22 research outputs found
Análisis de la expresión diferencial de genes involucrados en las vías metabólicas responsables de la síntesis de antocianinas en frutos de Fragaria chilensis ssp. chiloensis f. chiloensis y Fragaria chiloensis ssp. chilensis f. patagónica
133 p.El objetivo de la tesis doctoral fue realizar un estudio comparativo de la pigmentación de
fruto dentro de las dos formas botánicas de Fragaria chiloensis ssp. chiloensis. El estudio fue abordado a nivel transcripcional y químico. Para ello, frutos de ambas formas botánicas, f. chiloensis (frutilla nativa blanca) y f. patagonica (frutilla nativa roja), fueron recolectados en cuatro distintos estadios de desarrollo y maduración (verde pequeño, verde grande, blanco y maduro). A partir de fruto completo, sus órganos constituyentes (receptáculo y
aquenio) y tejidos, se analizaron los perfiles transcripcionales de genes estructurales y regulatorios (factores de transcripción) involucrados en las vías de biosíntesis de compuestos fenilpropanoides responsables de la formación de antocianinas a lo largo de los diferentes estadios. Mediante este exhaustivo análisis transcripcional, se seleccionó uno de
los genes regulatorios, FcMYB1, debido a su expresión diferencial detectada entre
receptáculo de fruto rojo y blanco. El ortólogo de este gen aislado en frutilla comercial demostró ser un supresor de la acumulación de pigmentos antociánicos en el sistema heterólogo de Nicotiana. Para caracterizar su función de manera homóloga en Fragaria chiloensis ssp. chiloensis f. chiloensis, frutos de frutilla blanca en estadio verde grande fueron agroinyectados con una cepa de A. tumefaciens portadora de una construcción de RNAi para FcMYB1 y cosechados en estadio maduro. Este trabajo demostró que la supresión génica del factor de transcripción FcMYB1 propició la aparición de un fenotipo de frutos más pigmentados que los frutos control agroinyectados con vector vacío. Consecuentemente, los genes flavonoides finales relacionados con la biosíntesis de proantocianidinas mostraron niveles muy bajos de transcritos de leucoantocianidina reductasa (LAR) y antocianidina reductasa (ANR) en contraste con los niveles aumentados de transcritos de genes directamente relacionados con la biosíntesis de pigmentos antociánicos, antocianidina sintasa (ANS) y UDP-glicosiltransfersa (UFGT). Esta
redirección a nivel transcripcional de la vía flavonoides coincidió con una mayor
acumulación de antocianinas en frutos agroinyectados con la construcción RNAi-FcMYB1 detectadas por HPLC-DAD.
En conclusión, por medio del estudio comparativo en frutos contrastantes en pigmentación de una misma especie de frutilla, se detectaron diferencias en los niveles de transcritos de genes estructurales y regulatorios. Tras este análisis se seleccionó un factor de transcripción que demostró ser importante en la producción de pigmentos en esta especie.
Los genes diferencialmente expresados (estructurales y/o regulatorios) identificados en esta investigación pueden ser empleados como marcadores moleculares para asistir los programas de mejoramiento genético de frutilla./ABSTRACT: The aim of this doctoral thesis was to perform a comparative study of the fruit pigmentation
of two botanical forms of Fragaria chiloensis ssp. chiloensis. The study was carried out at
the transcriptional and chemical level. For this purpose, fruits of both botanical forms, f. chiloensis (white native strawberry) and f. patagonica (red native strawberry), were
collected and sorted in four distinct developmental and ripening stages (small green, large green, white and ripe). From whole fruit, their constituent organs (receptacle and achene) and tissues, the transcriptional profiles of structural and regulatory (transcription factors)
genes involved in anthocyanin related biosynthesis pathways were assessed among the
different stages. By means of this exhaustive transcriptional analysis, FcMYB1, a regulatoty gene was selected due to its differential expression detected between the receptacle of red and white fruits. Its orthologous gene isolated from the commercial strawberry demonstrated it to be a suppressor of the anthocyanin pigment as shown by accumulation in the heterologous system Nicotiana. For characterizing its function in a homologue manner in Fragaria chiloensis ssp. chiloensis f. chiloensis, fruits of white strawberry at large green stage were agroinjected with an A. tumefaciens strain bearing a RNAi construct for FcMYB1 and collected at ripe stage. According to this work, the gene suppression of this FT FcMYB1 favored a more pigmented phenotype in these fruits than in control fruits agroinjected with empty vector. Consequently, the final flavonoid genes related with proanthocyanidin biosynthesis showed very low levels of leucoanthocyanidin reductase (LAR) and anthocyanidin reductase (ANR) in contrast to the elevated transcript levels of
genes closely related to anthocyanic pigment biosynthesis, anthocyanidin synthase (ANS) y
UDP-glycosyltransferse (UFGT). This flavonoid pathway redirection at the transcriptional
level coincided with a greater accumulation of anthocyanin in RNAi-FcMYB1 agroinjected
fruits assessed by HPLC-DAD. In conclusion, through this comparative study carried out in fruits with contrasting pigmentation in the same strawberry species, differences in transcript levels of structural and regulatory genes were detected. After this analysis, a transcription factor that proved to be important in the pigment production in this specie was selected. Differentially expressed (structural and/or regulatory) genes identified in this research
could be used as molecular markers for assisting strawberry breeding programs
The global response to the COVID-19 pandemic: how have immunology societies contributed?
