(n.) A special kind of spore resulting from the fertilization of an oosphere by antherozoids.
(n.) A fertilized oosphere in the ovule of a flowering plant.
Example Sentences:
(1) Encapsulated sexual stages (oospores), held at 23-26 degrees C for up to 35 days or frozen for 8-10 days, were infective to mosquito larvae for up to 48 days after immersion in water and during that time over 50% of the oospores germinated.
(2) Enrichment of the phospholipid fraction of total cell lipid of P. ultimum with unsaturated fatty acids promoted oospore induction, and enhanced levels of unsaturated fatty acids in the neutral lipid fraction increased oospore viability.
(3) The rates of development of Lagenidium giganteum were determined in the four larval instars of Culex quinquefasciatus Say held at 15, 20, 25, 27, 30, and 34 degrees C. The fastest development was in second instars held at 34 degrees; vesicles and oospores occurred in 50% of the larvae (the median development time) 19.7 and 25.0 h, respectively, after infection.
(4) The greatest median time to the formation of vesicles was in third instars at 15 degrees C (185.6 h) and for oospores was in second instars at 15 degrees C (152.3 h).
(5) The fungus did not form oospores in fourth instars at 15 degrees C. The median developmental rates of vesicles and oospores in each instar were fit to the Sharpe & DeMichele model, which may be used to predict the effects of different temperatures on the in-vivo developmental rate of the fungus.
(6) For some pythiaceous fungi, the levels of sterols required for the maturation of oospores with appropriate phospholipid medium supplementation suggest that these compounds are necessary only for the sparking and critical domain roles previously described in other fungi.
(7) The antheridial protoplast migrates through a pore in the adjacent wall and fuses with the oogonial protoplast to produce a thick-walled reticulate oospore.
(8) quinquefasciatus at 6-7 days after treatment while encapsulated oospores gave 100% control at 11 days posttreatment.
(9) The formation of oogonia, antheridia, and oospores also occurred.
(10) Oospores which were desiccated in the field following application provided consistently high larval infection levels after reflooding of the fields.
(11) aphanidermatum and P. myriotylum grew from mycelium on GAM, but their oospores did not germinate nor could they be isolated from soilon this medium.
(12) This species produces echinulate, spherical oospores.
(13) The fungus is rapidly cleared from mice following intraperitoneal injection of large quantities of mycelium and oospores.
(14) Induction and maturation of the sexual stage (oospores) of the facultative mosquito parasite Lagenidium giganteum (Oomycetes: Lagenidiales) are complex developmental processes regulated by calcium-dependent events.
(15) Enrichment of the polar and neutral lipid fractions of the LGCA and LGBS strains with unsaturated fatty acids promoted oospore induction, and increased oospore viability.
(16) A calcium chelator (EGTA), an ionophore (chlortetracycline), and inhibitors of the calcium-binding protein calmodulin (dibucaine, trifluoperazine, chlorpromazine) disrupted several discrete developmental steps associated with oosporogenesis: induction of antheridia, gametangial fusion, meiosis, oospore wall formation, and subsequent spore maturation.
(17) P. oligandrum oospores germinated abundantly when host species were present.
(18) A third isolate of this mosquito pathogen, the North Carolina strain (LGNC), requires sterols plus phospholipids to produce oospores in vitro.
(19) The requirement for an exogenous source of sterols for sexual reproduction by several members of the Pythiaceae has been questioned by reports of apparent induction and maturation of oospores on defined media supplemented with phospholipids in the absence of sterols.
(20) Using developmentally synchronized cultures of Lagenidium giganteum (Oomycetes: Lagenidiales), a facultative parasite of mosquito larvae, it has been documented that oxidative lipid metabolism is necessary for the induction and subsequent maturation of its sexual stage, the oospore.
Sporangium
Definition:
(n.) A spore case in the cryptogamous plants, as in ferns, etc.
Example Sentences:
(1) This "belt," usually first observed toward the center of the sporangium, developed without changing thickness or appearance over the surface of the forespore.
(2) It is proposed that simple, eucarpic, monocentric chytrids which discharge zoospores following dissolution of the sporangium wall evolved into multipapilliate species of Rhizophydium and 2 lines of evolution from these species are documented with examples.
(3) The cytoplasmic sporangium cleavage is brought about by the fusion of flagellar sheaths and cleavage vesicles.
(4) The mature resting sporangium (RS) wall of Coelomomyces dodgei (Chytridiomycetes; Blastocladiales) consists of three principal layers: (I) an outer pigmented layer (1.8-2.2 microns) that contains polysaccharide, (II) a middle electron translucent layer (1.3-1.6 microns) comparatively free of polysaccharide, and (III) an inner layer (125 nm) rich in polysaccharide that surrounds the meiospores.
(5) By inference, the sporulation division septum locus is distal to the ultimate normal cell division septum, i.e., proximal to the "old" pole of the B. megaterium sporangium.
(6) With the progress of spore encapsulation, the tyrocidine production migrated from the soluble fraction into the forespore, terminating with the separation of forespores from the sporangium membrane.
(7) Similarity of these bodies to sporangium-like structures is suggested.
(8) Using a transcriptional fusion of the spoIVC gene to the lacZ gene of Escherichia coli, we found that spoIVC expression was turned on at the third to fourth hour of sporulation (at about the developmental stage [IV] that its products are required in spore formation) and that this transcription was largely restricted to the mother cell chamber of the sporangium.
(9) However, a decrease in bacterial toxicity occurred with sporangium lysis.
(10) The transcriptional activity of the two genomes of the sporangium during spore formation was determined by pulse-labeling bacteria with 3H-uracil at different times of sporulation and preparing them for high resolution autoradiography.
(11) It was placed into group 3 of the genus Bacillus on the basis of its cellular morphology, the morphology of the sporangium, and the location of the spore within the cell.
(12) This suggests that the selective incorporation into the sporangium of either the "older" or "younger" chromosome of a vegetative cell does not occur in the course of spore formation.
(13) To investigate whether expression of spoIIM is required in the forespore compartment of the sporangium, we have constructed a new integrational vector, pKSV7, which contains temperature-sensitive replication functions derived from pE194ts.
(14) The electronmicroscopic examination of the colony revealed sporangium containing spores and characteristic dense body and plastids in the spores.
(15) The ability of Achlya to incorporate [1-14C]acetate into lipid was maximal at the time of sporangium formation, and glycerides were the principal component of total lipid to become 14C-labelled at all stages of the life cycle.
(16) The transcellular electric current apparently plays no role in sporangium formation or in spore cleavage.
(17) The peritumoural region of a squamous cell carcinoma of the tongue when examined with light and electron microscope showed nodular bodies in the submucosa with all the distinctive features of 'sporangium and 'spores' of rhinosporidiosis.
(18) A septum within each sporangium divides the forespore from the basal or parasporal portion of the cell.
(19) Sporulation in Bacillus subtilis is a simple developmental system in which a single cell undergoes differentiation to two 'sister' cells, namely the prespore and the sporangium.
(20) Subsequently, the young cell elongates, becomes somewhat deformed, and then emerges through a narrow aperture in the inflexible coats of the spore, finally rupturing the sporangium.