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Globozoospermia
Globozoospermia is a rare and severe form of monomorphic teratozoospermia. This means that the spermatozoa show the same abnormality, and over 85% of spermatozoa in sperm have this abnormality. Globozoospermia is responsible for less than 0.1% of male infertility. It is characterised by round-headed spermatozoa without acrosomes, an abnormal nuclear membrane and midpiece defects. Affected males therefore suffer from either reduced fertility or infertility. Studies suggest that globozoospermia can be either total (100% round-headed spermatozoa without acrosomes) or partial (20-60% round acrosomeless spermatozoa with normal sperm also identified in the sperm count), however it is unclear whether these two forms are variations on the same syndrome, or actually different syndromes. Infertility in this condition results from the sperm heads missing their acrosome. These sperm, therefore, have a characteristic round or spherically shaped head. Given the absence of the acrosome, these sper ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
DPY19L2
Dpy-19-like 2 (C. elegans) is a protein that in humans is encoded by the DPY19L2 gene. Function The protein encoded by this gene belongs to the dpy-19 (developmental pluripotancy-associated) family. It is highly expressed in testis, and is required for sperm head elongation and acrosome formation during spermatogenesis. Mutations in this gene are associated with an infertility Infertility is the inability of a person, animal or plant to reproduce by natural means. It is usually not the natural state of a healthy adult, except notably among certain eusocial species (mostly haplodiploid insects). It is the normal state ... disorder, spermatogenic failure type 9 (SPGF9). References Further reading * * * * * {{gene-12-stub Human proteins ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
SPATA16
Spermatogenesis-associated protein 16 is a mammalian protein encoded by the SPATA16 gene. SPATA16, also known as NYD-SP12, is a developmental protein that aids in differentiation of germ cells for spermatogenesis and participates in acrosome formation for appropriate sperm-egg fusion. SPATA16 is located on chromosome 3 at position 26.31 (reverse strand) and is a member of the tetratricopeptide repeat-like superfamily, which facilitate interactions and assemblies between proteins and protein complexes. Identification SPATA16 (NYD-SP12) was first identified by a research lab in 2002, led by Dr. Jiahao Sha, at Nanjing Medical University in Nanjing, China. The research team used cDNA microarrays to compare expression levels of genes between adult and fetal human testes. It was discovered that the expression levels of SPATA16 were higher in adult testes than fetal testes, which signified that the gene is required for complete spermatogenesis once a male reaches puberty. Expression of S ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Teratospermia
Teratospermia or teratozoospermia is a condition characterized by the presence of sperm with abnormal morphology that affects fertility in males. Causes The causes of teratozoospermia are unknown in most cases. However, Hodgkin's disease, coeliac disease, and Crohn's disease may contribute in some instances. Lifestyle and habits (smoking, toxin exposure, etc.) can also cause poor morphology. Varicocele is another condition that is often associated with decreased normal forms (morphology). In cases of globozoospermia (sperm with round heads), the Golgi apparatus is not transformed into the acrosome that is needed for fertilization. Symptoms and treatment The presence of abnormally-shaped sperm can negatively affect fertility by preventing transport through the cervix and/or preventing sperm from adhering to the ovum. Achieving a pregnancy may be difficult. In testing for teratozoospermia, sperm are collected, stained and analyzed under a microscope to detect abnormalities. These a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Acrosome
The acrosome is an organelle that develops over the anterior (front) half of the head in the spermatozoa (sperm cells) of many animals including humans. It is a cap-like structure derived from the Golgi apparatus. In placental mammals the acrosome contains degradative enzymes (including hyaluronidase and acrosin). These enzymes break down the outer membrane of the ovum, called the zona pellucida, allowing the haploid nucleus in the sperm cell to join with the haploid nucleus in the ovum. This shedding of the acrosome, or acrosome reaction, can be stimulated ''in vitro'' by substances a sperm cell may encounter naturally such as progesterone or follicular fluid, as well as the more commonly used calcium ionophore A23187. This can be done to serve as a positive control when assessing the acrosome reaction of a sperm sample by flow cytometry or fluorescence microscopy. This is usually done after staining with a fluoresceinated lectin such as FITC-PNA, FITC-PSA, FITC-ConA, or flu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nuclear Membrane
The nuclear envelope, also known as the nuclear membrane, is made up of two lipid bilayer membranes that in eukaryotic cells surround the nucleus, which encloses the genetic material. The nuclear envelope consists of two lipid bilayer membranes: an inner nuclear membrane and an outer nuclear membrane. The space between the membranes is called the perinuclear space. It is usually about 10–50 nm wide. The outer nuclear membrane is continuous with the endoplasmic reticulum membrane. The nuclear envelope has many nuclear pores that allow materials to move between the cytosol and the nucleus. Intermediate filament proteins called lamins form a structure called the nuclear lamina on the inner aspect of the inner nuclear membrane and give structural support to the nucleus. Structure The nuclear envelope is made up of two lipid bilayer membranes, an inner nuclear membrane and an outer nuclear membrane. These membranes are connected to each other by nuclear pores. Two sets of in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Intracytoplasmic Sperm Injection
