HORENSTEIN, E A; CANTINO, E C
Horenstein, E. A. (Michigan State University, East Lansing) and E. C. Cantino. Dark-induced morphogenesis in synchronized cultures of Blastocladiella britannica. J. Bacteriol. 84:37-45. 1962-A method is described for growing synchronized, single generations of a million cells or more of the aquatic fungus, Blastocladiella britannica, uniformly suspended in agitated liquid media. The effects of population density upon the cell volume, dry weight, and generation time are described. The all-or-none effect of light and dark upon differentiation of thin-walled cells and thick-walled, pitted, resistant-sporangial cells, respectively, has been demonstrated, and the point of no return for both morphological pathways defined. PMID:14448881
Avelar, Gabriela Mól; Glaser, Talita; Leonard, Guy; Richards, Thomas A; Ulrich, Henning; Gomes, Suely L
Phototaxis in flagellated zoospores of the aquatic fungus Blastocladiella emersonii depends on a novel photosensor, Blastocladiella emersonii GC1 (BeGC1), comprising a type I (microbial) rhodopsin fused to a guanylyl cyclase catalytic domain, that produces the conserved second messenger cyclic GMP (cGMP). The rapid and transient increase in cGMP levels during the exposure of zoospores to green light was shown to be necessary for phototaxis and dependent on both rhodopsin function and guanylyl cyclase activity. It is noteworthy that BeGC1 was localized to the zoospore eyespot apparatus, in agreement with its role in the phototactic response. A putative cyclic nucleotide-gated channel (BeCNG1) was also identified in the genome of the fungus and was implicated in flagellar beating via the action of a specific inhibitor (l-cis-diltiazem) that compromised zoospore motility. Here we show that B. emersonii expresses a K(+) channel that is activated by cGMP. The use of specific channel inhibitors confirmed the activation of the channel by cGMP and its K(+) selectivity. These characteristics are consistent with the function of an ion channel encoded by the BeCNG1 gene. Other blastocladiomycete fungi, such as Allomyces macrogynus and Catenaria anguillulae, possess genes encoding a similar K(+) channel and the rhodopsin-guanylyl cyclase fusion protein, while the genes encoding both these proteins are absent in nonflagellated fungi. The presence of these genes as a pair seems to be an exclusive feature of blastocladiomycete fungi. Taken together, these data demonstrate that the B. emersonii cGMP-activated K(+) channel is involved in the control of zoospore motility, most probably participating in the cGMP-signaling pathway for the phototactic response of the fungus. PMID:26150416
Scheib, Ulrike; Stehfest, Katja; Gee, Christine E; Körschen, Heinz G; Fudim, Roman; Oertner, Thomas G; Hegemann, Peter
Blastocladiomycota fungi form motile zoospores that are guided by sensory photoreceptors to areas of optimal light conditions. We showed that the microbial rhodopsin of Blastocladiella emersonii is a rhodopsin-guanylyl cyclase (RhGC), a member of a previously uncharacterized rhodopsin class of light-activated enzymes that generate the second messenger cyclic guanosine monophosphate (cGMP). Upon application of a short light flash, recombinant RhGC converted within 8 ms into a signaling state with blue-shifted absorption from which the dark state recovered within 100 ms. When expressed in Xenopus oocytes, Chinese hamster ovary cells, or mammalian neurons, RhGC generated cGMP in response to green light in a light dose-dependent manner on a subsecond time scale. Thus, we propose RhGC as a versatile tool for the optogenetic analysis of cGMP-dependent signaling processes in cell biology and the neurosciences. PMID:26268609
Protein synthesis during sporulation in Blastocladiella emersonii is developmentally regulated as revealed using (35S)methionine pulse labeling and two-dimensional gel electrophoresis. A large increase in the synthesis of several proteins is associated with particular stages. A large number of basic proteins are synthesized exclusively during late sporulation. Changes in translatable mRNA species were also detected by two-dimensional gel electrophoresis of the polypeptides produced in a cell-free rabbit reticulocyte lysate primed with RNA prepared at different stages of sporulation. The synthesis of several proteins during sporulation seems to be transcriptionally controlled. Most of the sporulation-specific messages are not present in the mature zoospores. (Author)
