A count of SPERM in the ejaculum, expressed as number per milliliter.

The anterior portion of the spermatozoon (SPERMATOZOA) that contains mainly the nucleus with highly compact CHROMATIN material.

The structural and functional changes by which SPERMATOZOA become capable of oocyte FERTILIZATION. It normally requires exposing the sperm to the female genital tract for a period of time to bring about increased SPERM MOTILITY and the ACROSOME REACTION before fertilization in the FALLOPIAN TUBES can take place.

The maturing process of SPERMATOZOA after leaving the testicular SEMINIFEROUS TUBULES. Maturation in SPERM MOTILITY and FERTILITY takes place in the EPIDIDYMIS as the sperm migrate from caput epididymis to cauda epididymis.

Passive or active movement of SPERMATOZOA from the testicular SEMINIFEROUS TUBULES through the male reproductive tract as well as within the female reproductive tract.

Interactive processes between the oocyte (OVUM) and the sperm (SPERMATOZOA) including sperm adhesion, ACROSOME REACTION, sperm penetration of the ZONA PELLUCIDA, and events leading to FERTILIZATION.

An assisted fertilization technique consisting of the microinjection of a single viable sperm into an extracted ovum. It is used principally to overcome low sperm count, low sperm motility, inability of sperm to penetrate the egg, or other conditions related to male infertility (INFERTILITY, MALE).

The cap-like structure covering the anterior portion of SPERM HEAD. Acrosome, derived from LYSOSOMES, is a membrane-bound organelle that contains the required hydrolytic and proteolytic enzymes necessary for sperm penetration of the egg in FERTILIZATION.

The inability of the male to effect FERTILIZATION of an OVUM after a specified period of unprotected intercourse. Male sterility is permanent infertility.

The middle piece of the spermatozoon is a highly organized segment consisting of MITOCHONDRIA, the outer dense fibers and the core microtubular structure.

The fusion of a spermatozoon (SPERMATOZOA) with an OVUM thus resulting in the formation of a ZYGOTE.

The thick, yellowish-white, viscid fluid secretion of male reproductive organs discharged upon ejaculation. In addition to reproductive organ secretions, it contains SPERMATOZOA and their nutrient plasma.

Centers for acquiring and storing semen.

The process by which semen is kept viable outside of the organism from which it was derived (i.e., kept from decay by means of a chemical agent, cooling, or a fluid substitute that mimics the natural state within the organism).

The convoluted cordlike structure attached to the posterior of the TESTIS. Epididymis consists of the head (caput), the body (corpus), and the tail (cauda). A network of ducts leaving the testis joins into a common epididymal tubule proper which provides the transport, storage, and maturation of SPERMATOZOA.

The quality of SEMEN, an indicator of male fertility, can be determined by semen volume, pH, sperm concentration (SPERM COUNT), total sperm number, sperm viability, sperm vigor (SPERM MOTILITY), normal sperm morphology, ACROSOME integrity, and the concentration of WHITE BLOOD CELLS.

A tough transparent membrane surrounding the OVUM. It is penetrated by the sperm during FERTILIZATION.

The male gonad containing two functional parts: the SEMINIFEROUS TUBULES for the production and transport of male germ cells (SPERMATOGENESIS) and the interstitial compartment containing LEYDIG CELLS that produce ANDROGENS.

The emission of SEMEN to the exterior, resulting from the contraction of muscles surrounding the male internal urogenital ducts.

The capacity to conceive or to induce conception. It may refer to either the male or female.

The species Physeter catodon (also called Physeter macrocephalus), in the family Physeteridae. The common name is derived from the milky wax substance in its head (spermaceti). The species also produces an intestinal secretion AMBERGRIS, which was previously used in perfumes. The sperm whale is the largest toothed MAMMAL in the world.

Preservation of cells, tissues, organs, or embryos by freezing. In histological preparations, cryopreservation or cryofixation is used to maintain the existing form, structure, and chemical composition of all the constituent elements of the specimens.

A condition of suboptimal concentration of SPERMATOZOA in the ejaculated SEMEN to ensure successful FERTILIZATION of an OVUM. In humans, oligospermia is defined as a sperm count below 20 million per milliliter semen.

A mature haploid female germ cell extruded from the OVARY at OVULATION.

Proteins found in SEMEN. Major seminal plasma proteins are secretory proteins from the male sex accessory glands, such as the SEMINAL VESICLES and the PROSTATE. They include the seminal vesicle-specific antigen, an ejaculate clotting protein; and the PROSTATE-SPECIFIC ANTIGEN, a protease and an esterase.

