(n.) A small membranous bladder or tube in which are inclosed the seedlike reproductive particles or sporules of lichens and certain fungi.
Example Sentences:
(1) Fungi of the class Pyrenomycetes (Ascomycotina) form a morphological series ranging from those that shoot ascospores (sexual spores) forcibly from the ascus (spore sac) to fungi that ooze ascospores or have no obvious mechanism for ascospore release.
(2) Our results suggest that once the cells are fully derepressed no mitochondrial genetic information has to be expressed during meiosis and ascus formation.
(3) Although growth of two yeast strains characterized by consistent production of two diploid spores per ascus was inhibited in complex presporulation media containing amitrole, a fraction of the cells produced were able to form asci with more than two spores after transfer to acetate sporulation medium.
(4) Due to the characteristic shape of the ascus and ascospores, T. burgeffiana is to be considered a synonym of M. pulcherrima.
(5) Although the rna mutants do not regulate ribosome synthesis during sporulation, all of these diploid strains fail to complete sporulation at 34 degrees C. The cells are arrested after the second meiotic nuclear division but before ascus formation.
(6) strains develop normally to the stage of ascus formation.
(7) The selected hybrids, which carried the greater part of the parental genetic markers and produced asci containing 2,3 and 4 spores per ascus, were placed on sporulation medium.
(8) 2 x n X2 tests showed that frequencies of individual ascus classes from different perithecia were generally homogeneous, as were second division segregation frequencies.
(9) The proportion of spindle overlap and recombinational asci within the group did not change as shown by ascus dissection.
(10) It was demonstrated that the production of less than four spores per ascus in this yeast is not the result of a lack of meiotic products but of the nonutilization of nuclei from meiosis.
(11) The forespores then elongate, close off, and become separated from the ascus cytoplasm by membranes.
(12) The mechanical force responsible apparently originates from the formation of an ectoplasmic mucilage capable of exerting pressure over all of the ascus contents; when the apex of the peduncle ruptures, the ascospores are violently released.
(13) When partially repressed cells were treated with EthBr, no ascus formation was observed after transfer to sporulation medium.
(14) In fungi that produce an ascus containing four spores, a gene conversion event is manifested as 3:1 or 1:3 (or more rarely 4:0 or 0:4) segregations, in contrast to the normal mendelian 2:2 segregation.
(15) The increase in spore numbers per ascus is attributed either to the induction by amitrole in growth medium of cells with more than one nucleus or to the restoration of normal meioses in the multispored asci.
(16) On the basis of mode of ascus formation and ascospore morphology it is included in the genus Metschnikowia Kamienski as a new species, M. lunata.
(17) Ascus formation occurs after isogamous copulation between sexual protuberances which develop at the ends of arthrospores or between two cells, adjacent mycelial cells, or arthrospores.
(18) Ascus formation in Debaryomyces hansenii includes fusion of two cells, usually mother and daughter while still attached to each other, through short protuberances developed from the cross wall between them.
(19) Metschnikowia australis can be differentiated from other Metschnikowia species and varieties by its inability to form chlamydospores, the formation of two needle-shaped ascospores per ascus, lack of glucose fermentation, and lack of assimilation of both methyl-alpha-D-glucoside and glucono-delta-lactone.
(20) Amitrole treatment causes multispored ascus production by cells of a yeast strain whose asci normally contain two diploid spores.
Spore
Definition:
(n.) One of the minute grains in flowerless plants, which are analogous to seeds, as serving to reproduce the species.
(n.) An embryo sac or embryonal vesicle in the ovules of flowering plants.
(n.) A minute grain or germ; a small, round or ovoid body, formed in certain organisms, and by germination giving rise to a new organism; as, the reproductive spores of bacteria, etc.
(n.) One of the parts formed by fission in certain Protozoa. See Spore formation, belw.
Example Sentences:
(1) After absorption of labeled glucose, two pools of trehalose are found in dormant spores, one of which is extractable without breaking the spores, and the other, only after the spores are disintegrated.
(2) The dose response initially resembled that described by Scholer (1959) in which one million spores killed the majority of mice.
(3) Abnormal synaptonemal complexes were seen in all 19 crosses of N. crassa and N. intermedia that were examined, including matings between standard laboratory strains, inversions, Spore killers, and strains collected from nature.
(4) The mutant spores are pleomorphic and differ both in shape and size from the wild-type spores.
(5) The results presented here substantiate the hypothesis that in S. cerevisiae trehalose supplies energy during dormancy of the spores and not during the germination process.
(6) The fungicidal activity of six rabbit neutrophil cationic peptides (NP) against resting (dormant) spores, preincubated (swollen) spores, and hyphae of Aspergillus fumigatus and Rhizopus oryzae was examined.
(7) In the electron microscope large aggregates of beta glycogen particles were seen in the cytoplasm of sporoplasm cells in mature spores.
(8) The spore germination was synchronized by selection of the spores of the definite size and maintenance at a temperature of 0 degrees.
(9) GAD activity appeared in mutant spores after germination and increased to levels comparable to parent spores after 9 min of germination.
(10) The Ca++-form and H+-form spores of Clostridium botulinum 33A were investigated in vivo with respect to their water sorption and heat-resistance characteristics.
(11) Salt concentrations slightly lower than those providing inhibition tended to extend spore outgrowth time at low temperatures.
(12) The AL spores and the GN spores were morphologically distinct.
(13) Studies demonstrated the fact that there are present within the malignant cell and in the immediate area bacterial spores arising from one of several varieties of plant bacteria.
(14) The stages observed were diplokaryotic cells, sporogonial plasmodia, unikaryotic sporoblasts, and spores.
(15) The rod-shaped organism was motile, did not form spores, and had a gram-negative wall structure.
(16) Numerous factors influenced its activity: method of spore production, inherent spore resistance characteristics, alkalination, storage time and storage temperature.
(17) The inoculum level of infected spores in nutrient broth-yeast extract-glucose medium affected the transducing efficiency of SP-10 in lysates of these cultures.
(18) It can be dissociated from the spores using divalent metal chelators and will reassemble on the spores in the presence of calcium.
(19) Stable messenger ribonucleic acid (mRNA) was shown to be involved in both enterotoxin synthesis and synthesis of other spore coat proteins in Clostridium perfringens.
(20) Effects of alpha- or beta-D-glucose on the respiration of germinated spores (only germinated spores not including swollen spores and elongated spores) of Bacillus subtilis and B. megaterium were studied.