Round Spores Research Articles

Propionispora hippei sp. nov., a novel Gram-negative, spore-forming anaerobe that produces propionic acid.

A Gram-negative, spore-forming anaerobe, KS(T), was isolated from an enrichment culture that was set up for anaerobic degradation of the aliphatic polyester poly(propylene adipate). The strain had the cellular organization of Sporomusa, vibrio-shaped cells and terminal round spores, and fermented sugars and sugar alcohols to propionic and acetic acid. Based on the morphological and physiological features as well as on a 16S rRNA gene similarity of 98 %, it was grouped with Propionispora vibrioides. A relatively low DNA-DNA hybridization value with the type strain of this species (47 %), and differences in substrate utilization and spore morphology, suggested that the strain should be classified in a separate species, Propionispora hippei sp. nov., with KS(T) as the type strain (=DSM 15287(T)=ATCC BAA-665(T)).

Dictyostelium discoideum developmentally regulated genes whose expression is dependent on MADS box transcription factor SrfA.

The MADS box transcription factor SrfA is required for spore differentiation in Dictyostelium discoideum. srfA null strains form rounded spores that do not resist adverse environmental conditions. Five genes whose expression is dependent on SrfA have been isolated by differential hybridization. One of these genes, sigC, is identical to phg1b, previously characterized in mutants with altered adhesive properties and found to encode a nine-transmembrane-domain protein. This gene is transcribed into two mRNAs as the result of alternative splicing of two internal exons. The slower-migrating mRNA codes for a shorter protein that lacks the first transmembrane fragment and is not expressed in srfA null strains. The other four genes (sigA, sigB, sigD, and 45D) are expressed only during late developmental stages. In situ hybridization experiments showed that expression of sigA, sigB, and sigD is restricted to the sorus of developing structures. sigA codes for a homologue of malate dehydrogenase that converts pyruvate to malate to replenish the tricarboxylic acid cycle. sigB encodes a protein with significant similarity to the GP63 metalloproteinase of Leishmania, leishmanolysin. The sequence of SigD is highly similar to that of several spore coat proteins of D. discoideum, and it may play a role in that structure. The gene 45D codes for an RNA-binding protein homologue whose expression is also dependent on the GATA transcription factor stalky (StkA). The expression of sigB is also dependent on both SrfA and StkA. The expression of 45D, but not of sigA, sigB, sigC, and sigD, can be induced in srfA null cells by constitutive protein kinase A activation. Strains in which either sigA, sigB, or sigD is disrupted were isolated and found to form spores that are not detectably different from those of wild-type strains.

COMPARATIVE FECUNDITY ESTIMATION OF CULTURED FEMALE FISHES WITH MYXOSPOREAN AND FUNGAL INFECTIONS

This is the first trial so far in Egypt through upgrading the fish production by revealing specific ovarian myxozoan and fungal infections that affect their fecundity. Fecundity comparison was held between noninfected and infected Oreochromis niloticus and Cyprinus carpio with either Myxobolus spp. or Icthyophonus hoferi. The myxosporean parasite, Myxobolus spp. (with higher prevalence in both species ) appeared as numerous white large rounded spores embedded in the ovarian tissue causing excessive fibrosis. The fungus /. hoferi inspite of its lower prevalence among the 2 species, the white capsulated cysts and separate colonies caused ovarian atresia and fibrosis with inflammatory oedema. Drop of fecundity was represented by significant decrease in relative and absolute fecundity, total protein, gonadosomatic and hepatosomatic indices ranging from highly with 0. niloticus to moderately with C carpio. In O. niloticus ( more sensitive ) /. hoferi reflected a positive correlation with ovarian weight and gonadosomatic index, while Myxobolus spp. recorded a negative correlation between ovarian weight and the body parameters (weight, length & depth).

