In mammals, proAKAP4 and AKAP4 are both specifically localized to the fibrous sheath of the principal piece of the flagellum and are largely known to be involved in the flagellum structure and sperm motility (Sergeant et al., 2019)
In mammals, proAKAP4 is synthetized from spermatid stage during spermatogenesis and full stock of proAKAP4 is present in the ejaculated spermatozoa.
The pro-AKAP4 precursor is processed to a “mature” AKAP4 protein that is playing a central role in flagellar structure, hypermotility, capacitation and fertility.
The amounts of proAKAP4 positive spermaozoa is then predicting sperm quality and male fertility as found in humans, large animals and small mammals (Delehedde et al., 2019).
Examples of AKAP4 and proAKAP4 expressions in bull and horse semen
Bull semen Horse semen
The 4MID® kits are complete ELISA kits with all reagents and buffers to quantify proAKAP4 in semen samples (fresh, chilled or frozen semen) :
Examples of applications of the 4MID Kits
Use for select semen before cryopreservation / predict post-thaw motility
Use to predict shelf life
Use to select extenders to improve shelf life, etc.