Krings, Michael; Taylor, Thomas N; Martin, Helmut
Litter layers in the Lower Devonian (~ 410 Ma) Rhynie chert were inhabited by a wide variety of saprotrophic fungi, however, only a few of these organisms have been described formally. A new microfungus, Trewinomyces annulifer gen. et sp. nov., occurs as tufts on decaying land plant axes from the Rhynie chert. The fungus consists of an intramatrical rhizoidal system and an erect extramatrical hypha (stalk) that bears a single, terminal sporangium. One or two successive rings often are present in the stalk immediately below the sporangium base. Overall morphology of T. annulifer resembles the extant genera Macrochytrium (Chytridiomycota) and Blastocladiella (Blastocladiomycota). However, the rhizoids are septate or pseudoseptate, a feature not known in extant zoosporic fungi, and thus render the systematic affinities of T. annulifer unresolved. Trewinomyces annulifer offers a rare view of the morphology of a distinctive Early Devonian saprotrophic microfungus. PMID:26740543
Isolamento e caracterização parcial de sequências homólogas a genes ribossomais (rDNA em Blastocladiella emersonii - DOI: 10.4025/actascibiolsci.v25i2.2037 Isolation and partial characterization of homologous sequences of ribosomal genes (rDNA in Blastocladiella emersonii
Luiz Carlos Correa
Full Text Available A definição e a caracterização de regiões de origens de replicação nos eucariotos superiores são ainda controversas. A iniciação da replicação é sítio-específica em alguns sistemas e, em outros, parece estar contida em regiões extensas. Regiões rDNA são modelos atrativos para o estudo de origens de replicação pela sua organização in tandem, reduzindo a área de estudo para o espaço restrito que codifica uma unidade de transcrição. Neste trabalho nós isolamos e caracterizamos parcialmente um clone que contém uma sequência ribossomal do fungo aquático Blastocladiella emersonii, Be97M20. Southern blots mostraram diversos sítios para enzimas de restrição Eco RI, HindIII e SalI. Northern blot de RNA total hibridado contra uma sonda feita com Be97M20 confirmou a sua homologia com o gene ribossomal 18S. A caracterização detalhada, incluindo o mapeamento de restrição completo, subclonagem, sequenciamento e análise em géis bidimensionais proverão informações adicionais importantes sobre a estrutura e dinâmica desta regiãoThe definition and the characterization of replication origins regions in higher eukaryotes are still controversial. The initiation of the replication is site-specific in some systems but seems to occur in large regions in others. Because of its in tandem organization, reducing the area to the restricted space that codifies an unit of transcription, rDNA regions are attractive models to study replication origins. In this work we isolated and started to characterize a clone that contains a ribosomal sequence from the aquatic fungus B. emersonii, Be97M20. Southern blots showed several sites for the restrition enzymes Eco RI, HindIII and SalI. A northern blot of total RNA, hybridized against a probe made from Be97M20, confirmed its homology with the ribosomal 18S gene. The detailed characterization, including complete restriction map, subcloning, sequence and analysis on bidimensional gels will
Full Text Available ) BeG120N18A01 BeG120N Blastocladiella emersonii cD... 46 2.3 1 ( CK406072 ) AUF_IfSpn_236_d17 Ictalur...44 8.9 1 ( CP000903 ) Bacillus weihenstephanensis KBAB4, complete genome. 44 8.9 1 ( CP000485 ) Bacillus thuringie...m 20.0 %: mitochondrial 12.0 %: plasma membrane 8.0 %: extracellular, including cell wall 4...792017 ) 90881534 Sea Urchin primary mesenchyme cell cDNA ... 40 1.9 2 ( EF494740 ) Blastocystis sp. NandII mitochondrion, compl...E60C09B02 BeE60C Blastocladiella emersonii cDNA... 46 2.3 1 ( AU269337 ) Dictyostel
Bazyli Czeczuga; Lucyna Woronowicz; Krystyna Brzozowska
The work was undertaken to investigate the mycoflora ot the lowland river Biebrza. Samples of water collected once a month over spring and autumn (1984) for hydrochemical analysis and studies of the fungus content. Twenty five species of fungi were found most of them in the river Biebrza. The following fungi unknown from Poland were found in the river Biebrza: Karlingia rosea, Blastocladiella britannica, Cladolegnia eccenirica, Centrospora filiformis and Flagellospora cunmla.
