4D time-lapse images of brain and trunk development in the larvacean Oikopleura dioica

The larvacean, Oikopleura dioica is a planktonic chordate, which is an emerging model organism with a short life cycle of 5 days and belongs to tunicates (urochordates). Organ formation in the trunk proceeds in seven hours from hatching of tailbud larvae at three hours after fertilization (hpf) to completion of organ formation in fully functional juveniles that start feeding at 10 hpf and are just miniature of adult form. Development of O. dioica has been described (Nishida, H., 2008 Development of the appendicularian Oikopleura dioica: culture, genome, and cell lineages. Dev. Growth Differ. 50, S239–S256.). The dataset contains 4D (3D+time) time-lapse images that were acquired during larval development using differential interference contrast optics, and wide-field fluorescent microscope, which visualize cell membrane and nuclei of the entire trunk region. In some cases, animal or vegetal hemisphere blastomeres are labelled to trace the descendants. The dataset would be generally utili..., To immobilize swimming larvae for time-lapse movies, the tail was cut off immediately after hatching with a fine knife made of tungsten wire. In other experiments, notochord development in the tail was suppressed by Brachyury DNA interference (Omotezako et al., 2015). Double-stranded PCR products (50 ng/µL) of Brachyury were injected into the ovarian cytoplasm. Brachyury DNAi did not affect trunk development. To visualize the cell membrane, 5 ng/µL FM-1-43 FX (Invitrogen, Carlsbad, CA, USA) was used in seawater. Larvae were transferred into FM seawater for at least 15 min before imaging. Live imaging of nuclei and chromosomes was performed using fluorescent proteins. 2 µg/µL Histone 2B (H2B)-EGFP mRNA (Kishi et al., 2014, 2017; Morita et al., 2020) was injected into the ovary syncytium of females on day five (approximately half a day before spawning) (Omotezako et al., 2015). After spawning and fertilization, embryos with the highest fluorescence intensity were selected and imaged after..., To look at the image sequence, one can open a single TIFF file in ImageJ/Fiji software. One can select color channels (c), z-sections (z), and run the movie (triangle). Time after hatching is indicated in most image sequences.,住囊虫（Oikopleura dioica）是一种浮游脊索动物，隶属于被囊动物门（tunicates，尾索动物亚门urochordates），同时也是一种生命周期仅为5天的新兴模式生物。其躯干的器官发生过程仅耗时7小时：从受精后3小时（hours post fertilization，简称hpf）的尾芽幼虫孵化起，至受精后10小时（hpf）时即可完成全部器官发生，此时的幼体已具备完整生理功能并开始摄食，形态仅为成体的微缩版本。O. dioica的发育过程已有文献报道（Nishida, H., 2008 被囊动物住囊虫的发育：培养、基因组与细胞谱系. 《发育、生长与分化》, 50, S239–S256.）。 本数据集包含幼虫发育过程中采集的四维（3D+时间）延时成像数据：成像采用微分干涉差（differential interference contrast，简称DIC）光学系统与宽场荧光显微镜，可对整个躯干区域的细胞膜与细胞核进行可视化成像。部分实验中，研究人员会对动物极或植物极半球的卵裂球进行荧光标记，以追踪其细胞后裔的发育命运。本数据集总体上可应用于…… 为固定游动中的幼虫以进行延时成像，研究人员会在幼虫孵化后立即使用钨丝制成的显微手术刀切断其尾部。另有部分实验中，研究人员通过Brachyury DNA干扰技术（Omotezako等, 2015）抑制尾部脊索的发育：将浓度为50 ng/µL的Brachyury双链PCR产物注射至雌性个体的卵巢细胞质中，该Brachyury DNA干扰并不会对躯干发育造成影响。 为可视化细胞膜，研究人员在海水中添加浓度为5 ng/µL的FM-1-43 FX染料（Invitrogen公司，美国加利福尼亚州卡尔斯巴德），并将幼虫置于该染液海水中孵育至少15分钟后再进行成像。细胞核与染色体的活细胞成像则通过荧光蛋白标记实现：将浓度为2 µg/µL的组蛋白2B（H2B）-增强绿色荧光蛋白（EGFP）mRNA（Kishi等, 2014, 2017; Morita等, 2020）注射至产卵前5天（约产卵前半天）的雌性个体的卵巢合胞体中（Omotezako等, 2015）。产卵与受精后，研究人员会选取荧光强度最高的胚胎进行后续成像…… 若要查看图像序列，可在ImageJ/Fiji软件中打开单张TIFF格式文件，通过选择颜色通道（c）、Z轴切片（z）并点击播放按钮（三角图标）即可实现影像浏览。大多数图像序列中都会标注孵化后的时间信息。