Regulación del metabolismo secundario en hongos

El género Fusarium engloba cientos de especies de hongos saprófitos y patógenos ampliamente distribuidos en la naturaleza. Muchos son económicamente importantes por sus efectos dañinos en la agricultura, y otros poseen especial interés por la complejidad de su metabolismo secundario. Dicho metabolismo incluye la producción de compuestos de interés biotecnológico, como las giberelinas y los carotenoides. Nuestro grupo centra actualmente su atención en los mecanismo moleculares que controlan la síntesis de carotenoides en las especies F. fujikuroi y F. oxysporum. Se han identificado todos los genes de esta ruta biosintética (genes car) y al menos dos factores ambientales que modulan su expresión, la luz y la disponibilidad de nitrógeno. La organización genómica de los genes car indica dos funciones diferentes: la producción de una xantofila, la neurosporaxantina, y de una rodopsina, CarO. La producción de CarO fotoactiva requiere la síntesis tanto de la opsina como de su cromóforo, el retinal. Los cuatro genes necesarios para la producción de CarO y retinal están organizados en Fusarium en un cluster en cuya regulación participan al menos dos proteínas fotoreceptoras y una proteína de la familia RING finger, llamada CarS, que actúa como regulador negativo. Indicios cada vez más sólidos respaldan la participación en el mecanismo de regulación por luz y por la proteína CarS de ARNs no codificantes ubicados en una región intergénica anterior al propio gen carS. Las investigaciones se centran actualmente en desentrañar las bases moleculares del mecanismo de regulación mediado por CarS y ARNs no codificantes y su participación en otros procesos celulares, delatados por análisis de transcriptómica global.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tec

A novel lncRNA as a positive regulator of carotenoid biosynthesis in Fusarium

The fungi Fusarium oxysporum and Fusarium fujikuroi produce carotenoids, lipophilic terpenoid pigments of biotechnological interest, with xanthophyll neurosporaxanthin as the main end product. Their carotenoid biosynthesis is activated by light and negatively regulated by the RING-finger protein CarS. Global transcriptomic analysis identified in both species a putative 1-kb lncRNA that we call carP, referred to as Fo-carP and Ff-carP in each species, upstream to the gene carS and transcribed from the same DNA strand. Fo-carP and Ff-carP are poorly transcribed, but their RNA levels increase in carS mutants. The deletion of Fo-carP or Ff-carP in the respective species results in albino phenotypes, with strong reductions in mRNA levels of structural genes for carotenoid biosynthesis and higher mRNA content of the carS gene, which could explain the low accumulation of carotenoids. Upon alignment, Fo-carP and Ff-carP show 75-80% identity, with short insertions or deletions resulting in a lack of coincident ORFs. Moreover, none of the ORFs found in their sequences have indications of possible coding functions. We conclude that Fo-carP and Ff-carP are regulatory lncRNAs necessary for the active expression of the carotenoid genes in Fusarium through an unknown molecular mechanism, probably related to the control of carS function or expressio

The flavoproteins CryD and VvdA cooperate with the white collar protein WcoA in the Control of photocarotenogenesis in Fusarium fujikuroi

Light stimulates carotenoid biosynthesis in the ascomycete fungus Fusarium fujikuroi through transcriptional activation of the structural genes of the pathway carRA, carB, and cart, but the molecular basis of this photoresponse is unknown. The F. fujikuroi genome contains genes for different predicted photoreceptors, including the WC protein WcoA, the DASH cryptochrome CryD and the Vivid-like flavoprotein VvdA. We formerly found that null mutants of wcoA, cryD or vvdA exhibit carotenoid photoinduction under continuous illumina- tion. Here we show that the wild type exhibits a biphasic response in light induction kinetics experiments, with a rapid increase in carotenoid content in the first hours, a transient arrest and a subsequent slower increase. The mutants of the three photoreceptors show different kinetic responses: the wcoA mutants are defective in the rapid response, the cryD mutants are affected in the slower response, while the fast and slow responses were respectively enhanced and attenuated in the vvdA mutants. Transcriptional analyses of the car genes re- vealed a strong reduction of dark and light-induced transcript levels in the wcoA mutants, while minor or no reductions were found in the cryD mutants. Formerly, we found no change on carRA and carB photoinduction in vvdA mutants. Taken together, our data suggest a co- operative participation of WcoA and CryD in early and late stages of photoinduction of carot- enoid biosynthesis in F. fujikuroi, and a possible modulation of WcoA activity by VvdA. An unexpected transcriptional induction by red light of vvdA, cryD and carRA genes suggest the participation of an additional red light-absorbing photoreceptor

