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A spermatozoon is a motile sperm cell, or moving form of the haploid cell that is the male gamete. A spermatozoon joins an ovum to form a zygote.
Prostate-specific antigen (PSA), also known as gamma-seminoprotein or kallikrein-3 (KLK3), P-30 antigen, is a glycoprotein enzyme encoded in humans by the KLK3 gene. PSA is a member of the kallikrein-related peptidase family and is secreted by the epithelial cells of the prostate gland.
During fertilization, a sperm must first fuse with the plasma membrane and then penetrate the female egg cell to fertilize it. Fusing to the egg cell usually causes little problem, whereas penetrating through the egg's hard shell or extracellular matrix can be more difficult. Therefore, sperm cells go through a process known as the acrosome reaction, which is the reaction that occurs in the acrosome of the sperm as it approaches the egg.
Seminiferous tubules are located within the testes, and are the specific location of meiosis, and the subsequent creation of male gametes, namely spermatozoa.
Capacitation is the penultimate step in the maturation of mammalian spermatozoa and is required to render them competent to fertilize an oocyte. This step is a biochemical event; the sperm move normally and look mature prior to capacitation. In vivo, capacitation occurs after ejaculation, when the spermatozoa leave the vagina and enter the upper female reproductive tract. The uterus aids in the steps of capacitation by secreting sterol-binding albumin, lipoproteins, and proteolytic and glycosidasic enzymes such as heparin.
Acrosin is a digestive enzyme that acts as a protease. In humans, acrosin is encoded by the ACR gene. Acrosin is released from the acrosome of spermatozoa as a consequence of the acrosome reaction. It aids in the penetration of the Zona Pellucida.
Affinity chromatography is a method of separating a biomolecule from a mixture, based on a highly specific macromolecular binding interaction between the biomolecule and another substance. The specific type of binding interaction depends on the biomolecule of interest; antigen and antibody, enzyme and substrate, receptor and ligand, or protein and nucleic acid binding interactions are frequently exploited for isolation of various biomolecules. Affinity chromatography is useful for its high selectivity and resolution of separation, compared to other chromatographic methods.
Semenogelase is an enzyme. This enzyme catalyses the following chemical reaction
Hypospermia is a condition in which a man has an unusually low ejaculate volume, less than 1.5 mL. It is the opposite of hyperspermia, which is a semen volume of more than 5.5 mL. It should not be confused with oligospermia, which means low sperm count. Normal ejaculate when a man is not drained from prior sex and is suitably aroused is around 1.5–6 mL, although this varies greatly with mood, physical condition, and sexual activity. Of this, around 1% by volume is sperm cells. The U.S.-based National Institutes of Health defines hypospermia as a semen volume lower than 2 mL on at least two semen analyses.
Decapacitation factor (DF) is composed of sperm surface-associated proteins which modulate the fertilizing ability of spermatozoa. Decapacitation is a reversible process that converts fertile, capacitated sperm to less-fertile uncapacitated sperm. This activity is achieved by interaction between cholesterol, phospholipids and fibronectin-like substances and delivered via small vesicles in seminal plasma. DF prevents onset of capacitation. Many DFs are released in secretions from the epididymis and accessory organs of the male reproductive system. However, some DFs have been identified that are located on the acrosome of sperm. Normally, capacitation is initiated through the loss of DF before the spermatozoa can perform the acrosomal reaction. Physiologically decapacitation will inhibit the acrosomal reaction as DFs reassociate onto the sperm surface. For example, one way this can be achieved is through spermatozoal membrane stabilization by maintaining physiological cholesterol/phospholipid ratio.
Protein C inhibitor is a serine protease inhibitor (serpin) that limits the activity of protein C.
Kallikrein-2 is a protein that in humans is encoded by the KLK2 gene, and is particularly associated with prostatic tissue.
Semenogelin-1 is a protein that in humans is encoded by the SEMG1 gene. The protein encoded by this gene is the predominant protein in semen. The encoded secreted protein is involved in the formation of a gel matrix that encases ejaculated spermatozoa. The prostate-specific antigen (PSA) protease processes this protein into smaller peptides, with each possibly having a separate function. The proteolysis process breaks down the gel matrix and allows the spermatozoa to move more freely. Two transcript variants encoding different isoforms have been found for this gene.
Beta-microseminoprotein is a protein that in humans is encoded by the MSMB gene. For historical reasons, the scientific literature may also refer to this protein as Prostate secretory protein 94 (PSP94), microseminoprotein (MSP), microseminoprotein-beta (MSMB), beta-inhibitin, prostatic inhibin peptide (PIP), and inhibitin like material (ILM).
Semenogelin-2 is a protein that in humans is encoded by the SEMG2 gene.
Sperm-associated antigen 1 is a protein that in humans is encoded by the SPAG1 gene.
Calcium-binding tyrosine phosphorylation-regulated protein is a protein that in humans is encoded by the CABYR gene.
Prostasomes are extracellular vesicles secreted by the prostate gland epithelial cells into seminal fluid. They possess an unusual lipid composition and a tight and highly ordered structure of their lipid bilayer membrane, resembling that of lipid raft domains. Prostasomes appear to improve sperm motility and protect against attacks from the female immune defense during the passage to the egg.
Semen, also known as seminal fluid, is an organic bodily fluid created to contain spermatozoa. It is secreted by the gonads and other sexual organs of male or hermaphroditic animals and can fertilize the female ovum. Semen is produced and originates from the seminal vesicle, which is located in the pelvis. The process that results in the discharge of semen from the urethral orifice is called ejaculation. In humans, seminal fluid contains several components besides spermatozoa: proteolytic and other enzymes as well as fructose are elements of seminal fluid which promote the survival of spermatozoa, and provide a medium through which they can move or "swim". The fluid is adapted to be discharged deep into the vagina, so the spermatozoa can pass into the uterus and form a zygote with an egg.
Cysteine-rich secretory proteins, often abbreviated as CRISPs, are a group of glycoproteins. They are a subgroup of the CRISP, antigen 5 and Pr-1 (CAP) protein superfamily and also contain a domain related to the ShK toxins. They are substantially implicated in the functioning of the mammalian reproductive system. CRISPs are also found in a variety of snake venoms where they inhibit both smooth muscle contraction and cyclic nucleotide-gated ion channels.
References
- 1 2 de Lamirande E, Lamothe G (May 2010). "Levels of semenogelin in human spermatozoa decrease during capacitation: involvement of reactive oxygen species and zinc". Hum Reprod. 25 (7): 1619–1630. doi:10.1093/humrep/deq110. PMID 20501468.
- ↑ Entrez Gene: SEMG2 semenogelin II
- ↑ Edström, AM; Malm, J; Frohm, B; Martellini, JA; Giwercman, A; Mörgelin, M; Cole, AM; Sørensen, OE (Sep 1, 2008). "The major bactericidal activity of human seminal plasma is zinc-dependent and derived from fragmentation of the semenogelins". Journal of Immunology. 181 (5): 3413–21. doi:10.4049/jimmunol.181.5.3413. PMC 2585754 . PMID 18714013.