Transcriptional profiling of thymus tissue from rats flown on the SLS-2 mission

The Spacelab Life Sciences (SLS) program was a series of payloads that used the facilities of an entire Spacelab module to conduct a variety of life science investigations. The general objective of the research in the SLS programs was to study the acute and chronic changes that living systems undergo during exposure to the space environment. The specific objective of the Spacelab Life Sciences-2 (SLS-2) mission was to study the structural and functional changes occurring in the bone, muscle, blood, and balance systems of rats in response to space flight. Rats were housed in individual cages in the Research Animal Holding Facility (RAHF) and natural calcium in the food bar was replaced with a non-radioactive calcium isotope (40Ca). The General Purpose Transfer Unit (GPTU) was used to transfer rat cages from the RAHFs to the General Purpose Work Station (GPWS), enabling the crew to perform inflight experiment procedures on the rodents. To this end, a flight group (FLT) of 38-day old male Sprague-Dawley rats were launched from Kennedy Space Center (KSC) on 10/18/1993 and housed in Research Animal Housing Facility (RAHF) on the shuttle for 14 days before being returned alive to Earth. After splashdown, the FLT were decapitated, and dissection occurred on 11/1/1993. Asynchronous ground control animals (GC) were exposed identical environmental conditions as the FLT group except for noise profile, acceleration and vibration. GC animals were housed in SpaceLab-3 (SL-3) simulated cages and dissection occurred on 11/1/1993. Upon dissection, thymus tissues were preserved in liquid nitrogen and stored at -70 C before RNA was extracted. This dataset features 6 FLT and 6 GC biological replicates. In preparation for RNA extraction, thymus tissues were prepared by generating wedge cuts from the top and bottom of the tissue, designated as Cut1 and Cut2. RNA was then extracted from both sets of cuts for all samples. For all FLT and GC samples, purified RNA from Cut2 was selected for library construction. Additionally, purified RNA from Cut1 was also selected for library construction for only one FLT and one GC sample, FLT_F15_Cut1 and GC_G12_Cut1, respectively, which also included four technical replicates (LibRep1-4). All libraries were generated using the QIAseq UPX 3’ Transcriptome kit that enables 3’ gene expression analysis from purified RNA and sequenced around 40 M clusters at SE 93 bp.

空间生命科学（Spacelab Life Sciences, SLS）计划是一系列搭载完整空间实验室（Spacelab）舱段设施、开展各类生命科学研究的有效载荷任务。该计划下研究的总体目标是探究生命系统在暴露于太空环境时所经历的急性与慢性变化。空间生命科学-2（Spacelab Life Sciences-2, SLS-2）任务的具体目标是研究大鼠在太空飞行中，骨骼、肌肉、血液及平衡系统所发生的结构与功能变化。实验大鼠被饲养于实验动物饲养设施（Research Animal Holding Facility, RAHF）的独立笼盒中，且将饲料棒中的天然钙替换为非放射性钙同位素（⁴⁰Ca）。通用转运单元（General Purpose Transfer Unit, GPTU）用于将大鼠笼盒从实验动物饲养设施转运至通用工作站（General Purpose Work Station, GPWS），以便机组人员对啮齿类动物开展在轨实验操作。为此，38日龄的雄性斯普拉格-道利（Sprague-Dawley）大鼠飞行组（Flight Group, FLT）于1993年10月18日从肯尼迪航天中心（Kennedy Space Center, KSC）发射升空，在航天飞机搭载的实验动物饲养设施中饲养14天后被活体运回地球。溅落后，飞行组大鼠于1993年11月1日被断头处死并实施解剖。异步地面对照组（Asynchronous Ground Control, GC）的饲养环境与飞行组基本一致，仅在噪声谱、加速度及振动条件上存在差异。地面对照组大鼠被饲养于空间实验室-3（Spacelab-3, SL-3）模拟笼盒中，并于1993年11月1日进行解剖。解剖完成后，胸腺组织被置于液氮中保存，并在-70℃环境下储存直至RNA提取。本数据集包含6个飞行组生物学重复样本与6个地面对照组生物学重复样本。为开展RNA提取，实验人员对胸腺组织进行处理：从组织的上下两端切取楔形切片，分别记为Cut1与Cut2；随后从两组切片中均提取RNA。针对所有飞行组与地面对照组样本，均选取Cut2的纯化RNA进行文库构建。此外，仅针对1个飞行组样本FLT_F15_Cut1与1个地面对照组样本GC_G12_Cut1，额外选取其Cut1的纯化RNA进行文库构建，且该两组样本均设置了4个技术重复（LibRep1-4）。所有文库均采用QIAseq UPX 3’转录组试剂盒（QIAseq UPX 3’ Transcriptome kit）构建，该试剂盒可实现纯化RNA的3’端基因表达分析，测序采用单端93bp读长，每个样本产出约40M个簇。