CAMP-dependent protein kinase regulates Polysphondylium pallidum development

In eukaryotic cells, the universal second messenger cAMP regulates various aspects of development and differentiation. The primary target for cAMP is the regulatory subunit of cAMP-dependent protein kinase A (PKA), which, upon cAMP binding, dissociates from the catalytic subunit and thus activates it. In the soil amoeba Dictyostelium discoideum, the function of PKA in growth, development and cell differentiation has been thoroughly investigated and substantial information is available. To obtain a more general view, we investigated the influence of PKA on development of the related species Polysphondylium pallidum. Cells were transformed to overexpress either a dominant negative mutant of the regulatory subunit (Rm) from Dictyostelium that cannot bind cAMP, or the catalytic subunit (PKA-C) from Dictyostelium. Cells overexpressing Rm rarely aggregated and the few multicellular structures developed slowly into very small fruiting bodies without branching of secondary sorogens, the prominent feature of Polysphondylium. Few round spores with reduced viability were formed. When mixed with wild-type cells and allowed to develop, the Rm cells were randomly distributed in aggregation streams, but were later found in the posterior region of the culminating slug or were left behind on the surface of the substratum. The PKA-C overexpressing cells exhibited precocious development and formed more aggregates of smaller size. Moreover, expression of PKA-C under the control of the prestalk-specific ecmB promoter of Dictyostelium leads to protrusions from aggregation streams. We conclude that Dictyostelium PKA subunits introduced into Polysphondylium cells are functional as signal components, indicating that a biochemically similar PKA mechanism works in Polysphondylium.

Bacillus pycnus sp. nov. and Bacillus neidei sp. nov., round-spored bacteria from soil.

Bacillus sphaericus sensu lato currently consists of seven or more groups of unrelated taxa, one of which is B. sphaericus sensu stricto and another of which is Bacillus fusiformis. Members of two groups (groups 6 and 7), in common with all other B. sphaericus-like organisms, are unable to grow anaerobically or to use common hexoses, pentoses and hexitols as sources of carbon, have G+C contents of 34-36 mol % and form round spores. Groups 6 and 7 can be differentiated from other B. sphaericus-like organisms by low DNA relatedness and by variations in whole-cell fatty acid composition. Unique characteristics of group 6 include the ability to oxidize beta-hydroxybutyrate, the non-requirement for biotin and thiamin and failure to grow in 5% NaCl. Distinctive traits of group 7 include the inability to oxidize pyruvate and a requirement for biotin, thiamin and cystine for growth. These data show that groups 6 and 7 represent two novel species, for which the names Bacillus pycnus sp. nov. and Bacillus neidei sp. nov., respectively, are proposed; the corresponding type strains are NRRL NRS-1691T (= JCM 11075T) and NRRL BD-87T (= JCM 11077T).

Streptimonospora salina gen. nov., sp. nov., a new member of the family Nocardiopsaceae.

Actinomycete strain YIM 90002T (= CCTCC 99003T = CCRC 16284T) was isolated from a soil sample collected from a salt lake in the west of China. The aerial mycelium of this organism is well developed but not fragmented and, at maturity, forms short chains of spores. Spores in short chains are oval- to rod-shaped and have wrinkled surfaces. Substrate mycelium is branched with non-fragmenting hyphae and forms single oval to round spores borne on sporophores or dichotomously branching sporophores. Single spores have wrinkled surfaces. Single spores and spores in short chains are non-motile. Strain YIM 90002T contains meso-diaminopimelic acid, DD-diaminopimelic acid, glycine, lysine and aspartic acid in its cell wall and has glucose, galactose, ribose, xylose, arabinose and mannose as whole-cell sugars (no diagnostic sugars). The phospholipids are phosphatidylglycerol, phosphatidylinositol and phosphatidylethanolamine. The major menaquinones are MK-9(H6), MK-10(H2) and MK-10(H4). Phylogenetic data indicate that this strain belongs to the family Nocardiopsaceae. The morphological and physiological characteristics and chemotaxonomic and phylogenetic data for this strain differ from those of previously described actinomycetes. Therefore, a new genus, Streptimonospora, is proposed for this organism; the type species of the genus is Streptimonospora salina gen. nov., sp. nov., and the type strain of S. salina is strain YIM 90002T.

