Uniparental Genetic Heritage of Belarusians: Encounter of Rare Middle Eastern Matrilineages with a Central European Mitochondrial DNA Pool

Ethnic Belarusians make up more than 80% of the nine and half million people inhabiting the Republic of Belarus. Belarusians together with Ukrainians and Russians represent the East Slavic linguistic group, largest both in numbers and territory, inhabiting East Europe alongside Baltic-, Finno-Permic- and Turkic-speaking people. Till date, only a limited number of low resolution genetic studies have been performed on this population. Therefore, with the phylogeographic analysis of 565 Y-chromosomes and 267 mitochondrial DNAs from six well covered geographic sub-regions of Belarus we strove to complement the existing genetic profile of eastern Europeans. Our results reveal that around 80% of the paternal Belarusian gene pool is composed of R1a, I2a and N1c Y-chromosome haplogroups – a profile which is very similar to the two other eastern European populations – Ukrainians and Russians. The maternal Belarusian gene pool encompasses a full range of West Eurasian haplogroups and agrees well with the genetic structure of central-east European populations. Our data attest that latitudinal gradients characterize the variation of the uniparentally transmitted gene pools of modern Belarusians. In particular, the Y-chromosome reflects movements of people in central-east Europe, starting probably as early as the beginning of the Holocene. Furthermore, the matrilineal legacy of Belarusians retains two rare mitochondrial DNA haplogroups, N1a3 and N3, whose phylogeographies were explored in detail after de novo sequencing of 20 and 13 complete mitogenomes, respectively, from all over Eurasia. Our phylogeographic analyses reveal that two mitochondrial DNA lineages, N3 and N1a3, both of Middle Eastern origin, might mark distinct events of matrilineal gene flow to Europe: during the mid-Holocene period and around the Pleistocene-Holocene transition, respectively

60,000 years of interactions between Central and Eastern Africa documented by major African mitochondrial haplogroup L2

Mitochondrial DNA (mtDNA) haplogroup L2 originated in Western Africa but is nowadays spread across the entire continent. L2 movements were previously postulated to be related to the Bantu expansion, but L2 expansions eastwards probably occurred much earlier. By reconstructing the phylogeny of L2 (44 new complete sequences) we provide insights on the complex net of within-African migrations in the last 60 thousand years (ka). Results show that lineages in Southern Africa cluster with Western/Central African lineages at a recent time scale, whereas, eastern lineages seem to be substantially more ancient. Three moments of expansion from a Central African source are associated to L2: (1) one migration at 70-50 ka into Eastern or Southern Africa, (2) postglacial movements (15-10 ka) into Eastern Africa; and (3) the southward Bantu Expansion in the last 5 ka. The complementary population and L0a phylogeography analyses indicate no strong evidence of mtDNA gene flow between eastern and southern populations during the later movement, suggesting low admixture between Eastern African populations and the Bantu migrants. This implies that, at least in the early stages, the Bantu expansion was mainly a demic diffusion with little incorporation of local populations.This research received support from the European project “A European Initial Training Network on the History, Archaeology, and New Genetics of the Trans-Atlantic Slave Trade (EUROTAST)” (EU project: 290344). PSo is supported by FCT (the Portuguese Foundation for Science and Technology), European Social Fund, Programa Operacional Potencial Humano and the FCT Investigator Programme (IF/01641/2013). IPATIMUP integrates the i3S Research Unit, which is partially supported by FCT. This work is funded by FEDER funds through the Operational Programme for Competitiveness FactorsCOMPETE and National Funds through FCT, under the project “PEst-C/SAU/LA0003/2013”. FCT/MEC supports CBMA through Portuguese funds (PIDDAC) - PEst-OE/BIA/UI4050/2014. NORTE-07-0162FEDER-00018 (Contributos para o reforço da capacidade do IPATIMUP enquanto actor do sistema regional de inovação) and NORTE-07-0162-FEDER-000067 (Reforço e consolidação da capacidade infraestrutural do IPATIMUP para o sistema regional de inovação), both supported by Programa Operacional Regional do Norte (ON.2 – O Novo Norte), through FEDER funds under the Quadro de Referência Estratégico Nacional (QREN)

Passive smoking as an environmental health risk factor

Initially, tobacco was considered as a decorative plant and only later began to be treated as a herb with special therapeutic properties. With time, it was found that tobacco had strong insecticidal and addictive properties. There also occurred reports about the negative influence of tobacco on human health. The World Health Organization (WHO) classifies smoking as a chronic, progressive disease which is also ‘contagious’. It is also considered to be a neurobiotic addiction. Nicotine addiction does not cause changes in the behaviour or functioning of a smoker; however, it adversely affects his or her general health status and the health status of people within their environment. Passive smoking (so-called ETS – Environmental Tobacco Smoke), which means accompanying smokers negatively influences the health of passive smokers. Environmental tobacco smoke, on the one hand, is the result of spontaneous cigarette burning and, on the other hand, the result of the side-stream of cigarette smoke, as well as the smoke exhaled by active smokers. Health personnel should clearly and convincingly present the data concerning the adverse results of smoking, as well as the dangers of exposure to environmental tobacco smoke, thereby making their patients aware that breaking their addiction will not only be beneficial for their own health, but will also protect non-smokers in their environment from the adverse effects of exposure to environmental tobacco smoke

The history of Slavs inferred from complete mitochondrial genome sequences.

