(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.
Zygospore
Definition:
(n.) Same as Zygosperm.
(n.) A spore formed by the union of several zoospores; -- called also zygozoospore.
Example Sentences:
(1) Zygospore development in Blakeslea trispora was studied using light microscopy, scanning electron microscopy, transmission electron microscopy and freeze fracturing technique.
(2) However, normal mating efficiencies and high zygospore viability are observed in clonal culture, indicating the unbiased production of functional opposite mating-types.
(3) The zygospore contained a very high concentration of chitin (about 17%), three times more than the mycelial concentrations.
(4) Some of these non-recombinant individuals may be derived from "parthenospores" (dormant asexual cells resembling zygospores).
(5) In order to study the mechanism responsible for the uniparental transmission of the mitochondrial genome in crosses between Chlamydomonas reinhardtii and C. smithii, we have analyzed the fate of mitochondrial DNA during gametogenesis, zygospore differentiation and sporulation by hybridization experiments.
(6) In strain 137F of Chlamydomonas reinhardi, the zygospores undergo one round of nuclear DNA replication followed by three divisions to produce octospores.
(7) The young diploid zygote differentiates into dormant zygospore competent to complete meiosis, or more rarely (2-10% of cases) it undergoes mitosis to produce a stable diploid progeny.
(8) Using appropriate restriction enzymes, we have been unable to detect methylation of the mitochondrial DNA during gametogenesis or zygospore formation.
(9) Light is required for total elimination of mt+ mitochondrial DNA in the zygospores.
(10) Changes in the relative abundance of cell constituents of Entomophthora virulenta Hall & Dunn were studied during the various differentiation phases leading to the formation of zygospores.
(11) Zygophores interlock upon contact and then undergo six successive morphological changes to become a zygospore.
(12) Some zygospores do form in crosses of carA mutants and wild types.
(13) Zygospores from this strain undergo two rounds of nuclear DNA replication prior to the formation of octospores.
(14) The results obtained with D. discoideum macrocysts differ from those obtained with other cellular slime moulds--Dictyostelium mucoroides, Dictyostelium giganteum and Polysphondylium pallidum--and are reminiscent of the results reported for germinated zygospores of Phycomyces blakesleeanus.
(15) Descriptions and illustrations of both the zygosporic and sporangial states are presented.
(16) Almost all of the heat-tolerant isolates were pathogenic to suckling mice and had smooth or undulate, or smooth plus undulate zygospore walls.
(17) Although zygospore (mature zygote) formation in P. blakeslleeanus occurs in liquid glucoseglutamate medium, morphological observations are made more easily when cultures are grown on 1-mm-thick agar medium.