Brakenhoff R H, Ruuls R C, Jacobs E H, Schoenmakers J G, Lubsen N H
Laboratory of Molecular Biology, University of Nijmegen, The Netherlands.
Nucleic Acids Res. 1991 Mar 25;19(6):1279-84. doi: 10.1093/nar/19.6.1279.
Rodent gamma-crystallin promoters were recognized as lens-specific promoters in micro-injected Xenopus laevis tadpoles and targeted the expression of the chloramphenicol acetyl transferase (CAT) reporter gene to the tadpole lens. The onset of expression coincided with lens cell formation. The level of expression continued to increase up to 9 days of development (stage 47), stayed at that level till at least day 13 and dropped by only 57% at day 21. In contrast, the level of expression of a non-tissue-specific promoter, the SV40 early promoter, decreased rapidly in the eye during development and was only detectable up to stage 44 (day 5). The stability of the CAT activity in the lens was assessed by delivering a pulse of activity from a heat shock promoter-CAT fusion gene. The half-life of the CAT activity in the eye was the same as that in the tail. The increase in CAT activity in the lens thus depends upon continued activity of the injected gamma-crystallin promoters. Our data demonstrate that mammalian promoters can be used to target gene expression to specific tissues during Xenopus laevis development.
在显微注射的非洲爪蟾蝌蚪中，啮齿动物γ-晶状体蛋白启动子被识别为晶状体特异性启动子，并将氯霉素乙酰转移酶（CAT）报告基因的表达靶向到蝌蚪晶状体。表达的起始与晶状体细胞形成同时发生。表达水平持续增加直至发育9天（第47阶段），至少维持到第13天，在第21天仅下降57%。相比之下，非组织特异性启动子SV40早期启动子的表达水平在发育过程中在眼中迅速下降，仅在第44阶段（第5天）之前可检测到。通过从热休克启动子-CAT融合基因传递活性脉冲来评估晶状体中CAT活性的稳定性。眼中CAT活性的半衰期与尾巴中的相同。因此，晶状体中CAT活性的增加取决于注射的γ-晶状体蛋白启动子的持续活性。我们的数据表明，哺乳动物启动子可用于在非洲爪蟾发育过程中将基因表达靶向特定组织。
