The objective of the Rodent Research-9 (RR-9) mission was to use mice to understand the molecular basis of phenomena that affect astronauts during long-duration spaceflight particularly visual impairment and joint tissue degradation. To this end a flight group (FLT) of 10 week-old male C57BL/6J mice were launched from Kennedy Space Center (KSC) on 8/14/2017 and housed in Rodent Habitats on the ISS for 33 days before being returned alive to Earth. After splashdown in the Pacific Ocean the animals were transported to Loma Linda University (LLU) for testing euthanasia and dissection on 9/18/2018. A Basal Control (BSL) was housed in standard cages at Kennedy Space Center (KSC) and euthanized one day after launch of the FLT animals (8/15/2017). Ground Control (GC) and Vivarium Control (VIV) studies were planned to commence at KSC approximately one-week after the conclusion of the flight experiments. However all the GC and VIV mouse studies at KSC had to be cancelled due to Hurricane Irma and potential adverse effects on the animal housing facility. The GC and VIV studies were therefore rescheduled and begun in May 2018. The GC was euthanized and dissected 6/18/2018 - 6/20/2018 while the VIV was euthanized and dissected 6/22/2018 - 6/23/2018. Because this resulted in a different cohort of mice being used for the GC and VIV controls as compared to the flight (FLT) and basal (BSL) groups two cohort controls were included in the study. The first Cohort Control 1 (CC_C1) was from the same cohort as the FLT and BSL animals and was sacrificed and dissected 4 days after the FLT group (9/22/2017). The second Cohort Control 2 (CC_C2) was from the same cohort as the GC and VIV animals and was sacrificed and dissected 2-8 days after the GC and VIV groups (6/24/2018 - 6/26/2018). The CC_C1 and CC_C2 groups were housed in standard cages and fed standard chow in contrast to all other groups which received Rodent Foodbars. To clarify the connections between treatment groups and animal cohorts the following group abbreviations are used in the sample metadata: Flight (FLT_C1); Basal (BSL_C1); Ground Control (GC_C2); Vivarium Control (VIV_C2) Cohort Control 1 (CC_C1); Cohort Control 2 (CC_C2). Upon dissection livers were preserved in liquid nitrogen and stored at -80 C before RNA was extracted libraries generated (stranded ribodepleted) and sequenced (target 60 M clusters at PE 150 bp).

The JAXA MHU-2 mission had two objectives: 1) To increase understanding of effects of spaceflight on the gut environment (microbiota and metabolites) and immune system using multi-omics based analysis; 2) To evaluate whether fructo-oligosaccharides added to the diet as prebiotics improve the gut environment and immune function during spaceflight. Twelve 16-18 week old male C57BL/6J mice were singly housed in the JAXA Habitat Cage Units (HCUs) on the ISS for 30 days. Six flight mice were housed in microgravity while six were exposed to simulated 1g by centrifugation. These two flight groups were further divided in half so that three mice in each group received standard JAXA chow while the other three were fed chow supplemented with fructooligosaccharides (FOS). Mice were returned live and euthanized and dissected <1 day after splashdown. Ground controls (n=6) were asynchronous and housed in HCUs. Vivarium controls (n=6) were asynchronous and housed in standard habitats. Three ground control and three vivarium animals received standard chow while the other three each ground control and vivarium animals received FOS-supplemented chow. Ground and vivarium samples were dissected by a separate dissection team than flight samples. Femoral skin was dissected 30 minutes after euthanasia and snap frozen in liquid nitrogen. Total RNA was extracted and sequenced at a target depth of 60 M clusters per sample (ribodepleted paired end 150). Study Factor Levels: 1)Spaceflight ug Std. Chow: 3; 2)Spaceflight ug FOS: 3; 3) Spaceflight Artificial 1g Std. Chow: 3; 4)Spaceflight Artificial 1g FOS: 3; 5)Ground 1g Std. Chow: 3; 6)Ground 1g FOS: 3; 7)Vivarium 1g Std. Chow: 3; 8)Vivarium 1g FOS: 3

