Sequence polymorphisms of the mtDNA control region in a human isolate: the Georgians from Swanetia.
In this work, we analyzed the sequence diversity of the mtDNA control region (HVI and HVII) in a sample of 48 individuals from Swanetia (Georgia), using direct fluorescent-based sequencing methods. We identified 43 different mtDNA haplotypes resulting from 78 polymorphic sites (46 in HVI and 32 in HVII). Most of the variable positions identified in both HVI and HVII were transitions (82.6 and 71.9%, respectively). The frequency of length heteroplasmy in the homopolymeric C-stretch regions was the same for both segments (10.4%). The sequence diversity increased markedly when both hypervariable regions were analyzed jointly (HVI: 0.985, HVII: 0.975, HVI+HVII: 0.994). Accordingly, the probability of two randomly selected sequences matching (random match probability, RMP) decreased from 3.4% (HVI) to 2.6% (HVI+HVII), despite which the RMP values in Georgians remained higher than estimated in most Europeans. This suggests that the variability of maternal lineages tends to be lower in traditional human isolates and, therefore, the potential of discrimination of mtDNA in forensic analysis is more limited in this type of population. The incorporation of HVII data also contributed to the refinement of results regarding the genetic relationships among the samples included in the analyses, which stress the importance of considering HVII in both population and forensic genetics.
Departamento de Genética y Antropología Física, Facultad de Ciencia y Tecnología, Universidad del País Vasco, Bilbao, Bizkaia, Spain.
Miguel A
MA
Alfonso-Sánchez
Servicio de Genómica: Banco de ADN y Departamento de Zoología y Biología Celular Animal, Facultad de Farmacia, Universidad del País Vasco, 48940, Leioa, Bizkaia, Spain.
Cristina
C
Martínez-Bouzas
DataGene, Edificio BEAZ, Sangroniz 6, 48150, Sondika, Bizkaia, Spain.
Azucena
A
Castro
Departamento de Genética y Antropología Física, Facultad de Ciencia y Tecnología, Universidad del País Vasco, Bilbao, Bizkaia, Spain.
Jose A
JA
Peña
DataGene, Edificio BEAZ, Sangroniz 6, 48150, Sondika, Bizkaia, Spain.
Isabel
I
Fernández-Fernández
Molecular Biology and Human Diversity Laboratory, Department of Biological Sciences, Florida International University, Miami, FL, 33199, USA.
Rene J
RJ
Herrera
Servicio de Genómica: Banco de ADN y Departamento de Zoología y Biología Celular Animal, Facultad de Farmacia, Universidad del País Vasco, 48940, Leioa, Bizkaia, Spain. marian.mdepancorbo@ehu.es.
Marian M
MM
de Pancorbo
D001483:Base Sequence; D004272:DNA, Mitochondrial / Q000235:genetics*; D014644:Genetic Variation; D005828:Genetics, Population; D005846:Georgia (Republic) / Q000208:ethnology; D006239:Haplotypes; D006801:Humans; D008969:Molecular Sequence Data; D010802:Phylogeny; D011110:Polymorphism, Genetic; D017422:Sequence Analysis, DNA / Q000379:methods
D004272:DNA, Mitochondrial