Wianny F, Real F X, Mummery C L, Van Rooijen M, Lahti J, Samarut J, Savatier P
Laboratoire de Biologie Moléculaire et Cellulaire, UMR 49 CNRS, LA INRA 913, Ecole Normale Supérieure de Lyon, France.
Dev Dyn. 1998 May;212(1):49-62. doi: 10.1002/(SICI)1097-0177(199805)212:1<49::AID-AJA5>3.0.CO;2-2.
Gastrulation in rodents is associated with an increase in the rate of growth and with the start of differentiation within the embryo proper. In an effort to understand the role played by the cell cycle control in these processes, expression of cyclin D1, D2, and D3--three major positive regulators of the G1/S transition--has been investigated by in situ hybrization and RT-PCR. Cyclin D1 and D2 transcripts are first detected in the epiblast at gastrulation, when a proliferative burst occurs, and subsequently in its differentiated derivatives within the embryo proper, indicating that activation of their expression takes place prior to the differentiation of epiblast progenitors. In contrast, cyclin D3 transcript is undetectable in the epiblast itself and its expression is activated exclusively in extraembryonic tissues of both epiblast and trophoblast origin. During neurulation, expression of each cyclin D RNA is dynamically regulated along the anterior-posterior axis. In the hindbrain, cyclin D1 and D2 show distinct segment-specific restricted expression and this pattern is conserved between mouse and chick. These results strongly suggest that D-type cyclins act as developmental regulators.
啮齿动物的原肠胚形成与胚胎自身生长速率的增加以及分化的开始有关。为了了解细胞周期调控在这些过程中所起的作用，通过原位杂交和逆转录聚合酶链反应（RT-PCR）研究了细胞周期蛋白D1、D2和D3（G1/S转换的三个主要正向调节因子）的表达。细胞周期蛋白D1和D2转录本首先在原肠胚形成时的上胚层中被检测到，此时发生增殖爆发，随后在胚胎自身的分化衍生物中被检测到，这表明它们的表达激活发生在上胚层祖细胞分化之前。相比之下，细胞周期蛋白D3转录本在上胚层本身中无法检测到，其表达仅在源自上胚层和滋养层的胚外组织中被激活。在神经胚形成过程中，每种细胞周期蛋白D RNA的表达沿前后轴受到动态调节。在后脑，细胞周期蛋白D1和D2表现出明显的节段特异性限制性表达，这种模式在小鼠和鸡之间是保守的。这些结果强烈表明D型细胞周期蛋白作为发育调节因子发挥作用。
