Copia and Gypsy retrotransposons activity in sunflower (Helianthus annuus L.)

<p>Abstract</p> <p>Background</p> <p>Retrotransposons are heterogeneous sequences, widespread in eukaryotic genomes, which refer to the so-called mobile DNA. They resemble retroviruses, both in their structure and for their ability to transpose within the host genome, of which they make up a considerable portion. <it>Copia</it>- and <it>Gypsy</it>-like retrotransposons are the two main classes of retroelements shown to be ubiquitous in plant genomes. Ideally, the retrotransposons life cycle results in the synthesis of a messenger RNA and then self-encoded proteins to process retrotransposon mRNA in double stranded extra-chromosomal cDNA copies which may integrate in new chromosomal locations.</p> <p>Results</p> <p>The RT-PCR and IRAP protocol were applied to detect the presence of <it>Copia </it>and <it>Gypsy </it>retrotransposon transcripts and of new events of integration in unstressed plants of a sunflower (<it>Helianthus annuus </it>L.) selfed line. Results show that in sunflower retrotransposons transcription occurs in all analyzed organs (embryos, leaves, roots, and flowers). In one out of sixty-four individuals analyzed, retrotransposons transcription resulted in the integration of a new element into the genome.</p> <p>Conclusion</p> <p>These results indicate that the retrotransposon life cycle is firmly controlled at a post transcriptional level. A possible silencing mechanism is discussed.</p

Long-Term Microgravity Effects on Isometric Handgrip and Precision Pinch Force with Visual and Proprioceptive Feedback

The study and analysis of human physiology during short- and long-duration space flights are the most valuable approach in order to evaluate the effect of microgravity on the human body and to develop possible countermeasures in prevision of future exploratory missions and Mars expeditions. Hand performances such as force output and manipulation capacity are fundamental for astronauts’ intra- and extravehicular activities. Previous studies on upper limb conducted on astronauts during short-term missions (10 days) indicated a temporary partial reduction in the handgrip maximum voluntary contraction (MVC) followed by a prompt recovery and adaptation to weightlessness during the last days of the mission. In the present study, we report on the “Crew’s Health: Investigation on Reduced Operability” (CHIRO) protocol, developed for handgrip and pinch force investigations, performed during the six months increment 7 and increment 8 (2003-2004) onboard International Space Station (ISS). We found that handgrip and pinch force performance are reduced during long-term increments in space and are not followed by adaptation during the mission, as conversely reported during short-term increment experiments. The application of protocols developed in space will be eligible to astronauts during long-term space missions and to patients affected by muscle atrophy diseases or nervous system injury on Earth

BioRock:new experiments and hardware to investigate microbe–mineral interactions in space

In this paper, we describe the development of an International Space Station experiment, BioRock. The purpose of this experiment is to investigate biofilm formation and microbe–mineral interactions in space. The latter research has application in areas as diverse as regolith amelioration and extraterrestrial mining. We describe the design of a prototype biomining reactor for use in space experimentation and investigations on in situ Resource Use and we describe the results of pre-flight tests

Testing Laser-Structured Antimicrobial Surfaces Under Space Conditions: The Design of the ISS Experiment BIOFILMS

Maintaining crew health and safety are essential goals for long-term human missions to space. Attaining these goals requires the development of methods and materials for sustaining the crew’s health and safety. Paramount is microbiological monitoring and contamination reduction. Microbial biofilms are of special concern, because they can cause damage to spaceflight equipment and are difficult to eliminate due to their increased resistance to antibiotics and disinfectants. The introduction of antimicrobial surfaces for medical, pharmaceutical and industrial purposes has shown a unique potential for reducing and preventing biofilm formation. This article describes the development process of ESA’s BIOFILMS experiment, that will evaluate biofilm formation on various antimicrobial surfaces under spaceflight conditions. These surfaces will be composed of different metals with and without specified surface texture modifications. Staphylococcus capitis subsp. capitis, Cupriavidus metallidurans and Acinetobacter radioresistens are biofilm forming organisms that have been chosen as model organisms. The BIOFILMS experiment will study the biofilm formation potential of these organisms in microgravity on the International Space Station on inert surfaces (stainless steel AISI 304) as well as antimicrobial active copper (Cu) based metals that have undergone specific surface modification by Ultrashort Pulsed Direct Laser Interference Patterning (USP-DLIP). Data collected in 1 x g has shown that these surface modifications enhance the antimicrobial activity of Cu based metals. In the scope of this, the interaction between the surfaces and bacteria, which is highly determined by topography and surface chemistry, will be investigated. The data generated will be indispensable for the future selection of antimicrobial materials in support of human- and robotic-associated activities in space exploration