NEW OR INTERESTING PARMELIELLA SPECIES FROM THE ANDES AND CENTRAL AMERICA

Abstract: The Parmeliella nigrocincta complex in the northern Andean region is discussed. The commonest species, P. miradorensis Vain. (syn. nov. P. nigrocincta var. brasiliensis Malme), is a foliose-squamulose taxon of the Andean mist forests, with a fairly wide distribution. It also reaches the West Indies and Macaronesia. In addition, there is a thick, small-squamulose species with round spores, P. incrassata sp. nov., in the northen Andes. This species occurs at the forest limit, on Polylepis at higher altitudes (to 4500m) in the same region. Parmeliella nigrocincta s.str. does not appear to occur this far north, and appears to be restricted to more southern parts, mainly in Chile. There is a further species on rocks in the northern Andes, P. saxicola sp. nov., which is closely related to the cold-temperate P. triptophylla. An isidiate species, P. clavulifera sp. nov., is described from Mexico. It is somewhat reminiscent of P. miradorensis, but belongs in the P. pannosa complex. Lectotypes forP. miradorensis Vain. and P. nigrocincta var brasiliensis Malme have been selected.

Nucleotide sequence of the sspE genes coding for γ-type small, acid-soluble spore proteins from the round-spore-forming bacteria Bacillus aminovorans, Sporosarcina halophila and S. ureae

The single sspE genes coding for γ-type small, acid-soluble spore proteins (SASP) of three round-spore-forming bacteria, Bacillus aminovorans, Sporosarcina halophila and S. ureae, have been cloned and sequenced. While the deduced amino acid sequences of these three γ-type SASP show clear homology to those from six Bacillus species that do not form round spores, there are no residues conserved completely among the 9 sequences known. In addition, the 139 residue B. aminovorans protein is 35 residues larger than any other while the 60 residue S. halophila protein is one of the smallest. These data suggest that the sspE genes have been under little selective pressure in recent evolutionary time.

Myxosporean parasites of the genus Kudoa meglitsch, 1947 from some Gulf of Mexico fishes: Description of two new species and notes on their ultrastructure

Summary Species of the genus Kudoa infecting muscles are described from 7 fish hosts collected in salt and brackish waters along coastal Mississippi in the northern Gulf of Mexico. Two of 5 recorded species are regarded as new species. Kudoa shkae n. sp. from trunk muscles of Arius felis has rather rounded spores, average 7.5 urn in side view, which are formed within large polysporic plasmodia. The plasmodium boundary forms button-shaped projections abutting on intact sarcoplasm. K. leiostomi n. sp. from trunk muscles of Leiostomus xanthurus has spores quadrate in the apical view, averaging 9.1 μm in width; it also forms a large polysporic plasmodium. In spores of both species, the sporoplasm is represented by the cell doublet composed of an enveloped and an enveloping cell. Other unidentified species of Kudoa infected other fishes: one infected Cyprinodon variegatus, Fundulus grandis, and F. chrysotus; one infected Gambusia affinis; and one infected Menidia beryllina.

Isozymic and Chromosomal Evidence for the Allotetraploid Origin of Gymnocarpium dryopteris (Dryopteridaceae)

A critical examination of isozyme, chromosomal, and morphological characters in subspecies formerly included in Gymnocarpium dryopteris demonstrated that three sexual taxa can be distinguished. We recognize these taxa as distinct species: the widespread, fertile allotetraploid G. dryopteris, with one genome derived from the western diploid G. disjunctum and the other from G. appalachianum sp. nov., a previously undetected eastern North American diploid, which is de- scribed and illustrated here and for which we report a chromosome number of 2n = 80. Population comparisons of allele frequencies between G. disjunctum and G. appalachianum yielded an average Nei's genetic identity value (I) of 0.274. A wide-ranging assemblage of putatively triploid plants with both sterile, malformed spores and large, round spores capable of germination is believed to represent the backcrosses G. disjunctum x dryopteris and G. appalachianum x dryopteris. The name G. x brittonianum comb. nov. is applied here to G. disjunctum x dryopteris. A key to fertile species,

New round spore mutations in Neurospora crassa accompanying changes in a duplication closely linked to the R locus

Various genotypes can result in round ascospores in N. crassa (Mitchell 1966 Neurospora Newsl. 10:6; Barry et al. 1972 Neurospora Newsl. 19:17). I have observed that round ascospores can also originate in crosses where one parent is the apparent breakdown of a partial diploid heterozygous at the heterokaryon incompatibility locus het-5. The breakdown may remove one of the duplicated chromosome segments carrying a het-5 allele and possibly extend past the duplication and affect the nearby Round spore locus (R).

