ISSN:0022-3921    

DOI:10.1111/j.1550-7408.1961.tb01190.x

出版商:Blackwell Publishing Ltd    

年代:1961

数据来源: WILEY

摘要:

Intraspecific chemotaxis between gametes was demonstrated inChlamydomonas moewusiiGerloff var.rotundanov. var. which was previously used as C. sp. 24 (Tsubo Y. 1957). a heterothallic isogamous species from Japan. The reaction is unidirectional; the “+” gametes are attracted by the “—” gametes or cell‐free supernatant of medium in which the :“‐” gametes were suspended. In a study with 4 other isogamous heterothallicChlamydomonas — C. moewusiiGerloff,C. eugametosMoewus,C. reinhardiDangeard, andC. morewusiiGerloff var.tenuichlorisnov. var. — none of them revealed any intraspecific chemotactic behavior. However, as with the “—” gametes ofC. moewusiivar.rotunda, both mating types ofC. moewusii, C. eugametos, andC. moewusiivar.tenuichloriswere interspecifically attracted by the supernatant of the “—” culture of C.moewusiivar.rotunda. OnlyC. rein‐ hardishowed no chemotactic behavior in intra‐ or interspecific combinations.Although chemotaxis occurred in the above‐mentioaed combinations, neither agglutination nor pairing ner zygete formation followed at all in the same combinations. The“;–” cells ofC. moewusiivar.rotundakilled by osmium vaper and then washed no longer produced the chemotactic agent, but did agglutinate with living “+” cells. Therefore, evidently, chemo‐taxis is a separate step from agglutination and zygote‐for‐mation yet does not seem necessary in the mating of isoga‐mousChlamydomonas. Nonetheless, since this activity appears not in the vegetative but in the gametic stage, it seems to concern the sexual activity of the cells. In preliminary studies the chemotactic agent

ISSN:0022-3921    

DOI:10.1111/j.1550-7408.1961.tb01191.x

出版商:Blackwell Publishing Ltd    

年代:1961

数据来源: WILEY

摘要:

Seventy‐nine adult birds in 8 species were examined at autopsy for the presence ofTrypansoma avium.Films of thoracic blood were stained in Giemsa and later searched for trypanosomes. Marrow was removed from femora and humeri, mixed with Ringer's solution, and examined direct for living flagellates. Sixty‐four birds (81%) showed positive marrows; 5 (6%) had positive bloods. In the 15 birds with negative marrows, only 2 had trypanosomes in the blood. These data emphasize the advantage of marrow over blood examination in determining the incidence of avian trypanosomiasis and point up the excellence of fresh marrow examination in such stud

ISSN:0022-3921    

DOI:10.1111/j.1550-7408.1961.tb01192.x

出版商:Blackwell Publishing Ltd    

年代:1961

数据来源: WILEY

摘要:

The foed vacuoles ofParamecium aurelia, when examined in the electron microscope, are seen to be surrounded by small secondary vacuoles 0.05 ‐ 0.2 μ. in diameter. Similar small vacuoles also surround the deepest part of the buccal cavity. Young focd vacuoles,i.e.those containing well preserved bacteria, are encircled by a smooth. vacuolar membrane. In older food vacuoles the vacuolar membrane in a transverse section often appears more wavy with small gulfs and protuberances. It is suggested that the small surrounding vacuoles are formed by the vacuolar membrane of older vacuoles by means of a process similar to pinocytosis. There is no evidence, however, that formation of small surrounding vacuoles takes place by pinocytosis in young food vacuoles. Examination of the cytoplasmic membrane of the deepest parts of the buccal cavity shows a similar prccess of vacuole formation by pinocytos

ISSN:0022-3921    

DOI:10.1111/j.1550-7408.1961.tb01193.x

出版商:Blackwell Publishing Ltd    

年代:1961

数据来源: WILEY

摘要:

Six strains ofEntamoeba histolyticawere studied in an initial attempt to define some genetic characteristics. Sugar metabolism and drug sensitivity were the markers studied. The six strains showed little difference in characteristics and attempts to obtain mutations have been unsuccessful. The observed characeristics may be useful in helping to define the species.

ISSN:0022-3921    

DOI:10.1111/j.1550-7408.1961.tb01194.x

出版商:Blackwell Publishing Ltd    

年代:1961

数据来源: WILEY

摘要:

Eimeria leucopin. sp. (Sporozoa) is described from oocysts in the feces of the deer mousePeromyscus leu‐copus(Rafinesque) taken in the vicinity of Durham, North Carolina. The oocysts are ellipsoidal, occasionally ovoid, and rarely round, 14‐24 ± 14 ‐ 21 μ, mean of 19.2 ± 16.8 μ. Length‐width index 1.0 to 1.37, mean of 1.13. Micropyle absent. Oocyst wall composed of 2 layers. Clear residual bodies present. Sporocysts 11.5 ‐ 14.0 ± 6.5 ‐ 8.0 μ, mean 12 0 ± 6.8 μ Stieda body present. Minimum sporulation time about 74‐hours, sporulation range about 54 hours. Prepatent period 5 or 6 days with a 6 day patent period. Although the intensity of infection was light in all naturally infected hosts, the incidence of infection ranged from 16.6 to 71.9%E. leucopicould not be transferred to the sympatric go

