title: Spatially Explicit Models to Investigate Geographic Patterns in the Distribution of Forensic STRs: Application to the North-Eastern Mediterranean.
abstract: Human forensic STRs used for individual identification have been reported to have little power for inter-population analyses. Several methods have been developed which incorporate information on the spatial distribution of individuals to arrive at a description of the arrangement of diversity. We genotyped at 16 forensic STRs a large population sample obtained from many locations in Italy, Greece and Turkey, i.e. three countries crucial to the understanding of discontinuities at the European/Asian junction and the genetic legacy of ancient migrations, but seldom represented together in previous studies. Using spatial PCA on the full dataset, we detected patterns of population affinities in the area. Additionally, we devised objective criteria to reduce the overall complexity into reduced datasets. Independent spatially explicit methods applied to these latter datasets converged in showing that the extraction of information on long- to medium-range geographical trends and structuring from the overall diversity is possible. All analyses returned the picture of a background clinal variation, with regional discontinuities captured by each of the reduced datasets. Several aspects of our results are confirmed on external STR datasets and replicate those of genome-wide SNP typings. High levels of gene flow were inferred within the main continental areas by coalescent simulations. These results are promising from a microevolutionary perspective, in view of the fast pace at which forensic data are being accumulated for many locales. It is foreseeable that this will allow the exploitation of an invaluable genotypic resource, assembled for other (forensic) purposes, to clarify important aspects in the formation of local gene pools.
authors.affiliation: Department of Biology, University "Tor Vergata", Rome, Italy.
authors.forename: Francesco
authors.initials: F
authors.lastname: Messina
authors.affiliation: Department of Biology, University "Tor Vergata", Rome, Italy.
authors.forename: Andrea
authors.initials: A
authors.lastname: Finocchio
authors.affiliation: Pediatrics Department, TOBB-Economy and Technology University Hospital, Ankara, Turkey.
authors.forename: Nejat
authors.initials: N
authors.lastname: Akar
authors.affiliation: National Center for Thalassemias, Athens, Greece.
authors.forename: Aphrodite
authors.initials: A
authors.lastname: Loutradis
authors.affiliation: Department of Forensic Sciences, University of Crete School of Medicine, Heraklion, Crete, Greece.
authors.forename: Emmanuel I
authors.initials: EI
authors.lastname: Michalodimitrakis
authors.affiliation: Institute of Haematology and Blood Transfusion, Praha, Czech Republic.
authors.forename: Radim
authors.initials: R
authors.lastname: Brdicka
authors.affiliation: Department of Biology, University "Tor Vergata", Rome, Italy.
authors.forename: Carla
authors.initials: C
authors.lastname: Jodice
authors.affiliation: Department of Biology, University "Tor Vergata", Rome, Italy.
authors.forename: Andrea
authors.identifier: http://orcid.org/0000-0002-1146-7680
authors.initials: A
authors.lastname: Novelletto
mesh_terms: D053803:Forensic Genetics; D014644:Genetic Variation / Q000235:genetics*; D005828:Genetics, Population; D005838:Genotype; D005843:Geography; D006801:Humans; D019083:Mediterranean Region; D018895:Microsatellite Repeats / Q000235:genetics*; D008957:Models, Genetic