1985 - Mycological Society of America

36
protein synthesis followed by a slight increase
(to 30% of control levels) at the time that heat
shock proteins were detected. When proteins from
500 mM KC1-dissociated ribosomes from 32~-labeled
control (28'C) and heat-shocked (37.C) cells were
analysed by SDS gel electrophoresis and autoradiography,
several major changes in the phosphorylation
of ribosome-associated proteins were seen.
A basic 30 Kd small ribosomal subunit protein highly
phosphorylated in controls exhibited markedly
decreased 32~-labelling after heat shock. This
protein may be analogous to mammalian ribosomal
protein S6. In those ribosomes which were stable
in 500 mM KC1, however, decreased labelling of the
30 Kd protein during heat shock was not detected.
This observation suggests that changes in ribosomal
protein phosphorylation may be different in
ribosomes active in protein synthesis and in those
which are inactive. Heat shock also induced a
marked increase in the 32~-labelling of a 32 Kd
protein and a marked decrease in the 32p-labslling
of a 50 Kd protein. These proteins may be
initiation or elongation factors and their
modification may be involved in the rapid changes
observed in the rate of protein synthesis during
heat shock.
(Supported by NSERC, Canada)
Pekkala, D., see Silver, J. C.
Pendergrass, L, see Frederick, L., et. al.
J. C. PENDLAND and D. G. BOUCIAS. Department
of Entomology and Nematolo@y, University of Florida,
Gainesville, FL 32611.
Lectin-binding characteristics of several
entomogenous hyphomycetes.
The hyphomycetous insect pathogens, Nomuraea
rileyi, Paecilowces farinosus - ATCC 2b319,
Meta~hizium anisopliae and Beauveria bassiana were
tested with FITC labeled lectins. Concanavalin A,
specific for glucose and mannose residues, bound to
cell walls (hyphal body and/or mycelium) of all
fungi examined. Soybean and wheat germ agglutinins
(affinities for 8-acetylgalactosamine and
N-acetylglucosamine, respectively) bound
inconsistently to some cell wall areas.
Peanut
agglutinin, specific for galactose residues, bound
to walls of only 2. farinosus and B. bassiana.
Knowledge of the composition of fungal surface
residues may be important with respect to insect
defense mechanisms against the invading cells.
Lectins produced by insects (e-g. Anticarsia
gemmatalis) are known to be specifically inhibited
by galactose (or higher concentrations of glucose).
Fungal cells (P. farinosus, E. bssiana)a which
bear exposed galactose residues as detected by
FITC peanut agglutinin appear to be especially
efficient in removing hemagglutination activity
from Anticarsia hernolymph indicating absorption of
this insect lectin to fungal surfaces.
J. L PITT, K. A. WHEELER and A. D. HOCKING. CSIRO
Divn of Food Research, P.O. Box 52, North Ryde N.S.W.
2113, Australia Fungi from Indonesian dried fish
Involvement in a project on fish drying in the tropics provided
the opportunity to survey the occurrence of spoilage
and other fungi in salted and dried fish in Indonesia
About 50 samples of a variety of fish types have been examined.
As was to be expected, Eurotium and Aspergillus
species were frequently encountered. Other results were
surprising, for example the total absence of the I1dunt1
mould Wallemia sebi, traditionally regarded as the principal
cause of spoilage of salt fish Equally unexpected was
that the dominant spoilage fungus was an undescribed species,
which we have named Polypaecilum w. Other significant
spoilage fungi included Eurotium spp, Aspergillus
penicilloides and Basipetospora halophila (= Scopulariopsis
halophilica). The number and variety of Penicillia encountered
from a tropical environment was also surprising, and
these included several new species. Known mycotoxigenic
fungi were isolated only in low numbers. Preliminary
studies on factors influencing growth of these fungi, especially
water activity, temperature and NaCl concentration,
will also be discussed.
J. POMMERVILLE, K. HARDING, and B. STRICKLAND.
The Departments of Biology and Chemistry, Texas A&M
Univers~ty, College Station, TX 77843. Slrenin analogs for
the study of receptor recognition during male gamete
chemotaxis in Allomyces.
Sirenin, the sexual pheromone of the aquatic fungus,
Allomyces macrogynus (Burma 3-35), is produced by female
gametes and acts as an attractant for the male gametes.
In order to better understand the nature of thls
communication system, we have synthesized and examined
by chemotactic assay the structure of several sirenin
analogs several of which exhibit strong male attraction.
The synthesis of a dl01 compound containing the blcyclic
structure of sirenin but lacking a hydroxymethyl group on
the SIX-membered ring, exhibited activity comparable to
natural slrenln. This led us to test structures lacking the
b~cyclic structure but possessing the diol relationship of
the above compound. Such diols were found to be qulte
active, demonstrating that the bicyclic structure is not
necessary for chemotact~c activity. From the results of
other compounds tested, ~t is evident that the structural
requirements of the receptor site can be met by molecules
with structures varying considerably from the structure of
natural sirenin. The evidence suggests that the synthetic
diols are active because the two hydroxyl groups can bind
to the receptor site in the same manner as the two
hydroxyl groups in sirenin. Such preliminary studles will
make it possible to determine in detail the spec~ficity of
the receptor sites, examine the mechanisms of pheromone
inactivation by the male gametes, and investigate the
location, number, and nature of the receptor sltes.
Pommerville, J., see Aliaga, 6. R.
Pommerville, J., see Sewall, T.
Porter, D., see Lingle, W. L., et. al.
Poth, M. A., see Dunn, P. H., et. al.
Radford, P. T., see Blackwell, M., et. al.
S.A. REDHEAD and J.H. GINNS. Biosystematics fiesearch
Institute, Agricult~ire Canada, Ottawa, Ont., Canada,
KIA OC6.
Agaric geners causing brown rots.
Relatively Few species of agarics are capable of
causing a brown rot of wood. Species in the genera
Coprinus, Hygrophoropsis, Hypsizygus, Lentinus,
and Paxillus have been considered brown rotters.
The aSility to cause a brown rot is a generic
feature in tile aphyllophorales in refined
taxonomic schemes correlating this physiological