A condition in which the percentage of progressively motile sperm is abnormally low. In men, it is defined as

A group of simple proteins that yield basic amino acids on hydrolysis and that occur combined with nucleic acid in the sperm of fish. Protamines contain very few kinds of amino acids. Protamine sulfate combines with heparin to form a stable inactive complex; it is used to neutralize the anticoagulant action of heparin in the treatment of heparin overdose. (From Merck Index, 11th ed; Martindale, The Extra Pharmacopoeia, 30th ed, p692)

Artificial introduction of SEMEN or SPERMATOZOA into the VAGINA to facilitate FERTILIZATION.

Somewhat flattened, globular echinoderms, having thin, brittle shells of calcareous plates. They are useful models for studying FERTILIZATION and EMBRYO DEVELOPMENT.

Female germ cells derived from OOGONIA and termed OOCYTES when they enter MEIOSIS. The primary oocytes begin meiosis but are arrested at the diplotene state until OVULATION at PUBERTY to give rise to haploid secondary oocytes or ova (OVUM).

Proteins which are found in eggs (OVA) from any species.

A condition of having no sperm present in the ejaculate (SEMEN).

Sexual activities of animals.

A pair of highly specialized muscular canals extending from the UTERUS to its corresponding OVARY. They provide the means for OVUM collection, and the site for the final maturation of gametes and FERTILIZATION. The fallopian tube consists of an interstitium, an isthmus, an ampulla, an infundibulum, and fimbriae. Its wall consists of three histologic layers: serous, muscular, and an internal mucosal layer lined with both ciliated and secretory cells.

The secretory proteins of the seminal vesicles are proteins and enzymes that are important in the rapid clotting of the ejaculate. The major clotting protein is seminal vesicle-specific antigen. Many of these seminal vesicle proteins are under androgen regulation, and are substrates for the prostatic enzymes, such as the PROSTATE-SPECIFIC ANTIGEN, a protease and an esterase.

Surgical removal of the ductus deferens, or a portion of it. It is done in association with prostatectomy, or to induce infertility. (Dorland, 28th ed)

Substances that provide protection against the harmful effects of freezing temperatures.

Large marine mammals of the order CETACEA. In the past, they were commercially valued for whale oil, for their flesh as human food and in ANIMAL FEED and FERTILIZERS, and for baleen. Today, there is a moratorium on most commercial whaling, as all species are either listed as endangered or threatened.

The total process by which organisms produce offspring. (Stedman, 25th ed)

The deposit of SEMEN or SPERMATOZOA into the VAGINA to facilitate FERTILIZATION.

The status during which female mammals carry their developing young (EMBRYOS or FETUSES) in utero before birth, beginning from FERTILIZATION to BIRTH.

The plasma membrane of the egg.

The male reproductive organs. They are divided into the external organs (PENIS; SCROTUM;and URETHRA) and the internal organs (TESTIS; EPIDIDYMIS; VAS DEFERENS; SEMINAL VESICLES; EJACULATORY DUCTS; PROSTATE; and BULBOURETHRAL GLANDS).

The ratio of the number of conceptions (CONCEPTION) including LIVE BIRTH; STILLBIRTH; and fetal losses, to the mean number of females of reproductive age in a population during a set time period.

The injection of very small amounts of fluid, often with the aid of a microscope and microsyringes.

Splitting the DNA into shorter pieces by endonucleolytic DNA CLEAVAGE at multiple sites. It includes the internucleosomal DNA fragmentation, which along with chromatin condensation, are considered to be the hallmarks of APOPTOSIS.

Sexual union of a male and a female in non-human species.

Methods pertaining to the generation of new individuals, including techniques used in selective BREEDING, cloning (CLONING, ORGANISM), and assisted reproduction (REPRODUCTIVE TECHNIQUES, ASSISTED).

The chromosomal constitution of cells which deviate from the normal by the addition or subtraction of CHROMOSOMES, chromosome pairs, or chromosome fragments. In a normally diploid cell (DIPLOIDY) the loss of a chromosome pair is termed nullisomy (symbol: 2N-2), the loss of a single chromosome is MONOSOMY (symbol: 2N-1), the addition of a chromosome pair is tetrasomy (symbol: 2N+2), the addition of a single chromosome is TRISOMY (symbol: 2N+1).

Ducts that serve exclusively for the passage of eggs from the ovaries to the exterior of the body. In non-mammals, they are termed oviducts. In mammals, they are highly specialized and known as FALLOPIAN TUBES.