Clostridium aceticum (Wieringa), a microorganism producing acetic acid from molecular hydrogen and carbon dioxide.

Spores of Clostridium aceticum (Wieringa) from 1947 have been revived, and a study for a redescription of this microorganism has been carried out. C. aceticum was Gram negative. The cells were rodshaped and peritrichously flagellated. Round spores were formed in terminal position. The DNA contained 33 mol % guanine plus cytosine. The organism was obligately anaerobic and grew either chemolithotrophically with H2 + CO2 or chemoorganotrophically with compounds such as fructose, L-glutamate, L-malate or pyruvate. H2 and CO2 were converted to acetic acid according to the following equation: 2CO2 + 4H2 leads to CH3COOH + 2H2O The optimal temperature for growth was 30 degrees C. The optimal pH for chemolithotrophic growth was 8.3. The doubling times for chemolithotrophic and chemoorganotrophic growth were 25 and 8 h, respectively.

Immunological Studies on Pityrosporum Genus and Malassezia furfur

The antigenicity of Malassezia furfur from patients with tinea versicolor and 3 species of Pityrosporum was investigated using the antiserum against P. orbiculare. The Ouchterlony gel diffusion test revealed a considerable similarity between the antigenicities of P. orbiculare and P. ovale, and little similarity between P. orbiculare andP. canis. Similar results were obtained by immunofluorescence staining with the FITC-labeled P. orbiculare antiserum. Hyphae and round spores of M. furfur in the scales and biopsy specimens from the lesions in patients with tinea versicolor revealed specific fluorescence much the same as seen in cases of P. orbiculare or P. ovale. The FITC-labeled antiserum absorbed with P. orbiculare or P. ovale failed to give a positive reaction with hyphae and round spores of M. furfur. These findings suggest a similar antigenicity among P. orbiculare, P. ovale and M. furfur.

Plasma membrane proteins of Dictyostelium: The spore coat proteins

Spore coats were isolated following germination ofDictyostelium discoideum spores. They were found to contain five major proteins of apparent molecular weights of 60,000 (SP60), 68,000 (SP68), 70,000 (SP70), 96,000 (SP96), and 200,000 (SP200). Of these SP68 and SP96 were found to be glycoproteins. Analysis of the tryptic and chymotryptic fingerprints indicated that the major spore coat proteins are independent gene products and not derived by proteolytic cleavage of common percursors. These spore coat proteins are the major newly synthesized proteins seen in membranes late in development and account for the majority of the changes seen in membranes during culmination. They can be observed in membranes isolated from spores, most likely while in transit to the spore coat. SP60, SP68, and SP70 appear to be on the outer face of the spore coat since they are sensitive to proteolysis by Pronase added to intact spores while SP96 and SP200 are protected until the spore case is broken during germination. The spore coat proteins are not found in stalk cells or in several mutant strains blocked in spore formation including one strain, HL-6, which undergoes many of the biochemical differentiations of culmination but forms only stalk cells. The spore coat proteins do accumulate in a spore shape mutant, HU26, which forms small round spores rather than ellipsoid ones. Characterization of the spore coat proteins further defines the changes in membrane proteins during development ofDictyostelium and the processes of terminal differentiation in spores.