Full Text Available The work was undertaken to investigate the mycoflora ot the lowland river Biebrza. Samples of water collected once a month over spring and autumn (1984 for hydrochemical analysis and studies of the fungus content. Twenty five species of fungi were found most of them in the river Biebrza. The following fungi unknown from Poland were found in the river Biebrza: Karlingia rosea, Blastocladiella britannica, Cladolegnia eccenirica, Centrospora filiformis and Flagellospora cunmla.
Full Text Available tative calmodulin-like protein 6; 100 4e-20 DQ112161_1( DQ112161 |pid:none) Blastocladiella emersonii centri....6 1 ( AY789854 ) Clytia gracilis voucher 812IT calmodulin gene, pa... 46 1.6 1 ( DQ145721 ) Homo sapiens v-abl Abelson muri... AY542983_1( AY542983 |pid:none) Bigelowiella natans calmodulin mRN... 152 7e-36 ( P02597 ) RecName: Full...sfr*kr*wlckysrfkth infnw*kinkrrir*yvkrrknc*wpnfmlmnllellnqanhsik*gnvilknnnnnykk n...cidg818o22, 5'end,... 46 0.012 2 ( FM992691 ) Candida dubliniensis CD36 chromosome 4, complete ... 52 0.025
Full Text Available Preference for specific protein substrates together with differential sensitivity to activators and inhibitors has allowed classification of serine/threonine protein phosphatases (PPs into four major types designated types 1, 2A, 2B and 2C (PP1, PP2A, PP2B and PP2C, respectively. Comparison of sequences within their catalytic domains has indicated that PP1, PP2A and PP2B are members of the same gene family named PPP. On the other hand, the type 2C enzyme does not share sequence homology with the PPP members and thus represents another gene family, known as PPM. In this report we briefly summarize some of our studies about the role of serine/threonine phosphatases in growth and differentiation of three different eukaryotic models: Blastocladiella emersonii, Neurospora crassa and Dictyostelium discoideum. Our observations suggest that PP2C is the major phosphatase responsible for dephosphorylation of amidotransferase, an enzyme that controls cell wall synthesis during Blastocladiella emersonii zoospore germination. We also report the existence of a novel acid- and thermo-stable protein purified from Neurospora crassa mycelia, which specifically inhibits the PP1 activity of this fungus and mammals. Finally, we comment on our recent results demonstrating that Dictyostelium discoideum expresses a gene that codes for PP1, although this activity has never been demonstrated biochemically in this organism.
Avelar, Gabriela M; Schumacher, Robert I; Zaini, Paulo A; Leonard, Guy; Richards, Thomas A; Gomes, Suely L
Sensing light is the fundamental property of visual systems, with vision in animals being based almost exclusively on opsin photopigments . Rhodopsin also acts as a photoreceptor linked to phototaxis in green algae [2, 3] and has been implicated by chemical means as a light sensor in the flagellated swimming zoospores of the fungus Allomyces reticulatus ; however, the signaling mechanism in these fungi remains unknown. Here we use a combination of genome sequencing and molecular inhibition experiments with light-sensing phenotype studies to examine the signaling pathway involved in visual perception in the closely related fungus Blastocladiella emersonii. Our data show that in these fungi, light perception is accomplished by the function of a novel gene fusion (BeGC1) of a type I (microbial) rhodopsin domain and guanylyl cyclase catalytic domain. Photobleaching of rhodopsin function prevents accumulation of cGMP levels and phototaxis of fungal zoospores exposed to green light, whereas inhibition of guanylyl cyclase activity negatively affects fungal phototaxis. Immunofluorescence microscopy localizes the BeGC1 protein to the external surface of the zoospore eyespot positioned close to the base of the swimming flagellum [4, 5], demonstrating this is a photoreceptive organelle composed of lipid droplets. Taken together, these data indicate that Blastocladiomycota fungi have a cGMP signaling pathway involved in phototaxis similar to the vertebrate vision-signaling cascade but composed of protein domain components arranged as a novel gene fusion architecture and of distant evolutionary ancestry to type II rhodopsins of animals. PMID:24835457