Maden M
Developmental Biology Research Centre, King's College, London, United Kingdom.
Teratology. 1994 Oct;50(4):294-301. doi: 10.1002/tera.1420500404.
The distribution of cellular retinoic acid-binding proteins I and II (CRABP I and II) during the first 6 days of chick development has been investigated using immunoblotting. Since retinoic acid (RA) is teratogenic to some parts of the embryo, stimulatory to other parts, and has no effect on others it may be that the distribution of cytoplasmic proteins such as CRABP I and II plays some role in this differential activity. Neither protein is expressed in the day 2 embryo, but from day 3 onwards both proteins are expressed and CRABP I is in considerable excess over CRABP II. Within the day 4 embryo there is some significant variation in the distribution according to tissue type. Neural tissues, neural crest derivatives, and limb buds most strongly express CRABP I whilst other tissues contain only moderate levels, and heart and epidermis do not express CRABP I at all. CRABP II has a widespread distribution, although at a lower level than CRABP I, with the exception of somites and ectoderm which do not express it at all. In the limb buds, there is a significant variation in CRABP I levels across the anteroposterior axis which suggests that these two CRABPs may have different functions during development. The relationship of these distributions in the embryo to the role of endogenous RA and the teratogenic effects of RA is discussed.
利用免疫印迹法研究了雏鸡发育前6天细胞视黄酸结合蛋白I和II（CRABP I和II）的分布情况。由于视黄酸（RA）对胚胎的某些部分具有致畸作用，对其他部分有刺激作用，而对另一些部分则无影响，因此，诸如CRABP I和II等细胞质蛋白的分布可能在这种差异活性中发挥了某种作用。在第2天的胚胎中这两种蛋白均未表达，但从第3天起两种蛋白均有表达，且CRABP I的表达量大大超过CRABP II。在第4天的胚胎中，根据组织类型不同，分布存在一些显著差异。神经组织、神经嵴衍生物和肢芽中CRABP I表达最强，而其他组织中表达水平适中，心脏和表皮则根本不表达CRABP I。CRABP II分布广泛，尽管其水平低于CRABP I，体节和外胚层根本不表达CRABP II。在肢芽中，CRABP I水平沿前后轴存在显著差异，这表明这两种CRABP在发育过程中可能具有不同功能。本文讨论了胚胎中这些分布与内源性RA的作用以及RA致畸作用之间的关系。
