Fig. 1

Analysis of RNA-seq data from embryo chicken left gonads. a Schematic of experiments done in embryo and adult chicken. The developmental stages are shown below. b PCA plot of RNA-seq data from embryo chicken left gonads. c Number of DEGs and chromosomal allocation of embryo chicken left gonads, including three pairwise comparisons: male vs. female (M vs. F), male vs. reversal (M vs. R), reversal vs. female (R vs. F). Since male chicken do not have W chromosomes, the expressed genes on W chromosomes are marked as “down-regulation” in M vs. F and M vs. R. d Expression profiles of DEGs in three pairwise comparisons. Left: DEGs expression heatmap. Right: seven clusters of DEGs revealed by fuzzy c-means algorithm. The x axis represents each group, while the y axis represents log2-transformed, normalized intensity ratios in each group. e Top ten significantly enriched Gene Ontology terms for DEGs in each cluster