Clinical and laboratory techniques used to enhance fertility in humans and animals.

Chemical substances or agents with contraceptive activity in males. Use for male contraceptive agents in general or for which there is no specific heading.

The fertilized OVUM resulting from the fusion of a male and a female gamete.

Domesticated bovine animals of the genus Bos, usually kept on a farm or ranch and used for the production of meat or dairy products or for heavy labor.

A polyvinyl polymer of variable molecular weight; used as suspending and dispersing agent and vehicle for pharmaceuticals; also used as blood volume expander.

Glycosidic antibiotic from Streptomyces griseus used as a fluorescent stain of DNA and as an antineoplastic agent.

The male sex chromosome, being the differential sex chromosome carried by half the male gametes and none of the female gametes in humans and in some other male-heterogametic species in which the homologue of the X chromosome has been retained.

Proteins secreted by the epididymal epithelium. These proteins are both tissue- and species-specific. They are important molecular agents in the process of sperm maturation.

A slightly alkaline secretion of the endocervical glands. The consistency and amount are dependent on the physiological hormone changes in the menstrual cycle. It contains the glycoprotein mucin, amino acids, sugar, enzymes, and electrolytes, with a water content up to 90%. The mucus is a useful protection against the ascent of bacteria and sperm into the uterus. (From Dictionary of Obstetrics and Gynecology, 1988)

Surgical anastomosis or fistulization of the spermatic ducts to restore fertility in a previously vasectomized male.

The material of CHROMOSOMES. It is a complex of DNA; HISTONES; and nonhistone proteins (CHROMOSOMAL PROTEINS, NON-HISTONE) found within the nucleus of a cell.

The lipid- and protein-containing, selectively permeable membrane that surrounds the cytoplasm in prokaryotic and eukaryotic cells.

Human artificial insemination in which the husband's semen is used.

The female reproductive organs. The external organs include the VULVA; BARTHOLIN'S GLANDS; and CLITORIS. The internal organs include the VAGINA; UTERUS; OVARY; and FALLOPIAN TUBES.

A type of CELL NUCLEUS division, occurring during maturation of the GERM CELLS. Two successive cell nucleus divisions following a single chromosome duplication (S PHASE) result in daughter cells with half the number of CHROMOSOMES as the parent cells.

Human artificial insemination in which the semen used is that of a man other than the woman's husband.

Any of various animals that constitute the family Suidae and comprise stout-bodied, short-legged omnivorous mammals with thick skin, usually covered with coarse bristles, a rather long mobile snout, and small tail. Included are the genera Babyrousa, Phacochoerus (wart hogs), and Sus, the latter containing the domestic pig (see SUS SCROFA).

The convoluted tubules in the TESTIS where sperm are produced (SPERMATOGENESIS) and conveyed to the RETE TESTIS. Spermatogenic tubules are composed of developing germ cells and the supporting SERTOLI CELLS.

Inability to reproduce after a specified period of unprotected intercourse. Reproductive sterility is permanent infertility.

A phylum of the most familiar marine invertebrates. Its class Stelleroidea contains two subclasses, the Asteroidea (the STARFISH or sea stars) and the Ophiuroidea (the brittle stars, also called basket stars and serpent stars). There are 1500 described species of STARFISH found throughout the world. The second class, Echinoidea, contains about 950 species of SEA URCHINS, heart urchins, and sand dollars. A third class, Holothuroidea, comprises about 900 echinoderms known as SEA CUCUMBERS. Echinoderms are used extensively in biological research. (From Barnes, Invertebrate Zoology, 5th ed, pp773-826)

Pathological processes of the TESTIS.

Microscopy using an electron beam, instead of light, to visualize the sample, thereby allowing much greater magnification. The interactions of ELECTRONS with specimens are used to provide information about the fine structure of that specimen. In TRANSMISSION ELECTRON MICROSCOPY the reactions of the electrons that are transmitted through the specimen are imaged. In SCANNING ELECTRON MICROSCOPY an electron beam falls at a non-normal angle on the specimen and the image is derived from the reactions occurring above the plane of the specimen.

A type of IN SITU HYBRIDIZATION in which target sequences are stained with fluorescent dye so their location and size can be determined using fluorescence microscopy. This staining is sufficiently distinct that the hybridization signal can be seen both in metaphase spreads and in interphase nuclei.

Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.

Results of conception and ensuing pregnancy, including LIVE BIRTH; STILLBIRTH; SPONTANEOUS ABORTION; INDUCED ABORTION. The outcome may follow natural or artificial insemination or any of the various ASSISTED REPRODUCTIVE TECHNIQUES, such as EMBRYO TRANSFER or FERTILIZATION IN VITRO.

