刘永飞--斑马鱼的胚胎发育

Three: Blastula Period (2.25-5.25h)
We use the term blastula to refer to the period when the blastodisc begins to look ball-like, at the 128-cell stage, or eighth zygotic cell cycle, and until the time of onset of gastrulation,ca. cycle 14.
斑马鱼的特点
• • • • • • 成年鱼个体小，易于饲养 发育快速、性成熟期短、繁殖力强 胚胎体外发育，易于观察和操作 较完善的胚胎和遗传学操作技术 基因组序列的注释已经完成 品系资源丰富
Stages of Embryonic Development of the Zebrafish
Seven Broad Zygote Cleavage Blastula Gastrula Segmentation Pharyngula Hatching
Stages During the Cleavage Period
Two-cell stage (0.75h) Four-cell stage (1 h) Eight-cell stage (1.25h) Sixteen-cell stage (1.5h) Thirty two-cell stage (1.75h) Sixty four-cell stage (2 h)
Stages During the Zygote Period
One-cell stage
The zygote period. A:a few minutes after fertilization. B:about 10 min after fertil-i zation.
Two: Cleavage Period (0.75-2.25h)
Stages of Embryonic Development of the Zebrafish
刘永飞 20121902004
斑马鱼(Danio rerio)属于辐鳍亚纲(Ac tinop-terygii)鲤科(Cyprinidae)短担尼鱼 属(Danio)的一种硬骨鱼。原产于印度东部、 巴基斯坦、缅甸及孟加拉国的小溪、稻田及 恒河中游地区，是一种常见的热带观赏鱼， 因其体侧具有像斑马一样纵向的暗蓝与银色 相间的条纹而得名。
0-0.75h 0.75-2.25h 2.25-5.25h 5.25-10h 10-24h 24-28h 48-72h
One: Zygote Period (0-0.75h)
1. The newly fertilized egg is in the zygote period until the first cleavage occurs, about 40 minutes after fertilization. 2. The zygote is about 0.7 mm in diameter at the time of fertilization. 3. We include only a single stage called Onecell stage; however many changes are occurring, and one could easily subdivide the period.
Seven: Hatching Period (48-72h)
1. The time of hatching is not useful as a staging index for the zebrafish, in contrast to some other types of embryos, because individuals within a single developing clutch hatch sporadically during the whole 3rd day of development (at standard temperature), and occasionally later. 2. Whether or not an embryo has hatched, its development progresses, hour by hour, and generally individuals that have spontaneously hatched are not more developmentally advanced than ones remaining in their chorions. 3. We arbitrarily call the creatures “embryos” until the end of the 3rd day, and afterward, “larvae,” whether they haver: Gastrula Period (5.25-10h)
The morphogenetic cell movements of involution, convergence, and extension occur, producing the primary germ layers and the embryonic axis.
Face views of embryos during the blastula period. A:256-cell stage(2.5h). B: High stage (3.3h). C:Transition between the high and oblong stages(3.5h). D:Transition between the oblong and sphere stages (3.8h). E:Dome stage (4.3h). F: 30%-epiboly stage (4.7h).
Stages During the Blastula Period
128-cell stage (2.25h) 256-cell stage (2.5h) 512-cell stage (2.75h) lk-cell stage (3 h) High stage (3.25h) Oblong stage (3.66h) Sphere stage (4 h) Dome stage (4.33h) 30%-epiboly stage (4.66h)
斑马鱼的发展史
一. 20世纪70年代初，利用T4噬菌体研究遗传学的 美国俄勒冈大学著名遗传学家George Streisinger注意 到斑马鱼的优点，从宠物店购买了斑马鱼，开始研 究其养殖方法、观察其胚胎发育过程、发展一些相 关的遗传学技术。 • 二. 近十年后，他的研究组于1981年在Nature上发 表了第一篇具有深刻影响的论文（Production of clon es of homozygous diploid zebrafish）。在这篇论文中， 他们报导了斑马鱼的体外受精技术、单倍体诱导技 术，建立了纯合品系，并介绍了斑马鱼的第一个自 然突变体——golden。 •
Five: Segmentation Period (10-24h)
1. A wonderful variety of morphogenetic movements now occur, the somites develop, the rudiments of the primary organs become visible, the tail bud becomes more prominent and the embryo elongates. The first cells differentiate morphologically, and the first body movements appear. 2. The tail bud appears at the caudal end of the lengthening axis during the whole time.
Stages During the Pharyngula Period
High-pec stage (42h)
Prim-25 stage (36h)
Prim-12 stage (30h)
Prim-5 stage (24h)
A:Prim-5 stage (24h) ；B:Prim-12 stage (30h) ；F:Prim-25 stage (36h)；H:High-pec stage (42h).
Embryos during the cleavage period. A:Two-cell stage(0.75 h). 8: Four-cell s tage(1 h). C: Eight-cell stage (1.25h). D:Sixteen-cell stage (1.5 h). E:Thirty-two c ell stage(1.75 h). F: Sixty-four cell stage(2 h).
1. After the first cleavage the cells, divide at about 15-minute intervals. 2. The cytoplasmic divisions are meroblastic; they only incompletely undercut the blastodisc, and the blastomeres, or a specific subset of them according to the stage remain interconnected by cytoplasmic bridges. 3. The six cleavages that comprise this period frequently occur at regular orientations so that one can see how many blastomeres are present are by their arrangement; counting them is unneccessary.
三. 在其后的几年中，Streisinger和他的同事先后报 导了斑马鱼的卵裂特点、不同时期胚胎中细胞的发 育命运等，并发现斑马鱼脑中的许多神经元的排列 简单而有规律。这些研究成果的报导，证明了斑马 鱼适合用做模式动物，引起了许多发育生物学家的 关注。 • 四. 20世纪90年代初，曾在果蝇上通过诱变研究阐 明果蝇胚胎早期发育机理的德国发育生物学家Christi ne Nü sslein-Volhard，以及美国哈佛大学Wolfgang Dr ie-ver博士的研究组同时开始对斑马鱼进行大规模化 学诱变研究，到1996年他们共鉴定出约4000种斑马 鱼突变体，为研究脊椎动物发育的分子机理储备了 丰富的遗传资源，Development专门于1996年用一期 增刊发表了36篇相关论文。 •
Stages During the Segmentation Period
2-somite stage (10.7h) 5-somite stage (11.7h) 14-somite stage (16h) 20-somite stage (19h) 25-somite stage (21.5h)
Development during the gastrula period. A: 50%-epiboly stage (5.25h). B: Germ ring stage (5.7h). D: Shield stage (6h). H:75%-epiboly stage (8h). J: 90%-epiboly stage (9h). L: Bud stage (10h).
The embryo is most evidently now a bilaterally organized creature, entering the pharyngula period with a well developed notochord, and a newly completed set of somites that extend to the end of a long post-anal tail.
A:2-somite stage(10.7h)；F:5-somite stage(11.7h)；I:14-somite stage(16h)； M:20-somite stage(19h)；N:25-somite stage(21.5h).
Six: Pharyngula Period (24-48h)
Stages During the Gastrula Period
• • • • • • 50%-epiboly stage (5.25h) Germ-ring stage (5.66h) Shield stage (6h) 75%-epiboly stage (8h) 90%-epiboly stage (9h) Bud stage (10h)