Single‐parent expression (SPE) is defined as gene expression in only one of the two parents. SPE can arise from differential expression between parental alleles, termed non‐presence/absence (non‐PAV) SPE, or from the physical absence of a gene in one parent, termed PAV SPE. We used transcriptome data of diverse Zea mays (maize) inbreds and hybrids, including 401 samples from five different tissues, to test for differences between these types of SPE genes. Although commonly observed, SPE is highly genotype and tissue specific. A positive correlation was observed between the genetic distance of the two inbred parents and the number of SPE genes identified. Regulatory analysis showed that PAV SPE and non‐PAV SPE genes are mainly regulated by cis effects, with a small fraction under trans regulation. Polymorphic transposable element insertions in promoter sequences contributed to the high level of cis regulation for PAV SPE and non‐PAV SPE genes. PAV SPE genes were more frequently expressed in hybrids than non‐PAV SPE genes. The expression of parentally silent alleles in hybrids of non‐PAV SPE genes was relatively rare but occurred in most hybrids. Non‐PAV SPE genes with expression of the silent allele in hybrids are more likely to exhibit above high parent expression level than hybrids that do not express the silent allele, leading to non‐additive expression. This study provides a comprehensive understanding of the nature of non‐PAV SPE and PAV SPE genes and their roles in gene expression complementation in maize hybrids.

中文翻译：

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单亲表达驱动玉米杂种的动态基因表达互补

单亲表达（SPE）被定义为仅在两个亲本之一中的基因表达。SPE可能来自亲本等位基因之间的差异表达（称为不存在/不存在（non-PAV）SPE），也可能源自一个亲本中基因的物理缺失（称为PAV SPE）。我们使用了不同的玉米（Zea mays）近交和杂种的转录组数据，包括来自五个不同组织的401个样品，来测试这些类型的SPE基因之间的差异。尽管普遍观察到，SPE具有很高的基因型和组织特异性。在两个近交亲本的遗传距离与所鉴定的SPE基因的数量之间观察到正相关。监管分析表明，PAV SPE和非PAV SPE基因主要受顺式作用调控，在反式调节。启动子序列中的多态转座因子插入有助于PAV SPE和非PAV SPE基因的高水平顺式调控。与非PAV SPE基因相比，PAV SPE基因在杂种中的表达频率更高。非PAV SPE基因杂种中父母沉默的等位基因的表达相对较少，但大多数杂种中都存在。在杂种中具有沉默等位基因表达的非PAV SPE基因比不表达沉默等位基因的杂种更可能表现出较高的亲本表达水平，从而导致非加性表达。这项研究提供了对非PAV SPE和PAV SPE基因的性质及其在玉米杂种中基因表达互补中的作用的全面理解。