Fig 2: (A) GDNF mRNA expression (ratio) in dogs affected by chronic asymptomatic orchitis (CAO) and healthy controls (CG). (B) GDNF mRNA expression (ratio) in groups of early and late arrest (CAO) and control dogs (CG). The results are presented as Box and Whiskers. Datasets with asterisks differ significantly: ** p < 0.01, **** p < 0.0001.

Fig 3: Western blot of GDNF. Rat testis served as a positive control; a testis homogenate of a healthy control dog was used. Protein size in kilodalton (kDa) is given on the left side. (1) indicates rat testis homogenate, (2) canine testis protein and (L) the ladder; antibody indicates that this part of the membrane was incubated with the respective GDNF antibody. The antibody was replaced by an irrelevant isotype control (“isotype control”) or buffer (“negative control”).

Fig 4: Immunostaining against GDNF (polyclonal rabbit anti-human antibody, orb1089007, Biorbyt, 2 µg/mL, 200× magnification), (A) chronic asymptomatic orchitis (CAO) early arrest, (B) CAO late arrest, (C) healthy control dog, (D) negative control and isotype control (IK; small insert, scale bar: 50 µm). Positive signals are visible in Sertoli cell nuclei (black arrows), blood vessels (dotted arrows) and peritubular myoid cells (striped arrows).

Fig 5: Immunostaining against GDNF (polyclonal rabbit anti-human antibody, orb1089007, Biorbyt, 2 µg/mL, 200× magnification), (A) chronic asymptomatic orchitis (CAO) early arrest, (B) CAO late arrest, (C) healthy control dog, (D) negative control and isotype control (IK; small insert, scale bar: 50 µm). Positive signals are visible in Sertoli cell nuclei (black arrows), blood vessels (dotted arrows) and peritubular myoid cells (striped arrows).