The COVID-19 pandemic is shining a spotlight on the field of immunology like never before. To appreciate the diverse ways in which immunologists have contributed, Nature Reviews Immunology invited the president of the International Union of Immunological Societies and the presidents of 15 other national immunology societies to discuss how they and their members responded following the emergence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)
Sloan Digital Sky Survey IV: mapping the Milky Way, nearby galaxies, and the distant universe
We describe the Sloan Digital Sky Survey IV (SDSS-IV), a project encompassing three major spectroscopic programs. The Apache Point Observatory Galactic Evolution Experiment 2 (APOGEE-2) is observing hundreds of thousands of Milky Way stars at high resolution and high signal-to-noise ratios in the near-infrared. The Mapping Nearby Galaxies at Apache Point Observatory (MaNGA) survey is obtaining spatially resolved spectroscopy for thousands of nearby galaxies (median ). The extended Baryon Oscillation Spectroscopic Survey (eBOSS) is mapping the galaxy, quasar, and neutral gas distributions between and 3.5 to constrain cosmology using baryon acoustic oscillations, redshift space distortions, and the shape of the power spectrum. Within eBOSS, we are conducting two major subprograms: the SPectroscopic IDentification of eROSITA Sources (SPIDERS), investigating X-ray AGNs and galaxies in X-ray clusters, and the Time Domain Spectroscopic Survey (TDSS), obtaining spectra of variable sources. All programs use the 2.5 m Sloan Foundation Telescope at the Apache Point Observatory; observations there began in Summer 2014. APOGEE-2 also operates a second near-infrared spectrograph at the 2.5 m du Pont Telescope at Las Campanas Observatory, with observations beginning in early 2017. Observations at both facilities are scheduled to continue through 2020. In keeping with previous SDSS policy, SDSS-IV provides regularly scheduled public data releases; the first one, Data Release 13, was made available in 2016 July
Age at first birth in women is genetically associated with increased risk of schizophrenia
Prof. Paunio on PGC:n jäsenPrevious studies have shown an increased risk for mental health problems in children born to both younger and older parents compared to children of average-aged parents. We previously used a novel design to reveal a latent mechanism of genetic association between schizophrenia and age at first birth in women (AFB). Here, we use independent data from the UK Biobank (N = 38,892) to replicate the finding of an association between predicted genetic risk of schizophrenia and AFB in women, and to estimate the genetic correlation between schizophrenia and AFB in women stratified into younger and older groups. We find evidence for an association between predicted genetic risk of schizophrenia and AFB in women (P-value = 1.12E-05), and we show genetic heterogeneity between younger and older AFB groups (P-value = 3.45E-03). The genetic correlation between schizophrenia and AFB in the younger AFB group is -0.16 (SE = 0.04) while that between schizophrenia and AFB in the older AFB group is 0.14 (SE = 0.08). Our results suggest that early, and perhaps also late, age at first birth in women is associated with increased genetic risk for schizophrenia in the UK Biobank sample. These findings contribute new insights into factors contributing to the complex bio-social risk architecture underpinning the association between parental age and offspring mental health.Peer reviewe
Sloan Digital Sky Survey IV: mapping the Milky Way, nearby galaxies, and the distant universe
We describe the Sloan Digital Sky Survey IV (SDSS-IV), a project encompassing three major spectroscopic programs. The Apache Point Observatory Galactic Evolution Experiment 2 (APOGEE-2) is observing hundreds of thousands of Milky Way stars at high resolution and high signal-to-noise ratios in the near-infrared. The Mapping Nearby Galaxies at Apache Point Observatory (MaNGA) survey is obtaining spatially resolved spectroscopy for thousands of nearby galaxies (median ). The extended Baryon Oscillation Spectroscopic Survey (eBOSS) is mapping the galaxy, quasar, and neutral gas distributions between and 3.5 to constrain cosmology using baryon acoustic oscillations, redshift space distortions, and the shape of the power spectrum. Within eBOSS, we are conducting two major subprograms: the SPectroscopic IDentification of eROSITA Sources (SPIDERS), investigating X-ray AGNs and galaxies in X-ray clusters, and the Time Domain Spectroscopic Survey (TDSS), obtaining spectra of variable sources. All programs use the 2.5 m Sloan Foundation Telescope at the Apache Point Observatory; observations there began in Summer 2014. APOGEE-2 also operates a second near-infrared spectrograph at the 2.5 m du Pont Telescope at Las Campanas Observatory, with observations beginning in early 2017. Observations at both facilities are scheduled to continue through 2020. In keeping with previous SDSS policy, SDSS-IV provides regularly scheduled public data releases; the first one, Data Release 13, was made available in 2016 July