Endogenous status of retinoids and their cytosolic binding proteins in limb buds of chick vs mouse embryos.
Endogenous status of retinoids and their cytosolic binding proteins in limb buds of chick vs mouse embryos.
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鸡与小鼠胚胎肢芽中类维生素A及其胞质结合蛋白的内源状态。
DOI：
10.1006/dbio.1994.1262
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发表时间：
1994
影响因子：
2.7
通讯作者：
Collins,MD
中科院分区：
文献类型：
--
作者：
ScottJr,WJ;Walter,R;Tzimas,G;Sass,JO;Nau,H;Collins,MD
全反式维甲酸（RA）在肢体发育过程中的形态发生作用，特别是其在指导前/后模式形成中的活性仍然存在争议。我们已经测量了维甲酸和胞质结合蛋白的前片和后片的肢芽从prongaged鸡和小鼠胚胎，期望定位模式的形态学意义将是明显的跨物种。结果表明：（1）在小鼠肢芽中检测不到3，4-二脱氢视黄酸（ddRA），而ddRA的前体3，4-二脱氢视黄醇（ddROH）在小鼠肢芽中也不存在，而在鸡肢芽中含量较高;（2）较高浓度的形态发生活性类维生素A（RA + ddRA）鸡相比，小鼠肢芽;（3）高水平的视黄酯（4）鸡肢芽中胞质维甲酸结合蛋白（CRABP）水平较高，尤其是CRABP II，比小鼠肢芽中高10倍。在小鼠和鸡肢芽中观察到的一个有趣的发现是配体和胞质结合蛋白的浓度之间的差异。视黄醇（ROH）和ddROH以比细胞溶质视黄醇结合蛋白（CRBP）高得多的浓度存在。相反，RA和ddRA的浓度远低于CRABP。这些差异的任何形态学意义是未知的。与早期研究（Thaller和Eichele，1987）一样，在鸡肢芽中发现了RA的假定梯度，即高后部，但该梯度的幅度小于先前报道的幅度。我们还发现ddRA在这里研究的鸡肢芽的前部和后部中浓度相等，进一步削弱了RA梯度作为前/后图案形成中的直接力的想法。从配体和结合蛋白浓度和亲和力计算的维甲酸“游离”浓度在鸡后肢组织（2.0X）和小鼠肢芽中略高，浓度与小鼠核维甲酸受体的Kd相似
The morphogenetic role of all-trans-retinoic acid (RA) during limb development, especially its activity in directing anterior/posterior pattern formation remains controversial. We have measured retinoids and cytosolic binding proteins in anterior and posterior pieces of limb buds from comparably aged chick and mouse embryos expecting that localization patterns of morphological significance will be evident across species. Many species differences were found including: (1) nondetectable 3,4-didehydroretinoic acid (ddRA) in mouse limb buds, the predominant morphogenetically active retinoid in chick limbs; the precursor of ddRA, 3,4-didehydroretinol (ddROH), was also not present in mouse limb buds but found in high concentration in chick limb buds; (2) a higher concentration of morphogenetically active retinoid (RA + ddRA) in chick compared to mouse limb buds; (3) a high level of retinyl esters (1.5 μM) in chick limb bud, but undetectable concentration in mouse limb buds; and (4) a higher level of cytosolic retinoic acid binding proteins (CRABPs) in chick limb buds, especially CRABP II, which is 10× greater than in mouse limb buds. An interesting finding seen in mouse and chick limb buds was a disparity between the concentration of ligand and cytosolic binding protein. Retinol (ROH) and ddROH were present in much higher concentrations than cytosolic retinol binding protein (CRBP). Conversely, RA and ddRA were in far lower concentration than CRABPs. Any morphological significance of these disparities is unknown. A putative gradient of RA, high posteriorly, was found in chick limb buds as in earlier studies (Thaller and Eichele, 1987), but the magnitude of this gradient was less than previously reported. We also found ddRA in equal concentration in the anterior and posterior pieces of chick limb bud studied here, further weakening the idea of an RA gradient as the direct force in anterior/posterior pattern formation. The "free" concentration of retinoic acid, calculated from ligand and binding protein concentration and affinity, was slightly higher in posterior chick limb tissue (2.0X) and in mouse limb buds at a concentration similar to theKdof murine nuclear retinoic acid receptors