摘要:

ABSTRACTDuring spring and autumn, the total number of amoebae and the number ofAcanthamoebaspecies able to grow at 37°C were determined in six thermally polluted factory discharges and the surrounding surface waters. The isolatedAcanthamoebastrains were studied for growth in axenic medium, cytopathic effect in Vero cell cultures, and virulence in mice. Although more amoebae were isolated in autumn, the number ofAcanthamoebaspecies was lower than in spring, when the percent of pathogenic strains among the isolates was highest. Higher concentrations of amoebae were found in warm discharges, and more virulent strains occurred in thermal discharges than in surface waters

ISSN:0022-3921    

DOI:10.1111/j.1550-7408.1981.tb02804.x

出版商:Blackwell Publishing Ltd    

年代:1981

数据来源: WILEY

摘要:

ABSTRACTThe endogenous development ofEimeria christenseniwas studied in 10 two‐ to four‐week‐old kids inoculated with 106‐107sporulated oocysts. They were killed at intervals from two to 26 days after inoculation, and their tissues were examined for endogenous stages of the coccidian by light microscopy. Such stages were found in the small intestine and mesenteric lymph nodes. In the sexual cycle, two generations of meronts were found. The first generation developed in endothelial cells of lacteals in the jejunun and ileum and mesenteric lymph nodes, and mature meronts were first seen 14 days after inoculation. The second generation developed in epithelial cells of the glands of Lieberkuehn in the jejunum and ileum and in mesenteric lymph nodes, and its mature meronts were first seen by 16 days. Sexual stages were present mostly in epithelial cells of the tips and sides of the villi and less frequently in crypt cells of the jejunum and ileum. Mature macrogametes and microgamonts and oocysts were also first seen by 16 days. The prepatent period was 17 (14‐23) days; the patent ranged from 8 to more than 30 days. Sporulation time was 3‐4 days at 30°C.E. christenseniwas found to be pathogenic, kids inoculated with 1‐5 × 105sporulated oocysts exhibited the following signs: severe diarrhea, anorexia, polydipsia, poor hair coat, and extreme weakness. They recovered about a month later, but their growth rates appeared to be lower than those of uninoculated animals kept under the same conditions. One kid died 20 days after inoculation

ISSN:0022-3921    

DOI:10.1111/j.1550-7408.1981.tb02805.x

出版商:Blackwell Publishing Ltd    

年代:1981

数据来源: WILEY

摘要:

ABSTRACTStocks of theTetrahymena pyriformiscomplex have been collected in North America and their mating reactivity has been studied. In addition to stocks mating withTetrahymena americanis, T. borealis, T. pigmentosa, T. hyperangularis, andT. australis, stocks belonging to old syngen 5 and three new mating groups, numbers 13, 14, and 15, were discovered. Syngen 5 and groups 13 and 14 are distinct “biological” species, based on their reproductive isolation from other groups and on the ability of withingroup crosses to produce immature progeny. These species have been namedT. hegewischin. sp.,T. sonnebornin. sp., andT. nipissingin. sp., respectively. The cross between the two group 15 stocks did not produce immature progeny, and there is not sufficient evidence to conclude that this pair of stocks represents a separate species. Temperature tolerance measurements have been made on stocks representing all known micronucleate members of “pyriformis” complex. Within each species, the range of temperature tolerances is narrow; the average within‐species standard deviation is 0.63°C. The species averages range from 32.7 to 40.7°C. Using syngen numbers, the order from lowest to highest temperature tolerance is 9, 8, 10, 7, 6, 4, 13, 14, 12, 11, 5, 3, 2, 1. The large differences among species make temperature tolerance a useful aid in identification, but the origins of the differences among species

ISSN:0022-3921    

DOI:10.1111/j.1550-7408.1981.tb02806.x

出版商:Blackwell Publishing Ltd    

年代:1981

数据来源: WILEY

摘要:

ABSTRACTIn its amoeboid stage,Protacanthamoeba caledonican. g., n. sp. closely resembles the genusAcanthamoeba, on both light‐ and electron‐microscopical levels, including possession of a centrosphere with a plaque‐shaped centriole‐like body. The cyst wall differs from that ofAcanthamoebain lack of preformed exit pores and in fine structure; the occasional apparent division into exocyst and endocyst is due to irregular splitting. The strain isolated from a Scottish estuary did not grow at 37°C and did not grow normally on agar made with 25% sea water, but cysts remained viable after a week in full‐strength sea water.Protacanthamoeban. g. is distinguished fromAcanthamoebaon the basis of cyst structure, but it is assigned to the family Acant

ISSN:0022-3921    

DOI:10.1111/j.1550-7408.1981.tb02807.x

出版商:Blackwell Publishing Ltd    

年代:1981

数据来源: WILEY

摘要:

ABSTRACTPhytomonas davidi(Trypanosomatidae) possesses typical trypanosomatid organelles: subpellicular microtubules, kinetoplast‐mitochondrial complex, K‐DNA, and four subflagellar pocket microtubules. A greater concentration of subpellicular microtubules was observed in the latex forms than in those found in the salivary glands of its insect vector. Only in the latex flagellates (the stage with postnuclear torsion) were subpellicular microtubules interconnected by crossbridges observed. Morphology and development of mitochondrial aristae varied according to the source of the flagellates. Organisms taken from culture medium had extensively developed plate‐like cristae; sparse tubular cristae were observed in the latex forms; and highly developed tubular cristae were seen in flagellates from the lumen of the vector's salivary glands, though organisms in the salivary gland channels had few or

ISSN:0022-3921    

DOI:10.1111/j.1550-7408.1981.tb02808.x

出版商:Blackwell Publishing Ltd    

年代:1981

数据来源: WILEY

摘要:

