Males That Silence Their Father's Genes: Genomic Imprinting of a Complete Haploid Genome.
Males That Silence Their Father's Genes: Genomic Imprinting of a Complete Haploid Genome.
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沉默父亲基因的雄性：完整单倍体基因组的基因组印记。
DOI：
10.1093/molbev/msab052
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发表时间：
2021-05-19
影响因子：
10.7
通讯作者：
Ross L
中科院分区：
文献类型：
--
作者：
de la Filia AG;Mongue AJ;Dorrens J;Lemon H;Laetsch DR;Ross L
遗传冲突被认为是非孟德尔遗传生殖系统进化的关键驱动力，其中父母对其后代的遗传组成没有做出同等贡献。非孟德尔遗传的一个最不寻常的例子是父本基因组消除（PGE），这是一种在节肢动物中反复进化的单倍性形式。在PGE下，男性是二倍体，但只传递母系遗传的染色体，而父系遗传的同源物被排除在精子之外。这种不对称遗传被认为是通过父方和母方基因组之间的进化军备竞赛进化而来的。在几个PGE分支中，如粉蚧（半翅目：粉蚧科），父染色体不仅从精子中消除，而且在发育早期异染色质化，并被认为保持不活跃，这可能是由于亲本基因组之间的遗传冲突。在这里，我们提出了一个父源等位基因特异性转录组分析表明，在男性粉蚧表达是全球偏向于母体基因组。然而，高达70%的体细胞表达基因在某种程度上是父系表达的，而父系基因组表达在男性生殖道中受到更多限制，只有20%的基因显示出父系贡献。我们还表明，父母的起源特定的基因表达模式是非常相似的基因型，并与完全双亲表达的基因显示分子进化的速率升高。我们的研究结果提供了迄今为止昆虫全基因组基因组印记的最清晰的例子，并增强了我们对PGE的理解，这将有助于未来对进化理论关于这种不寻常的生殖策略起源的实证检验。
Genetic conflict is considered a key driver in the evolution of reproductive systems with non-Mendelian inheritance, where parents do not contribute equally to the genetic makeup of their offspring. One of the most extraordinary examples of non-Mendelian inheritance is paternal genome elimination (PGE), a form of haplodiploidy which has evolved repeatedly across arthropods. Under PGE, males are diploid but only transmit maternally inherited chromosomes, while the paternally inherited homologues are excluded from sperm. This asymmetric inheritance is thought to have evolved through an evolutionary arms race between the paternal and maternal genomes over transmission to future generations. In several PGE clades, such as the mealybugs (Hemiptera: Pseudococcidae), paternal chromosomes are not only eliminated from sperm, but also heterochromatinized early in development and thought to remain inactive, which could result from genetic conflict between parental genomes. Here, we present a parent-of-origin allele-specific transcriptome analysis in male mealybugs showing that expression is globally biased toward the maternal genome. However, up to 70% of somatically expressed genes are to some degree paternally expressed, while paternal genome expression is much more restricted in the male reproductive tract, with only 20% of genes showing paternal contribution. We also show that parent-of-origin-specific gene expression patterns are remarkably similar across genotypes, and that genes with completely biparental expression show elevated rates of molecular evolution. Our results provide the clearest example yet of genome-wide genomic imprinting in insects and enhance our understanding of PGE, which will aid future empirical tests of evolutionary theory regarding the origin of this unusual reproductive strategy.