Delineations of forest fungi

Summary Several forest fungi, primarily species that occur in Mississippi, are discussed, and three species are described as new. These includeBotryobasidium (subgenusBrevibasidium)croceum Lentz,Tharoopama mississippiensis Lentz, andHarpographium zonatum Lentz.Dactylium leptosporum (Sacc.)Lentz is recognized as a distinct species, rather than as a subspecies ofD. dendroides Fr. Allescheriella crocea (Mont.)Hughes,D. leptosporum andMelanographium cookei M. B. Ellis are reported from Mississippi for the first time. Attention is called to the fact thatM. citri (Fragoso &Ciferri)M. B. Ellis apparently has not previously been reported from the United States, although a specimen from Florida is in the National Fungus Collections.B. croceum evidently represents the basidiophorous stage ofA. crocea.     

Purification of human renin substrate.

Renin substrate, angiotensinogen, has been purified from human plasma by methods which permit the processing of large amounts of outdated bank blood. The purified protein is homogeneous by disc gel electrophoresis at pH 9.5. The specific activity of 18 nmol/mg corresponds to a molecular weight of 56,000, while a higher value, 90,000, is found by gel filtration. Chromatography of partially purified renin substrate on DEAE-cellulose in a descending pH gradient shows evidence for the existence of multiple forms. However, some of these forms appear to be lost after chromatography on hydroxylapatite.     

Phosphatidylserine-Dependent Catalysis of Stalk and Pore Formation by Synaptobrevin JMR-TMD Peptide

Although the importance of a SNARE complex in neurotransmitter release is widely accepted, there exist different views on how the complex promotes fusion. One hypothesis is that the SNARE complex’s ability to bring membranes into contact is sufficient for fusion, another points to possible roles of juxtamembrane regions (JMRs) and transmembrane domains (TMDs) in catalyzing lipid rearrangement, and another notes the complex’s presumed ability to bend membranes near the point of contact. Here, we performed experiments with highly curved vesicles brought into contact using low concentrations of polyethylene glycol (PEG) to investigate the influence of the synaptobrevin (SB) TMD with an attached JMR (SB-JMR-TMD) on the rates of stalk and pore formation during vesicle fusion. SB-JMR-TMD enhanced the rates of stalk and fusion pore (FP) formation in a sharply sigmoidal fashion. We observed an optimal influence at an average of three peptides per vesicle, but only with phosphatidylserine (PS)-containing vesicles. Approximately three SB-JMR-TMDs per vesicle optimally ordered the bilayer interior and excluded water in a similar sigmoidal fashion. The catalytic influences of hexadecane and SB-JMR-TMD on fusion kinetics showed little in common, suggesting different mechanisms. Both kinetic and membrane structure measurements support the hypotheses that SB-JMR-TMD 1) catalyzes initial intermediate formation as a result of its basic JMR disrupting ordered interbilayer water and permitting closer interbilayer approach, and 2) catalyzes pore formation by forming a membrane-spanning complex that increases curvature stress at the circumference of the hemifused diaphragm of the prepore intermediate state.     

Die Nervenversorgung der Kaninchenmilz

Ohne ZusammenfassungInauguraldissertation der medizinischen Fakultät der Freien Universität Berlin.     

Delineations of forest fungi: Morphology and relationships of vararia

Summary Vararia belongs in a group of hymenomycetes characterized by non-xanthochroic basidiocarps in which gloeocystidia are formed rather regularly. Basidia and gloeocystidia originate at a relatively deep level in a catahymenium or hyphidial hymenium; thus they are overgrown by continuing development of the hyphal elements. As a result, they may become deeply submerged in the structure of the basidiocarp, together with embedded basidiospores. Dichohyphidia are formed as dichotomously-branched structures of limited growth. Although commonly subulate, dichohyphidia may show a considerable range of form even within a single basidiocarp. In Melzer's iodine reagent they commonly exhibit a dextrinoid reaction by becoming reddish brown. Hyphae of basidiocarps and cultures of some species have clamp-connections; those of other species lack clamps. Spores of the various species may be fusoid-ellipsoid, ellipsoid, globose, or cylindric, and may have either prominent or obscure amyloid ornamentation or may be apparently non-amyloid. Together with cultural characteristics such as the presence or absence of oedocephaloid conidiophores and various hyphal modifications, the hyphal and spore characteristics of the basidiocarp seem to present a potential basis for division ofVararia into several subgenera or generic segregates. The preceding considerations form the basis for a discussion of the position and relationships ofVararia within the Aphyllophorales.