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

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

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

The process of germ cell development in the male from the primordial germ cells, through SPERMATOGONIA; SPERMATOCYTES; SPERMATIDS; to the mature haploid SPERMATOZOA.

Mature male germ cells derived from SPERMATIDS. As spermatids move toward the lumen of the SEMINIFEROUS TUBULES, they undergo extensive structural changes including the loss of cytoplasm, condensation of CHROMATIN into the SPERM HEAD, formation of the ACROSOME cap, the SPERM MIDPIECE and the SPERM TAIL that provides motility.

Movement characteristics of SPERMATOZOA in a fresh specimen. It is measured as the percentage of sperms that are moving, and as the percentage of sperms with productive flagellar motion such as rapid, linear, and forward progression.

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

17 beta-Hydroxy-1 alpha-methyl-5 alpha-androstan-3-one. A synthetic steroid with anabolic and androgenic activities.

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.

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.

Congenital conditions of atypical sexual development associated with abnormal sex chromosome constitutions including MONOSOMY; TRISOMY; and MOSAICISM.

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.

Brominated hydrocarbons are organic compounds containing carbon (C), hydrogen (H) atoms, and bromine (Br) atoms, where bromine atoms replace some or all of the hydrogen atoms in the hydrocarbon structure.

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 condition characterized by the dilated tortuous veins of the SPERMATIC CORD with a marked left-sided predominance. Adverse effect on male fertility occurs when varicocele leads to an increased scrotal (and testicular) temperature and reduced testicular volume.

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 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.).

Procedures to obtain viable sperm from the male reproductive tract, including the TESTES, the EPIDIDYMIS, or the VAS DEFERENS.

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.

Short tracts of DNA sequence that are used as landmarks in GENOME mapping. In most instances, 200 to 500 base pairs of sequence define a Sequence Tagged Site (STS) that is operationally unique in the human genome (i.e., can be specifically detected by the polymerase chain reaction in the presence of all other genomic sequences). The overwhelming advantage of STSs over mapping landmarks defined in other ways is that the means of testing for the presence of a particular STS can be completely described as information in a database.

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.

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).

Actual loss of portion of a chromosome.

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

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).

Pathological processes of the TESTIS.

Mapping of the KARYOTYPE of a cell.

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

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)

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

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.

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

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

Abnormal genetic constitution in males characterized by an extra Y chromosome.

Male germ cells derived from the haploid secondary SPERMATOCYTES. Without further division, spermatids undergo structural changes and give rise to SPERMATOZOA.

Specific regions that are mapped within a GENOME. Genetic loci are usually identified with a shorthand notation that indicates the chromosome number and the position of a specific band along the P or Q arm of the chromosome where they are found. For example the locus 6p21 is found within band 21 of the P-arm of CHROMOSOME 6. Many well known genetic loci are also known by common names that are associated with a genetic function or HEREDITARY DISEASE.

A type of male infertility in which no germ cells are visible in any of the biopsied SEMINIFEROUS TUBULES (type I) or in which germ cells are present in a minority of tubules (type II). Clinical features include AZOOSPERMIA, normal VIRILIZATION, and normal chromosomal complement.

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)

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

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

Pathological processes involving the male reproductive tract (GENITALIA, MALE).

In vitro method for producing large amounts of specific DNA or RNA fragments of defined length and sequence from small amounts of short oligonucleotide flanking sequences (primers). The essential steps include thermal denaturation of the double-stranded target molecules, annealing of the primers to their complementary sequences, and extension of the annealed primers by enzymatic synthesis with DNA polymerase. The reaction is efficient, specific, and extremely sensitive. Uses for the reaction include disease diagnosis, detection of difficult-to-isolate pathogens, mutation analysis, genetic testing, DNA sequencing, and analyzing evolutionary relationships.

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.

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

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

A variation from the normal set of chromosomes characteristic of a species.

A developmental defect in which a TESTIS or both TESTES failed to descend from high in the ABDOMEN to the bottom of the SCROTUM. Testicular descent is essential to normal SPERMATOGENESIS which requires temperature lower than the BODY TEMPERATURE. Cryptorchidism can be subclassified by the location of the maldescended testis.

An assisted reproductive technique that includes the direct handling and manipulation of oocytes and sperm to achieve fertilization in vitro.

Either of a pair of tubular structures formed by DUCTUS DEFERENS; ARTERIES; VEINS; LYMPHATIC VESSELS; and nerves. The spermatic cord extends from the deep inguinal ring through the INGUINAL CANAL to the TESTIS in the SCROTUM.

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

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.

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 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.

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

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

Removal and pathologic examination of specimens in the form of small pieces of tissue from the living body.

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

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

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

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

A genetic rearrangement through loss of segments of DNA or RNA, bringing sequences which are normally separated into close proximity. This deletion may be detected using cytogenetic techniques and can also be inferred from the phenotype, indicating a deletion at one specific locus.

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.

The stage in the first meiotic prophase, following ZYGOTENE STAGE, when CROSSING OVER between homologous CHROMOSOMES begins.