STUDIES ON AEROBIOLOGY‐ATMOSPHERIC FUNGAL SPORES

SummaryA survey of atmospheric fungal spores was carried out at Modinagar, situated in the western part of Uttar Pradesh (India). The site for the study represents a rural and semi‐industrial area. The incidence of the fungal spores in the air was studied by the simultaneous exposure of adhesive coated slides for 24 h and petri dishes containing culture media for 5 min daily all the year round (August 1975 to July 1976). The slides exhibited a preponderance of spores of: Alternaria; Beltrania; Cladosporium; Curvularia; Epicoccum; Fusarium; Helminthosporium; Nigrospora; Prathroda.; rust spores; smut spores; small round spores (spp. of Aspergillus, Penicillium, Mucor, Rhizopus), Thielaviopsis. Species of Alternaria, Aspergillus, Cladosporium, Fusarium, Penicillium, Verticillium and Thielaviopsis showed excellent growth on exposed culture media dishes. Several other types of spores were also found in comparatively low numbers. The seasonal and monthly variation of these air‐borne fungi were studied qualitatively and quantitatively.

Mosaic analysis of autonomy of spore development in Neurospora

Genetically mosaic rosettes of asci have been constructed by using as the female parent heterokaryons containing nuclei of two distinct genotypes. One nucleus contains the ascospore-autonomous color mutant, per-1 (perithecial-1). The other nucleus contains the ascus-autonomous dominant mutant R (round spore). The per-1 mutation is used to unambiguously determine the genotype of each ascus within the mature rosette of asci. Most rosettes of asci originate exclusively from either the per-1 R + nucleus or the per-1 + R nucleus. When both types occur within the same perithecium, individual asci are either one type or the other and asci of the same type are usually contiguous.

A dominant round spore mutant in Neurospora tetrasperma and its implications for ascospore development.

A new mutation (Rsp-1) in N. tetrasperma produces nearly all round spores when heterozygous in a cross. The gene maps 12 units from mating type in linkage group I and mutant cultures are female-sterile. Nongenetic reversal of dominance sometimes occurs, in that crosses heterozygous for round spores yield a few asci containing four spores of normal shapes. In the absence of crossovers between Rsp-1 and the centromere of its chromosome, these hetero-karyotic spores give rise to self-fertile mycelia which produce perithecia that contain round-spored asci. One never observes asci that contain both round and normal spores. Therefore, the nuclei included within ascospores do not determine the shape of the spores. Rather, dominance effects are exerted on the ascus as a whole, as if its development were controlled by the zygote.The round spores of N. tetrasperma contain two germ pores, and these are unsystematically situated. Evidence is presented to show that the position of pores is directly related to the development of the striation pattern.

Studies on the allergenic fungal spores of the Delhi, India, metropolitan area: Botanical aspects (aeromycology)

The prevalence of fungal spores in the Delhi atmosphere as determined by simultaneous exposure of one slide daily and three Petri dishes a day, at intervals for one full year, is herewith presented for the first time. On the slides the spores of Alternaria sp., Cladosporium sp., small round spores, Curvularia sp., and Helminthosporium sp. were most frequent in that order and together formed 83.5 per cent of the total spore count. In the Petri dishes, colonies of Cladosporium sp., Alternaria sp., Aspergillus sp., Curvularia sp., and Fusarium sp. were most common and formed about 85 per cent of the total colony count. There were two peak periods of fungal spore concentration in Delhi: one from September to November and the other from February to April. Thus, these aeromycologic findings seem to provide an additional explanation of our earlier clinical observations that most patients get their symptoms (or aggravation of symptoms) during these two seasons. There were drawbacks to adopting one method only, either slide exposure or Petri dish exposure, and distinct advantages to using both the techniques simultaneously.

A case of disseminating sporotrichosis from South Africa.

A case of disseminating S. schenckii infection is presented. Unusual clinical features included an extensive haemorrhagic ulceration (involving the entire body especially on the face) which was not, in the early stages of hospitalisation, considered mycotic.The fungus isolated, when injected into laboratory animals, showed some atypical features such as the absence of hyaline or asteroid bodies, the failure of any healing process even after 159 days exposure, the unprecedented, extracellular proliferation of round and cigar spores and the multiple budding of small, round spores to form cigar bodies.

Location of round spore (R), a dominant ascospore marker

Location of round spore (R), a dominant ascospore marker