Chauhan Anil K, Iaconcig Alessandra, Baralle Francisco E, Muro Andrés F
International Centre for Genetic Engineering and Biotechnology, Padriciano, 99, 34012-Trieste, Italy.
Gene. 2004 Jan 7;324:55-63. doi: 10.1016/j.gene.2003.09.026.
We have designed a novel approach using genetically engineered mice to make a systematic study of the EDA exon regulation of the fibronectin gene during development and aging. The genome of the mice was modified either by optimization of the EDA natural splice sites or by deleting the EDA region. The previous in vitro observation that the optimization of the splicing sites leads to constitutive inclusion of the EDA exon was confirmed in our animal model. In fact, all the adult tissues of the genetically modified mice showed only EDA(+) FN mRNA, demonstrating the fidelity of in vitro models, despite of the development- and aging-regulated splicing regulation of the EDA exon, and regardless of the presence of exonic elements described within the exon. This result indicates that the splicing regulatory elements of the EDA exon are dispensable in the presence of consensus splicing sites. Moreover, we demonstrate the autonomy of both the EDB and the IIICS alternatively spliced regions in adult mice lacking regulation of the alternative splicing at the EDA exon. We also show here the tight splicing regulation of all three alternative spliced regions of the FN gene at different time-points during development and aging of mice.
我们设计了一种新颖的方法，利用基因工程小鼠对纤连蛋白基因在发育和衰老过程中的EDA外显子调控进行系统研究。通过优化EDA天然剪接位点或删除EDA区域对小鼠基因组进行修饰。我们的动物模型证实了先前的体外观察结果，即剪接位点的优化导致EDA外显子的组成性包含。事实上，转基因小鼠的所有成年组织仅显示EDA(+) FN mRNA，这证明了体外模型的准确性，尽管存在EDA外显子的发育和衰老调节剪接调控，且无论外显子内所述外显子元件的存在情况如何。该结果表明，在存在共有剪接位点的情况下，EDA外显子的剪接调控元件是可有可无的。此外，我们证明了在成年小鼠中，缺乏EDA外显子可变剪接调控时，EDB和IIICS可变剪接区域的自主性。我们还在此展示了在小鼠发育和衰老的不同时间点，FN基因所有三个可变剪接区域的紧密剪接调控。
