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Mitochondrial DNA (mtDNA) U/K and J/T are sister haplogroups within the superhaplogroup R. They are both common in Europe, with a combined overall frequency similar to the one reported for H, the most common European haplogroup (40-50%). In this study, we selected 159 Italian subjects, already ascribed to U/K and J/T by RFLP typing, and assigned each mtDNA to specific clades/subclades by investigating at least one diagnostic coding region SNP. For each sister haplogroup, one multiplex PCR and one SNaPshot minisequencing reaction were set up targeting 16 U/K and 7 J/T coding region SNPs. Each mtDNA sample was clearly assigned to a specific subclade, which could be further subdivided into several minor sub-branches according to peculiar HVS I/II motifs. Such a molecular dissection of haplogroups U/K and J/T could be extremely useful to reduce the overall analysis time and labor intensive sequencing procedures in high volume forensic casework, for example when it is important to rapidly exclude samples in order to restrict the number of suspects.

Three geographic areas of Italy have been sampled and genotyped for 9 Y chromosome STRs: DYS19, DYS385, DYS388, DYS389 I and II, DYS390, DYS391, DYS392, DYS393. Sampling was focused on residents of small areas, well distant from major urban centres. Only individuals whose grandfather would live in the same area were included. A total of 210 unrelated individuals were collected. Distribution of genetic variation across the three samples and comparison with previously published Italian database indicated that so far Y chromosome diversity has been only partially explored in the Italian Peninsula.

The polymorphic short tandem repeat (STR) locus DYS385 mapping to the male-specific region of human Y chromosome, was used to reinvestigate 125 unrelated Italian males, from our data archive, who had been previously typed for 7 different Y-specific STRs (DYS19, DYS389 I and II, DYS390, DYS391, DYS392, DYS393), defining a haplotype now widely adopted in the forensic context. The aim of this study was to improve the information value of the original haplotype in view of its application to issues of personal identification and parental analysis. DYS385 proved to be highly polymorphic (94.5% gene diversity) and the overall individualization capacity of the 8-loci haplotype was raised to 93.6%, with 117 unique assets out of 125 tested samples.

Abstract: The 17 Y-chromosomal short tandem repeats (STRs) included in the AmpFlSTR Yfiler Amplification Kit (AB Applied Biosystems) (DYS19, DYS389I, DYS389II, DYS390, DYS391, DYS392, DYS393, DYS385ab, DYS437, DYS438, DYS439, DYS448, DYS456, DYS458, DYS635 and GATA H4.1) were typed in 292 samples from seven Italian regions. Population comparisons with other European samples were undertaken; for this purpose, two databases were collated from the literature: (a) 19 population samples including >2900 Yfiler profiles, and (b) 67 population samples including >15,000 minimum haplotype profiles. A total of 276 different Yfiler haplotypes were observed in Italy, and only one of them was shared among our seven population samples. The overall haplotype diversity (0.9996) was comparable to other European samples. AMOVA indicates that among population variance depends on the amount of Y-STRs used, being higher when using minimal haplotypes. This is probably due to the fact that Yfiler profiles are represented by singleton haplotypes in all the population samples raising the diversity values to the maximum theoretical value. AMOVA results seems to depend even more strongly on the amount of population samples used, the among population variance in Italy ranging from 2.82% to 11.03% (using 15 and 32 Italian populations samples, respectively). Variance is not as strongly stratified geographically within Italy, although it is notorious that latitude is more important than longitude in the distribution of variance. The results also indicated that Italy is less stratified than other European samples. The present study contributes to enrich the Y-chromosome databases regarding high-resolution Y-chromosome data sets and demonstrates that extended Y-STR profiles substantially increases the discriminatory capacity in individual identification for forensic purposes. [Copyright &y& Elsevier]

Abstract: The genetic structure of Italy appears to be mainly shaped by pre-Roman historical events. The studies carried out so far show a major North–South cline, possibly the result of two distinct main demic processes: the first colonisation of the area during the Palaeolithic period and the subsequent Neolithic expansion from the Middle East. However, the demographic contribution of these events is still a matter of debate. We here report mitochondrial DNA (mtDNA) data from nine population groups covering the main Italian regions: Central Liguria (N =50), East Friuli (N =51), South Latium (N =48), Central Marche (N =53), West Calabria (N =50), Central Campania (N =50), South Apulia (N =53), and two populations from Sicily (East and West Sicily, N =40 each). Haplogroup frequency spectra indicate clear differences at a regional level and haplotype sharing among populations is low. [Copyright &y& Elsevier]

Abstract: The investigation into the genetic diversity of humans has become fundamental to the understanding of the pre-history and history of populations, and it is presently addressing crucial issues concerning human evolution that intersect with demographic, cultural and linguistic events. Numerous studies have been recently focused on the Italian Peninsula, and the current set of data regarding this country can now fit into a general frame in which local differences seems to emerge and be interpreted in the context of other cultural and historical knowledge. However, a comprehensive study based on multiple genetic systems and on extensive sampling is still missing. Here we report new data on the Y chromosome and mitochondrial DNA (mtDNA) over a significantly larger Italian sample. In particular we address four geographic sites that in the past have been the theatre of significant events in the framework of Italy''s peopling: Latium (central-west), Piceno (central-east), Calabria (south-west) and Messapia (south-east). Concerning the Y polymorphisms, we based our study on STR and SNP markers in order to tackle population events positioned at various stages of the evolutionary history of Italy on the male side, and to account for local differences. In a similar way, mtDNA has been analyzed for the control region and for a selection of informative mtDNA coding region SNPs. The availability of both sets of loci including slow- and fast-evolving markers has enabled us to undertake multiple-level comparisons. We paid special interest to the distribution of genetic variability across our populations and we aimed to compare the mainframe emerging from the haploid male and female inherited loci. Preliminary results provided us with intriguing inferences regarding the prehistory and history of Italy. [Copyright &y& Elsevier]