Cristian Capelli

Founding Mothers of Jewish Communities: Geographically Separated Jewish Groups Were Independently Founded by Very Few Female Ancestors

We have analyzed the maternally inherited mitochondrial DNA from each of nine geographically separated Jewish groups, eight non-Jewish host populations, and an Israeli Arab/Palestinian population, and we have compared the differences found in Jews and non-Jews with those found using Y-chromosome data that were obtained, in most cases, from the same population samples. The results suggest that most Jewish communities were founded by relatively few women, that the founding process was independent in different geographic areas, and that subsequent genetic input from surrounding populations was limited on the female side. In sharp contrast to this, the paternally inherited Y chromosome shows diversity similar to that of neighboring populations and shows no evidence of founder effects. These sex-specific differences demonstrate an important role for culture in shaping patterns of genetic variation and are likely to have significant epidemiological implications for studies involving these populations. We illustrate this by presenting data from a panel of X-chromosome microsatellites, which indicates that, in the case of the Georgian Jews, the female-specific founder event appears to have resulted in elevated levels of linkage disequilibrium.

A Y chromosome census of the British Isles

The degree of population replacement in the British Isles associated with cultural changes has been extensively debated. Recent work has demonstrated that comparisons of genetic variation in the British Isles and on the European Continent can illuminate specific demographic processes in the history of the British Isles. For example, Wilson et al. used the similarity of Basque and Celtic Y chromosomes to argue for genetic continuity from the Upper Palaeolithic to the present in the paternal history of these populations (see also ). Differences in the Y chromosome composition of these groups also suggested genetic signatures of Norwegian influence in the Orkney Islands north of the Scottish mainland, an important center of Viking activities between 800 and 1300 A.D. More recently, Weale et al. argued for substantial Anglo-Saxon male migration into central England based on the analysis of eight British sample sets collected on an east-west transect across England and Wales. To provide a more complete assessment of the paternal genetic history of the British Isles, we have compared the Y chromosome composition of multiple geographically distant British sample sets with collections from Norway (two sites), Denmark, and Germany and with collections from central Ireland, representing, respectively, the putative invading and the indigenous populations. By analyzing 1772 Y chromosomes from 25 predominantly small urban locations, we found that different parts of the British Isles have sharply different paternal histories; the degree of population replacement and genetic continuity shows systematic variation across the sampled areas.

A Predominantly Indigenous Paternal Heritage for the Austronesian-Speaking Peoples of Insular Southeast Asia and Oceania

Modern humans reached Southeast Asia and Oceania in one of the first dispersals out of Africa. The resulting temporal overlap of modern and archaic humans-and the apparent morphological continuity between them-has led to claims of gene flow between Homo sapiens and H. erectus. Much more recently, an agricultural technology from mainland Asia spread into the region, possibly in association with Austronesian languages. Using detailed genealogical study of Y chromosome variation, we show that the majority of current Austronesian speakers trace their paternal heritage to Pleistocene settlers in the region, as opposed to more-recent agricultural immigrants. A fraction of the paternal heritage, however, appears to be associated with more-recent immigrants from northern populations. We also show that the northern Neolithic component is very unevenly dispersed through the region, with a higher contribution in Southeast Asia and a nearly complete absence in Melanesia. Contrary to claims of gene flow (under regional continuity) between H. erectus and H. sapiens, we found no ancestral Y chromosome lineages in a set of 1,209 samples. The finding excludes the possibility that early hominids contributed significantly to the paternal heritage of the region.

Population Structure in the Mediterranean Basin: A Y Chromosome Perspective

The Mediterranean region has been characterised by a number of pre‐historical and historical demographic events whose legacy on the current genetic landscape is still a matter of debate. In order to investigate the degree of population structure across the Mediterranean, we have investigated Y chromosome variation in a large dataset of Mediterranean populations, 11 of which are first described here. Our analyses identify four main clusters in the Mediterranean that can be labelled as North Africa, Arab, Central‐East and West Mediterranean. In particular, Near Eastern samples tend to separate according to the presence of Arab Y chromosome lineages, suggesting that the Arab expansion played a major role in shaping the current genetic structuring within the Fertile Crescent.

