Eimeria (Protozoa: Eimeriidae) of the Cottontail Rabbit Sylvilagus audubonii in Northeastern Colorado, with Descriptions of Three New Species

SYNOPSIS. All of 100 cottontail rabbits Sylvilagus audubonii were found to be infected with 1-6 species of Eimeria. Three new species, E. audubonii, E. neoirresidua and E. poudrei are described from this host. Sub-spherical oocysts of E. audubonii average 21.2 by 17.1 μ; polar body, micropyle, oocyst residuum and sporocyst residuum are all absent; ellipsoidal sporocysts average 12.9 by 5.8 μ. Ovoid to ellipsoidal oocysts of E. neoirresidua average 25.7 by 17.9 μ; polar body and oocyst residuum are absent; micropyle and sporocyst residuum are present; ellipsoidal sporocysts average 14.5 by 6.4 μ. Ovoid to ellipsoidal oocysts of E. poudrei average 26.0 by 18.1 μ; polar body is lacking; micropyle, oocyst residuum and sporocyst residuum are present; ellipsoidal sporocysts average 14.4 by 6.4 μ. Three species of Eimeria previously described in the literature, E. maior Honess, 1939, E. media form honessi Carvalho, 1943 and E. environ Honess, 1939 are redescribed. A detailed structural and statistical analysis of each species is presented with at least 200 sporulated oocysts measured in each instance. A host list and a key to the Eimeria of cottontails is given. The use of detailed studies of oocyst size and structure as a tool for specific diagnosis of the Eimeria of cottontails is discussed.     

Starch Metabolism, Respiration, and Shoot Formation in Tobacco Callus Cultures

The starch content of shoot-forming and non-shoot-forming tobacco callus cultured in light and darkness was determined. A variety of carbohydrates and cytokinins incorporated into the culture medium were effective in bringing about starch accumulation and shoot formation in the tissue. In addition, the respiratory activity of the callus, grown in the presence or absence of gibberellic acid, was measured. A strong correlation between the starch content of the tissue, its rate of respiration, and shoot formation was observed.     

C-Type Virus associated with Gibbon Lymphosarcoma

C-TYPE viruses have been established as the causal agents of leukaemia in murine and feline species and have been characterized^1,2. C-type virus is also probably associated with fibrosarcoma in non-human primates^3–6. To determine whether viruses with identical characteristics are associated with other neoplasms in simian species, we looked for C-type viruses in cases of leukaemia. A gibbon (Hylobates lar) with a disseminated tumour (later confirmed as lymphosarcoma) was made available to the Comparative Oncology Laboratory by Dr Malcolm Jones of the University of California, San Francisco Medical Center. The principal sites of involvement (lymph node, liver and bone marrow) were extensively overrun with massive neoplastic cells, which were predominantly prolymphocytic forms. Electron microscopy revealed C-type particles identical to those observed in vitro in sections from lymph nodes, liver, spleen and bone marrow.     

A Cotyledonary Inhibitor of Root Nodulation in Pisum sativum

Root nodule formation was studied in 11-day-old seedlings of Pisum sativum L. cv. Alaska, which were inoculated with Rhizobium leguminosarum at the time of planting. On intact plants an identical nodulation pattern was observed in the lateral roots attached to the two xylem strands connected to the cotyledons. When one cotyledon was removed before germination, however, a highly significant increase in nodultion was observed on the lateral roots attached to the xylem strand which no longer was connected to a cotyledon. Excision of one cotyledon also caused an alteration in the radial location of root nodules on the primary root. Under these conditions there was a distinct promotion of nodular proliferations in the root cortex opposite the primary phloem poles. The fact that removal of one cotyledon increased nodulation on the lateral roots but had no effect on the rhizobial infection of lateral root hairs suggested that a cotyledonary inhibitor acts at a step between the infection process and the appearance of a macroscopic nodule. The data were interpreted in terms of an inhibitor of cortical cell division which is translocated from the cotyledons to the developing root via the phloem.     

