卵质分离期间的紫外线照射会阻止海鞘胚胎的原肠胚形成、感觉细胞诱导和轴形成。

Ultraviolet irradiation during ooplasmic segregation prevents gastrulation, sensory cell induction, and axis formation in the ascidian embryo.

作者信息

Jeffery W R

机构信息

Department of Zoology, University of Texas, Austin 78712.

出版信息

Dev Biol. 1990 Aug;140(2):388-400. doi: 10.1016/0012-1606(90)90088-z.

DOI:10.1016/0012-1606(90)90088-z

PMID:2373259

Abstract

The effect of ultraviolet (uv) light on embryonic development was examined in the ascidian Styela clava. uv irradiation (3.0 x 10(-3) J mm-2) of the entire surface of fertilized eggs during ooplasmic segregation prevented gastrulation, sensory cell induction, and embryonic axis formation. The uv-irradiated embryos completed ooplasmic segregation and cleaved normally, but vegetal blastomeres did not invaginate at the beginning of gastrulation, sensory cells in the larval brain did not develop tyrosinase or melanin pigment, and the larval tail did not develop. Endoderm, epidermis, and muscle cells differentiated in the uv-irradiated embryos, however, as evidenced by expression of endodermal alkaline phosphatase (AP), an epidermal-specific antigen, and alpha-actin, myosin heavy chain, and acetylcholinesterase (AChE) in muscle cells. Higher doses of uv light (6.0-9.0 x 10(-3) J mm-2) suppressed expression of the epidermal antigen and muscle cell markers, whereas the development of endodermal AP was insensitive. Irradiation at various times between fertilization and the 16-cell stage revealed that gastrulation, sensory cell differentiation, and axis formation are sensitive to uv light only during ooplasmic segregation. Irradiation of restricted regions of the zygote during ooplasmic segregation showed that the uv-sensitive components are localized in the vegetal hemisphere. The absorption characteristics of the uv-sensitive components suggest that they are nucleic acids. The results show that uv-sensitive components that specify gastrulation, sensory cell induction, and embryonic axis formation are localized in the vegetal hemisphere of Styela eggs.

摘要

在海鞘柄海鞘中研究了紫外线（uv）对胚胎发育的影响。在卵质分离期间对受精卵的整个表面进行紫外线照射（3.0×10⁻³ J mm⁻²）可阻止原肠胚形成、感觉细胞诱导和胚胎轴形成。紫外线照射的胚胎完成了卵质分离并正常分裂，但在原肠胚形成开始时植物性卵裂球没有内陷，幼虫脑中的感觉细胞没有发育酪氨酸酶或黑色素，并且幼虫尾巴没有发育。然而，在紫外线照射的胚胎中内胚层、表皮和肌肉细胞发生了分化，这可通过内胚层碱性磷酸酶（AP）、一种表皮特异性抗原以及肌肉细胞中的α-肌动蛋白、肌球蛋白重链和乙酰胆碱酯酶（AChE）的表达来证明。更高剂量的紫外线（6.0 - 9.0×10⁻³ J mm⁻²）抑制了表皮抗原和肌肉细胞标志物的表达，而内胚层AP的发育不敏感。在受精至16细胞期之间的不同时间进行照射表明，原肠胚形成、感觉细胞分化和轴形成仅在卵质分离期间对紫外线敏感。在卵质分离期间对合子的受限区域进行照射表明，对紫外线敏感的成分位于植物性半球。对紫外线敏感成分的吸收特性表明它们是核酸。结果表明，决定原肠胚形成、感觉细胞诱导和胚胎轴形成的对紫外线敏感的成分位于柄海鞘卵的植物性半球。