Drosophila melanogaster, a model system for comparative studies on the responses to real and simulated microgravity

A key requirement to enhance our understanding of the response of biological organisms to different levels of gravity is the availability of experimental systems that can simulate microgravity and hypergravity in ground-based laboratories. This paper compares the results obtained from analysing gene expression profiles of Drosophila in space versus those obtained in a random position machine (RPM) and by centrifugation. The correlation found validates the use of the RPM simulation technique to establish the effects of real microgravity on biological systems. This work is being extended to investigate Drosophila development in another gravity modifying instrument, the levitation magnet.Peer Reviewe

Fármaco inhibidor de la proteína s1-spike del virus sars-cov-2 a partir de quimera hsace2/fago t4 con base hexagonal suministrable vía oral inhalatoria

Resumen del Proyecto: Fármaco inhibidor de la proteína s1-spike del virus sars-cov-2 a partir de quimera hsace2/fago t4 con base hexagonal suministrable vía oral inhalatoriaTrabado de investigacio

The “Gene” Experiment in the Spanish Soyuz Mission to the International Space Station. II. Effects of oxygen concentration constrain

This is a manuscript version. The Final online version of this article (http://www.springerlink.com/content/m21585633538t8q3/) contains supplementary material, which is available to authorized users.In the GENE experiment performed during an 11-day Soyuz Mission to the International Space Station (ISS), we intended to determine if microgravity affects Drosophila metamorphosis processes. Control experiments were performed including a 1g ground control parallel to the ISS flight samples and a Random Position Machine microgravity simulated control. A preliminary analysis of the results indicates that five hundred to one thousand genes change their expression profiles depending on the cut-off levels selected. Especially affected among them are the mitochondrial ones (an example with the respiratory chain is presented). We show here that there is a synergic effect of the constraints introduced to meet the requirements of the space experiment (mainly, a cold step and the use of hermetically closed Type-I containers). The cold transport step to the launch site was introduced to slow down the pupal development. The hermetically closed Type I containers were required to ensure the containment of the fixative (acetone) in the experiment. As shown here, the oxygen concentration inside the container was not optimal but fully compatible with pupal development. It is highly likely that such combined environmental effects will become a common finding in these types of studies as they become more complicated and extensive. They could open the way to understand how the gene expression patterns and the actual phenotypes can adjust to the environment. These findings indicate the importance of a vigorous ground based program in support of real microgravity experiments. Only then we can utilize the ISS in order to understand the consequences of the modified environment in outer space on living organisms.Peer reviewe

Comparative analysis of Drosophila melanogaster and Caenorhabditis elegans gene expression experiments in the European Soyuz flights to the International Space Station

The European Soyuz missions have been one of the main routes for conducting scientific experiments onboard the International Space Station, which is currently in the construction phase. A relatively large number of life and physical sciences experiments as well as technology demonstrations have been carried out during these missions. Included among these experiments are the Gene experiment during the Spanish “Cervantes” Soyuz mission and the ICE-1st experiment during the Dutch “Delta” mission. In both experiments, full genome microarray analyses were carried out on RNA extracted from whole animals recovered from the flight. These experiments indicated relatively large scale changes in gene expression levels in response to spaceflight for two popular model systems, Drosophila melanogaster (Gene) and Caenorabditis elegans (ICE-1st). Here we report a comparative analysis of results from these two experiments. Finding orthologous genes between the fruit fly and the nematode was far from straightforward, reducing the number of genes that we could compare to roughly 20% of the full comparative genome. Within this sub-set of the data (2286 genes), only six genes were found to display identical changes between species (decreased) while 1809 genes displayed no change in either species. Future experiments using ground simulation techniques will allow producing a better, more comprehensive picture of the putative set of genes affected in multicellular organisms by changes in gravity and getting a deeper understanding of how animals respond and adapt to spaceflight.The support of the all organizations and people involved in the Cervantes and Delta missions, the Spanish Space Program (Spanish Ministery of Education and Science), the Dutch Space Program, ESA, the CNES and NASA that made possible this work is gratefully acknowledged.Peer reviewe

