Sperm capacitation

Reproductive Biology and Endocrinology volume 17Article number: Cite this article. Metrics details. Sperm capacitation involves physiological changes that spermatozoa must undergo in the female reproductive tract or in vitro to obtain the ability to bind, penetrate and fertilize the egg. Up to date, several methods have been developed to characterize this complex biological process, sperm capacitation.

A process that is used to retrieve the spermatozoa in a semen sample that have the greatest probability of fertilising. Sperm capacitation is a natural process that takes place in semen after it has been ejaculated and it is essential for fertilising the ovum. This process takes place when ejaculated semen comes into contact with the female genital tract. There are several ways of performing this process in the laboratory and achieving a sample of spermatozoa that are suitable for use in assisted reproduction techniques. Sperm capacitation is the set of natural physical changes that a spermatozoon undergoes in order to be able to fertilise the ovum. This occurs in vivo following ejaculation when the spermatozoa come into contact with the different fluids in the female genital tract. It ceases to move in straight lines and starts to fluctuate as a result of powerful movement of the head to the right and to the left.

Sperm capacitation

Federal government websites often end in. The site is secure. Mammalian sperm must undergo a series of biochemical and physiological modifications, collectively called capacitation, in the female reproductive tract prior to the acrosome reaction AR. In the present review, we summarize some of the signaling events that are involved in capacitation. The activation of PKA during capacitation depends mainly on cyclic adenosine monophosphate cAMP produced by the bicarbonate-dependent soluble adenylyl cyclase. This activation of PKA leads to an increase in actin polymerization, an essential process for the development of hyperactivated motility, which is necessary for successful fertilization. Actin polymerization is mediated by PIP 2 in two ways: first, PIP 2 acts as a cofactor for phospholipase D PLD activation, and second, as a molecule that binds and inhibits actin-severing proteins such as gelsolin. Tyrosine phosphorylation of gelsolin during capacitation by Src family kinase SFK is also important for its inactivation. Ejaculated mammalian spermatozoa should reside in the female genital tract for several hours before gaining the ability to fertilize the egg. In humans however, sperm must move out of the seminal plasma immediately after ejaculation and appear in the fallopian tube within minutes. As soon as sperm are moving out of the ejaculate and passing the cervical mucus, they undergo several biochemical changes collectively called capacitation, 1 , 2 which was first independently reported nearly six decades ago by Austin 3 and Chang.

Cross NL.

Federal government websites often end in. The site is secure. In mammals, fertilization occurs via a comprehensive progression of events. Freshly ejaculated sperm have yet to acquire progressive motility or fertilization ability. They must first undergo a series of biochemical and physiological changes, collectively known as capacitation. Capacitation is a significant prerequisite to fertilization. During the process of capacitation, changes in membrane properties, intracellular ion concentration and the activities of enzymes, together with other protein modifications, induce multiple signaling events and pathways in defined media in vitro or in the female reproductive tract in vivo.

Federal government websites often end in. The site is secure. Mammalian sperm must undergo a series of biochemical and physiological modifications, collectively called capacitation, in the female reproductive tract prior to the acrosome reaction AR. In the present review, we summarize some of the signaling events that are involved in capacitation. The activation of PKA during capacitation depends mainly on cyclic adenosine monophosphate cAMP produced by the bicarbonate-dependent soluble adenylyl cyclase. This activation of PKA leads to an increase in actin polymerization, an essential process for the development of hyperactivated motility, which is necessary for successful fertilization. Actin polymerization is mediated by PIP 2 in two ways: first, PIP 2 acts as a cofactor for phospholipase D PLD activation, and second, as a molecule that binds and inhibits actin-severing proteins such as gelsolin. Tyrosine phosphorylation of gelsolin during capacitation by Src family kinase SFK is also important for its inactivation. Ejaculated mammalian spermatozoa should reside in the female genital tract for several hours before gaining the ability to fertilize the egg.

Sperm capacitation

Sperm capacitation refers to the physiological changes spermatozoa must undergo in order to have the ability to penetrate and fertilize an egg. This term was first coined in by Colin Russell Austin based on independent studies conducted by Austin and Min Chueh Chang and published in Since the initial reports and emergence of the term, the details of the process have been elucidated due to technological advancements. Recognition of the phenomenon was quite important to early in vitro fertilization experiments as well as to the fields of embryology and reproductive biology.

03820

Frontiers in Cell and Developmental Biology. Indeed, one of the most dynamic properties acquired by capacitating spermatozoa is an ability to recognize the zona pellucida: only capacitated spermatozoa can bind to this structure Dun et al. Non-mammalian spermatozoa do not require this capacitation step and are ready to fertilize an oocyte immediately after release from the male. However, cryopreserved sperm showed damage on a variety of ways like decrease in intracellular pH and cAMP and have been deemed to be more sensitive to capacitating agents [ ]. Furthermore, membrane permeant ROS scavengers such as 2-mercaptoethanol have been reported to have a profound inhibitory impact on tyrosine phosphorylation Aitken et al. Functional attenuation of human sperm by novel, non-surfactant spermicides: precise targeting of membrane physiology without affecting structure. Molecular nature of calicin, a major basic protein of the mammalian sperm head cytoskeleton. The binding of cAMP to the regulatory subunits of PKA allows the dissociation of the tetramer and activation of the catalytic subunits. However while apocynin does clearly inhibit ROS generation by human sperm suspensions, the possibility cannot be excluded that such inhibition is a reflection of low-level leukocyte contamination, NOX2 being the major oxidase of phagocytic leukocytes. Comprehensive proteomic analysis of bovine spermatozoa of varying fertility rates and identification of biomarkers associated with fertility.

Capacitation is the penultimate [1] step in the maturation of mammalian spermatozoa and is required to render them competent to fertilize an oocyte.

However, the exact role of this pathway remains unknown. Cross NL. As a result, a great variability of results is reported in the literature. Proteasome function is regulated by cyclic AMP-dependent protein kinase through phosphorylation of Rpt6. Federal government websites often end in. Dragileva, E. Carnegie, G. CatSper activity was directly recorded in using the patch-clamp method Kirichok et al. Muro, Y. Prostasomes: inhibitors of capacitation and modulators of cellular signalling in human sperm. Albumin as a zinc carrier: properties of its high-affinity zinc-binding site. Human sperm capacitation is blocked by inhibitors of any of he elements of the ERK pathway and its upstream modulators including Grb2 to MEK [ , ]. Jensen, L.