Figure 2

Preterm birth results in early transcriptional alterations in the kidney. (a) Hierarchical clustering analysis on RNA-seq data revealed the expression profiles clustering into three groups at the early time point (18 and 20 dpc), with apparent differences between the 18 dpc animals from those at 20 dpc. (b) A principal component analysis also showed clear dissociations between 18 and 20 dpc expression profiles. Among the 20 dpc animals, there was sex-dependent clustering. Gene Ontology (GO) enrichment analyses (c) and (d) on differentially expressed genes (DEGs) between preterm and term 20 kidneys revealed enrichment of the fat-soluble vitamin related pathways in an analysis adjusted (d) or not adjusted (c) for sex. (e) Hierarchical clustering analysis on the expression profiles of 27 dpc animals. (f) A principal component analysis of 27 dpc expression data also showed dissociations between preterm and term expression profiles and a sex-dependent clustering. (g) GO enrichment analysis on DEGs of 27 dpc without adjusting for sex showed small catabolic processes as the top GO term. (h) A Venn diagram showed overlaps of DEGs between 20 and 27 dpc analyses. Six overlapped DEGs were identified (4 up-regulated genes and 2 down-regulated genes) with the same direction of the alterations at 20 and 27 dpc.