HelloMed Nait,

If the Spermatozoan undergone Acrosome reaction then it acquires a "hyperactive motility pattern" by which its flagellum produces vigorous whip-like movements that propel the sperm through the cervical canal and uterine cavity, until it reaches the isthmus of the fallopian tube.

Dear Med,

the Sanketh response is not just accurate. The pathways of the hyperactivation and this of the acrosomal reaction are different. The hyperactivated sperm can undergo the acrosomal reaction or not. The capacitation comes before the hyperactivation. The acrosome reacted sperm can be hyperactivated.

Best regards

Pavel

The hyperactivated sperm can undergo the acrosomal reaction or not.

The acrosome reaction and hyperactivated motility are not interdependent, and occur in different compartments of the spermatozoon. Although human sperm in vitro can exhibit hyperactivated motility quite soon after they are removed from seminal plasma and incubated under capacitating conditions, it is thought that human sperm in vivo exhibit hyperactivated motility only after they have reached the oviduct. We know that hyperactivated spermatozoa do not have the right kinematics to penetrate cervical mucus (their amplitude of lateral head displacement is too high), and Ruth Shalgi provided evidence that hyperactivated spermatozoa are much less likely to be able to traverse the oviductal isthmus. There is also evidence that the torque generated by the tail movement in hyperactivated spermatozoa (when the head is bound to a surface) is an order of magnitude greater than the force required to break covalent bonds.

The acrosome reaction occurs when the spermatozoon reaches the zona pellucida. While the enzymes released during the acrosome reaction are able to soften the zona pellucida matrix and support sperm penetration, the sperm still needs to be motile to get through the zona and reach the oocyte plasma membrane. Since the flagellar movement of hyperactivated motility is enough to break chemical bonds (such as those made between receptors), it makes sense, then, that the spermatozoon retains this type of motility until it reaches the plasma membrane and binds to it.

So, in nature, the acrosome-reacted spermatozoon would retain hyperactivated motility.

Many thanks for your responses.

dear Mortimer, it seems obvious in vivo, I don't know if this has been demonstrated in vitro 

I will agree with Sharon. It is also important to evaluate the capacitation process and the approximate timing of the acrosome reaction. Looking back, few decades ago there were "two schools" arguing which physiological process (enzymes or hyperactivated motility) claims the penetration process. It is a synergistic action.

Dear Med Nait;

ACROSOME REACTION (AR)  IS THE FINAL STAGE OF CAPACITATION THAT ESSENTIALLY INVOLVES HYPERACTIVETED MOTILITY BEFOREHAND.

UPON THE REACTION OCCURS, SPERM CELLS DIE INEVITABLY. AFTER THIS STAGE, ONLY THE NUCLEUS AND SOME PART OF CENTRIOLS WILL BE ENCAPSULATED BY THE OOCYTES' ACTION, NAMELY THE ENDOCYTOSIS THROUGH THE OOLEMMA.

DEGENERATIVE OR PREMATURE ACROSOME REACTION MAY ALSO OCCUR DURING SEMEN HANDLING FOR CRYOPRESERVATION (cryoinjury) OR PHYSIOLOGICAL TRANSPORT (premature AR) WITHIN THE GENITAL TRACT FOLLOWING THE MATING AND/OR INSEMINATION.

For further information please see the Papers /CHAPTERS written by R. Yanagimachi. I also attache two of my papers about the ACROSOME REACTON (enclosed files, below).

Regards,

Omer