(n.) The male germ cell in animals and plants, the essential element in fertilization; a microscopic animalcule-like particle, usually provided with one or more cilia by which it is capable of active motion. In animals, the familiar type is that of a small, more or less ovoid head, with a delicate threadlike cilium, or tail. Called also spermatozoon. In plants the more usual term is antherozoid.
Example Sentences:
(1) The spermatozoid content of DNA was analyzed using the Feulgen staining method and the relative content of histone proteins by the Alfert and Geschwind staining method.
(2) The presence of antibodies against spermatozoids was considered as an important factor associated with AIDS and previous states of the AIDS detected by OKT8 greater than 30% of lymphocytes.
(3) The authors analyzed in 196 sterile women the ovulation mucus by the microagglutination test and found a high anti-spermatozoidal activity in 24 (12%) women.
(4) The predominant cytologic features were granulomatous inflammation (nontuberculous and non-foreign body) and spermatozoids (intrahistiocytic or as extracellular spermatic debris).
(5) The Hynie method was observed to have some advantages over other methods: it is easy to apply and provides exact data which are useful in determining spermatozoidal deficiencies in sterility cases.
(6) In animals of both subgroups the spermatozoid concentration in the epididymal suspension was lowered and the relative content of spermatozoids with morphologically abnormal heads in suspension smears was increased.
(7) The microtubules on the outside of the nucleus of the mature spermatozoid of Pteridium form a complex with the envelope, and the perinuclear space is eliminated.
(8) A relationship between transferrin and spermatozoid concentration in sperm was shown.
(9) This membrane also undergoes growth, the outer layer extending into the cytoplasm and surrounding spermatozoid mitochondria.
(10) This layer may be important in preventing other spermatozoids from fusing with the egg.
(11) Similarly, the incubation of spermatozoids obtained from the tail of the epididymis with CPhM causes them to produce only 7% fertilization, instead of the normal rate of 80%.
(12) The prognosis depends on the alterations seen on the sperm count parameters; but there is no threshold figure under which no pregnancy is observed (except for zero), concerning the count, the gradual mobility or the morphology of the spermatozoids.
(13) The quantitative yield is given for DNA and RNA preparations from the mentioned objects, the molecular weight of roach and bream DNA, nucleotide composition of roach DNA as well as fractional composition of bream spermatozoids RNA are determined.
(14) The ultrastructure of the mature spermatozoid of Marsilea vestita was studied after its release from the microspore and prior to its penetration of the egg.
(15) After spermatozoid penetration, a new extracellular layer appears above the surface of the egg, beginning in the region of sperm penetration and spreading across the top of the egg.
(16) Changes in the nucleus and the cytoplasm of both the spermatozoids and spermatides were revealed at the early stages of their formation.
(17) Circadian rhythm of activity of 3H-leucine incorporation into antheridial cells of Chara vulgaris, in natural photoperiod was compared with changes in mitotic activity of antheridial filament cells which form spermatozoids.
(18) Any abnormality often severely compromises the ability to fertilize spermatozoids.
(19) The various criteria of the sperm count then examined, emphasizing the importance of studying the morphology, on optical as well as electron microscopy, since it is the spermatozoid's morphology as well as their mobility that differentiate fertile man from infertile ones.
(20) is fertilized by small biflagellate spermatozoids and both monoecious and dioecious species are found.
Zooid
Definition:
(a.) Pertaining to, or resembling, an animal.
(n.) An organic body or cell having locomotion, as a spermatic cell or spermatozooid.
(n.) An animal in one of its inferior stages of development, as one of the intermediate forms in alternate generation.
(n.) One of the individual animals in a composite group, as of Anthozoa, Hydroidea, and Bryozoa; -- sometimes restricted to those individuals in which the mouth and digestive organs are not developed.
Example Sentences:
(1) 5-HT antigenicity in the postpharyngeal commissure indicates the initiation of the development of a new zooid.
(2) At the onset of takeover (T = 3 hr), B3F12.9 immunostaining became diffuse or absent at the anterior end, which paralleled the axis of contraction of the dying zooid, whereas the posterior end retained its labeling integrity.
(3) The latter process is similar to the degeneration of old individuals, or zooids, that precedes maturation of each new generation of asexual buds.
(4) The rate of cell fission was retarded in colchicine-containing media, but nevertheless short-stalked colonies with apparently normal zooids were formed.
(5) Site-specific reactions were also observed in larval tail muscle and the siphon muscles of postmetamorphic zooids.
(6) Here we describe a monoclonal antibody (B3F12.9) that recognizes a novel 57 Kd polypeptide (under reducing conditions) localized to the perivisceral extracellular matrix (PVEM) of buds and zooids, as well as blood cells of Botryllus by immunofluorescence and immunogold labeling of tissue sections.
(7) Here we describe comparisons of in vitro reactions of a) mixtures of cells from allogeneic animals and b) cells taken from animals at the zooid-resorption ("takeover") stage of colony development.
(8) Botryllus schlosseri is a colonial ascidian whose asexually derived, clonally modular systems of zooids exhibit developmental synchrony.
(9) The capsule of the dormant bud has some structural features in common with the black stolon of the adult zooids.
(10) A second impulse was recorded from individual zooids, probably generated by the polypide's nervous system.
(11) The colonial tunicate Botryllus schlosseri undergoes cyclic blastogenesis where feeding zooids are senescened and resorbed and a new generation of zooids takes over the colony.
(12) They form the probable route of transfer of yolk from the zooids to the dormant bud.
(13) These findings indicate that takeover is a dynamic process in which extracellular matrix breakdown proceeds in a polarized fashion, beginning at the anterior end of each zooid and gradually propagating toward the posterior end.
(14) In many attributes, these various junctions are more similar to those found in the tissues of vertebrates, than to those in the invertebrates, which the adult zooid forms of these lowly chordates resemble anatomically.
(15) The neoblast and mitosis distributions in the daughter zooid during its asexual reproduction cycle duplicate those observed in the maternal zooid.
(16) No larvae metamorphosed into oozooids with situs inversus viscerum, but in this study two oozooids extruded blastozooids showing this anomaly; these blastozooids budded "reversed" zooids in turn, so that entire clonal lines showed the anomaly.
(17) Under 2,000 rads some of the irradiated zooids within this type of union started to regenerate, and at 1,000 rads no resorption was recorded, even though the number of zooids decreased in the irradiated part.
(18) During their active feeding phase, zooids exhibited a uniform labeling pattern of PVEM along their anteroposterior (A-P) axis.
(19) With doses of 3,000-4,000 rads and above, irradiation arrested the formation of new buds and interrupted normal takeover, turning the colony into a chaotic bulk of vessels, buds, and zooid segments.
(20) During the first few days after fission, the number of neoblasts decreases in the portion of the body immediately adjoining the site of daughter zooid detachment and considerably increases in the regenerative bud.