Fig. 6

Estimation of functional dominancy by MTD genes through phylogenomic analysis (a) segregation ratios of heterozygotes and wild-type segregants in mutants of MTD1 by T-DNA insertion, and results of Chi-square test (χ²). b Schematic view of MTD1 structure and mutated position by T-DNA insertions and deletion generated by CRISPR/Cas9. Grey boxes indicate exon; lines, UTR or intron; reverse triangles, T-DNA; red box, target region of CRISPR/Cas9. Genomic DNA sequences from wild type and gtd1–2 are shown. c Phenotypes of pollen grains from wild type and mtd1–2. Germinated pollen and grains stained with Lugol’s iodine, auramine O, or calcofluor white were observed under bright field and fluorescence microscopes. Bar = 20 μm. Panicles at filling stage of wild type and mtd1–2 were observed. d Expression patterns according to developmental stages of pollen were analyzed using 22 microarray data from indica rice (5 stages for anthers, 3 for pollen) and 42 microarray data from japonica rice (8 stages for anthers, 5 for pollen). Anatomical meta-expression data from ROAD were used to check expression patterns in other tissues. ACF, archesporial cell-forming stage; BG, bi-cellular gametophyte stage; Fl, flowering stage; GP, germinating pollen; Me, meiotic stage; Me1, meiotic leptotene stage; Me2, meiotic zygotene-pachytene stage; Me3, meiotic diplotene-tetrad stage; MP, mature pollen stage; PMe, pre-meiosis; TG, tri-cellular pollen stage; UG, uni-cellular gametophyte stage. Yellow color in heatmap indicates high level of expression; dark-blue, low expression