A whiplike motility appendage present on the surface cells. Prokaryote flagella are composed of a protein called FLAGELLIN. Bacteria can have a single flagellum, a tuft at one pole, or multiple flagella covering the entire surface. In eukaryotes, flagella are threadlike protoplasmic extensions used to propel flagellates and sperm. Flagella have the same basic structure as CILIA but are longer in proportion to the cell bearing them and present in much smaller numbers. (From King & Stansfield, A Dictionary of Genetics, 4th ed)

The human male sex chromosome, being the differential sex chromosome carried by half the male gametes and none of the female gametes in humans.

A potent androgenic steroid and major product secreted by the LEYDIG CELLS of the TESTIS. Its production is stimulated by LUTEINIZING HORMONE from the PITUITARY GLAND. In turn, testosterone exerts feedback control of the pituitary LH and FSH secretion. Depending on the tissues, testosterone can be further converted to DIHYDROTESTOSTERONE or ESTRADIOL.

Liquids transforming into solids by the removal of heat.

A basic element found in nearly all organized tissues. It is a member of the alkaline earth family of metals with the atomic symbol Ca, atomic number 20, and atomic weight 40. Calcium is the most abundant mineral in the body and combines with phosphorus to form calcium phosphate in the bones and teeth. It is essential for the normal functioning of nerves and muscles and plays a role in blood coagulation (as factor IV) and in many enzymatic processes.

Chemical agents that increase the permeability of biological or artificial lipid membranes to specific ions. Most ionophores are relatively small organic molecules that act as mobile carriers within membranes or coalesce to form ion permeable channels across membranes. Many are antibiotics, and many act as uncoupling agents by short-circuiting the proton gradient across mitochondrial membranes.

The restriction of a characteristic behavior, anatomical structure or physical system, such as immune response; metabolic response, or gene or gene variant to the members of one species. It refers to that property which differentiates one species from another but it is also used for phylogenetic levels higher or lower than the species.

A cationic cytochemical stain specific for cell nuclei, especially DNA. It is used as a supravital stain and in fluorescence cytochemistry. It may cause mutations in microorganisms.

Contraceptive methods based on immunological processes and techniques, such as the use of CONTRACEPTIVE VACCINES.

The number of males per 100 females.

A subphylum of chordates intermediate between the invertebrates and the true vertebrates. It includes the Ascidians.

Vaccines or candidate vaccines used to prevent conception.

Elements of limited time intervals, contributing to particular results or situations.

The order of amino acids as they occur in a polypeptide chain. This is referred to as the primary structure of proteins. It is of fundamental importance in determining PROTEIN CONFORMATION.

A saclike, glandular diverticulum on each ductus deferens in male vertebrates. It is united with the excretory duct and serves for temporary storage of semen. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)

A chlorinated PROPANEDIOL with antifertility activity in males used as a chemosterilant in rodents.

Inbred ICR mice are a strain of albino laboratory mice that have been selectively bred for consistent genetic makeup and high reproductive performance, making them widely used in biomedical research for studies involving reproduction, toxicology, pharmacology, and carcinogenesis.

Morphological and physiological development of EMBRYOS.

The procedure of removing TISSUES, organs, or specimens from DONORS for reuse, such as TRANSPLANTATION.

A cutaneous pouch of skin containing the testicles and spermatic cords.

A genus of the family Muridae having three species. The present domesticated strains were developed from individuals brought from Syria. They are widely used in biomedical research.

In gonochoristic organisms, congenital conditions in which development of chromosomal, gonadal, or anatomical sex is atypical. Effects from exposure to abnormal levels of GONADAL HORMONES in the maternal environment, or disruption of the function of those hormones by ENDOCRINE DISRUPTORS are included.

The measurement of an organ in volume, mass, or heaviness.

Within a eukaryotic cell, a membrane-limited body which contains chromosomes and one or more nucleoli (CELL NUCLEOLUS). The nuclear membrane consists of a double unit-type membrane which is perforated by a number of pores; the outermost membrane is continuous with the ENDOPLASMIC RETICULUM. A cell may contain more than one nucleus. (From Singleton & Sainsbury, Dictionary of Microbiology and Molecular Biology, 2d ed)

Large, hoofed mammals of the family EQUIDAE. Horses are active day and night with most of the day spent seeking and consuming food. Feeding peaks occur in the early morning and late afternoon, and there are several daily periods of rest.

