Elena Bosch

The Genetic Legacy of Religious Diversity and Intolerance: Paternal Lineages of Christians, Jews, and Muslims in the Iberian Peninsula

Most studies of European genetic diversity have focused on large-scale variation and interpretations based on events in prehistory, but migrations and invasions in historical times could also have had profound effects on the genetic landscape. The Iberian Peninsula provides a suitable region for examination of the demographic impact of such recent events, because its complex recent history has involved the long-term residence of two very different populations with distinct geographical origins and their own particular cultural and religious characteristics—North African Muslims and Sephardic Jews. To address this issue, we analyzed Y chromosome haplotypes, which provide the necessary phylogeographic resolution, in 1140 males from the Iberian Peninsula and Balearic Islands. Admixture analysis based on binary and Y-STR haplotypes indicates a high mean proportion of ancestry from North African (10.6%) and Sephardic Jewish (19.8%) sources. Despite alternative possible sources for lineages ascribed a Sephardic Jewish origin, these proportions attest to a high level of religious conversion (whether voluntary or enforced), driven by historical episodes of social and religious intolerance, that ultimately led to the integration of descendants. In agreement with the historical record, analysis of haplotype sharing and diversity within specific haplogroups suggests that the Sephardic Jewish component is the more ancient. The geographical distribution of North African ancestry in the peninsula does not reflect the initial colonization and subsequent withdrawal and is likely to result from later enforced population movement—more marked in some regions than in others—plus the effects of genetic drift.

Recent male-mediated gene flow over a linguistic barrier in Iberia, suggested by analysis of a Y-chromosomal DNA polymorphism.

We have examined the worldwide distribution of a Y-chromosomal base-substitution polymorphism, the T/C transition at SRY-2627, where the T allele defines haplogroup 22; sequencing of primate homologues shows that the ancestral state cannot be determined unambiguously but is probably the C allele. Of 1,191 human Y chromosomes analyzed, 33 belong to haplogroup 22. Twenty-nine come from Iberia, and the highest frequencies are in Basques (11%; n=117) and Catalans (22%; n=32). Microsatellite and minisatellite (MSY1) diversity analysis shows that non-Iberian haplogroup-22 chromosomes are not significantly different from Iberian ones. The simplest interpretation of these data is that haplogroup 22 arose in Iberia and that non-Iberian cases reflect Iberian emigrants. Several different methods were used to date the origin of the polymorphism: microsatellite data gave ages of 1,650, 2,700, 3,100, or 3,450 years, and MSY1 gave ages of 1,000, 2,300, or 2,650 years, although 95% confidence intervals on all of these figures are wide. The age of the split between Basque and Catalan haplogroup-22 chromosomes was calculated as only 20% of the age of the lineage as a whole. This study thus provides evidence for direct or indirect gene flow over the substantial linguistic barrier between the Indo-European and non-Indo-European-speaking populations of the Catalans and the Basques, during the past few thousand years.

High resolution Y chromosome typing: 19 STRs amplified in three multiplex reactions.

Nineteen Y-specific short tandem repeat (STR) loci have been amplified in 768 samples from the Iberian Peninsula in order to evaluate their usefulness in forensic casework. Two previously published multiplex reactions by Thomas et al. [Hum. Genet. 6 (1999) 577] (MS1, modified here: DYS19, DYS388, DYS390, DYS391, DYS392 and DYS393) and by Ayub et al. [Nucl. Acids Res. 28 (2000) e8] (CTS: DYS434, DYS435, DYS436, DYS437, DYS438 and DYS439) plus a novel one reported here (EBF: DYS385, DYS389, DYS460, DYS461, DYS462 and amelogenin) have been used. DYS385, DYS439 and DYS391 were the most informative loci with allele diversities of 0.7997, 0.6683 and 0.5940, respectively. A total of 635 different haplotypes were observed, of which 573 (90.24%) were found in single individuals. The overall haplotype diversity was 0.9988 and that obtained by each multiplex system was 0.9812 for EBF, 0.9292 for MS1 and 0.9089 for CTS.

Homogeneity and distinctiveness of Polish paternal lineages revealed by Y chromosome microsatellite haplotype analysis

Abstract. Different regional populations from Poland were studied in order to assess the genetic heterogeneity within Poland, investigate the genetic relationships with other European populations and provide a population-specific reference database for anthropological and forensic studies. Nine Y-chromosomal microsatellites were analysed in a total of 919 unrelated males from six regions of Poland and in 1,273 male individuals from nine other European populations. AMOVA revealed that all of the molecular variation in the Polish dataset is due to variation within populations, and no variation was detected among populations of different regions of Poland. However, in the non-Polish European dataset 9.3% (P<0.0001) of the total variation was due to differences among populations. Consequently, differences in RST-values between all possible pairs of Polish populations were not statistically significant, whereas significant differences were observed in nearly all comparisons of Polish and non-Polish European populations. Phylogenetic analyses demonstrated tight clustering of Polish populations separated from non-Polish groups. Population clustering based on Y-STR haplotypes generally correlates well with the geography and history of the region. Thus, our data are consistent with the assumption of homogeneity of present-day paternal lineages within Poland and their distinctiveness from other parts of Europe, at least in respect to their Y-STR haplotypes. Electronic supplementary material to this paper can be obtained by using the Springer LINK server located at http://dx.doi.org/10.1007/s00439-002-0728-0.