The objective of the Rodent Research-7 mission (RR-7) was to study the impact of the space environment on the gut microbiota of two strains of mice and how any changes in-turn affect the immune system metabolic system and circadian or daily rhythms. To this end ten 11-week-old female C57BL/6J and ten 11-week-old female C3H/HeJ mice were flown to the International Space Station on June 29 2018 on SpaceX-15 and housed in two Rodent Habitats. Samples of food swabs from living surfaces and fecal pellets were collected from each animal before launch and regularly during the mission. The mission also involved extended video collection (48 hr video segments per Habitat) to monitor circadian rhythms and on-orbit mass measurement. After 25 days on-orbit half of the mice of each strain were euthanized on the ISS with Ketamine/Xylazine/Acepromazine and cardiac puncture after which carcasses were segmented in three sections and preserved in RNA later. After 75-76 days the remaining 5 animals from each group were euthanized and processed in the same manner. The 25-day dissected carcasses returned on SpX-15 and the 75-day dissected carcasses returned on SpX-16. In addition to the Flight group three ground control groups were also part of the study: Basal (representing the pre-launch state) Vivarium (standard vivarium housing for the same duration of time as flight) and Ground (same habitat in the International Space Station Environment Simulator ISSES). Twenty mice (10 of each strain) were included in each of these control groups which were euthanized and processed on the same schedule and in the same manner as the flight samples. Dissections for tissues from all experimental groups were completed by the PI groups along with NASA s Biospecimen Sharing Program in February 2019. GeneLab received dorsal skin samples from forty C57BL/6J mice: 10 Basal 5 Ground (25 days) 5 Ground (75 days) 5 Flight (25 days) 5 Flight (75 days) 5 Vivarium (25 days) 5 Vivarium (75 days). GeneLab received dorsal skin samples from forty C3H/HeJ mice: 10 Basal 5 Ground (25 days) 5 Ground (75 days) 5 Flight (25 days) 5 Flight (75 days) 5 Vivarium (25 days) 5 Vivarium (75 days). From these skin samples RNA was extracted libraries generated (stranded ribodepleted) and sequenced (target 60 M clusters at PE 98 bp).

The wild type Col-0 plants and the Sku-6 mutant plants of the Col-0 background were germinated on ISS or on the ground and the gene expression profiles in roots at 4 days or 8 days were established. The Sku6 gene (At2g03680) codes for a protein that localizes to microtubule within the cortical array and putatively acting as an intramolecular linker. The development of Col-0 and Sku-6 plants on orbit differs from that on the ground as demonstrated by the comparison of the gene expression profiles between 4 days old to 8 days old plant in the two environments. However the development of Sku-6 mutant plants also differs from Col-0 at either age and in either environment suggesting the role of the genetic background in these developmental decisions. The 4 days old Sku-6 roots in orbit engaged more genes than the 4 days old Col-0 roots in orbit but also more than the 4 days old Sku-6 roots on the ground. Overall the 4 days old roots differentially expressed more genes in spaceflight relative to ground than the 8 days old roots of either genotype.

The International Space Station (ISS) is a unique habitat for humans and microorganisms. Here, we report the results of the ISS experiment EXTREMOPHILES, including the analysis of microbial communities from several areas aboard at three time points. We assess microbial diversity, distribution, functional capacity and resistance profile using a combination of cultivation-independent analyses (amplicon and shot-gun sequencing) and cultivation-dependent analyses (physiological and genetic characterization of microbial isolates, antibiotic resistance tests, co-incubation experiments). We show that the ISS microbial communities are highly similar to those present in ground-based confined indoor environments and are subject to fluctuations, although a core microbiome persists over time and locations. The genomic and physiological features selected by ISS conditions do not appear to be directly relevant to human health, although adaptations towards biofilm formation and surface interactions were observed. Our results do not raise direct reason for concern with respect to crew health, but indicate a potential threat towards material integrity in moist areas.

The JAXA MHU-2 mission had two objectives: 1) To increase understanding of effects of spaceflight on the gut environment (microbiota and metabolites) and immune system using multi-omics based analysis; 2) To evaluate whether fructo-oligosaccharides added to the diet as prebiotics improve the gut environment and immune function during spaceflight. Twelve 16-18 week old male C57BL/6J mice were singly housed in the JAXA Habitat Cage Units (HCUs) on the ISS for 30 days. Six flight mice were housed in microgravity while six were exposed to simulated 1g by centrifugation. These two flight groups were further divided in half so that three mice in each group received standard JAXA chow while the other three were fed chow supplemented with fructooligosaccharides (FOS). Mice were returned live and euthanized and dissected <1 day after splashdown. Ground controls (n=6) were asynchronous and housed in HCUs. Vivarium controls (n=6) were asynchronous and housed in standard habitats. Three ground control and three vivarium animals received standard chow while the other three each ground control and vivarium animals received FOS-supplemented chow. Ground and vivarium samples were dissected by a separate dissection team than flight samples. Dorsal skin was dissected 30 minutes after euthanasia and snap frozen in liquid nitrogen. Total RNA was extracted and sequenced at a target depth of 60 M clusters per sample (ribodepleted paired end 150). Study Factor Levels: 1)Spaceflight ug Std. Chow: 3; 2)Spaceflight ug FOS: 3; 3) Spaceflight Artificial 1g Std. Chow: 3; 4)Spaceflight Artificial 1g FOS: 3; 5)Ground 1g Std. Chow: 3; 6)Ground 1g FOS: 3; 7)Vivarium 1g Std. Chow: 3; 8)Vivarium 1g FOS: 3.