Introducción al Deep Learning. Aplicación en R

Estamos empezando a ver como algo normal utilizar el asistente de nuestro teléfono móvil, usar el traductor, buscar en google simplemente echando una foto, coches que frenan al encontrar un obstáculo delante, etc. Todas estas actividades no eran posibles hace relativamente pocos años, y es que la Inteligencia Artificial, la encargada de estas tareas, nació en el siglo pasado. Este trabajo consiste en introducir unas de las ramas de aprendizaje dentro de esta ciencia, que pese a nacer en los años 50 del siglo pasado, ya está más que presente en nuestro día a día. Se trata del Deep Learning, o Aprendizaje Profundo. El Deep Learning, englobado dentro del Maching Learning, es una rama de la Inteligencia Artificial. Es un método de aprendizaje automático, formado por diferentes capas de aprendizaje. Su estructura se basa en las Redes Neuronales, que son métodos de aprendizaje por capas. Cada modelo de Redes Neuronales tiene una composición diferente y puede usarse para realizar unas tareas en especial. El trabajo se inicia con una introducción al Deep Learning, y da una visión de su historia y sus precedentes. Seguidamente se introduce cómo funciona, que es a través de las Redes Neuronales. En este aspecto, se centra en las Redes Neuronales Convolucionales. Por último, se lleva a cabo dos aplicaciones en el lenguaje R donde se intentará clasificar unas imágenes; primero en blanco y negro, y luego a color, utilizando la librería Keras.We are getting used to using our smartphone asistance, the automatic translator, searching in Google just by taking a photo, seeing cars which are able to stop if case some obstacle is on the road, etc. All this activities were not possible a few years ago and the reason is that Artificial Intelligence, which is responsible for this tasks, were born in the last century. This project consists in introducing one field from inside this science, which in spite of beeing born in the 50s, it is already present daily in our lifes. We are talking about Deep Learning. Deep Learning, which is included inside Maching Learning, it is a subcategory of Artificial Intelligence. It is a self learning method, form by diferent learning layers. It is Neural Networks the structures which Deep Learning models are made of. Each Neural Network model has a diferent composition and can be used in some specific tasks. This project starts with an introduction to Deep Learning, its history and its precedents. Right after it is introduced how Deep Learning works, what is through Neural Networks. About this topic, we will focus on Convolutional Neural Networks (CNN). Finally, two applications are done in R lenguage where we will try to clasify some images, first in black and white, and then in color, all using the keras libraryUniversidad de Sevilla. Grado en Estadístic

Comparative transcriptomic analysis unveils interactions between the regulatory CarS protein and light response in Fusarium

Background The orange pigmentation of the agar cultures of many Fusarium species is due to the production of carotenoids, terpenoid pigments whose synthesis is stimulated by light. The genes of the carotenoid pathway and their regulation have been investigated in detail in Fusarium fujikuroi. In this and other Fusarium species, such as F. oxysporum, deep-pigmented mutants affected in the gene carS, which encodes a protein of the RING-finger family, overproduce carotenoids irrespective of light. The induction of carotenogenesis by light and its deregulation in carS mutants are achieved on the transcription of the structural genes of the pathway. We have carried out global RNA-seq transcriptomics analyses to investigate the relationship between the regulatory role of CarS and the control by light in these fungi. Results The absence of a functional carS gene or the illumination exert wide effects on the transcriptome of F. fujikuroi, with predominance of genes activated over repressed and a greater functional diversity in the case of genes induced by light. The number of the latter decreases drastically in a carS mutant (1.1% vs. 4.8% in the wild-type), indicating that the deregulation produced by the carS mutation affects the light response of many genes. Moreover, approximately 27% of the genes activated at least 2-fold by light or by the carS mutation are coincident, raising to 40% for an 8-fold activation threshold. As expected, the genes with the highest changes under both regulatory conditions include those involved in carotenoid metabolism. In addition, light and CarS strongly influence the expression of some genes associated with stress responses, including three genes with catalase domains, consistent with roles in the control of oxidative stress. The effects of the CarS mutation or light in the transcriptome of F. oxysporum were partially coincident with those of F. fujikuroi, indicating the conservation of the objectives of their regulatory mechanisms. Conclusions The CarS RING finger protein down-regulates many genes whose expression is up-regulated by light in wild strains of the two investigated Fusarium species, indicating a regulatory interplay between the mechanism of action of the CarS protein and the control by light.España, Ministerio de Economía y Competitividad, project BIO2015–69613-REspaña, Junta de Andalucía project CTS-6638 CTS-66

Diseño de un sistema de calefacción solar para la cámara de secado en la empresa de curtiembre el AL-CE.