A conjugated protein which is the oxygen-transporting pigment of muscle. It is made up of one globin polypeptide chain and one heme group.

A genus of livebearing cyprinodont fish comprising the guppy and molly. Some species are virtually all female and depend on sperm from other species to stimulate egg development. Poecilia is used in carcinogenicity studies as well as neurologic and physiologic research.

Echinoderms having bodies of usually five radially disposed arms coalescing at the center.

Microscopy of specimens stained with fluorescent dye (usually fluorescein isothiocyanate) or of naturally fluorescent materials, which emit light when exposed to ultraviolet or blue light. Immunofluorescence microscopy utilizes antibodies that are labeled with fluorescent dye.

A subfamily in the family MURIDAE, comprising the hamsters. Four of the more common genera are Cricetus, CRICETULUS; MESOCRICETUS; and PHODOPUS.

A form of male HYPOGONADISM, characterized by the presence of an extra X CHROMOSOME, small TESTES, seminiferous tubule dysgenesis, elevated levels of GONADOTROPINS, low serum TESTOSTERONE, underdeveloped secondary sex characteristics, and male infertility (INFERTILITY, MALE). Patients tend to have long legs and a slim, tall stature. GYNECOMASTIA is present in many of the patients. The classic form has the karyotype 47,XXY. Several karyotype variants include 48,XXYY; 48,XXXY; 49,XXXXY, and mosaic patterns ( 46,XY/47,XXY; 47,XXY/48,XXXY, etc.).

A post-MORULA preimplantation mammalian embryo that develops from a 32-cell stage into a fluid-filled hollow ball of over a hundred cells. A blastocyst has two distinctive tissues. The outer layer of trophoblasts gives rise to extra-embryonic tissues. The inner cell mass gives rise to the embryonic disc and eventual embryo proper.

The excretory duct of the testes that carries SPERMATOZOA. It rises from the SCROTUM and joins the SEMINAL VESICLES to form the ejaculatory duct.

A TETRACYCLINE with a 7-chloro substitution.

Electrophoresis in which a polyacrylamide gel is used as the diffusion medium.

The part of a cell that contains the CYTOSOL and small structures excluding the CELL NUCLEUS; MITOCHONDRIA; and large VACUOLES. (Glick, Glossary of Biochemistry and Molecular Biology, 1990)

Any of various ruminant mammals of the order Bovidae. They include numerous species in Africa and the American pronghorn.

The process of cumulative change over successive generations through which organisms acquire their distinguishing morphological and physiological characteristics.

Chemical substances that are destructive to spermatozoa used as topically administered vaginal contraceptives.

Supporting cells projecting inward from the basement membrane of SEMINIFEROUS TUBULES. They surround and nourish the developing male germ cells and secrete ANDROGEN-BINDING PROTEIN and hormones such as ANTI-MULLERIAN HORMONE. The tight junctions of Sertoli cells with the SPERMATOGONIA and SPERMATOCYTES provide a BLOOD-TESTIS BARRIER.

The reproductive cells in multicellular organisms at various stages during GAMETOGENESIS.

Test for tissue antigen using either a direct method, by conjugation of antibody with fluorescent dye (FLUORESCENT ANTIBODY TECHNIQUE, DIRECT) or an indirect method, by formation of antigen-antibody complex which is then labeled with fluorescein-conjugated anti-immunoglobulin antibody (FLUORESCENT ANTIBODY TECHNIQUE, INDIRECT). The tissue is then examined by fluorescence microscopy.

Glycoproteins found on the membrane or surface of cells.

The removal of secretions, gas or fluid from hollow or tubular organs or cavities by means of a tube and a device that acts on negative pressure.

A major gonadotropin secreted by the adenohypophysis (PITUITARY GLAND, ANTERIOR). Follicle-stimulating hormone stimulates GAMETOGENESIS and the supporting cells such as the ovarian GRANULOSA CELLS, the testicular SERTOLI CELLS, and LEYDIG CELLS. FSH consists of two noncovalently linked subunits, alpha and beta. Within a species, the alpha subunit is common in the three pituitary glycoprotein hormones (TSH, LH, and FSH), but the beta subunit is unique and confers its biological specificity.

The chromosomal constitution of cells, in which each type of CHROMOSOME is represented twice. Symbol: 2N or 2X.

Agents that emit light after excitation by light. The wave length of the emitted light is usually longer than that of the incident light. Fluorochromes are substances that cause fluorescence in other substances, i.e., dyes used to mark or label other compounds with fluorescent tags.

The performance of dissections, injections, surgery, etc., by the use of micromanipulators (attachments to a microscope) that manipulate tiny instruments.