Drosophila Behaviour & Gene expression in altered gravity conditions: Comparison between Space and ground facilities

Manuscript versionPrevious experiments in space (unmanned satellites, space shuttle and the International Space Station, ISS), have shown that adult Drosophila flies change their motile behaviour in microgravity. A consistent increase in motility in space was found in these experiments, but mature flies (two weeks old) showed less increase than recently hatched flies. In the case of relatively long exposure to microgravity, the aging of male flies measured upon return to Earth was increased, with flies dying earlier than the corresponding in-flight 1g centrifuge or ground controls. The older flies, which experienced a smaller increase in motility, did not show this acceleration in the aging process. More recently we have performed comparative experiments using ground simulation facilities. Preliminary experiments using a random positioning machine (RPM) indicate that the effects of this simulation approach on the behavior of Drosophi l a a r e o f s m a l l e r m a g n i t u d e t h a n t h e corresponding exposure to real microgravity. Further experiments are in progress to confirm this effect. However, when exposed to magnetic levitation, flies exposed to simulated weightlessness increased markedly their motile behavior compared with 1g controls both inside and outside the magnet. This altered gravity-related increase in motility was also less pronounced in more mature flies. This motility effect at the levitation position reproduces the results in real microgravity indicating the interest for space science of this simulation approach. Similar experiments are being performed in the Larger Diameter Centrifuge (LDC) located in ESTEC (the Netherlands) and indicate that 6g, 12g and 20g are key points in the hypergravity response in flies. Our experiments have shown that developmental processes from embryo to adult proceeded normally in the magnet, the RPM and the LDC. In terms of gene expression, preliminary results i n d i c a t e t h a t t h e a f f e c t e d s e t o f g e n e s u n d e r hypergravity responds in general in an opposite direction than that induced by the real or simulated microgravity exposure. The interest in conducting comparative parallel experiments in the complete spectrum of ground simulation methods is shown in the above studies and will be achieved in the near future.Peer reviewe

Spaceflight-related suboptimal conditions can accentuate the altered gravity response of Drosophila transcriptome

Genome-wide transcriptional profiling shows that reducing gravity levels during Drosophila metamorphosis in the International Space Station (ISS) causes important alterations in gene expression: a large set of differentially expressed genes (DEGs) are observed compared to 1g controls. However, the preparation procedures for spaceflight and the nonideal environmental conditions on board the ISS subject the organisms to additional environmental stresses that demonstrably affect gene expression. Simulated microgravity experiments performed on the ground, under ideal conditions for the flies, using the random position machine (RPM), show much more subtle effects on gene expression. However, when the ground experiments are repeated under conditions designed to reproduce the additional environmental stresses imposed by spaceflight procedures, 79% of the DEGs detected in the ISS are reproduced by the RPM experiment. Gene ontology analysis of them shows they are genes that affect respiratory activity, developmental processes and stress-related changes. Here, we analyse the effects of microgravity on gene expression in relation to the environmental stresses imposed by spaceflight. Analysis using 'gene expression dynamics inspector' (GEDI) self-organizing maps reveals a subtle response of the transcriptome to microgravity. Remarkably, hypergravity simulation induces similar response of the transcriptome, but in the opposite direction, i.e. the genes promoted under microgravity are usually suppressed under hypergravity. These results suggest that the transcriptome is finely tuned to normal gravity and that microgravity, together with environmental constraints associated with space experiments, can have profound effects on gene expression. © 2010 Blackwell Publishing Ltd.This work was supported by grants from the Spanish Space Program in the ‘Plan Nacional de Investigación Científica y Desarrollo Tecnológico’ [ESP2001-4522-PE and ESP2006-13600-C02-01 to Marco. and ESP2006-13600-C02-02 to Medina.] and the Dutch NWO-ALW-SRON grant [MG-057 to van Loon]. R. Herranz during the Cervantes mission and D. Lavan during the post-flight analysis were supported by Spanish Ministerio de Educación y Ciencia within the FPI fellowship program.Peer Reviewe