ISSN:0022-3921    

DOI:10.1111/j.1550-7408.1961.tb01195.x

出版商:Blackwell Publishing Ltd    

年代:1961

数据来源: WILEY

摘要:

Tritrichomonas foetus, Pentatrichomonas gallinarum, and nasal and fecal forms ofTrichomonas suisgrew well in NIH Thioglycollate Broth with 1% beef serum, and produced acid end‐products. Succinic acid was the major acid produced byT. foetus P. gallinarum, and the nasalT. suis, accounting for over 50% of the total acid for each. The fecalT. suisproduced more lactic than succinic acid; about 45% of the total acid was not accounted for. Pyruvic acid was found in small amounts in all cultures. The lactic/pyruvic ratio was about 2.5 for the two swine forms, and about 1.0 for the other two. The nasal form ofT. suisproduced much more total acid than the others.O2uptake, CO2production, H2evolution, and anaerobic acid formation varied with age of organism. Respiratory activity was highest at 12 hours but varied considerably thereafter. The nature of the buffer used in manometric experiments also affected the results.Glucose, mannose, fructose and galactose most stimulated respiration. Disaccharides were slowly utilized (lactose and sucrose were not used byP. gallinarum). In a few cases lactate, pyruvate, formate, and malate stimulated O2uptake.Evidence was obtained for hexokinase, phosphohexoisomer‐ase, phosphofructokinase, aldolase, and glucose‐6‐phcsphate dehydrogenase in all 4 organisms. Phosphoglucomutase was demonstrated inT. foetusand the fecalT. suis. T. foetusandP. gallinarumshowed evidence of phosphoglyceromutase and enolase.T. suis(fecal) andP. gallinarumhad malic dehydrogenase, andP. gallinarumgave evidence of “malic enzyme” activity. Formic dehydrogenase activity was marked in all and presumptive evidence for a formic hydrogenlyase system was obtained forT. foetusandP. gallinarum.Study of reactions involving pyruvate and malate (with a possible linkage to a hexose monophosphate shunt) might perhaps provide a key to a better understanding of trichmonad

ISSN:0022-3921    

DOI:10.1111/j.1550-7408.1961.tb01196.x

出版商:Blackwell Publishing Ltd    

年代:1961

数据来源: WILEY

摘要:

A microsporidian infection in a laboratory clone ofHydra littoralishas been observed, and the parasite has been tentatively identified as a species ofPlistophora. Infected hydra continue to bud and regenerate normally and show no significant physiological or morphological changes. Sexual crossing of infected and non‐infected animals shows that the infection is transmitted by the ovum but not by the sperm. Continuous exposure of infected hydra to Fumidil B in solution resulted in the disappearance of allPlistophoraspores after a five week period of treatment, and the clones of the treated animals have remained parasite‐free for more than a y

ISSN:0022-3921    

DOI:10.1111/j.1550-7408.1961.tb01197.x

出版商:Blackwell Publishing Ltd    

年代:1961

数据来源: WILEY

摘要:

Oxidative assimilation of acetate byEuglena graciliswas studied using methyl‐ and carboxyl‐labeled radioactive acetate. Of the total carbon utilized, 40% was oxidized to CO2and 60% was assimilated; 20% of the CO2produced was derived from the methyl carbon, and 80% from the car‐boxyl carbon of acetate. Seventy % of the carbon assimilated was derived from the methyl carbon and 30% from the carboxyl. The results suggest that assimilation involves decarboxylation of Krebs‐cycle oxalacetate and assimilation of the resulting pyruvate.In the presence of ethanol a greater proportion of the acetate carbon is assimilated, though the total acetate consumption is almost un

ISSN:0022-3921    

DOI:10.1111/j.1550-7408.1961.tb01198.x

出版商:Blackwell Publishing Ltd    

年代:1961

数据来源: WILEY

摘要:

Four species ofParamecium, P. calkinsi, P. mul‐timicronucleatum, P. bursaria, andP. trichium, were treated in the following way. Counted numbers (100 or 200) were irradiated with X‐rays in 2 ml air‐tight Nylon syringes in steps of 50,000 r begining with this dosage and extending up to at least 450,000 r. For each experiment, the four different species were irradiated simultaneously each in one syringe. Survival and reproduction were then followed for at least 48 hours by expressing irradiated specimens from the syringes into spot plates.P. trichiumwas the most radiosensitive and recovery and reproduction occurred only after the lower dosages.P. calkinsiwas the most radioresistant and showed relatively fast recovery and reproduction even after moderately high dosages. With certain high dosages, reproduction was blocked temporarily for 24‐30 hours, after which there was not only recovery from irradiation but a gradually in creased reproductive rate. The greater the dosage, the slower the recovery to reproductive

ISSN:0022-3921    

DOI:10.1111/j.1550-7408.1961.tb01199.x

出版商:Blackwell Publishing Ltd    

年代:1961

数据来源: WILEY