To shed more light on the processes leading to crystallization of a Slavic identity, we investigated variability of complete mitochondrial genomes belonging to haplogroups H5 and H6 (63 mtDNA genomes) from the populations of Eastern and Western Slavs, including new samples of Poles, Ukrainians and Czechs presented here. Molecular dating implies formation of H5 approximately 11.5-16 thousand years ago (kya) in the areas of southern Europe. Within ancient haplogroup H6, dated at around 15-28 kya, there is a subhaplogroup H6c, which probably survived the last glaciation in Europe and has undergone expansion only 3-4 kya, together with the ancestors of some European groups, including the Slavs, because H6c has been detected in Czechs, Poles and Slovaks. Detailed analysis of complete mtDNAs allowed us to identify a number of lineages that seem specific for Central and Eastern Europe (H5a1f, H5a2, H5a1r, H5a1s, H5b4, H5e1a, H5u1, some subbranches of H5a1a and H6a1a9). Some of them could possibly be traced back to at least ∼4 kya, which indicates that some of the ancestors of today's Slavs (Poles, Czechs, Slovaks, Ukrainians and Russians) inhabited areas of Central and Eastern Europe much earlier than it was estimated on the basis of archaeological and historical data. We also sequenced entire mitochondrial genomes of several non-European lineages (A, C, D, G, L) found in contemporary populations of Poland and Ukraine. The analysis of these haplogroups confirms the presence of Siberian (C5c1, A8a1) and Ashkenazi-specific (L2a1l2a) mtDNA lineages in Slavic populations. Moreover, we were able to pinpoint some lineages which could possibly reflect the relatively recent contacts of Slavs with nomadic Altaic peoples (C4a1a, G2a, D5a2a1a1)

The Level of Dental Anxiety in Students of the First Year of Studies From Lublin Universities

Dental anxiety is a very important factor affecting the efficacy of prevention, diagnosis and treatment of dental diseases, both in patients in the developmental age and in young adults. Anxiety is considered an emotional state with negative connotations. The aim of the study was to determine the level of dental anxiety in first year university students, the intent being to help to develop an individual treatment plan in this group of patients. The study involved 280 students including 230 females and 50 males. Of these, 122 patients were from the Medical University of Lublin, 79 from University of Life Sciences and 79 from University of Maria Curie-Skłodowska. The mean age of the study subjects was 21 years and 8 months ± 3,9 months. No differences in the level of dental anxiety between women and men were observed. The highest level of dental anxiety was observed among students of University of Life Sciences, while the lowest level was observed among students of the Medical Universit

Complete mtDNA phylogenetic tree of subhaplogroup A8.

<p>The tree is rooted in haplogroup N. Mutations are scored relative to rCRS. Four additional complete genome sequences were taken from the literature listed in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0054360#pone.0054360.s003" target="_blank">Table S1</a>. The mutations are transitions, unless suffix (A, C, T or G) that represents the transversion is added. Insertions are marked by an “ins” and deletions are marked by “del” following the position of inserted or deleted nucleotide. Haplogroup names are in boldface. Haplotype names are in green. The mutations that are haplogroup diagnostic are listed below the haplogroup name. Branches consisting haplotypes identified in Slavic populations are highlighted in green.</p

Complete mtDNA phylogenetic tree of subhaplogroups L.

<p>The tree is rooted in haplogroup L0. Mutations are scored relative to rCRS. The mutations are transitions, unless suffix (A, C, T or G) that represents the transversion is added. Insertions are marked by an “ins” and deletions are marked by “del” following the position of inserted or deleted nucleotide. Haplogroup names are in boldface. Haplotype names are in green. The mutations that are haplogroup diagnostic are listed below the haplogroup name. Complete mitochondrial genome sequences taken from the literature are listed in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0054360#pone.0054360.s003" target="_blank">Table S1</a>. Branches consisting haplotypes identified in Slavic populations are highlighted in green.</p

Complete mtDNA phylogenetic tree of haplogroup H5.

<p>The schematic tree is based on phylogenetic tree presented on <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0054360#pone.0054360.s001" target="_blank">Figure S1</a>. Time estimates (in kya) shown for mtDNA subclades are based on the complete genome substitutions <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0054360#pone.0054360-Soares2" target="_blank">[42]</a>. The circle size is proportional to the number of individuals sharing the haplotype. Geographical origin is indicated by different colours: green - central and eastern Europe (Czech Republic, Poland, Russia, Slovakia, Ukraine); yellow – southern Europe (Italy, Spain); red – western Europe (Austria, Germany, Netherlands); blue – northern Europe (Denmark, Finland, Ireland, United Kingdom, Orkney Islands); violet – Africa (Tunisia); black – Near East (Israel, Jordan); pink – southern Caucasus (Armenia, Georgia); grey – America (Philadelphia); white - unknown origin.</p