The direct struggle between individuals for environmental necessities or for a common goal.

Abnormal number or structure of chromosomes. Chromosome aberrations may result in CHROMOSOME DISORDERS.

The quantity of volume or surface area of CELLS.

Genetically identical individuals developed from brother and sister matings which have been carried out for twenty or more generations, or by parent x offspring matings carried out with certain restrictions. All animals within an inbred strain trace back to a common ancestor in the twentieth generation.

A deoxyribonucleotide polymer that is the primary genetic material of all cells. Eukaryotic and prokaryotic organisms normally contain DNA in a double-stranded state, yet several important biological processes transiently involve single-stranded regions. DNA, which consists of a polysugar-phosphate backbone possessing projections of purines (adenine and guanine) and pyrimidines (thymine and cytosine), forms a double helix that is held together by hydrogen bonds between these purines and pyrimidines (adenine to thymine and guanine to cytosine).

Identification of proteins or peptides that have been electrophoretically separated by blot transferring from the electrophoresis gel to strips of nitrocellulose paper, followed by labeling with antibody probes.

Cell separation is the process of isolating and distinguishing specific cell types or individual cells from a heterogeneous mixture, often through the use of physical or biological techniques.

The family Gryllidae consists of the common house cricket, Acheta domesticus, which is used in neurological and physiological studies. Other genera include Gryllotalpa (mole cricket); Gryllus (field cricket); and Oecanthus (tree cricket).

The selection or choice of sexual partner in animals. Often this reproductive preference is based on traits in the potential mate, such as coloration, size, or behavioral boldness. If the chosen ones are genetically different from the rejected ones, then NATURAL SELECTION is occurring.

The chromosomal constitution of cells, in which each type of CHROMOSOME is represented once. Symbol: N.

Endometrial implantation of EMBRYO, MAMMALIAN at the BLASTOCYST stage.

A genotoxicological technique for measuring DNA damage in an individual cell using single-cell gel electrophoresis. Cell DNA fragments assume a "comet with tail" formation on electrophoresis and are detected with an image analysis system. Alkaline assay conditions facilitate sensitive detection of single-strand damage.

The human female sex chromosome, being the differential sex chromosome carried by half the male gametes and all female gametes in humans.

Cell surface proteins that bind signalling molecules external to the cell with high affinity and convert this extracellular event into one or more intracellular signals that alter the behavior of the target cell (From Alberts, Molecular Biology of the Cell, 2nd ed, pp693-5). Cell surface receptors, unlike enzymes, do not chemically alter their ligands.

Cytoplasm stored in an egg that contains nutritional reserves for the developing embryo. It is rich in polysaccharides, lipids, and proteins.

An ionophorous, polyether antibiotic from Streptomyces chartreusensis. It binds and transports CALCIUM and other divalent cations across membranes and uncouples oxidative phosphorylation while inhibiting ATPase of rat liver mitochondria. The substance is used mostly as a biochemical tool to study the role of divalent cations in various biological systems.

A form of fluorescent antibody technique commonly used to detect serum antibodies and immune complexes in tissues and microorganisms in specimens from patients with infectious diseases. The technique involves formation of an antigen-antibody complex which is labeled with fluorescein-conjugated anti-immunoglobulin antibody. (From Bennington, Saunders Dictionary & Encyclopedia of Laboratory Medicine and Technology, 1984)

The performance of surgical procedures with the aid of a microscope.

Technique using an instrument system for making, processing, and displaying one or more measurements on individual cells obtained from a cell suspension. Cells are usually stained with one or more fluorescent dyes specific to cell components of interest, e.g., DNA, and fluorescence of each cell is measured as it rapidly transverses the excitation beam (laser or mercury arc lamp). Fluorescence provides a quantitative measure of various biochemical and biophysical properties of the cell, as well as a basis for cell sorting. Other measurable optical parameters include light absorption and light scattering, the latter being applicable to the measurement of cell size, shape, density, granularity, and stain uptake.

Establishing the father relationship of a man and a child.

Morphological and physiological development of EMBRYOS or FETUSES.

A unisexual reproduction without the fusion of a male and a female gamete (FERTILIZATION). In parthenogenesis, an individual is formed from an unfertilized OVUM that did not complete MEIOSIS. Parthenogenesis occurs in nature and can be artificially induced.

A bundle of MICROTUBULES and MICROTUBULE-ASSOCIATED PROTEINS forming the core of each CILIUM or FLAGELLUM. In most eukaryotic cilia or flagella, an axoneme shaft has 20 microtubules arranged in nine doublets and two singlets.

