RNA-seq analysis of genes regulated by S5 at different development stages

Hybrid sterility is a major form of postzygotic reproductive isolation, which is a widespread phenomenon in plants. Hybrids between two subspecies of the Asian cultivated rice (Oryza sativa L.), indica and japonica, are usually highly sterile. A killer-protector system composed of three closely linked genes, ORF3, ORF4 and ORF5 at the S5 locus, has been unveiled to regulate hybrid female fertility. We performed transcriptomic analysis of wild type Balilla, sterile BalillaORF5+ (Balilla with a transformed ORF5+) and fertility-restored BalillaORF3+ORF5+ (Balilla with a transformed ORF3+ and a transformed ORF5+) at S1 (before meiosis), S2 (during meiosis) and S3 (after meiosis) respectively. By comparing the differentially expressed genes in different comparisons, we proposed a model for the mechanisms of the S5 mediated hybrid sterility. Overall design: Transcriptome of two replicates of Balilla, BalillaORF5+ and BalillaORF3+ORF5+ at S1, S2, and S3 stages were collected, respectively. Differentially expressed genes in BalillaORF5+ vs. Balilla and BalillaORF3+ORF5+ vs. Balilla were analyzed further.