CLDN1 and gestational diabetes: Additionally, quantitative PCR analysis demonstrated that the relative expression of the mRNAs encoding the tight junction proteins ZO-1 (1.80 ± 0.05 vs. 0.82 ± 0.04, p < 0.0001), occluding (1.41 ± 0.14 vs. 0.90 ± 0.04, p < 0.0001), claudin-1 (1.35 ± 0.05 vs. 0.84 ± 0.04, p < 0.0001), and mucin1 (1.52 ± 0.05 vs. 0.66 ± b0.04, p < 0.0001) in the jejunal tissue of GDM recipient mice was significantly downregulated (Figures 5E–H).