Late specification of veg1 lineages to endodermal fate in the sea urchin embryo
Late specification of veg1 lineages to endodermal fate in the sea urchin embryo
复制标题
DOI：
10.1006/dbio.1997.8814
复制
发表时间：
1998-03-01
影响因子：
2.7
通讯作者：
Davidson, EH
中科院分区：
文献类型：
--
作者：
Ransick, A;Davidson, EH
用DiI谱系示踪剂标记红球海胆第6卵裂veg（1）和veg（2）层胚胎的单个卵裂球，并通过囊胚和原肠胚阶段跟踪后代的处置，以确定其各自的内胚层和外胚层贡献。在原肠胚后胚胎的内胚层中，veg（1）来源的细胞构成了几乎所有的预期后肠和大约一半的预期中肠，而veg（2）来源的细胞构成了预期前肠和一半的中肠。口服veg（1）克隆始终比离口veg（1）克隆贡献更多的细胞到内胚层。口服veg（1）克隆沿着原肠沿着延伸到前肠区域，而非口服veg（1）克隆仅提供少量的后肠细胞，但大量的外胚层细胞延伸到预期的幼虫顶点。谱系表达的植物板标记Endo16更精确地确定相结合的谱系示踪剂注射与整装原位杂交。Endo16在所有参与原肠胚形成的细胞中都有表达。新细胞向Endo16结构域的募集发生在这些细胞实际内陷之前。在囊胚阶段，Endo16表达呈放射状扩展，直到veg（2）谱系中的所有细胞表达该基因。原肠胚形成的第一阶段，包括植物板的正常屈曲和原肠的初级内陷，仅涉及veg（2）谱系的Endo16表达细胞。随着原肠开始伸长，标志着原肠胚形成第二阶段的开始，Endo16不对称地扩增到蔬菜来源的细胞中，根据谱系追踪观察，这将有助于后肠和中肠。结果表明，相对较晚的规范蔬菜（1）衍生的细胞，导致后期招聘到周边的植物板领土原肠胚的进行。veg（1）来源的细胞在胚胎口侧的差异募集通过不成比例地增加口侧有能力参与原肠胚形成的细胞数量，引入了对原肠胚形成的口侧偏好。(C)北京：科学出版社.
Single blastomeres of the sixth-cleavage veg(1) and veg(2) tiers of Strongylocentrotus purpuratus embryos were labeled with DiI lineage tracer, and the disposition of the progeny was followed through the blastula and gastrula stages in order to determine their respective endodermal and ectodermal contributions. In the endoderm of postgastrula embryos, veg(1)-derived cells constituted nearly all of the prospective hindgut and about half of the prospective midgut, while veg(2)-derived cells made up the prospective foregut and half the midgut. Oral veg(1) clones consistently contributed more cells to endoderm than aboral veg(1) clones. Oral veg(1) clones extended along the archenteron up to the foregut region, while aboral veg(1) clones contributed only small numbers of hindgut cells but large patches of ectoderm cells that extended Out to the prospective larval vertex, The oral/aboral asymmetry in veg(1) allocations was also demonstrated using chimeric embryos, the animal halves of which were labeled with a rhodamine-dextran. Lineages expressing the vegetal plate marker Endo16 were more precisely determined by combining lineage tracer injection with whole-mount in situ hybridization. Endo16 expression was found in all cells that are going to participate in gastrulation. Recruitment of new cells to the Endo16 domain occurs in advance of the actual invagination of those cells. During the blastula stages Endo16 expression expands radially until all cells in the veg(2) lineages express this gene, The first phase of gastrulation, including the normal buckling of the vegetal plate and primary invagination of the archenteron, involves only the Endo16-expressing cells of the veg(2) lineages. As the archenteron begins to elongate, marking the onset of the second phase of gastrulation, there is an asymmetric expansion of Endo16 into the veg(1)-derived cells that will contribute to the hindgut and midgut in accordance with lineage tracing observations. The results indicate a relatively late specification of veg(1)-derived cells, resulting in late recruitment to the periphery of the vegetal plate territory as gastrulation proceeds. Differential recruitment of veg(1)-derived cells on the oral side of the embryo introduces an oral bias to gastrulation by disproportionately increasing the number of cells on the oral side that are competent to participate in gastrulation. (C) 1998 Academic Press.