University of British Columbia Botanical Garden and Centre for Plant Research, and Department of Botany, University of British Columbia, British Columbia, Canada.
Genetics. 2010 Apr;184(4):975-83. doi: 10.1534/genetics.109.112557. Epub 2010 Jan 25.
Interspecific hybridization plays an important role in plant adaptive evolution and speciation, and the process often results in phenotypic novelty. Hybrids can show changes in genome structure and gene expression compared with their parents including chromosomal rearrangments, changes in cytosine methylation, up- and downregulation of gene expression, and gene silencing. Alternative splicing (AS) is a fundamental aspect of the expression of many genes. However alternative splicing patterns have not been examined in multiple genes in an interspecific plant hybrid compared with its parents. Here we studied alternative splicing patterns in an interspecific Populus hybrid and its parents by assaying 40 genes using reverse transcription PCR. Most of the genes showed identical alternative splicing patterns between the parents and the hybrid. We found new alternative splicing variants present in the hybrid in two SR genes involved in the regulation of splicing and alternative splicing. The novel alternative splicing patterns included changes in donor and acceptor sites to create a new exon in one allele of PtRSZ22 in the hybrid and retention of an intron in both alleles of PtSR34a.1 in the hybrid, with effects on the function of the corresponding truncated proteins, if present. Our results suggest that novel alternative splicing patterns are present in a small percentage of genes in hybrids, but they could make a considerable impact on the expression of some genes. Changes in alternative splicing are likely to be an important component of the genetic changes that occur upon interspecific hybridization.
种间杂交在植物适应性进化和物种形成中起着重要作用，并且该过程通常会导致表型新颖性。与亲本相比，杂种可以表现出基因组结构和基因表达的变化，包括染色体重排、胞嘧啶甲基化变化、基因表达的上调和下调以及基因沉默。可变剪接（AS）是许多基因表达的基本方面。然而，与亲本相比，在种间植物杂种中尚未检查多个基因的可变剪接模式。在这里，我们通过使用逆转录 PCR 检测 40 个基因，研究了种间杨树杂种及其亲本中的可变剪接模式。大多数基因在亲本和杂种之间表现出相同的可变剪接模式。我们在两个参与剪接和可变剪接调控的 SR 基因中发现了新的可变剪接变体，这些变体存在于杂交种中。在杂种 PtRSZ22 的一个等位基因中，通过改变供体和受体位点创建了一个新的外显子，而在杂种 PtSR34a.1 的两个等位基因中保留了一个内含子，这可能会影响相应截短蛋白的功能（如果存在）。我们的研究结果表明，在杂种的一小部分基因中存在新的可变剪接模式，但它们可能会对一些基因的表达产生重大影响。可变剪接的改变可能是种间杂交发生遗传变化的重要组成部分。
