Culture and reproductive systems of 11 species of Mycetozoans

The culture and reproductive systems of 10 species (16 isolates) of myxomycetes and one species (one isolate) of protostelid were investigated. A single isolate of Ceratiomyxa fructiculosa was grown on agar and found to be nonheterothallic. This is the first report of spore-to-spore cultivation of this species and the first report of a reproductive system in the protostelids. Isolates of the myxomycetes Didymium dubium, Didymium iridis, Didymium vaccinum, Licea biforis, Perichaena vermicularis, Physarum gyrosum, Physarum pusillum (six isolates) and Semimorula liquescens all were nonheterothallic. This is the first report of culture and a reproductive system for D. vaccinum, the first report of nonheterothallism for S. liquescens and the second report of nonheterothallic isolates of D. dubium, Licea biforis, Perichaena vermicularis and P. gyrosum. The nonheterothallic isolate of D. iridis is one of many reported for this species, and the six nonheterothallic isolates of P. pusillum add to the seven nonheterothallic and two heterothallic isolates already known. In addition, five of the isolates of P. pusillum apparently represent a small form that is adapted to an ephemeral micohabitat, and the sixth is a yellow form of a species that is typically white. The Didymium ?ovoideum isolate and the two Physarum didermoides isolates have heterothallic reproductive systems. The D. ?ovoideum isolate is somewhat different from most isolates of this species in its morphology and reproductive system. It is not compatible with any of the heterothallic isolates of long-stalked Didymium, including the A0 biological species already determined for D. ovoideum; therefore, it is either a new biological species of D. ovoideum or a separate new species. The two heterothallic isolates of P. didermoides form a multiple allelic mating-type series with four alleles.     

Inheritance, biochemical abnormalities, and clinical features of feline mucolipidosis II: the first animal model of human I-cell disease

Mucolipidosis II (ML II), also called I-cell disease, is a unique lysosomal storage disease caused by deficient activity of the enzyme N-acetylglucosamine-1-phosphotransferase, which leads to a failure to internalize enzymes into lysosomes. We report on a colony of domestic shorthair cats with ML II that was established from a half-sibling male of an affected cat. Ten male and 9 female kittens out of 89 kittens in 26 litters born to clinically normal parents were affected; this is consistent with an autosomal recessive mode of inheritance. The activities of three lysosomal enzymes from affected kittens, compared to normal adult control cats, were high in serum (11-73 times normal) but low in cultured fibroblasts (9-56% of normal range) that contained inclusion bodies (I-cells), reflecting the unique enzyme defect in ML II. Serum lysosomal enzyme activities of adult obligate carriers were intermediate between normal and affected values. Clinical features in affected kittens were observed from birth and included failure to thrive, behavioral dullness, facial dysmorphia, and ataxia. Radiographic lesions included metaphyseal flaring, radial bowing, joint laxity, and vertebral fusion. In contrast to human ML II, diffuse retinal degeneration leading to blindness by 4 months of age was seen in affected kittens. All clinical signs were progressive and euthanasia or death invariably occurred within the first few days to 7 months of life, often due to upper respiratory disease or cardiac failure. The clinical and radiographic features, lysosomal enzyme activities, and mode of inheritance are homologous with ML II in humans. Feline ML II is currently the only animal model in which to study the pathogenesis of and therapeutic interventions for this unique storage disease.     

Plasma electrolyte and metabolite concentrations associated with pentobarbital or pentobarbital-propofol anesthesia during three weeks' mechanical ventilation and intensive care in dogs

Propofol and pentobarbital were used for deep sedation during prolonged mechanical ventilation (3 weeks) and nutritional supplementation in 17 clinically normal dogs in an intensive care setting. Tolerance developed to both drugs. Propofol, in combination with pentobarbital, at an infusion rate of 75 micrograms/kg of body weight per minute was preferred. Pentobarbital infusion alone, begun at the rate of 5 to 6 mg.kg-1.h-1, was satisfactory. The combination of both drugs provided smooth, stable anesthesia and required minimal interventions by intensive care unit personnel. Blood gas tensions and electrolyte, parathyroid hormone (PTH), and metabolite concentrations were generally stable throughout, unless condition of the dog deteriorated (e.g., infection, pneumothorax). Hematocrit and red blood cell count decreased with time, likely attributable principally to multiple blood sample collections. White blood cell count, alkaline phosphatase, phosphate, fibrinogen, cholesterol, and triglyceride values increased with time, in association with pentobarbital and the combination of pentobarbital and propofol. Some of these changes appear to have been related to generic responses to stress and inflammation, some to altered metabolism, and some to the lipid solvent of propofol. The increase in triglyceride concentration was greater when propofol was used. Mortality was 47%, with death occurring between days 2 and 18.     

