acrosome

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Related to Acrosome reaction: Cortical reaction, capacitation

acrosome

 [ak´ro-sōm]
the caplike, membrane-bound structure covering the anterior portion of the head of a spermatozoon; it contains enzymes involved in penetration of the ovum.
Acrosome of a spermatozoon. From Applegate, 2000.
acrosome reaction changes in the spermatozoon that result in development of perforations in the acrosome, allowing release of enzymes that facilitate fertilization.

ac·ro·some

(ak'rō-sōm),
A caplike organelle or saccule derived from Golgi elements that surround the anterior two thirds of the nucleus of a sperm. Enzymes contained within this structure probably facilitate the sperm's penetration of the zona pellucida of the oocyte.
Synonym(s): acrosomal cap, head cap
[acro- + G. soma, body]

acrosome

/ac·ro·some/ (ak´ro-sōm) the caplike, membrane-bound structure covering the anterior portion of the head of a spermatozoon; it contains enzymes for penetrating the oocyte.

acrosome

(ăk′rə-sōm′)
n.
A caplike structure at the anterior end of a spermatozoon that produces enzymes aiding in egg penetration.

ac′ro·so′mal (-sō′məl) adj.

acrosome

[ak′rəsōm′]
Etymology: Gk, akron + soma, body
the caplike structure surrounding the anterior end of the head of a spermatozoon. It is derived from the Golgi apparatus within the cytoplasm and contains degradative enzymes that function in the penetration of the ovum during fertilization. Also called acrosomal cap, acrosomal head cap. See also acrosomal reaction. acrosomal, adj.

Acrosome

A membrane-bound cap-like structure at the head of a spermatozoon that contains lytic enzymes—e.g., acrosin hyaluronidase—which degrade the ovum’s zona pellucida, allowing the penetration of one sperm.

acrosome

Reproduction biology A membrane-bound cap-like structure at the head of a spermatozoon that contains lytic enzymes–acrosin hyaluronidase which degrade the outer coat of the egg and allow the penetration of one sperm. See Acrosome reaction. Cf Capacitation.

ac·ro·some

(ak'rō-sōm)
A caplike organelle that surrounds the anterior two thirds of the nucleus of a sperm. Within this cap are enzymes that are thought to facilitate entry of the sperm into the oocyte.
[acro- + G. soma, body]

acrosome

A tiny sac or double membrane in the head of a SPERMATOZOON that contains the digestive enzymes needed to break down the protective cell membrane of the egg (OVUM) and allow penetration. Release of these enzymes is called the acrosome reaction.
Acrosomeclick for a larger image
Fig. 8 Acrosome . Head of a typical mammalian sperm.

acrosome

a membrane-bound sac derived from the GOLGI APPARATUS, located at the tip of the sperm. The acrosome plays an important role in fertilization. It contains enzymes that, when the sac ruptures upon contact with the egg, aid in penetration of the egg membrane, so allowing transfer of the sperm nucleus to the egg cell. See Fig. 8 .

acrosome

the caplike, membrane-bounded structure that covers the anterior portion of the head of the mammalian spermatozoon; it is bounded by an inner and an outer membrane and contains enzymes involved in penetration of the ovum.

acrosome reaction
fusion of the outer acrosomal membrane with the sperm plasma membrane, and the breakdown of the fused complex, after the attachment of the spermatozoon to the zona pellucida. It is induced by substances from the egg investments and releases enzymes involved in penetration of the ovum.
References in periodicals archive ?
Low level of ROS has also been shown to be essential for fertilization, acrosome reaction and motility.
Acrosome reaction test and western blotting for tyrosine phosphorylation levels (proteins of 105 and 81 kDa) were performed after 2 h of incubation in the four types of media.
Other ROS such as nitric oxide and the superoxide anion also are shown to promote capacitation and the acrosome reaction (15).
2) induction of the acrosome reaction, and 3) fusion of the spermatozoon and the oocyte.
Acrosin is one of the principal components in the acrosome, has trypsin-like activity and is secreted after the Acrosome Reaction (RA).
Each type of ASAB may interfere directly or indirectly with a different step in the fertilization process, including sperm motility, sperm penetration of the cervical mucus, sperm capacitation and the acrosome reaction, sperm binding and penetration of the zona pellucida, zona reaction, gamete fusion, cleavage, and embryo development.
Known as the acrosome reaction, it involves firing an armour-piercing warhead of digestive enzymes at the egg.
But the extra energy also seemed to speed up the enzyme release, known as the acrosome reaction.
Of all the ART treatments, ICSI in particular has been scrutinized because the direct injection of a sperm into an egg bypasses several phases of normal fertilization, such as the acrosome reaction and sperm-egg binding and fusion.
In several studies with normal bovine and human sperm and one preliminary study with sperm of patients with male factor infertility, ATP significantly improved the performance of both normal and malfunctioning sperm manifested by increased rates of the acrosome reaction (a pre-requisite step for fertilization) and fertilization.
Mn2+: A potent antioxidant and stimulator of sperm capacitation and acrosome reaction in crossbred cattle bulls.