Liana Pliss
@university of latvia
Molecular biology
Dr.biol.
EDUCATION
PhD
University of Latvia
RESEARCH, TEACHING, or OTHER INTERESTS
Multidisciplinary, Biochemistry, Genetics and Molecular Biology, Aging, Genetics
Scopus Publications
Scopus Publications
Dita Pelnena, Birute Burnyte, Eriks Jankevics, Baiba Lace, Evelina Dagyte, Kristina Grigalioniene, Algirdas Utkus, Zita Krumina, Jolanta Rozentale, Irina Adomaitiene,et al.
Informa UK Limited
Abstract The most common mitochondrial disorder in children is Leigh syndrome, which is a progressive and genetically heterogeneous neurodegenerative disorder caused by mutations in nuclear genes or mitochondrial DNA (mtDNA). In the present study, a novel and robust method of complete mtDNA sequencing, which allows amplification of the whole mitochondrial genome, was tested. Complete mtDNA sequencing was performed in a cohort of patients with suspected mitochondrial mutations. Patients from Latvia and Lithuania (n = 92 and n = 57, respectively) referred by clinical geneticists were included. The de novo point mutations m.9185T>C and m.13513G>A, respectively, were detected in two patients with lactic acidosis and neurodegenerative lesions. In one patient with neurodegenerative lesions, the mutation m.9185T>C was identified. These mutations are associated with Leigh syndrome. The present data suggest that full-length mtDNA sequencing is recommended as a supplement to nuclear gene testing and enzymatic assays to enhance mitochondrial disease diagnostics.
Astrīda Krūmiņa, Liāna Pliss, Gunita Zariņa, Agrita Puzuka, Agnese Zariņa, Baiba Lāce, Didzis Elferts, Andrey Khrunin, Svetlana Limborska, Jānis Kloviņš,et al.
Walter de Gruyter GmbH
Abstract 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” LW b , 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.
Egija Zole, Krista Zadinane, Liana Pliss, and Renate Ranka
Informa UK Limited
Abstract We studied telomere length (TL) and mitochondrial DNA (mtDNA) copy number variations in individuals from Latvian Caucasian population in different age groups. We showed a positive correlation between TL and mtDNA copy number in individuals of up to 90 years of age; however, this correlation was not observed in the 90–100 years age group. While TL shortened with age and mtDNA content decreased with increasing age, in this study it was observed that mtDNA copy number in nonagenarians was slightly higher than in the 60–89 years age group. The presence of heteroplasmy in the mtDNA HVS-I control region did not correlate with TL and mtDNA copy number. TL and mtDNA values also did not differ between mitochondrial haplogroups. In conclusion, while both TL and mtDNA are involved in the aging process and link between these cell components exists, nonagenarians may have differences in senescence-related pathways and systems, which may function as a protective mechanism that allows them to live longer.
Liana Pliss, Līga Timša, Siiri Rootsi, Kristiina Tambets, Inese Pelnena, Egija Zole, Agrita Puzuka, Areta Sabule, Sandra Rozane, Baiba Lace,et al.
Wiley
SummaryVariations of the nonrecombining Y‐chromosomal region were investigated in 159 unrelated Baltic‐speaking ethnic Latvians from four different geographic regions, using 28 biallelic markers and 12 short tandem repeats. Eleven different haplogroups (hgs) were detected in a regionally homogeneous Latvian population, among which N1c, R1a, and I1 cover more than 85% of its paternal lineages. When compared its closest geographic neighbors, the composition of the Latvian Y‐chromosomal gene pool was found to be very similar to those of Lithuanians and Estonians. Despite the comparable frequency distribution of hg N1c in Latvians and Lithuanians with the Finno‐Ugric‐speaking populations from the Eastern coast of the Baltic Sea, the observed differences in allelic variances of N1c haplotypes between these two groups are in concordance with the previously stated hypothesis of different dispersal ways of this lineage in the region. More than a third of Latvian paternal lineages belong specifically to a recently defined R1a‐M558 hg, indicating an influence from a common source within Eastern Slavic populations on the formation of the present‐day Latvian Y‐chromosome gene pool.
Asta Ščėsnaitė-Jerdiakova, Liāna Pliss, Guntis Gerhards, Elīna Pētersone Gordina, Agnija Gustiņa, Ilva Pole, Egija Zole, Jānis Ķimsis, Inta Jansone, and Renāte Ranka
Walter de Gruyter GmbH
Abstract 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 Rīga, 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.
Egija Zole, Didzis Elferts, Janis Kimsis, Astrida Krumina, Kristaps Narels, Ilva Pole, Renate Ranka, and Liana Pliss
Elsevier BV
Egija Zole, Liana Pliss, Renate Ranka, Astrida Krumina, and Viesturs Baumanis
Bentham Science Publishers Ltd.
The shortening of telomeres with ageing is a well-documented observation; however, the reported number of nucleotides in telomeres varies between different laboratories and studies. Such variability is likely caused by ethnic differences between the populations studied. Until now, there were no studies that investigated the variability of telomere length in a senescent Latvian population of the most common mitochondrial haplogroups, defined as H (45%), U (25%), Y chromosomal N1c (40%) and R1a1 (40%). Telomere length was determined in 121 individuals in different age groups, including a control group containing individuals of 20-40 years old and groups of individuals between 60-70 years old, 71-80 years old, 81-90 years old, and above 90 years old. Telomere length was determined using the Southern blot telomeric restriction fragment assay (TRF). Decreased telomere length with ageing was confirmed, but a comparison of centenarians and individuals between 60-90 years of age did not demonstrate a significant difference in telomere length. However, significant variability in telomere length was observed in the control group, indicating probable rapid telomere shortening in some individuals that could lead up to development of health status decline appearing with ageing. Telomere length measured in mononuclear blood cells (MNC) was compared with the telomere length measured in whole peripheral white blood cells (WBC) using TRF. Telomere length in MNC was longer than in WBC for the control group with individuals 20 to 40 years old; in contrast, for the group of individuals aged 65 to 85 years old, measured telomere length was shorter in MNC when compared to WBC.
