Copyright Ó 2010 by the Genetics Society of America
DOI: 10.1534/genetics.109.112557
An Interspecific Plant Hybrid Shows Novel Changes in Parental Splice Forms
of Genes for Splicing Factors
Moira Scascitelli, Marie Cognet1 and Keith L. Adams2
University of British Columbia Botanical Garden and Centre for Plant Research, and Department of Botany,
University of British Columbia, Vancouver, British Columbia V6T 1Z4, Canada
Manuscript received November 29, 2009
Accepted for publication January 23, 2010
ABSTRACT
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.
H YBRIDIZATION between different species has
been a common occurrence during plant evo-
lution and it is thought to play an important role in
followed by chromosome doubling to create an allo-
polyploid hybrid, or alternatively, two polyploid species
can hybridize to create a new allopolyploid.
adaptive evolution, speciation, the transfer of genetic Interspecific hybridization can have considerable
adaptations, and ecological transitions (Arnold 1997; effects on the genome, including chromosome