In recent years nuclear pre-mRNA processing has taken center stage as an important regulator of gene expression and ultimately growth and development. Large-scale genome and cDNA sequencing projects together with bioinformatic analyses of these sequences have revealed that alternative splicing of pre-mRNAs contributes greatly to transcriptome and proteome complexity in eukaryotes. During the last few years, tremendous progress has been made in understanding various aspects of pre-mRNA processing including alternative splicing and its importance in plant growth and development as well as in...