Population Genetics of Y-Chromosome Short Tandem Repeats in Humans

Abstract. Eight human short tandem repeat polymorphisms (STRs) also known as microsatellites—DYS19, DYS388, DYS390, DYS391, DYS392, DYS393, DYS389I, and DYS389II, mapping in the Y chromosome—were analyzed in two Iberian samples (Basques and Catalans). Allele frequency distributions showed significant differences only for DYS392. Fst and gene diversity index (D) were estimated for the Y STRs. The values obtained are comparable to those of autosomal STR if corrections for the smaller effective population size on the Y chromosome are taken into account. This suggests that Y-chromosome microsatellites might be as useful as their autosomal counterparts to both human population genetics and forensics. Our results also reinforce the hypothesis that selective sweeps in the Y chromosome in recent times are unlikely. Haplotypes combining five of the loci were constructed for 71 individuals, showing 29 different haplotypes. A haplotype tree was constructed, from which an estimate of 7,000 to 60,000 years for the age of the Y-chromosome variation in Iberia was derived, in accordance with previous estimates obtained with mtDNA sequences and nuclear markers.

Mitochondrial DNA variation and the origin of the Europeans

Abstract Sequences from the mitochondrial DNA (mtDNA) control region were analyzed in nine European and West Asian populations. They showed low genetic heterogeneity when compared to world populations. However, a Caucasoid population tree displayed a robust east-west gradient. Within-population diversity (ascertained through various parameters) and mean pairwise differences declined from east to west, in a pattern compatible with ancient population migration and expansion from the Middle East. Estimated expansion times indicate a Paleolithic event with important differences among populations according to their geographical position and thus a slower tempo than previously believed. The replacement of Neanderthals by anatomically modern humans, fully compatible with the present results, may have been a slower and more complex process than cultural change suggests.

Allele Frequencies for 20 Microsatellites in a Worldwide Population Survey

20 microsatellite polymorphisms: HUMHPRT, HUMD3S1358, HUMTH01, HUMACPP, HUMVWF, HUMD16S310, HUMD4S243, HUMTPO, HUMFES/FPS, HUMF13A1, HUMDHFRP2, HUMD11S2010, HUMD13S767, HUMD9S926, HUMD2S1328, HUMD14S306, HUMD18S848, HUMD5S818, HUMD7S820 and HUMFGA were analyzed in a worldwide survey covering five continents and allele frequencies are given. There is a high heterogeneity in allele frequencies among continents. A neighbor-joining tree based on Fst distance shows a pattern of differentiation that may reflect the role of drift in the development of genetic differences among humans. The variation found between continents confirms the usefulness of tetranucleotide microsatellites in human genetic variation studies.

Native American Y Chromosomes in Polynesia: The Genetic Impact of the Polynesian Slave Trade

Since Thor Heyerdahl asserted that Polynesia was first colonized from the Americas (Heyerdahl 1950), geneticists have sought--but have not found--any evidence to support his theories. Here, Native American Y chromosomes are detected on the Polynesian island of Rapa. However, this, together with other odd features of the islands Y-chromosomal gene pool, is best explained as the genetic impact of a 19th century Peruvian slave trade in Polynesia. These findings underscore the need to account for history before turning to prehistory and the value of archival research to understanding modern genetic diversity. Although the impact of the Atlantic slave trade on the distribution of modern genetic diversity has been well appreciated, this represents the first study investigating the impact of this underappreciated episode on genetic diversity in the Pacific.

Y-chromosomal STR haplotypes in Inuit and Danish population samples

Nineteen Y-chromosomal short tandem repeats (STRs), DYS19, DYS389-I, DYS389-II, DYS390, DYS391, DYS392, DYS393, DYS385, DYS388, DYS434, DYS435, DYS436, DYS437, DYS438, DYS439, DYS460, DYS461 and DYS462 were typed in Inuit (n=70) and Danish (n=62) population samples.

Draft Genome Sequence of the Aeromonas diversa Type Strain

ABSTRACT We present here the first genome sequence of the Aeromonas diversa type strain (CECT 4254T). This strain was isolated from the leg wound of a patient in New Orleans (Louisiana) and was originally described as enteric group 501 and distinguished from A. schubertii by DNA-DNA hybridization and phenotypical characterization.