Mitonuclear sex determination? Empirical evidence from bivalves.
Mitonuclear sex determination? Empirical evidence from bivalves.
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线粒体性别决定？
DOI：
10.1101/2023.07.05.547839
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发表时间：
2023
期刊：
影响因子：
--
通讯作者：
Havird,JustinC
中科院分区：
文献类型：
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作者：
Smith,ChaseH;Mejia-Trujillo,Raquel;Breton,Sophie;Pinto,BrendanJ;Kirkpatrick,Mark;Havird,JustinC
在许多动物中，核DNA中编码的遗传元件决定了个体的性别。在某些具有双单亲遗传（DUI）的双壳类谱系中，线粒体DNA（mtDNA）被假设有助于性别决定。在这些情况下，女性将女性mtDNA传给所有后代，而男性mtDNA（M mtDNA）仅从父亲传给儿子。由于M mtDNA的遗传方式与Y染色体相同，因此有人假设mtDNA可能与性别决定有关。然而，线粒体和核基因在性别决定中的作用尚未在DUI双壳类中得到验证。本研究利用DNA、RNA和线粒体短非编码RNA（sncRNA）序列分析技术，探讨了淡水蚌Potamilus streckersoni（双壳纲：蚌目）性发育途径中线粒体和核元件的作用。我们发现，M线粒体DNA脱落的sncRNA部分在男性特异性线粒体基因，目标是一个假设参与女性发育和线粒体自噬的途径。RNA-seq证实了该基因靶标在女性中显著上调，支持线粒体sncRNA在基因沉默中的直接作用。这些发现支持了M mtDNA抑制雌性发育的假说。全基因组的遗传分化和杂合性模式不支持核性别决定区，虽然我们不能拒绝，核因素参与性别决定。我们的研究结果提供了进一步的证据，线粒体基因座有助于多样化，非呼吸功能和额外的见解，一个非正统的性别决定系统。
Genetic elements encoded in nuclear DNA determine the sex of an individual in many animals. In certain bivalve lineages that possess doubly uniparental inheritance (DUI), mitochondrial DNA (mtDNA) has been hypothesized to contribute to sex determination. In these cases, females transmit a female mtDNA to all offspring, while male mtDNA (M mtDNA) is transmitted only from fathers to sons. Because M mtDNA is inherited in the same way as Y chromosomes, it has been hypothesized that mtDNA may be responsible for sex determination. However, the role of mitochondrial and nuclear genes in sex determination has yet to be validated in DUI bivalves. In this study, we used DNA, RNA, and mitochondrial short noncoding RNA (sncRNA) sequencing to explore the role of mitochondrial and nuclear elements in the sexual development pathway of the freshwater musselPotamilus streckersoni(Bivalvia: Unionida). We found that the M mtDNA sheds a sncRNA partially within a male-specific mitochondrial gene that targets a pathway hypothesized to be involved in female development and mitophagy. RNA-seq confirmed the gene target was significantly upregulated in females, supporting a direct role of mitochondrial sncRNAs in gene silencing. These findings support the hypothesis that M mtDNA inhibits female development. Genome-wide patterns of genetic differentiation and heterozygosity did not support a nuclear sex-determining region, although we cannot reject that nuclear factors are involved with sex determination. Our results provide further evidence that mitochondrial loci contribute to diverse, nonrespiratory functions and additional insights into an unorthodox sex-determining system.