RNA sequencing of Brassica napus seeds at different developmental stages

Understanding the regulation of lipid metabolism is vital for genetic engineering of Brassica napus (B. napus) to increase oil yield or modify oil composition. We report the application of Illumina Hiseq 2000 for transcriptome profiling of seeds of B. napus at different developmental stages, which may uncover the dynamic changes in lipid metabolism and reveal key genes involved in lipid biosynthesis and degradation. Total RNA from developing seeds at 2, 4, 6, and 8 weeks after pollination (WAP) were isolated and sequenced separately. The gene expression levels of all samples were quantified and normalized by the DESeq normalization. We found that the biosynthesis of fatty acids is a dominant cellular process from 2 to 6 WAP, while the degradation mainly happens after 6 WAP. Two genes, encoding for acetyl-CoA carboxylase and acyl-ACP desaturase, might be critical for fatty acid biosynthesis in oil rape seeds. This study provides insight into the mechanism underlying lipid metabolism and reveals candidate genes that are worthy of further investigation for their values in genetic engineering of B. napus. Overall design: Whole Transcriptome profiling of developing Brassica napus seeds at 2, 4, 6, 8 WAP by RNA sequencing using Illumina HiSeq 2000.