(n.) A special cell in certain cryptogamous plants containing oospheres, as in the rockweeds (Fucus), and the orders Vaucherieae and Peronosporeae.
Example Sentences:
(1) This immunocytochemical evidence supports the hypothesis that the DNA of the inactive X-chromosome of the human 17-week gestation oogonium is methylated.
(2) In situ nucleic acid hybridization showed that the synthesis of nucleolar DNA begins in oogonium and proceeds slowly through leptotene and zygotene when a small amount of extrachromosomal nucleolar DNA is produced.
(3) These vesicles (V1) are formed originally in unfertilized eggs by smooth endoplasmic reticulum (SER) after release of the eggs from the oogonium.
(4) In connection with this, it is suggested that the term "oogonium" (which is used to designate such cells in the literature) be retained only for proliferating i-cells containing finely filamentous nuclear material in the cytoplasm in the genital zone of the hydra.
(5) In this way, in vitro development from oogonium to larva has been maintained for several generations.
(6) P. diclinum (synonymous with P. gracile sensu Middleton) showed minor differences in vesicle, oospore and oogonium size from P. destruens.
(7) Prior to meiosis in triploid gynogenetic all-female forms of Poeciliopsis, the chromosome number of the nucleus of the triploid oogonium is raised endomitotically to hexaploid.
Sac
Definition:
(n.) See Sacs.
(n.) The privilege formerly enjoyed by the lord of a manor, of holding courts, trying causes, and imposing fines.
(n.) See 2d Sack.
(n.) A cavity, bag, or receptacle, usually containing fluid, and either closed, or opening into another cavity to the exterior; a sack.
Example Sentences:
(1) Both apertures were repaired with great caution using individual sutures without resection of the hernial sac.
(2) Tracheal mucus transport rate (TMTR) and quantitative clearance of aerosolized Escherichia coli from the trachea, lung, and air sac were measured in healthy unanesthetized turkeys and in turkeys exposed by aerosol to a La Sota vaccine strain of Newcastle disease virus (NDV).
(3) The wall of the yolk sac thickens as a result of this infolding and the densely packed capillaries.
(4) After intravenous or dorsal lymph sac injections of 3H-22:6, most of the retinal label was seen in rod photoreceptor cells.
(5) The buccal glands of adults of the Southern Hemisphere lamprey Geotria australis consist of a pair of small, bean-shaped, hollow sacs, embedded within the basilaris muscle in the region below the eyes and to either side of the piston cartilage.
(6) Ultrastructural examination of noncartilaginous regions of the tumor demonstrated mesenchymal cells with features suggestive of cartilaginous differentiation, viz, scalloped cell membranes, sac-like distension of abundant rough endoplasmic reticulum, and a matrix containing fibrillary and finely granular material.
(7) On the other hand, esophageal emptying of solid isotopic meals may show the persistence of food in the diverticular sac long time after the meal.
(8) Both genes are expressed in the fetal liver, gut, and visceral endoderm of the yolk sac and are repressed shortly after birth in the liver and gut.
(9) The in vitro absorption by rat jejunal and ileal gut sacs of soluble antigen-antibody complexes and of antigen alone was compared.
(10) In two almost identical experiments, all OTC treatment groups had significantly lower mean air sac lesion scores than the unmedicated challenged controls.
(11) After clusters of pigmented epithelial cells have rested immobile in the yolk sac of Blennius pholis for 2-4 days (Trinkaus, '88), their constituent cells transform into mesenchymal, dendritic melanocytes.
(12) The patient, a 28-year-old woman, in her ninth week of pregnancy, was operated on for stage Ia, mixed germ cell tumor (grade 3 immature teratoma + yolk sac tumor) of AFP decreased to the normal level.
(13) Using the experimental model of the everted sac prepared from rat jejuna, kinetic studies on [14C]oleic acid uptake from bile salt micelles were conducted in the presence and absence of phosphatidylcholine.
(14) Cadmium, anti-visceral yolk sac antibody (AVYS) and trypan blue all inhibited pinocytosis in a concentration-dependent fashion when added to the culture medium, although at low concentrations trypan blue was slightly stimulatory.
(15) In each rabbit, a single fetal sac was opened, the umbilical vessels were cannulated and the placenta was perfused in situ with buffered Krebs solution containing Dextran.
(16) Although small amounts of AFP are synthesized by sharks in the liver, the greatest site of synthesis is actually the stomach, with smaller amounts synthesized in the intestinal mucosa; no synthesis was observed in the shark yolk sac.
(17) A stem cell line has been obtained with cell culture, having a germ cell character and a yolk sac configuration.
(18) We postulate that the apposition of trophotaenial epithelium to the internal ovarian epithelium constitutes a placental association equivalent to a noninvasive, epithelioform of an inverted yolk sac placenta.
(19) In vivo recirculating perfusion (n = 5) and in vitro everted sac incubation (n = 8) were employed.
(20) In the second hypertrophied form [Type II], the endoplasmic reticulum is very prominent and occurs as a series of grossly dilated sacs of irregular shape.