ABSTRACTThe ultrastructure ofRhodomonas lacustriswas examined using scanning and transmission electron microscopy, and the pigments were scanned in vivo by the opal plate technique. The periplast is composed of hexagonal plates, with trichocysts at the corners. This cryptomonad lacks a gullet but has a deep ventral furrow, in which more than 20 large ejectosomes are located. The chloroplast has mainly three thylakoids per lamella, and it is structurally reminiscent of that of certain haptophycean flagellates. The pigments appear to be as usual within the photosynthetic cryptomonads, with phycoerythrin type PE I (phycocyanin was not detected). Other cellular inclusions (e.g., lysosome‐like vesicles and the contractile vacuolar complex) are also discusse

ISSN:0022-3921    

DOI:10.1111/j.1550-7408.1981.tb02809.x

出版商:Blackwell Publishing Ltd    

年代:1981

数据来源: WILEY

摘要:

ABSTRACTThe somatic cortex ofSpathidium spathulais described ultrastructurally. The pellicle consists of an outer membrane and an underlying alveolar system. Numerous membrane‐bound mucocysts and spherical electron‐opaque bodies have similar circular sites of attachment to the outer membrane. Below these are a microfibrillar zone and an underlying region of rough ER. Mitochondria are lined up under the rough ER in longitudinal cortical ridges. Parasomal sacs are found near the basal bodies and are associated with cytoplasmic membranous sacs. Various microtubular and fiber systems are associated with single basal bodies: (1) a short kinetodesmal fiber; (2) two transverse microtubular ribbons and a transverse fiber; (3) a postciliary microtubular ribbon, initially sandwiched by two fibers, which gives rise to longitudinal subpellicular microtubules extending posteriorly for a distance of some four or five basal bodies; and (4) a system of overlapping subkinetal microtubules. A three‐dimensional reconstruction is included. The somatic cortex ofS spathulais similar to that reported for other Haptorida of the ciliate subclass Gymnost

ISSN:0022-3921    

DOI:10.1111/j.1550-7408.1981.tb02810.x

出版商:Blackwell Publishing Ltd    

年代:1981

数据来源: WILEY

摘要:

ABSTRACTTriplet conjugants ofParamecium multimicronucleatum, in each of which the third cell unites by its anterior and to a posterior part of one of the conjugating pair, are induced by conjugation inducing chemicals, KCl and acriflavine in a Ca11‐poor condition. If the triplets are prematurely transferred to medium free of such chemicals, the third cells usually separate and no macronuclear fragmentation occurs in them. But in third cells of long lasting triplets, macromuclear fragmentation regularly begings at ∼12 In after chemical treatment Staluhzaton of cell union and determmation of macronuclear fragmentation occured between ∼100 and ∼130 min after initiation of chemical treatment. Electron‐microscopic observation of the stabilized third cell revealed that the two cell membranes at the uniting region were partially fused to form cytoplasmic bridges. Chemically treated cells began to cases feeding before the cell union and fully ceased such activity at ∼130 min after th

ISSN:0022-3921    

DOI:10.1111/j.1550-7408.1981.tb02811.x

出版商:Blackwell Publishing Ltd    

年代:1981

数据来源: WILEY

摘要:

ABSTRACTStages of mitosis of the micronuclei ofStentor coeruleuswere described as seen by transmission electron microscopy. Cells in division and those regenerating new oral membranelles were studied. Microtubules were found in early prophase in the karyoplasm and interspersed between the condensing chromatin. A monaxial intranuclear spindle is formed by early metaphase, with kinetochore microtubule attachment sites on the chromosomes. The spindle elongates, separating the daughter nuclei at anaphase. A new nuclear envelope, consisting of two unit membranes, begins to form at late anaphase. Small segments of membrane found in the space between the newly forming and the old micronuclear envelopes appear to fuse to form the new nuclear envelope. No ultrastructural differences were found in the mitotic nuclei of cells in division or regeneration.

ISSN:0022-3921    

DOI:10.1111/j.1550-7408.1981.tb02812.x

出版商:Blackwell Publishing Ltd    

年代:1981

数据来源: WILEY

摘要:

ABSTRACTFollowing conjugation in ciliates, the usual fate of the old pre‐conjugant macronucleus is resorption. In some species, however, old macronuclei, or their fragments, have the ability to reform functional vegetative macronuclei when new macronuclear anlagen are defective. The present work onEuplotesshows that if anlagen are allowed to carry out their essential roles in early exconjugant development, including influence on cortical reorganization such that feeding can resume, they can then be permanently damaged by UV‐microbeam irradiation and regeneration of old macronuclear fragments can occur.E. aediculatusexconjugants were anlage‐irradiated at 40–60 hr of development and the irradiated cells cultured individually and fed. Squashes revealed enlargement and anteriorward migration of the persistent (posterior) macronuclear fragments. The first post‐conjugant fission of such cells was delayed (times ranged 6–43 days) and did not seem to involve the damaged anlagen, which remained rudimentary, did not divide along with the cells, and were subsequently resorbed. It appeared that cell fission was supported by the fragments of the old macronuclei, which either divided or partitioned themselves between the two daughter cells. Mating tests performed on early clones derived from irradiated exconjugants revealed ample conjugation competence; intraclonal conjugation in such clones was also apparent. The absence of the immature period seen in normal exconjugants provides further evidence that the clones arose from cells with regenerated

ISSN:0022-3921    

DOI:10.1111/j.1550-7408.1981.tb02813.x

出版商:Blackwell Publishing Ltd    

年代:1981

数据来源: WILEY