Phylogeny of the genus trichoderma based on sequence analysis of the internal transcribed spacer region 1 of the rDNA cluster

Sequences of the internal transcribed spacer region 1 (ITS1) of the ribosomal DNA were used to determine the phylogenetic relationships of species of Trichoderma sect. Pachybasium. To this end, 85 strains-including all the available ex-type strains-were analyzed. Parsimony analysis demonstrated that the section is nonmonophyletic, distributing the 85 strains among three main groups that were supported by bootstrap values. Group A comprises two clades (A1 and A2), with A1 including T. polysporum, T. piluliferum, and T. minutisporum, while A2 included T. hamatum, T. pubescens, and T. strigosum in addition to species previously included in sect. Trichoderma (i.e., T. viride, T. atroviride, and T. koningii). The ex-type strain of T. fasciculatum formed a separate branch basal to clade A. Clade B contained the sect. Pachybasium members T. harzianum, T. fertile, T. croceum, T. longipile, T. strictipile, T. tomentosum, T. oblongisporum, T. flavofuscum, T. spirale, and the anamorphs of Hypocrea semiorbis and H. cf. gelatinosa. Sequence differences among clades A1, A2, and B were in the same order of magnitude as between each of them and T. longibrachiatum, which was used as an outgroup in these analyses. Sequence differences within clades A1, A2, and B were considerably smaller: in some cases (i.e., T. virens and T. flavofuscum; T. strictipile and H. cf. gelatinosa), the ITS1-sequences were identical, suggesting conspecifity. In other cases (e.g., T. crassum and T. longipile; T. harzianum, T. inhamatum, T. croceum, T. fertile, and H. semiorbis; T. hamatum and T. pubescens; and T. viride, T. atroviride, and T. koningii) differences were in the range of 1-3 nt only, suggesting a very close phylogenetic relationship. The sequence of a previously described aggressive mushroom competitor group of T. harzianum strains (Th2) was strikingly different from that of the ex-type strain of T. harzianum and closely related species and is likely to be a separate species. Copyright 1998 Academic Press.     

A study on the amoebo-flagellate transformation in the slime moldEchinostelium minutum de Bary

Summary The structure and behavior of the non-flagellate and flagellate phases of the slime moldEchinostelium minutum de Bary are here described from living cultures examined with phasecontrast microscopy. The ultrastructure of the myxamoebal and swarm cell phases was studied in sectioned material fixed sequentially with glutaraldehyde-acrolein and OsO₄.The nearly spherical myxamoeba has two pairs of juxtanuclear centrioles with associated microtubular arrays. During the amoebo-flagellate transformation each pair of centrioles assumes an anterior position in the cell and becomes arranged at right angles to one another within a cone of microtubules. This microtubular cytoskeleton extending under the plasmalemma establishes the twisted, narrowly ovoid form of the swarm cell. Each centriole functions potentially as a basal body. When transformed in phosphate buffer pH 6.8 at 12 °C and a cell concentration of 5×10⁵/ml, the myxamoebae develop 1 to 8 flagella. The average number of flagella per swarm cell is 2.7. After approximately 2 hours the swarm cells begin to revert to myxamoebae by resorption of their flagella. The phylogenetic implications of these light and ultrastructural observations are discussed with regard to possible evolutionary relationships between theProtostelia andMyxomycetes.     

Induction of diabetes in nonobese diabetic mice by Th2 T cell clones from a TCR transgenic mouse

We have produced a panel of cloned T cell lines from the BDC-2.5 TCR transgenic (Tg) mouse that exhibit a Th2 cytokine phenotype in vitro but are highly diabetogenic in vivo. Unlike an earlier report in which T cells obtained from the Tg mouse were cultured for 1 wk under Th2-promoting conditions and were found to induce disease only in NOD.scid recipients, we found that long-term T cell clones with a fixed Th2 cytokine profile can transfer disease only to young nonobese diabetic (NOD) mice and never to NOD.scid recipients. Furthermore, the mechanism by which diabetes is transferred by a Tg Th2 T cell clone differs from that of the original CD4+ Th1 BDC-2.5 T cell clone made in this laboratory. Whereas the BDC-2.5 clone rapidly causes disease in NOD.scid recipients less than 2 wk old, the Tg Th2 T cell clones can do so only when cotransferred with other diabetogenic T cells, suggesting that the Th2 T cell requires the presence of host T cells for initiation of disease.