Figure 2

Genome-wide transcriptional changes occur at the involution switch, but not at the lactation switch. (A) Each data point represents the number of genes that are differentially transcribed relative to the previous time point. Five times as many transcriptional changes occur between full lactation, L9, and involution, I2, compared to any other transition between time points. (B) Each data point represents the number of genes that are differentially transcribed at that reproductive stage relative to early pregnancy, time point P1. These transcriptional changes suggest a gradual divergence from early pregnancy that increases until full lactation, L9, with a possible convergence to the pre-lactation state at involution. (C) Each data point represents the number of genes that are differentially transcribed at that time point relative to early involution, time point I2. The closest transcriptional state to I2 is P17. Of the 2,468 genes with statistically different expression in the transition from L9 to I2, 1,688 of these genes are not different between P17 and I2. Therefore, the involution switch is characterized by a partial reversion to the pre-lactation transcriptional state.