Rosalind Silverman-Gavrila (2011) CIL:8073, Drosophila melanogaster. CIL. Dataset

Early embryonic divisions in Drosophila are syncytial. Nuclei undergo mitosis synchronously for the first 14 nuclear cycles, followed by cellularization (Foe and Alberts, 1983). At nuclear cycle 10, nuclei are at the embryo cortex and can be easily visualized. Silverman's first movie (an ASCB 2005 Celldance contest winner) shows a Drosophila embryo of a line expressing a fusion protein of GFP and tubulin (Grieder et al., 2000). This fusion protein enables the visualization of spindle assembly and disassembly during 4 consecutive divisions. Spindle assembly starts when the nuclear membrane breaks down and microtubules are produced at centrosomes that are at opposite positions of nuclei. Next, microtubules attach to chromosomes and assemble onto a bipolar spindle. When the chromosomes segregate, the spindles elongate. Chromosome movement to poles is favored by disassembly of the microtubules to which they are connected. The other microtubules that are not attached to chromosomes form the midbody. In late telophase, midbodies disassemble. Next, the centrosomes duplicate and migrate to opposite positions of the nuclei and the cycle of spindle assembly starts again. With every cycle, the spindles are smaller and closer.

Embryos were collected 2 hours after they were laid, dechorionated with 50% bleach and visualized by confocal microscopy. Images were captured with a Nikon Eclipse TE2000-E inverted microscope (Nikon Mississauga, ON, Canada) using a Plan Apochromat 40 x 1.5/NA1.0 oil immersion lens. The visualization setting included a Perkin Elmer Life Sciences UltraVIEW confocal spinning disk (Perkin Elmer Life Sciences, Missisauga, ON, Canada) and a Hamamatsu Orca-ER camera (Hamamatsu Photonics, Hamamatsu, Japan). Images were acquired at room temperature, every 8 seconds at 3-5 Z series of 40 m steps using the MetaMorph software (Universal Imaging, West Chester, PA).

Quicktime video. Digitization process: Recompressed with H.264 codec, automatic keyframes selected, and data rate reduced (restricted to 768 kbs optimized for streaming) in Quicktime Pro. New file size: 2.48 Mb; Duration: 00:00:25.29; Dimensions: 297 x 504; FPS: 15.5; Data rate: 801.18 kbs; Codec: H.264.

在果蝇的早期胚胎分裂过程中，细胞质是合胞体的。在最初的14个细胞核周期内，细胞核同步进行有丝分裂，随后发生细胞化（Foe 和 Alberts，1983年）。在细胞核周期10时，细胞核位于胚胎皮质，可轻易进行可视化。Silverman 的首部电影（ASCB 2005 年 Celldance 竞赛优胜作品）展示了表达 GFP 和微管融合蛋白的果蝇胚胎（Grieder 等，2000年）。该融合蛋白使得在连续4次分裂过程中纺锤体的组装与解体过程得以可视化。纺锤体的组装始于核膜的破裂以及位于细胞核相对位置的细胞中心体产生微管。随后，微管附着于染色体上，组装成双极纺锤体。当染色体分离时，纺锤体变长。由于与染色体相连的微管解体，染色体向两极的移动受到促进。未附着于染色体的其他微管形成中体。在晚期的终变期，中体会发生解体。接着，细胞中心体复制并迁移到细胞核的对侧位置，纺锤体的组装周期再次开始。随着每个周期的进行，纺锤体逐渐变小并靠近。胚胎在产出后2小时内收集，使用50%的漂白剂脱去卵壳并利用共聚焦显微镜进行可视化。图像通过尼康 Eclipse TE2000-E 倒置显微镜（尼康密西沙加，加拿大）和Plan Apochromat 40 x 1.5/NA1.0 油浸镜头捕捉。可视化设置包括Perkin Elmer Life Sciences UltraVIEW 共聚焦旋转盘（Perkin Elmer Life Sciences，密西沙加，加拿大）和Hamamatsu Orca-ER 摄像头（Hamamatsu Photonics，日本）。图像在室温下以每8秒3-5层40微米的Z序列进行采集，使用MetaMorph 软件（Universal Imaging，西切斯特，宾夕法尼亚州）。

Quicktime 视频数字化过程：使用H.264编解码器重新压缩，自动选择关键帧，并通过Quicktime Pro将数据率降低（限制为768 kbs，优化为流媒体传输）。新文件大小：2.48 Mb；时长：00:00:25.29；尺寸：297 x 504；帧率：15.5；数据率：801.18 kbs；编解码器：H.264。