Baiba Lace, Inga Kempa, Linda Piekuse, Ieva Grinfelde, Janis Klovins, Liana Pliss, Astrida Krumina, and Alexandre R. Vieira
Wiley
Isolated cleft lip and/or palate (CL/CLP) is a complex congenital anomaly with many contributing factors. There are several genes involved in the aetiology of CL/CLP, they are different in selected populations. In a previous study, the mitochondrial haplotypes of Latvian subjects with CL/CLP were characterized. Latvian subjects with CL/CLP have mostly mitochondrial haplogroups U4/U5 compared with the ethnic population of Latvia. The aim of this study was to stratify the results of genotyping based on European mitochondrial DNA (mtDNA) haplotypes. DNA samples from 108 patients with CL/CLP and from 182 unrelated and unaffected individuals selected randomly in Latvia (used as controls) were obtained for investigation. In this study, we analysed the data taking into consideration mitochondrial haplogroups and found that gene associations depended on the genetic origin of the population. The phenotype of patients with non-U haplotypes was associated with markers in wingless-type MMTV integration site family, member 3 (WNT3), collagen, type XI, alpha 2 (COL11A2), and fibroblast growth factor receptor 1 (FGFR1), whereas patients with U4 and U5 haplotypes showed significant association with WNT3 and COL11A2. It is unlikely that mtDNA variants play a direct role in the development of CL/CLP; rather, they may be a surrogate for population substructure and provide a tool to increase homogeneity and statistical power.
Liana Pliss, Andis Brakmanis, Renate Ranka, Didzis Elferts, Astrida Krumina, and Viesturs Baumanis
Elsevier BV
A. Puzuka, N. Pronina, I. Grinfelde, Ju. Erenpreiss, V. Lejing, Ja. Bars, L. Pliss, I. Pelnena, V. Baumanis, and A. Krumina
Pleiades Publishing Ltd
Alexandre R. Vieira, Liana Pliss, Inese Pelnena, Astrida Krumina, Viesturs Baumanis, and Baiba Lace
Elsevier BV
Kristīne Baumane, Liāna Pliss, and Guna Laganovska
Walter de Gruyter GmbH
Atrial Natriuretic Peptide Gene and Plasma Pro-ANP Concentration in Patients with Primary Open-Angle GlaucomaAtrial natriuretic peptide (ANP) appears to have a physiological role in volume and pressure homeostasis. Increased cardiac expression and synthesis of ANP suggest a possible local paracrine function in a number of tissues including the eye. Therefore, the identification of genetic markers may prove to be an important advance in the diagnosis of patients with glaucoma and hypertension. Plasma pro-ANP concentration was measured in 30 clinical patients. A significant elevated level of prehormone was observed in glaucoma patients with blood hypertension. Also, the distribution of the genotypes and alleles of the HpaII, SmaI and ScaI polymorphisms of the ANP gene was examined in 20 hypertensive patients with glaucoma and normotensive controls. The frequencies of the ANP genotypes and alleles did not differ significantly between controls and hypertensive patients. PCR-RFLP (polymerase chain reaction—restriction fragment length polymorphism) analysis shows a T2238→C transition in three hypertensive patients within the stop codon leading to the translation of ANP with an additional arginine. In the current study we also searched for any alterations in the 5' proximal promoter region of the ANP gene (-595 bp - -384 bp) in 20 glaucoma patients with hypertension using PCR-based SSCP (single-strand conformation polymorphism) analysis. No significant alterations in the 5' proximal promoter region of the ANP gene were observed among hypertensive patients. The structure of the ANP hormone encoded gene suggests potential importance in various diseases, but the regulatory function of ANP in the eye requires further investigations.
L. Pliss, K. Tambets, E.‐L. Loogväli, N. Pronina, M. Lazdins, A. Krumina, V. Baumanis, and R. Villems
Wiley
SummaryMitochondrial DNA (mtDNA) variation was investigated in a sample of 299 Latvians, a Baltic‐speaking population from Eastern Europe. Sequencing of the first hypervariable segment (HVS‐I) in combination with analysis of informative coding region markers revealed that the vast majority of observed mtDNAs belong to haplogroups (hgs) common to most European populations. Analysis of the spatial distribution of mtDNA haplotypes found in Latvians, as well as in Baltic‐speaking populations in general, revealed that they share haplotypes with all neighbouring populations irrespective of their linguistic affiliation. Hence, the results of our mtDNA analysis show that the previously described sharp difference between the Y‐chromosomal hg N3 distribution in the paternally inherited gene pool of Baltic‐speaking populations and of other European Indo‐European speakers does not have a corresponding maternal counterpart.
Kristiina Tambets, Siiri Rootsi, Toomas Kivisild, Hela Help, Piia Serk, Eva-Liis Loogväli, Helle-Viivi Tolk, Maere Reidla, Ene Metspalu, Liana Pliss,et al.
Elsevier BV
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.