Validación del cuestionario sobre la salud del paciente–9 (PHQ-9) en internos de medicina humana de una universidad de referencia del Perú durante la pandemia COVID-19: Validation of the Patient Health Questionnaire-9 (PHQ-9) in human medicine interns at a reference university in Peru during the COVID-19 pandemic

Objectives: Validate a questionnaire to establish the perception of difficulties in the development of research projects in the students of the research area of ​​the Faculty of Human Medicine of the Peruvian University Los Andes. Methods: Validation study of a questionnaire designed and based on a Likert scale applied to the students of the subjects of Research process, Thesis seminar I and Thesis seminar II with stratified random probability sampling, content validity analysis and construct by expert judgment and statistical analysis of reliability with Cronbach's alpha. Results: The sample consisted of 85 students who agreed to be part of the study, of which 64,70% belonged to the female gender with an average age of 23 ± 5 years, subject of thesis seminar I 36,47%, Process research 34,12%, thesis seminar II 29,41%; 64,71% expressed difficulties in preparing the research project in formulating the theoretical framework and methodology, 62,35% in writing the bibliography and annexes, 61,18% in posing the problem and formulating hypotheses, in definition of the title 58,82% and in preparation of the administration of the project plan 47,06%. Cronbach's alpha reliability was 0,969. Conclusions: The questionnaire is reliable and valid, it has high internal consistency and valid criteria.Objetivos: Validar un cuestionario para establecer la percepción de dificultades en la elaboración de proyectos de investigación en los estudiantes del área de investigación de la Facultad de Medicina Humana de la Universidad Peruana Los Andes (UPLA). Métodos: Estudio de validación de un cuestionario diseñado y basado en una escala de Likert aplicado a los estudiantes de las asignaturas de Proceso de investigación, Seminario de tesis I y Seminario de tesis II con muestreo probabilístico aleatorio estratificado, análisis de validez del contenido y constructo por juicio de expertos y el análisis estadístico de la confiabilidad con alfa de Cronbach. Resultados: La muestra estuvo constituida por 85 estudiantes que aceptaron ser parte del estudio, de los cuales el 64,70 % pertenecieron al género femenino con una edad media de 23 ± 5 años, asignatura de Seminario de tesis I 36,47%, Proceso de investigación 34,12%, Seminario de tesis II 29,41%; manifestaron dificultades en la elaboración del proyecto de investigación en formulación del marco teórico y metodología el 64,71 %, en redacción de bibliografía y anexos el 62,35 %, en planteamiento del problema y formulación de las hipótesis el 61,18 %, en definición del título el 58,82 % y en elaboración de la administración del plan del proyecto el 47,06 %. La confiabilidad alfa de Cronbach fue 0,969. Conclusiones: El cuestionario es confiable y válido, tiene consistencia interna alta y validez de criterio adecuada

The “Gene” Experiment in the Spanish Soyuz Mission to the International Space Station. Effects of cold transportation

Manuscript version. Final Article available on the publisher site. http://www.springerlink.com/content/k5w4j8747211p13h/?p=1823d8063e69447cbbb58584de4e2425&pi=3If exploration of outer space is going to be a major human enterprise in the future, it is important to establish the nature of the biological response to the space environment. In one of the recent Soyuz missions to serve the ISS, the Spanish Soyuz Mission in October 2003, we sent a group of Drosophila pupae that underwent almost complete development there. Microarray analyses of the RNAs extracted from flies fixed in the ISS revealed that a relatively large set of genes (15% of the total number assayed) suffered a significant expression change in these conditions. Furthermore, the samples had to be transported to the launch site and it was necessary to slow down their development by exposing them to a lower temperature, fully compatible with pupal development. Such a pre-exposure had an effect by itself on the pattern of gene expression observed after pupal development at normal temperature, but the two environmental factors seemed to act synergistically. These findings indicate the importance of maintaining a vigorous scientific program in the ISS to understand the consequences of the modified environment in outer space on living organisms.Peer reviewe