The Function(s) of Bird Song

Male bird song may attract and stimulate females and may repelmales, but the evidence that song is essential for accomplishingthese "main functions" is not abundant. Correlations betweenmale song traits (such as repertoire size or singing rate) andcomponents of fitness reveal that important information, perhapsabout overall male quality, is available for listeners. To determinewhether birds use that information, however, will require researchersto manipulate song traits independently of male quality. Havingthen determined more rigorously the "current utility" of song,we will more clearly be able to infer how selection has shapedparticular song traits. We envision progress in understandingthe function(s) of bird song if investigators 1) thoroughlydescribe natural events, 2) use lucidly stated, multiple workinghypotheses, 3) realize the potential differences in song functionamong divergent taxonomic units, 4) transcend correlationalstudies by doing ingenious manipulative experiments, and 5)reason carefully when developing scenarios of evolutionary origin.     

Two-Dimensional Gel Mapping and N-Terminal Sequencing of LMW-Glutenin Subunits

Low-molecular-weight glutenin subunits from the wheat (Triticumaestivum L.) cultivar ‘Chinese Spring’ were mappedusing two dimensional electrophoresis (isoelectric focusingversus SDS-polyacrylamide gel electrophoresis). Protein spotswere electroblotted on to polyvinylidene difluoride membraneand characterized by N-terminal amino acid sequencing. Mostof the proteins that had accessible N-termini gave sequencesin agreement with known sequences for low-molecular-weight glutenins,-type gliadins, and -type gliadins. Two variants which havenot been seen in direct sequencing before were found. The gluteninstarting material was also reduced, alkylated, and partiallyfractionated by reverse-phase high performance liquid chromatography.Sequencing of these fractions, each of which contained a mixtureof proteins, confirmed the presence of the glutenin variantsfound in the spot sequencing. Key words: Glutenin, electroblotting, amino acid sequences     

Non‐trophic effects of oribatid mites on cord‐forming basidiomycetes in soil microcosms

1. Saprotrophic cord‐forming basidiomycetes are the primary agents of decomposition in forest ecosystems. Collembola and oribatid mites affect fungal growth and foraging, and therefore decomposition, through direct mycelial grazing. 2. Grazing on the fungal species Hypholoma fasciculare, Resinicium bicolor and Phanerochaete velutina by the collembola Folsomia candida, and the oribatid mites Steganacarus magnus, Euzetes globulus and Hermannia gibba was investigated in soil microcosms. 3. Folsomia candida grazed on all fungal species: radial extent of R. bicolor, hyphal coverage of all fungal species, and fractal dimension of R. bicolor and P. velutina were all reduced. Oribatid mites did not graze the fungi but did affect mycelial morphology. Steganacarus magnus caused a reduction in the radial extent of H. fasciculare, and the hyphal coverage and fractal dimension in both H. fasciculare and R. bicolor. Euzetes globulus and H. gibba reduced the hyphal coverage of P. velutina. 4. Oribatid mites are associated with a cornucopia of chemical secretions with possible anti‐fungal properties. Chemical analysis of H. gibba opisthonotal secretions revealed four main compounds, all of which are new to the known spectrum of opisthonotal components. The most abundant was (E)‐β‐farnesene. 5. Treatment effects were species‐specific in terms of both fungal and invertebrate species. This study provides the first evidence of non‐grazing effects of oribatid mites on fungal growth and morphology. This could potentially influence the spatial organisation of mycelium in forest soils and therefore the ability of fungi to locate, colonise and decompose dead organic matter.     

Carbon Sources for Polytomella caeca

SUMMARY. The colorless phytomonad, Polytomella caeca , has been grown in simple media with each of the following as the sole energy source: propionate, butyrate, valerate; butyl and amyl alcohols; DL-glyceraldehyde, and alpha-ketoglutaric acid. These compounds did not support growth in simple media: caproate, caprylic acid, isobutyrate, propyl, isopropyl and isobutyl alcohols. At present, C₅, seems to be the limit of length of the fatty acids that are suitable carbon and energy sources. Iso compounds were not utilized. The pH in the acid media increased during incubation; that in alcohol media decreased.