Browsing by Author "Pliss, Liana"

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    The link between mitochondrial DNA hypervariable segment I heteroplasmy and ageing among genetically unrelated Latvians
    (2011-07) Pliss, Liana; Brakmanis, Andis; Ranka, Renate; Elferts, Didzis; Krumina, Astrida; Baumanis, Viesturs
    Various studies have demonstrated that mitochondrial DNA (mtDNA) heteroplasmy tends to increase with age and that the observed frequency of heteroplasmy among populations mostly depends on the way it is measured. Therefore, we investigated age-related association on the presence of mtDNA heteroplasmy within the hypervariable segment 1 (HVS-I) in a selected study group. The study group consisted of 300 maternally unrelated Latvians ranging in age from 18 to over 90. years. To determine the optimal method for mtDNA heteroplasmy detection, three approaches were used: (i) SURVEYOR Mutation Detection Kit, (ii) sequencing and (iii) denaturing gradient-gel electrophoresis (DGGE). Among the studied individuals, 30.3% were found to be heteroplasmic. The distribution of heteroplasmy statistically significantly increased with individuals' age (17%; 95% confidence interval [CI] 0.095-0.244 in the 18-40. year age group vs. 39%; [CI] 0.294-0.487 in the > 90 year age group). Heteroplasmy occurred in a total of 21 different positions within HVS-I, and was the most frequent at fast-mutated positions 16189, 16304 and 16311. The results indicate that heteroplasmy in HVS-I is relatively common and occurs in a broad spectrum of sites. The above is supported by evidence to eventual increase of the probability of heteroplasmy with age due to specific mitochondrial haplogroup background.
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    Morphological characterisation and molecular sex determination of human remains from the 15th-17th centuries in Latvia
    (2015-04-01) Ščesnaite-Jerdiakova, Asta; Pliss, Liana; Gerhards, Guntis; Gordina, Elina Petersone; Gustiņa, Agnija; Pole, Ilva; Zole, Egija; Kimsis, Janis; Jansone, Inta; Ranka, Renate
    Sex determination is one of the most important and initial steps in human profile identification from archaeological material. The aim of the current study was to evaluate the application of molecular approaches alongside morphological methods for sex determination in archaeological human skeletal remains. Human skeletal remains were excavated from three cemeteries: St Gertrude Old Church, Dom Square and St Peter's Church, of 15th-17th century burials in Riga, Latvia. Morphological and molecular genetic methods, including amplification of genes AMELX/Y and SRY were used to analyse seven skeletal remains. The conducted analyses of morphological features identified sex in all seven cases (two females and five males). By molecular analyses of mediaeval DNA it was possible to determine sex in five of seven (71%) samples. In all positive cases full agreement between morphological estimation and molecular genetic methods was observed. To conclude, DNA analysis can be considered for sex identification in cases with no signs of sexual dimorphism (juvenile skeletons) or partially preserved skeletons.
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    Population Genetics of Latvians in the Context of Admixture between North-Eastern European Ethnic Groups
    (2018-06-01) Krumiņa, Astrida; Pliss, Liana; Zariņa, Gunita; Puzuka, Agrita; Zariņa, Agnese; Lace, Baiba; Elferts, Didzis; Khrunin, Andrey; Limborska, Svetlana; Kloviņš, Janis; Gailite Piekuse, Linda; Scientific Laboratory of Molecular Genetics
    This article presents a review on population genetics of Latvians, which alongside Lithuanians are the two extant Baltic speaking populations. The article provides a description of genome-wide single nucleotide polymorphism (SNP) data and contains a comparative analysis of the results of studies performed on classical autosomal genetic markers, mitochondrial DNA (mtDNA) and the non-recombining part of the Y chromosome (NRY), with data on neighbouring populations. The study also covers data of recently performed ancient DNA (aDNA) studies carried out on samples from the territory of today's Latvia. The results of population genetic studies have shown a mixture of eastern and western genetic traits in present-day Latvians with only small differences between Latvian subpopulations. Studies of the Baltic "tribal gene" LWb, as well as the gene's SERPINA1 allele PIZ have indicated the presence of a considerable Baltic admixture in the neighbouring Finno-Ugric and Slavic populations. Although mtDNA analyses have shown that Latvians genetically in general belong to the same common gene pool as most of the Europeans, the Y-chromosomal lineage composition suggests that they are most similar to Northern and Eastern European populations of Lithuanians, Estonians, and Eastern-Slavic populations, which are ethnogenetically closest to them. The analysis of aDNA from the Early and Middle Neolithic did not present any genomic evidence of gene-flow from Central European farmers or any mitochondrial or Y-chromosomal haplogroups that are typical for them in the hunter-gatherers from the territory of today's Latvia and Lithuania.
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    The Western and Eastern Roots of the Saami - The Story of Genetic "Outliers" Told by Mitochondrial DNA and Y Chromosomes
    (2004-04) Tambets, Kristiina; Rootsi, Siiri; Kivisild, Toomas; Help, Hela; Serk, Piia; Loogväli, Eva Liis; Tolk, Helle Viivi; Reidla, Maere; Metspalu, Ene; Pliss, Liana; Balanovsky, Oleg; Pshenichnov, Andrey; Balanovska, Elena; Gubina, Marina; Zhadanov, Sergey; Osipova, Ludmila; Damba, Larisa; Voevoda, Mikhail; Kutuev, Ildus; Bermisheva, Marina; Khusnutdinova, Elza; Gusar, Vladislava; Grechanina, Elena; Parik, Jüri; Pennarun, Erwan; Richard, Christelle; Chaventre, Andre; Moisan, Jean Paul; Barać, Lovorka; Peričić, Marijana; Rudan, Pavao; Terzić, Rifat; Mikerezi, Ilia; Krumina, Astrida; Baumanis, Viesturs; Koziel, Slawomir; Rickards, Olga; De Stefano, Gian Franco; Anagnou, Nicholas; Pappa, Kalliopi I.; Michalodimitrakis, Emmanuel; Ferák, Vladimir; Füredi, Sandor; Komel, Radovan; Beckman, Lars; Villems, Richard
    The Saami are regarded as extreme genetic outliers among European populations. In this study, a high-resolution phylogenetic analysis of Saami genetic heritage was undertaken in a comprehensive context, through use of maternally inherited mitochondrial DNA (mtDNA) and paternally inherited Y-chromosomal variation. DNA variants present in the Saami were compared with those found in Europe and Siberia, through use of both new and previously published data from 445 Saami and 17,096 western Eurasian and Siberian mtDNA samples, as well as 127 Saami and 2,840 western Eurasian and Siberian Y-chromosome samples. It was shown that the "Saami motif" variant of mtDNA haplogroup U5b is present in a large area outside Scandinavia. A detailed phylogeographic analysis of one of the predominant Saami mtDNA haplogroups, U5b1b, which also includes the lineages of the "Saami motif," was undertaken in 31 populations. The results indicate that the origin of U5b1b, as for the other predominant Saami haplogroup, V, is most likely in western, rather than eastern, Europe. Furthermore, an additional haplogroup (H1) spread among the Saami was virtually absent in 781 Samoyed and Ob-Ugric Siberians but was present in western and central European populations. The Y-chromosomal variety in the Saami is also consistent with their European ancestry. It suggests that the large genetic separation of the Saami from other Europeans is best explained by assuming that the Saami are descendants of a narrow, distinctive subset of Europeans. In particular, no evidence of a significant directional gene flow from extant aboriginal Siberian populations into the haploid gene pools of the Saami was found.