Location of aquaporins 3, 7 and 10 in frozen-thawed ejaculated and cauda epididymal spermatozoa from the Iberian ibex, mouflon, and chamois

Spermatozoa collected from the cauda epididymis of wild ruminants are more cryoresistant than ejaculated spermatozoa. Changes in the membrane location of aquaporins (AQPs) follow the osmotic changes that occur during freeze-thawing, and might influence the cryosurvival of spermatozoa depending on their source. This work reports the location of AQP3, AQP7 and AQP10 in the cauda epididymal and post-ejaculation spermatozoa of three wild mountain ungulate species (Iberian ibex, mouflon, and chamois), as determined by Western blotting (WB) and immunocytochemistry (ICC) using commercial rabbit polyclonal primary antibodies. WB confirmed the presence of all three AQPs in the spermatozoa of all the studied species, while ICC showed AQP3 to be mainly located in the sperm acrosome, mid-piece, principal piece, and end piece, both in cauda epididymal and ejaculated cells. The percentage of ejaculated spermatozoa showing AQP3 in the principal piece was higher in the ibex than in the chamois (P