals born in Venezuela.

Genetic diversity of Y-specific STRs in chimpanzees (Pan troglodytes).

Using the primers described for humans, sequences for 11 Y-specific microsatellites (DYS434, DYS435, DYS436, DYS437, DYS438, DYS439, GATA A10, A7.1, A7.2, C4, and H4 [Gusmão et al., in press]), previously described in 10 male chimpanzees (Pan troglodytes), were confirmed in nine additional male chimpanzees. Sequences for nine additional microsatellites (DYS19, DYS385I and II, DYS389I and II, DYS390, DYS391, DYS392, and DYS393) were determined in all 19 male chimpanzees; homology to human Y-Short Tandem Repeat (STRs) was confirmed by sequencing. Good amplification results were not obtained for DYS19 and DYS385I/II. Two amplicons were obtained for DYS389I/II, but in contrast to humans, the larger fragment was not Y-specific. Moreover, no polymorphism was observed for DYS434, DYS435, or GATA A10. Consequently, these eight STRs were eliminated from further analyses, and haplotype and allele frequencies were estimated for the remaining 12 STRs. A high haplotype diversity value was found (1.000 +/- 0.017), demonstrating the usefulness and informative power of these Y-STRs for future studies on chimpanzee population genetics.

STR data for the AmpFlSTR profiler plus loci from Macau (China).

Allele frequencies for the nine STRs included in the AmpFlSTR profiler plus kit (D3S1358, VWA, FGA, D8S1179, D21S11, D18S51, D5S818, D13S317 and D7S820) were estimated from a sample of 87 unrelated individuals living in the region of Macau, a territory located in the southeastern coast of China.

7-Locus Y chromosome haplotype profiling in a northern Spain population.

Allele and haplotype frequencies for 7 Y-specific STR loci (DYS19, DYS389-I, DYS389-II, DYS390, DYS391, DYS392, DYS393) had been determined in a sample of 107 unrelated males living in Cantabria, a region in northern Spain, by means of two multiplex PCRs.

Sequence structure of 12 novel Y chromosome microsatellites and PCR amplification strategies.

In this work, we present sequencing data for 12 recently reported Y STR loci (DYS434, DYS435, DYS436, DYS437, DYS438, DYS439, GATA A10, GATA 7.1, GATA 7.2, GATA C4, GATA H4, GATA A4), as well as the PCR multiplex strategies we implemented for their detection. Sequenced allelic ladders were constructed and a nomenclature for these new systems is proposed based on the sequence structure and following ISFG recommendations.GATA A4 and DYS439 are likely the same STR. They have the same STR structure and the alleles are always the same in the same individuals.Sequence polymorphisms were observed in the GATA C4 and DYS437 STRs. The variation in DYS437 was associated with a specific population group and is very interesting not only for forensic genetics but also for anthropological studies.

Y-chromosome STR haplotypes from a Western Mediterranean population sample.

Nine Y-chromosome STRs were investigated in a male population sample from the Western Mediterranean region of Valencia (Eastern Spain). Complete nine Y-chromosomal STRs haplotypes were obtained in 140 individuals, among which 113 different haplotypes were observed. The most common haplotype was shared by 5% of the sample, while 99 haplotypes were unique. The gene diversity was 0.9892 and the discrimination capacity was 0.8071. Significant population differences were observed with respect to other Iberian populations, such as the Basques and Northern Portugueses.

Alternative primers for DYS391 typing: advantages of their application to forensic genetics.

The amplification of the STR DYS391, using the primers described in the Genome Data Base (GDB: G00-365-251), shows not only an additional band to the Y-specific one in males with a size range of 26 bp less than those of DYS391 locus alleles, but also a polymorphic pattern in females in the same size range as the additional band observed in males. The DYS391 pattern in families reflects a Y-specific linked locus and also a polymorphic X locus with an X-linked pattern of inheritance. A first screening in the X homologous locus allowed the identification of five different alleles. Allele frequencies were explored in different population groups for both the Y locus and the homologous locus in the X chromosome showing a similar allele distribution pattern in the X and Y homologous loci. An alternative reverse primer was designed to amplify the Y-chromosome specific STR in order to improve the specificity and applicability of this system to forensic genetics. Comparative results of the amplification with the new and the previously described primers proved that with this new primer there is a substantial increase in the specificity of the amplification. Moreover, a smaller fragment is amplified with a size out of the range of the alleles of the other Y-STRs usually used in forensic applications, therefore simplifying its inclusion in multiplex systems.

Genetic diversity of nine STRs in two northwest Iberian populations: Galicia and northern Portugal.

The genotyping of two population samples from Galicia and northern Portugal was performed for nine STR loci using a single multiplex reaction with the AmpF/STR Profiler Plus PCR amplification kit which co-amplifies the systems D3S1358, vWA, FGA, D8S1179, D21S11, D18S51, D5S818, D13S317, D7S820 and the XY homologous gene amelogenin. Allele frequencies for these nine tetranucleotide repeat markers were calculated and no significant differences were observed when comparing these two populations. Conformity with Hardy-Weinberg equilibrium proportions was good for all systems in both samples. The combined power of exclusion was 99.981% and 99.980% in Galicia and northern Portugal, respectively and the combined power of discrimination was greater than 99.999%. Segregation analysis of all loci detected two incompatibilities, one in D3S1358 (out of 112 meioses) and another in D7S820 (out of 104 meioses). Both could be explained by single-step mutations. In general co-amplification was good except for some relatively degraded samples in which poor amplification was observed for the largest STRs. Nevertheless the system is technically robust even when small amounts of template DNA are used and in the addition is highly informative and time-saving. However, caution should be taken in the interpretation of profiles in degraded samples and the apparently high mutation rate of D3S1358 and D7S820 should also be kept in mind.