Mutation Accumulation in a Selfing Population: Consequences of Different Mutation Rates between Selfers and Outcrossers

Currently existing theories predict that because deleterious mutations accumulate at a higher rate, selfing populations suffer from more intense genetic degradation relative to outcrossing populations. This prediction may not always be true when we consider a potential difference in deleterious mutation rate between selfers and outcrossers. By analyzing the evolutionary stability of selfing and outcrossing in an infinite population, we found that the genome-wide deleterious mutation rate would be lower in selfing than in outcrossing organisms. When this difference in mutation rate was included in simulations, we found that in a small population, mutations accumulated more slowly under selfing rather than outcrossing. This result suggests that under frequent and intense bottlenecks, a selfing population may have a lower risk of genetic extinction than an outcrossing population

“October Revolution and Tuva”: a Roundtable (Kyzyl, 7 November 2017)

This is an overview of a roundtable which was held on November 7, 2017, at the Alan Maadyr National Museum of the Republic of Tuva, to mark the 100th anniversary of the October Revolution of 1917. The event was organized by the Tuvan Institute for the Humanities and Applied Social and Economic Studies. Among the roundtable’s participants were scholars, Communist Party veterans, members of the Verkhovny Khural (Tuva’s parliament), and students of Tuvan State University and of Kyzyl’s secondary schools. This overview covers the main points of the scholarly papers devoted to various aspects of Tuva’s Soviet-time experience – its politics, culture, education, etc. ‘Veterans of labor’, eyewitnesses of this period, put the significance of the Revolution and subsequent transformations in the context of their own lives. They believe that their parents and themselves would never have achieved any success and would never have been able to do as much as they did, without the establishment of the Soviet power in the region. The roundtable participants, representing the scholarly and political consensus in the region, agreed that the Great October Revolution of 1917 in Russia had a most direct and positive impact on the development of Tuva, tying the small republic and the great Northern power ever closer to each other

Круглый стол «Урянхаец Субедей — Великий полководец» (г. Кызыл, 4 декабря 2015 г.)

В статье представлен обзор работы круглого стола «Урянхаец Субедей — Великий полководец», прошедшего в Национальном музее Республики Тыва 4 декабря 2015 г. Организатор — Тувинский институт гуманитарных и прикладных социально-экономических исследований. Круглый стол был посвящен 840-летию монгольского полководца XII–XIII вв., соратника Чингисхана. Он был родом из урянхайцев — одной из этнических групп, составивших основу этноса тувинцев. В работе круглого стола приняли участие ведущие ученые Тувы, Бурятии, Монголии. Обсуждались вопросы истории — изучения личностей времен империи Чингисхана, а также популяризации исторических знаний о выдающихся личностях истории региона в деле воспитания молодых поколений. Инициатор проведения круглого стола, д-р филол. наук, профессор К. А. Бичелдей предложил развить научное направление, связанное с изучением жизни и деятельности Субедея и дал ему название «субедееведение». Он подчеркнул тот факт, который подтвердили ученые Монголии: в науке не оспаривается вопрос этнического происхождения главного военачальника Чингисхана. Поэтому, по мнению ученого, можно считать Субедея достоянием Тувы и использовать это в воспитательных целях. Участники собрания обменялись результатами исследований источников, в том числе «Сокровенного сказания монголов», где много сведений о Субедее. Обсудили вопрос современного художественного осмысления образа монгольского военачальника современными писателями, драматургами, художниками. Приняли резолюцию круглого стола с рядом принятых обязательств организаций Тувы по научной и популяризаторской работе

The extent of inbreeding depression as a function of deleterious mutation rate.

<p>Mean inbreeding depression under complete outcrossing (<i>S</i> = 0; solid line) and complete selfing (<i>S</i> = 1; broken line), were obtained analytically for an infinite population (equations 1a, b). The dashed-dotted line shows the threshold level of inbreeding depression ( = 0.5), below which selfing is evolutionarily stable. Selection parameters are set to be <i>h</i> = 0.2 and <i>s</i> = 0.1, based on available data for <i>Drosophila melanogaster </i><a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0033541#pone.0033541-Mukai1" target="_blank">[19]</a>, <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0033541#pone.0033541-Crow1" target="_blank">[20]</a>.</p

The rate of mutation accumulation as a function of population size.

<p>For each combination of <i>U</i> ( = 0.1, 0.3, and 0.5) and <i>s</i> ( = 0.01 and 0.1), simulation results are illustrated for populations under complete selfing (<i>S</i> = 1; broken lines), predominant selfing with slight outcrossing (<i>S</i> = 0.97; heavy solid lines), or complete outcrossing (<i>S</i> = 0; thin solid lines). The average rate of mutation accumulation was obtained by taking the arithmetic mean over 1000 generations after the systems reached steady states. Error bars indicate the standard deviations. Throughout, the degree of dominance was <i>h</i> = 0.2. The data points for situations with no fixation (i.e. when the mutation accumulation rate was zero) were omitted from the figure. Note that ordinates are given in (common) logarithmic scale. Note also that the ranges of parameters shown in the two axes vary among panels.</p

Comparison of the mutation accumulation rates when deleterious mutation rates vary between mating systems.

<p>Simulation results are illustrated for populations under complete selfing (<i>S</i> = 1; broken lines), predominant selfing with slight outcrossing (<i>S</i> = 0.97; heavy solid lines), or complete outcrossing (<i>S</i> = 0; thin solid lines). The selection coefficient was either <i>s</i> = 0.01 (A, B) or 0.1 (C, D), with <i>h</i> = 0.2 in all cases. Distinct rates of deleterious mutation were assigned to selfing and outcrossing populations, for which appropriate mutation rates were predicted from the analytical model as developed in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0033541#pone.0033541.s001" target="_blank">Text S1</a>. The mutation rate was kept at <i>U</i> = 0.1 (A, C) or 0.3 (B, D) for populations with complete selfing or slight outcrossing, whereas <i>U</i> = 0.5 for completely outcrossing populations. Error bars indicate the standard deviations. Note that ordinates are given in (common) logarithmic scale. The data points for situations with no fixation (i.e. when the mutation accumulation rate was zero) were omitted from the figure. Note also that the range of population size shown in the horizontal axis varies among panels.</p

Binding properties of IgGs to SIV antigens.

<p>The non-NAb cocktail, ten non-NAb IgG lots derived from ten macaques, and CAb were subjected to immunoblotting (ZeptoMetrix). A representative result from two experiments is shown.</p

Predominant nonsynonymous env mutations.

<p>Viral cDNAs encoding Env were amplified from plasma RNAs obtained at 7-9 months (R10-001, R10-004, and R06-029) or 12 months (other animals) and subjected to sequencing analysis. Amino acid substitutions are shown. The asterisk (*) represents a deletion and the double asterisk (**) represents coexistence of multiple deletion patterns. </p