Fig. 4

Total and allele-specific expression of female-sterility candidates during flower bud development. B, D, G, and H represent early development stages of flower development sequenced in RNA-seq in [27]. a Total normalized expression (RPKM) of VviPLATZ, VviFsex, and APRT3 in males (blue circles) and females (orange squares) of V. sylvestris, and hermaphrodites (purple triangles) of V. vinifera. Each point represents a biological replicate. b–d Allele-specific normalized expression. Blue dots, orange triangles, and gray diamonds represent Y-specific, X-specific, and summed expression, respectively in the three sexes: hermaphrodite (b), male (c), and female (d). RNA-seq data were genotyped, and the coverage of X and Y variants was extracted from vcf file and averaged by gene. Only variants common to Y and Yh were included in the analysis of hermaphrodite data. Read counts were normalized by library. Each point represents a biological replicate. e Genetic model for the female-sterility mutation in V. sylvestris. APRT3y inhibits the cytokinin pathway, which results in carpel inhibition and ovule abortion. This may be reinforced by the action of VviPLATZy and VviFSEXy by unknown mechanisms. f Modified model in V. vinifera. APRT3y expression is not enough to trigger the carpel inhibition and ovule abortion. Actions of VviPLATZy and VviFSEXy may also be modified