Ancient protocols for the crime scene? Similarities and differences between forensic genetics and ancient DNA analysis.

We provide a short overview on some current issues in the fields of forensic genetics and ancient DNA (aDNA) analysis. We discuss about the existence of the possible points of contact between the two disciplines, in terms of open problems and the inherent approach to their solution. We mainly focus on the problem of results authentication, its theoretical and technical aspects.

Protocols for ancient DNA typing.

Molecular analysis of fossil and archaeological remains has been established as a powerful tool in providing new insight in phylogenetic investigations. The overlapping set of molecular modifications and degradation that forensic samples share with archaeological specimen suggests the application of similar technical approaches to the respective biological material. Polymerase chain reaction is the molecular technique of choice for the retrieval of specimen deoxyribonucleic acid (DNA) molecules. Because of intrinsic sensitivity, potential contaminations from exogenous DNA sources must be monitored through the entire process by the introduction of multiple blank controls. Cloning and sequencing of polymerase chain reaction products often is the only way to discriminate between contaminations and endogenous sequences as well as to identify variable positions from nucleotide modifications/DNA polymerase errors. Phylogenetic analysis and investigations of the pattern of substitutions are an additional and necessary step to validate the retrieved sequence. Comparison with available related samples (modern or extinct) is critical to correctly validate the results and to avoid artifactual data.

A repository of 14 PCR-loci Italian gene frequencies in the world wide web

A collection of 6830 typing results produced by the Immunohematology Laboratory at the UCSC, pertaining to 11 STRs (FES/FPS, vWA31, HUMTH01, F13A1, MBP, D21S11, D7S460, D18S51, CD4, TPOX, CSF1PO) and 3 AmpFLPs (D1S80, APO-B, COL2A1), is publicly available as an electronic archive at a website.

Genetic variation at the ApoB 3′ HVR minisatellite locus in the Mbenzele Pygmies from the Central African Republic

This study analyzes the polymorphic minisatellite ApoB 3′ HVR in the Mbenzele Pygmies from the Central African Republic. A total of 14 alleles was observed, with frequencies ranging from 0.020 (19, 21, 27, and 45 repeat unit alleles) to 0.210 (37 repeat unit allele). Departure from Hardy‐Weinberg equilibrium was not statistically significant. The estimated heterozygosity was 0.874 ± 0.016. Taking data from the literature into consideration, the results support the hypothesis that the Africans are different from non‐Africans due to greater ApoB 3′ HVR genetic diversity and a unimodal profile of ApoB 3′ HVR allele frequency distribution. Interpopulational relationships were also analyzed using an FST based genetic distance. The results highlight the similarity between the Mbenzele Pygmies and Bantu‐speaking groups (Ewondo and Zulu), and the divergence between the Mbenzele and San, the two groups which are often considered to be the most direct descendants of proto‐Africans. Am. J. Hum. Biol. 12:588–592, 2000.

High-resolution analysis of male genomes by the addition of nine biallelic polymorphisms to the classic 8-STR forensic haplotype

DNA typing of male-specific polymorphisms is a well-established procedure of molecular analysis. A haplotype of eight different human male Y-specific short tandem repeats (STRs) has been intensively used for forensic casework. This haplotype has also been effectively used to address specific problems of population genetics. A collection of 50 male genomes from our laboratory previously genotyped for 8-Y-STR has been reinvestigated with a battery of eight single nucleotide polymorphisms (SNPs) mapping to the Y-chromosome. The addition of these biallelic markers provided additional identification power. Population investigation revealed genetic structure in Italy, with notably implications in Forensic Genetics. D 2003 Elsevier Science B.V. All rights reserved.

Y chromosome genetic structure in the Italian peninsula

We investigated Y chromosome populations structure in the Italian peninsula by means of a number of microsatellites and SNPs markers. Genetic analysis revealed a certain degree of heterogeneity between samples at both haplotype (hpt) and haplogroup (hg) level. Implications in genetic history and forensic are discussed. D 2003 Published by Elsevier B.V.