Copia and Gypsy retrotransposons: activity in sunflower and related species.

Retrotransposons are the prevalent and ubiquitous class of repetitive DNA sequences and constitute the bulk of the eukaryote genomes. The peculiar ability to move in different chromosomal location makes them part of the so-called mobile DNA, discovered by Barbara McClintock sixty years ago. During eukaryotic genome evolution, retrotransposons showed up the bias to invade the host genome via an effective replicative “copy and paste” mechanism based on an RNA intermediate. This RNA encodes enzymes committed to the retrotranscription and the integration back in the genome of a double stranded DNA daughter copy. As a consequence, retrotransposon are repeated and widespread in the genome of eukaryotes. Such features have allowed the developing of reliable molecular marker tools during last decade. One of these tools, to be used for LTR-retrotransposons, that display at 5’- and 3’-ends two long terminal repeats and are the most frequent class in plants, is the IRAP (Inter-Retrotransposon Amplified Polymorphism) protocol. It has been applied to study genetic variability in thirty-six wild accessions, twenty-six cultivars of sunflower (Helianthus annuus L.) and in thirty-nine species belonging to the genus Helianthus. Retrotransposon transcriptional and post-transcriptional activity have been also investigated by means of RT-PCR experiments and polymorphisms analysis in sunflower. Experiments indicate that Helianthus annuus genome harbours active retrotransposons, on the other hand their activity is controlled by the host to prevent hazardous effects due to retroposition, an event that occurred in the past and made retrotransposon proliferation responsible of a large genetic variability both at interspecific and intraspecific level

The Coenzyme Q10 (CoQ10) as Countermeasure for Retinal Damage Onboard the International Space Station: the CORM Project

Cells, tissues and organs of astronauts aboard the International Space Station (ISS) are exposed to the damaging effects of microgravity and cosmic radiation. Space Agencies are forced to find effective therapeutic countermeasures to safeguard astronauts’ health. Since retina is one of the most vulnerable target, we undertook a project entitled The Coenzyme Q10 (CoQ10) as countermeasure for retinal damage onboard the International Space Station: the CORM project, funded by the Italian Space Agency (ASI) and launched in the summer 2017. We selected CoQ10 as promising candidate drug, having previously first demonstrated its direct antiapoptotic property due to its ability to inhibit mitochondrial depolarization. Beside apoptosis prevention, the parameters we are measuring to evaluate the therapeutic effectiveness of CoQ10 are attenuation of cytoskeleton modifications, lowering of telomeric DNA damages, and exome and whole transcriptome alterations. Here, we present preliminary on-ground experiments that have been carried out in human retinal pigment epithelial ARPE-19 cells and the experimental design of the CORM experiment aboard the ISS. The results obtained by the CORM project will pave the way to countermeasures for astronauts who will face long-term missions

BIOKIS: a model payload for multidisciplinary experiments in microgravity.

In this paper we report about 1 the BIOKIS 2 payload: a multidisciplinary set of experiments and measurements in the fields of Biology and Dosimetry performed in microgravity. BIOKIS took advantage of the last STS-134 Endeavour mission and engineering state of the art in Space Life Science. The BIOKIS payload is compact, efficient, and capable to host experiments with different samples and science disciplines. Moreover, the time overlap of biological experiments and dosimetry measurements will produce more insightful information