Intracytoplasmic sperm injection (ICSI ) is an in vitro fertilization (IVF) procedure in which a single sperm cell is injected directly into the cytoplasm of an egg. This technique is used in order to prepare the gametes for the obtention of embryos that may be transferred to a maternal uterus. With this method, the acrosome reaction is skipped. There are several differences between classic IVF and ICSI. However, the steps to be followed before and after insemination are the same. In terms of insemination, ICSI needs only one sperm cell per oocyte, while IVF needs 50,000–100,000. This is because the acrosome reaction has to take place and thousands of sperm cells have to be involved in IVF. Once fertilized, the egg is transformed into a pre-embryo and it has to be transferred to the uterus to continue its development. The first human pregnancy generated by ICSI was carried out in 1991 by Gianpiero Palermo and his team. Round spermatid injection (ROSI) Round spermatid inject ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Zona Pellucida
The zona pellucida (plural zonae pellucidae, also egg coat or pellucid zone) is a specialized extracellular matrix that surrounds the plasma membrane of mammalian oocytes. It is a vital constitutive part of the oocyte. The zona pellucida first appears in unilaminar primary oocytes. It is secreted by both the oocyte and the ovarian follicles. The zona pellucida is surrounded by the Corona radiata (embryology), corona radiata. The corona is composed of cells that care for the egg when it is emitted from the ovary. This structure binds spermatozoa, and is required to initiate the acrosome reaction. In the mouse (the best characterised mammalian system), the zona glycoprotein, ZP3, is responsible for sperm binding, adhering to proteins on the sperm plasma membrane. ZP3 is then involved in the induction of the acrosome reaction, whereby a spermatozoon releases the contents of the acrosome, acrosomal vesicle. The exact characterisation of what occurs in other species has become more ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
PICK1
Protein Interacting with C Kinase - 1 is a protein that in humans is encoded by the ''PICK1'' gene. Function The protein encoded by this gene contains a PDZ domain, through which it interacts with protein kinase C, alpha (PRKCA). This protein may function as an adaptor that binds to and organizes the subcellular localization of a variety of membrane proteins. It has been shown to interact with multiple glutamate receptor subtypes, monoamine plasma membrane transporters, as well as non-voltage gated sodium channels, and may target PRKCA to these membrane proteins and thus regulate their distribution and function. This protein has also been found to act as an anchoring protein that specifically targets PRKCA to mitochondria in a ligand-specific manner. Three transcript variants encoding the same protein have been found for this gene. Interactions PICK1 has been shown to interact with: * ACCN2, * BNC1, * Dopamine transporter, * GRIA2, * GRIA3, * GRIA4, * GRIK1, * GRIK2, * ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Immunofluorescence
Immunofluorescence is a technique used for light microscopy with a fluorescence microscope and is used primarily on microbiological samples. This technique uses the specificity of antibodies to their antigen to target fluorescent dyes to specific biomolecule targets within a cell, and therefore allows visualization of the distribution of the target molecule through the sample. The specific region an antibody recognizes on an antigen is called an epitope. There have been efforts in epitope mapping since many antibodies can bind the same epitope and levels of binding between antibodies that recognize the same epitope can vary. Additionally, the binding of the fluorophore to the antibody itself cannot interfere with the immunological specificity of the antibody or the binding capacity of its antigen. Immunofluorescence is a widely used example of immunostaining (using antibodies to stain proteins) and is a specific example of immunohistochemistry (the use of the antibody-antigen rel ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Assisted Reproductive Technology
Assisted reproductive technology (ART) includes medical procedures used primarily to address infertility. This subject involves procedures such as in vitro fertilization (IVF), intracytoplasmic sperm injection (ICSI), cryopreservation of gametes or embryos, and/or the use of fertility medication. When used to address infertility, ART may also be referred to as fertility treatment. ART mainly belongs to the field of reproductive endocrinology and infertility. Some forms of ART may be used with regard to fertile couples for genetic purpose (see preimplantation genetic diagnosis). ART may also be used in surrogacy arrangements, although not all surrogacy arrangements involve ART. The existence of sterility will not always require ART to be the first option to consider, as there are occasions when its cause is a mild disorder that can be solved with more conventional treatments or with behaviors based on promoting health and reproductive habits. Procedures General With ART, the pr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
