Figure 6

Heat map of contigs differentially expressed between the ten different gonadic categories of P. margaritifera . Clusters of the 1,993 differentially expressed contigs (rows) were obtained with K-means clustering using Spearman’s correlation. Contigs showing similar expression profiles on all samples (columns) clustered together. (M/F)E: male/female at early stage; (M/F)I: male/female at intermediate stage; (M/F)M: male/female at mature stage; (M/F)R: male/female at stage of regression; Inv: gonads in sexual inversion; and Und: gonad sex is undetermined. Four main expression profiles are identified: Males and Females (genes expressed in both sexes with expression changing over the course of gametogenesis, 561 contigs); Males (genes highly expressed in males with expression increasing over the course of spermatogenesis, 815 contigs); Females (genes highly expressed in females with expression increasing over the course of oogenesis, 574 contigs); and genes more expressed in undetermined, early, regressed gonads and in gonads in sexual inversion (43 contigs). Color represents the normalized expression after variance-stabilizing transformation (DESeq). Expression levels are depicted with a color scale, in which shades of red represent higher expression and shades of green represent lower expression.