Fig 1.
A Venn diagram showing overlaps between human sperm proteins among the NOR group (green circle) and TER group (blue circle).
Fig 2.
Enrichment of the 39 overlapping proteins (red squares) in the TGF-β signalling pathway in human sperm (TER versus NOR).
Table 1.
The list of the 6 DEPs in the TGF-β signalling pathway in human sperm (TER versus NOR).
Fig 3.
The LTBP1 protein expression levels in human sperm.
Values are shown as mean ± SEM, TER (n = 16) versus NOR (n = 14). *p < 0.05; unpaired Student’s t test.
Fig 4.
The STRING protein-protein interaction network.
These proteins are included in the TGF-β signalling pathway. The red, green, and blue colours represent molecular function terms, including TGF-β receptor activity, TGF-β binding, and cytokine binding, respectively.
Fig 5.
The mRNA expression of LTBP1 and TGFBR1 genes in human sperm.
Values are shown as mean ± SEM, TER (n = 16) versus NOR (n = 14). **p < 0.01 and ***p < 0.001; unpaired Student’s t test.
Fig 6.
Immunostaining for TGF-βR1 expression in human sperm at 1000x magnification.
A black arrow indicates an immunopositive spermatozoon, whereas a red arrow indicates an immunonegative spermatozoon.
Fig 7.
The TGF-βR1 protein expression in human sperm.
Values are shown as mean ± SEM, TER (n = 16) versus NOR (n = 14). **p < 0.01; unpaired Student’s t test.
Fig 8.
Correlations between the percentage of normal sperm morphology and the expression of proteins in human sperm.
(A) LTBP1 (B) TGF-βR1. A linear regression line (black line) was fitted to all data points.