Single cell transcriptional profiling of spleens from mice flown on Rodent Research Reference Mission-2

In the Rodent Research Reference Mission (RRRM-2), forty female C57BL/6NTac mice were flown on the International Space Station. To assess differences in outcomes due to age, twenty 12 week-old and twenty 29 week-old mice were flown, respectively. To directly assess spaceflight effects, half of the young and old mice (10 old, 10 young) were sacrificed on-orbit after 55-58 days (ISS Terminal, ISS-T), while the other half (10 old, 10 young) were returned live to Earth after 32 days and allowed to recover for 24 days (Live Animal Return, LAR) before sacrifice. ISS-T and LAR mice were the same age at sacrifice. Both the ISS-T and LAR animals had independent ground controls (10 mice per group housed in flight hardware in matched environmental conditions), basal controls (10 mice per group sacrificed 2 days before launch), and vivarium controls (10 mice per group housed within standard vivarium habitats). Thus RRRM-2 included a total of 160 mice. This study includes single cell transcriptional profiling data from the spleens from 4 young LAR flight animals, 4 old LAR flight animals, 4 young LAR ground control animals, and 4 old LAR ground control animals.

啮齿类研究参考任务（Rodent Research Reference Mission, RRRM-2）中共纳入40只雌性C57BL/6NTac小鼠开展国际空间站（International Space Station, ISS）飞行实验。为探究年龄对实验结局的影响，研究分别设置20只12周龄与20只29周龄的小鼠参与太空飞行。

为直接评估太空飞行的生物学效应，年轻与年老小鼠各取半数（10只年老、10只年轻）在在轨飞行55至58天后实施安乐死，该分组记为空间站终末组（ISS Terminal, ISS-T）；剩余各10只年老、10只年轻小鼠则在飞行32天后被活体返回地球，经过24天的恢复饲养后再行安乐死，该分组记为活体动物返回组（Live Animal Return, LAR）。ISS-T组与LAR组小鼠在安乐死时的年龄完全一致。

ISS-T组与LAR组小鼠均设有三类对照：独立地面对照组（每组10只，饲养于与飞行硬件匹配的环境条件中）、发射前基础对照组（每组10只，于发射前2天实施安乐死）以及标准饲养室对照组（每组10只，饲养于标准实验动物饲养笼舍）。因此，RRRM-2研究总计纳入160只小鼠。

本数据集包含来自4只年轻LAR飞行组、4只年老LAR飞行组、4只年轻LAR地面对照组以及4只年老LAR地面对照组小鼠的脾脏单细胞转录谱分析数据。