Lectin purified from peanuts (ARACHIS HYPOGAEA). It binds to poorly differentiated cells and terminally differentiated cells and is used in cell separation techniques.

Linear POLYPEPTIDES that are synthesized on RIBOSOMES and may be further modified, crosslinked, cleaved, or assembled into complex proteins with several subunits. The specific sequence of AMINO ACIDS determines the shape the polypeptide will take, during PROTEIN FOLDING, and the function of the protein.

Warm-blooded vertebrate animals belonging to the class Mammalia, including all that possess hair and suckle their young.

The normality of a solution with respect to HYDROGEN ions; H+. It is related to acidity measurements in most cases by pH = log 1/2[1/(H+)], where (H+) is the hydrogen ion concentration in gram equivalents per liter of solution. (McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)

Theoretical representations that simulate the behavior or activity of biological processes or diseases. For disease models in living animals, DISEASE MODELS, ANIMAL is available. Biological models include the use of mathematical equations, computers, and other electronic equipment.

Mapping of the KARYOTYPE of a cell.

A family of multisubunit cytoskeletal motor proteins that use the energy of ATP hydrolysis to power a variety of cellular functions. Dyneins fall into two major classes based upon structural and functional criteria.

Diminished or absent ability of a female to achieve conception.

A reagent commonly used in biochemical studies as a protective agent to prevent the oxidation of SH (thiol) groups and for reducing disulphides to dithiols.

The fluid surrounding the OVUM and GRANULOSA CELLS in the Graafian follicle (OVARIAN FOLLICLE). The follicular fluid contains sex steroids, glycoprotein hormones, plasma proteins, mucopolysaccharides, and enzymes.

The span of viability of a cell characterized by the capacity to perform certain functions such as metabolism, growth, reproduction, some form of responsiveness, and adaptability.

Paired ducts in the human male through which semen is ejaculated into the urethra.

Quaternary ammonium analog of ethidium; an intercalating dye with a specific affinity to certain forms of DNA and, used as diiodide, to separate them in density gradients; also forms fluorescent complexes with cholinesterase which it inhibits.

Injuries to DNA that introduce deviations from its normal, intact structure and which may, if left unrepaired, result in a MUTATION or a block of DNA REPLICATION. These deviations may be caused by physical or chemical agents and occur by natural or unnatural, introduced circumstances. They include the introduction of illegitimate bases during replication or by deamination or other modification of bases; the loss of a base from the DNA backbone leaving an abasic site; single-strand breaks; double strand breaks; and intrastrand (PYRIMIDINE DIMERS) or interstrand crosslinking. Damage can often be repaired (DNA REPAIR). If the damage is extensive, it can induce APOPTOSIS.

Procedures for collecting, preserving, and transporting of specimens sufficiently stable to provide accurate and precise results suitable for clinical interpretation.

A form of interference microscopy in which variations of the refracting index in the object are converted into variations of intensity in the image. This is achieved by the action of a phase plate.

Sexual stimulation or gratification of the self.

The entity of a developing mammal (MAMMALS), generally from the cleavage of a ZYGOTE to the end of embryonic differentiation of basic structures. For the human embryo, this represents the first two months of intrauterine development preceding the stages of the FETUS.

Signal transduction mechanisms whereby calcium mobilization (from outside the cell or from intracellular storage pools) to the cytoplasm is triggered by external stimuli. Calcium signals are often seen to propagate as waves, oscillations, spikes, sparks, or puffs. The calcium acts as an intracellular messenger by activating calcium-responsive proteins.

Liquid components of living organisms.

Conjugated protein-carbohydrate compounds including mucins, mucoid, and amyloid glycoproteins.

The female sex chromosome, being the differential sex chromosome carried by half the male gametes and all female gametes in human and other male-heterogametic species.

A widely distributed order of perching BIRDS, including more than half of all bird species.

A family of membrane-anchored glycoproteins that contain a disintegrin and metalloprotease domain. They are responsible for the proteolytic cleavage of many transmembrane proteins and the release of their extracellular domain.

The network of channels formed at the termination of the straight SEMINIFEROUS TUBULES in the mediastinum testis. Rete testis channels drain into the efferent ductules that pass into the caput EPIDIDYMIS.

Cellular release of material within membrane-limited vesicles by fusion of the vesicles with the CELL MEMBRANE.