The root apex is an important section of the plant root involved in environmental sensing and cellular development. Analyzing the gene profile of root apex in diverse environments is important and challenging especially when the samples are limiting and precious such as in spaceflight. The feasibility of using tiny root sections for transcriptome analysis was examined in this study. To understand the gene expression profiles of the root apex Arabidopsis thaliana Col-0 roots were sectioned into Zone-I (0.5 mm root cap and meristematic zone) and Zone-II (1.5 mm transition elongation and growth terminating zone). Gene expression was analyzed using microarray and RNA seq. Both the techniques arrays and RNA-Seq identified 4180 common genes as differentially expressed (with > two-fold changes) between the zones. In addition 771 unique genes and 19 novel TARs were identified by RNA-Seq as differentially expressed which were not detected in the arrays. Single root tip zones can be used for full transcriptome analysis; further the root apex zones are functionally very distinct from each other. RNA-Seq provided novel information about the transcripts compared to the arrays. These data will help optimize transcriptome techniques for dealing with small rare samples.

Metagenome analysis of ISS cargo resupply vehicles (CRV)

The objective of the Rodent Research-5 (RR-5) study was to evaluate bone loss in mice during spaceflight and to determine if treatment with a modified version of NEL-like molecule-1 (NELL-1) can reduce or prevent bone loss that would otherwise occur during spaceflight. To this end a cohort of forty 30-weeks-old female BALB/cAnNTac mice were flown to the ISS and housed in the Rodent Habitat. Six days after launch half of the mice were treated with NELL-1 (10 mg/kg in 0.3 ml PBS) while the other half were treated with vehicle control (0.3 ml PBS). Fourteen days after launch animals were again treated with NELL-1 or vehicle control as before except that all animals were also injected with the bone marker calcein green (20 mg/kg in 0.1 ml). Injections of vehicle NELL-1 and bone markers were intraperitoneal. After all forty mice on orbit received two treatments; ten control mice and ten experimental mice were randomly selected for live animal return (LAR). At approximately 30 days after launch the twenty LAR mice were transported live back to Earth. Animals were allowed to recover for 30 days in standard habitats before euthanasia via intraperitoneal injection with ketamine/xylazine. During the recovery the animals received another two treatments. GeneLab received RNA later preserved femoral skin from nine live animal return and ten matching ground control mice. These were from the vehicle control animals only. RNA was extracted libraries generated (stranded ribodepleted) and sequenced (target 60 M clusters at PE 150 bp).

The objective of the Rodent Research-5 (RR-5) study was to evaluate bone loss in mice during spaceflight and to determine if treatment with a modified version of NEL-like molecule-1 (NELL-1) can reduce or prevent bone loss that would otherwise occur during spaceflight. To this end a cohort of forty 30-weeks-old female BALB/cAnNTac mice were flown to the ISS and housed in the Rodent Habitat. Six days after launch half of the mice were treated with NELL-1 (10 mg/kg in 0.3 ml PBS) while the other half were treated with vehicle control (0.3 mls PBS). Fourteen days after launch animals were again treated with NELL-1 or vehicle control as before except that all animals were also injected with the bone marker calcein green (20 mg/kg in 0.1 ml). Injections of vehicle NELL-1 and bone markers were intraperitoneal. After all forty mice on orbit received two treatments; ten control mice and ten experimental mice were randomly selected for live animal return (LAR). At approximately 30 days after launch the twenty LAR mice were transported live back to Earth. Animals were allowed to recover for 30 days in standard habitats before euthanasia via intraperitoneal injection with ketamine/xylazine. During the recovery the animals received another two treatments. GeneLab received RNA later preserved dorsal skin from ten live animal return and ten matching ground control mice. These were from the vehicle control animals only. RNA was extracted libraries generated (stranded ribodepleted) and sequenced (target 60 M clusters at PE 150 bp).