Fig. 6

The impact of premature birth on the molecular pathways of lung development. A Principal component analysis (PCA) shows preterm pups clustering closely to, yet well separated from, term pups of the same gestational age. Samples were sequenced in three different RNA-sequencing runs and batch-effect correction was applied. B Number of differentially expressed genes between preterm rabbit pups and age-matched term pups at different time points. Upregulated and downregulated genes are shown in red and blue, respectively. C Heatmap representing expression levels during normal development or after premature birth. Gene set 1 and gene set 2 refer to genes and pathways respectively upregulated and downregulated in term pups but not modulated in preterm pups; gene set 3 and gene set 4 refer to genes and pathways respectively upregulated and downregulated in preterm pups but not modulated in term pups. The last number in sample names indicates in which RNA-sequencing run the sample was sequenced. Z-score-normalized expression level is indicated on a low-to-high scale (blue–white–red). Main pathways enriched in each gene set are indicated on the right