The homologous chromosomes that are dissimilar in the heterogametic sex. There are the X CHROMOSOME, the Y CHROMOSOME, and the W, Z chromosomes (in animals in which the female is the heterogametic sex (the silkworm moth Bombyx mori, for example)). In such cases the W chromosome is the female-determining and the male is ZZ. (From King & Stansfield, A Dictionary of Genetics, 4th ed)

Nonionic surfactant mixtures varying in the number of repeating ethoxy (oxy-1,2-ethanediyl) groups. They are used as detergents, emulsifiers, wetting agents, defoaming agents, etc. Octoxynol-9, the compound with 9 repeating ethoxy groups, is a spermatocide.

The sequence of PURINES and PYRIMIDINES in nucleic acids and polynucleotides. It is also called nucleotide sequence.

A species of fruit fly much used in genetics because of the large size of its chromosomes.

An order of fresh water fish with 18 families and over 1600 species. The order includes CHARACINS, hatchetfish, piranhas, and TETRAS.

The process of germ cell development from the primordial GERM CELLS to the mature haploid GAMETES: ova in the female (OOGENESIS) or sperm in the male (SPERMATOGENESIS).

A family of marsupials in the order Diprotodontia, native to Australia and possessing vestigial tails. There is a single living genus and species: Phascolarctos cinereus, the koala.

Histochemical localization of immunoreactive substances using labeled antibodies as reagents.

Myoglobin which is in the oxidized ferric or hemin form. The oxidation causes a change in color from red to brown.

A specific pair of GROUP E CHROMOSOMES of the human chromosome classification.

The capability of bearing live young (rather than eggs) in nonmammalian species. Some species of REPTILES and FISHES exhibit this.

A species of nematode that is widely used in biological, biochemical, and genetic studies.

A group of GLYCOLIPIDS in which the sugar group is GALACTOSE. They are distinguished from GLYCOSPHINGOLIPIDS in lacking nitrogen. They constitute the majority of MEMBRANE LIPIDS in PLANTS.

An in situ method for detecting areas of DNA which are nicked during APOPTOSIS. Terminal deoxynucleotidyl transferase is used to add labeled dUTP, in a template-independent manner, to the 3 prime OH ends of either single- or double-stranded DNA. The terminal deoxynucleotidyl transferase nick end labeling, or TUNEL, assay labels apoptosis on a single-cell level, making it more sensitive than agarose gel electrophoresis for analysis of DNA FRAGMENTATION.

A species of the true toads, Bufonidae, found in South America.

Abnormal number or structure of the SEX CHROMOSOMES. Some sex chromosome aberrations are associated with SEX CHROMOSOME DISORDERS and SEX CHROMOSOME DISORDERS OF SEX DEVELOPMENT.

Age of the biological father.

Differential and non-random reproduction of different genotypes, operating to alter the gene frequencies within a population.

Slender, cylindrical filaments found in the cytoskeleton of plant and animal cells. They are composed of the protein TUBULIN and are influenced by TUBULIN MODULATORS.

The discharge of an OVUM from a rupturing follicle in the OVARY.

An adenine nucleotide containing one phosphate group which is esterified to both the 3'- and 5'-positions of the sugar moiety. It is a second messenger and a key intracellular regulator, functioning as a mediator of activity for a number of hormones, including epinephrine, glucagon, and ACTH.

Any liquid or solid preparation made specifically for the growth, storage, or transport of microorganisms or other types of cells. The variety of media that exist allow for the culturing of specific microorganisms and cell types, such as differential media, selective media, test media, and defined media. Solid media consist of liquid media that have been solidified with an agent such as AGAR or GELATIN.

A genus of SEA URCHINS in the family Arbaciidae. They have only one spheridium (stalked body) per ambulacral area (contains tube feet); most sea urchins have several spheridia per area.

The application of high intensity ultrasound to liquids.

A genus of SEA URCHINS in the family Strongylocentrotidae. They possess more than three pore pairs per ambulacral plate. The species STRONGYLOCENTROTUS PURPURATUS is commonly used for research.

The sum of the weight of all the atoms in a molecule.

Fluorescent probe capable of being conjugated to tissue and proteins. It is used as a label in fluorescent antibody staining procedures as well as protein- and amino acid-binding techniques.

An intermediate in the synthesis of cholesterol.

Proteins which are found in membranes including cellular and intracellular membranes. They consist of two types, peripheral and integral proteins. They include most membrane-associated enzymes, antigenic proteins, transport proteins, and drug, hormone, and lectin receptors.

The granulosa cells of the cumulus oophorus which surround the OVUM in the GRAAFIAN FOLLICLE. At OVULATION they are extruded with OVUM.