(1) Mature sporangia comprised about 30% of the total, were usually unilamellar, 100-400 microns in diameter, and contained a mixture of immature and mature endospores.
(2) The most recently discovered species, Enterocytozoon bieneusi, is known only from the small intestinal enterocytes of patients with the acquired immunodeficiency syndrome, and is easily differentiated from other microsporidia by the precocious development of spore organelles in the sporont and by the poor development of the endospore layer of the spore wall.
(3) Electron microscopic examination of these mutants revealed that these mutations blocked endospore formation at an early stage before septation and caused extensive cell lysis.
(4) More importantly, we tested and verified the hypothesis that there is a relationship between concentrations of dormant, viable endospores of T. vulgaris in lake sediments and the extent of agriculture in the catchments of the lakes.
(5) They were, therefore, shown to be aleuriospores (microcondia), and not endospores.
(6) Male ICR mice were challenged intracerebrally with endospores of Coccidioides immitis and then treated with water (control), fluconazole, amphotericin B (Fungizone), or ketoconazole (Nizoral).
(7) These, in contrast to exospores of the majority of the actinomycetes, are endospores according to their structure and the following criteria: thermostability, the presence of dipicolinic acid, the structure of ultrathin cross-sections studied by electron microscopy, the resistance to novobiocin.
(8) During the process of endospore formation in Bacillus subtilis the appearance of the mother-cell transcription factor sigma K by conversion from its inactive precursor pro-sigma K is coupled to events under the control of the forespore transcription factor sigma G. This intercompartmental coupling is believed to be mediated by the products of a sporulation locus called spoI V F because certain bypass-of-forespore (bof) mutations that map at the spoI V F locus relieve the dependence of pro-sigma K processing on the action of sigma G in the forespore.
(9) The spherule-endospore cycle was maintained in tissue culture medium for 84 days without the formation of detectable hyphae.
(10) Gene expression during endospore formation by Bacillus subtilis is controlled in part by a sporulation-induced form of RNA polymerase, E sigma 29.
(11) The sequential appearance of sigma subunits, which change the promoter recognition specificity of RNA polymerase, may have a key role in controlling the temporal pattern of gene expression required for endospore development in B. subtilis.
(12) Chemical analyses showed that the amount of protein present in vegetative cells of the rifampicin-treated cultures was twice as great as in the untreated cultures but the total protein content of endospores was the same in both cases.
(13) This chitinase, isolated from 48-h culture filtrate of the spherule-endospore-phase C. immitis by affinity adsorption to chitin, formed a line of identity with the IDCF reference antigen and participated in the complement fixation reaction with human serum.
(14) Terminally located, heat-resistant endospores were formed on plates of an enriched agar medium supplemented with L-rhamnose.
(15) The relative abundance of endospores and vegetative cells as well as the protein distributions of these subpopulations may be readily determined from flow microfluorometry data.
(16) A new species, Bacillus naganoensis, is proposed for an obligately aerobic, moderately acidophilic, endospore-forming bacterium that produces a thermostable, aciduric pullulanase (EC 3.2.1.41).
(17) Deletion of sigE, the structural gene for the sporulation-induced RNA polymerase sigma factor, sigma E, prevented endospore formation by Bacillus subtilis.
(18) Because these obligate bacterial parasites of nematodes have not been cultured axenically, the taxonomic relationships described here for each species are based mainly on developmental morphology, fine structure of the respective sporangia and endospores, and their pathogenicity on nematode species.
(19) The results suggest that the crystal and endospore contain one or more common proteins.
(20) Cells were formed, which resembled bacterial endospores by their formation and structure; however, typical refractive spores with envelopes and cortex have not been detected.
Exospore
Definition:
(n.) The extreme outer wall of a spore; the epispore.
Example Sentences:
(1) These, in contrast to exospores of the majority of the actinomycetes, are endospores according to their structure and the following criteria: thermostability, the presence of dipicolinic acid, the structure of ultrathin cross-sections studied by electron microscopy, the resistance to novobiocin.
(2) Cell differentiation in non-sulphur purple bacteria is complicated, as compared to binary fission, during bud formation with production of hyphae and special resting cells of the exospore type, and can be demonstrated in the folowing series of microorganisms: Rhodopseudomonas sulfidophila leads to Rh.
(3) Spores were typical of Amblyospora, being ovoid when fresh, truncate when stained, and having an exospore of two membranous layers subtended by a thick amorphous layer, an electron-lucent endospore, an anisofilar polar filament, and a polaroplast comprised of an anterior region of close-packed lamellae and a posterior region of expanded sacs.
(4) Each spore contains a single nucleus, a polar tubule with four to nine coils, thin electron-dense exospore and thick, electron-lucent endospore.
(5) Each spore was surrounded by a thin, electron-dense exospore; a thick electron-lucent endospore; and a thin cell membrane.
(6) Exospore smooth or undulate, 170 to 310 nm thick, endospore 60 to 160 nm.
(7) The spores averaged 1 x 1.5-2.0 microns, had six to eight polar filament coils, displayed monokaryotic nuclei, and possessed relatively thick endospores with irregularly shaped exospores.