Diseño de un sistema de calefacción solar mediante el uso de un colector solar de placa plana bajo la Norma Ecuatoriana de Construcción (NEC-10, 1996). Se partió del proceso convencional que utilizaba la quema de gas licuado de petróleo (GLP), a fin de obtener las variables de temperatura, tiempo y humedades que definen su proceso y sustituirlas por otro medio de generación de calor sin perder las características físico - químicas que requiere un cuero seco. Se acopló el modelo solar en las instalaciones actuales donde ha dejado de funcionar un sistema de calefacción con generación de vapor, el cual hacía uso de un caldero. Su implementación partió de la construcción del colector solar con materiales de bajo costo y fácil construcción, un sistema de tuberías que traslade el fluido trasportador, un tanque de almacenamiento donde se guarde el calor generado y un sistema de tuberías internas que se encuentran dentro de la cámara de secado. Se midió la eficiencia de transferencia de calor del sistema obteniendo un valor de 22ºC para el proceso de secado utilizando energía solar, siendo menor a los 30ºC requeridos por el sistema convencional convirtiéndolo en un proceso de secado lento. Haciendo uso de un fluido se midió la caracterización del cuero seco, donde la humedad luego del proceso de secado llega a 8,98% obteniendo una reducción de humedad del 43,87% en comparación con el sistema convencional que es del 52.75%. Se concluyó que reemplazando la energía solar por la energía con que funcionaba el sistema de secado anteriormente se obtiene un producto que conserva sus características físico – químicas. Se recomienda recubrir la cámara de secado con un aislamiento tanto en paredes como en el techo del mismo para que el sistema sea más eficiente y su vida útil no se vea afectada por las situaciones climáticas ni por su mal funcionamiento.Design of a solar heating system by the use of a flat plate solar collector under the Ecuadorian Construction Standard (NEC-10, 1996). It started from the conventional process that used liquefied petroleum gas (GLP) burning, in order to obtain the variables of temperature, time and humidity that define its process and replace them with another means of heat generation without losing the physical and chemical characteristics that dry leather requires. The solar model was coupled in the current installations where it has stopped working a heating system with steam generation, which made use of a cauldron. Its implementation started with the construction of the solar collector with materials of low cost and easy construction, a piping system that transports the transporting fluid, a storage tank where the generated heat and a system of internal pipes that are inside the drying chamber are stored. The heat transfer efficiency of the system was measured obtaining a value of 22º C for the drying process using solar energy, being less than. The 30º C required by the conventional system turning it into a process of slow drying. Using a fluid, the dry leather characterization was measured, where moisture after the drying process reaches 8.89%, obtaining a humidity reduction of 43.87% compared to the conventional system, which is 52.75%. It concluded that replacing the solar energy by the energy with which the drying system worked previously produces a product that retains its physical and chemical characteristics. It is recommended to coat the drying chamber with insulation in both walls and roof of the same to make the system more efficient and life is not affected by weather conditions or malfunction

Fungal Secondary Metabolism

Definition: Fungal secondary metabolites (SMs) comprise a vast collection of compounds expendable for these organisms under laboratory conditions. They exhibit enormous chemical diversity, and usu- ally belong to four major families: terpenoids, polyketides, non-ribosomal peptides, or a combination of the last two. Their functions are very diverse and are normally associated with a greater fitness of the producing fungi in their environment, which often compete with other microorganisms or interact with host plants. Many SMs have beneficial applications, e.g., as antibiotics or medical drugs, but others, known as mycotoxins, are harmful to health

Light-dependent functions of the Fusarium fujikuroi CryD DASH cryptochrome in development and secondary metabolism

