SmithRNAs: could mitochondria ‘bend’ nuclear regulation?

This poster is <b>part of a broad study on mitochondrial
biology</b>, performed through a non-canonical experimental model of mitochondrial
inheritance, the Doubly Uniparental Inheritance (DUI), in the Manila clam <i>Ruditapes
philippinarum</i>. DUI evolved from maternal inheritance of Mitochondria and
has been proposed to be a <b>resolved genomic conflict</b>, triggered by
selfish genes of putative viral origin, invading mtDNAs of some bivalve
species, and <b>switching ancestral hermaphroditism into gonochorism</b>. Accordingly, <b>mitochondria </b>in DUI species <b>were
suggested to affect the genetic cascade of germ line determination</b>,
and <b>RNA interference was a reasonable candidate mechanism</b> for this
feature. Actually, in libraries of processed small RNAs (i.e. not from RNA turnover) from enriched mitochondrial fractions
of clam testes and ovaries<b>, we found several highly transcribed small non coding RNAs </b>(sncRNAs),
<b>produced by either F- or M-mtDNAs</b>. We therefore named them:<b> </b><b>s</b><b>mall mitochondrial highly
transcribed RNAs (smithRNAs).</b>

本海报属于一项关于线粒体生物学（mitochondrial biology）的系统性研究，该研究以菲律宾蛤仔（*Ruditapes philippinarum*）为实验对象，采用了非经典的线粒体遗传实验模型——双重单亲遗传（Doubly Uniparental Inheritance, DUI）。DUI起源于线粒体的母系遗传，目前被认为是一种已厘清的基因组冲突：其触发机制为疑似病毒起源的自私基因入侵部分双壳类物种的线粒体DNA（mitochondrial DNA, mtDNA），并将祖先的雌雄同体状态转变为雌雄异体。据此，有研究推测DUI物种的线粒体可影响生殖系决定的遗传级联反应，而RNA干扰（RNA interference）是该特性的合理候选机制。实际上，我们在菲律宾蛤仔精巢与卵巢的富集线粒体组分所制备的加工后小RNA文库（即非来源于RNA降解代谢的小RNA文库）中，发现了数种由F型或M型mtDNA编码的高转录活性小非编码RNA（small non-coding RNAs, sncRNAs）。因此我们将其命名为：线粒体高转录小RNA（small mitochondrial highly transcribed RNAs, smithRNAs）。