DASH (Drosophila, Arabidopsis, Synechocystis, human) cryptochromes (cry-DASHs) constitute a subgroup of the photolyase cryptochrome family with diverse light-sensing roles, found in most taxonomical groups. The genome of Fusarium fujikuroi,a phytopathogenic fungus with a rich secondary metabolism, contains a gene encoding a putative cry-DASH, named CryD. The expression of the cryD gene is induced by light in the wild type, but not in mutants of the “white collar” gene wcoA. Targeted acryD mutants show light-dependent phenotypic alterations, including changes in morphology and pigmentation, which disap- pear upon reintroduction of a wild-type cryD allele. In addition to microconidia, the colonies of the acryD mutants produced under illumination and nitrogen starvation large septated spores called macroconidia, absent in wild-type colonies. The acryD mutants accumulated similar amounts of carotenoids to the control strain under constant illumination, but produced much larger amounts of bikaverin under nitrogen starvation, indicating a repressing role for CryD in this biosynthetic pathway. Addi- tionally, a moderate photoinduction of gibberellin production was exhibited by the wild type but not by the acryD mutants. The phenotypic alterations of the acryD mutants were only noticeable in the light, as expected from the low expression of cryD in the dark, but did not correlate with mRNA levels for structural genes of the bikaverin or gibberellin biosynthetic pathways, suggest- ing the participation of CryD in posttranscriptional regulatory mechanisms. This is the first report on the participation of a cry- DASH protein in the regulation of fungal secondary metabolism

Gibberella fujikuroi mutants obtained with UV radiation and N-methyl-N'-nitro-N-nitrosoguanidine

N-methyi-N'-nitro-N-nitrosoguanidine (nitrosoguanidine) and to a lesser extent UV radiation are very mutagenic for Gibberella microconidia. The recommended nitrosoguanidine doses lead to much higher frequencies of mutants than are found in other microorganisms. The frequency of mutants among the survivors increases linearly with the nitrosoguanidine dose (molar concentration x time); the absolute number of viable mutants in a given population reaches a maximum for a dose of ca. O.7 M · s. The microconidia are uninucleate. The onset of germination brings about increased lethality of nitrosoguanidine, but it does not modify the action of UV radiation. Mycelia are more resistaót than spores to both agents. Visible Ulumination eft'ectively prevents lethality when given immediately alter UV irradiation. Auxotrophs and color mutants are very easily obtained. Pink adenine auxotrophs and several classes of color mutants are aft'ected in the biosynthesis of the carotenoid pigment, neurosporaxanthin

Impact of the White Collar Photoreceptor WcoA on the Fusarium fujikuroi Transcriptome

The proteins of the White Collar 1 family (WC) constitute a major class of flavin photoreceptors, widely distributed in fungi, that work in cooperation with a WC 2 protein forming a regulatory complex. The WC complex was investigated in great detail in Neurospora crassa, a model fungus in photobiology studies, where it controls all its major photoresponses. The fungus Fusarium fujikuroi, a model system in the production of secondary metabolites, contains a single WC-1 gene called wcoA. The best-known light response in this fungus is the photoinduction of the synthesis of carotenoids, terpenoid pigments with antioxidant properties. Loss of WcoA in F. fujikuroi results in a drastic reduction in the mRNA levels of the carotenoid genes, and a diversity of morphological and metabolic changes, including alterations in the synthesis of several secondary metabolites, suggesting a complex regulatory role. To investigate the function of WcoA, the transcriptome of F. fujikuroi was analyzed in the dark and after 15-, 60- or 240-min illumination in a wild strain and in a formerly investigated wcoA insertional mutant. Using a threshold of four-fold change in transcript levels, 298 genes were activated and 160 were repressed in the wild strain under at least one of the light exposures. Different response patterns were observed among them, with genes exhibiting either fast, intermediate, and slow photoinduction, or intermediate or slow repression. All the fast and intermediate photoresponses, and most of the slow ones, were lost in the wcoA mutant. However, the wcoA mutation altered the expression of a much larger number of genes irrespective of illumination, reaching at least 16% of the annotated genes in this fungus. Such genes include many related to secondary metabolism, as well as others related to photobiology and other cellular functions, including the production of hydrophobins. As judged by the massive transcriptomic changes exhibited by the wcoA mutant in the dark, the results point to WcoA as a master regulatory protein in F. fujikuroi, in addition to a central function as the photoreceptor responsible for most of the transcriptional responses to light in this fungus.España Ministerio de Economía y Competitividad, grant BIO2015-69613-RMinisterio de Ciencia e Innovación , MCI, Agencia Estatal de Investigación, AEI, and Fondo Europeo de Desarrollo Regional, FEDER, grant RTI2018-101902-B-I00)España Ministerio de Economía y Competitividad, grant BIO2015-71703-RED