Differential expression of the Brunol/CELF family genes during Xenopus laevis early development

The BRUNOL/CELF family of RNA-binding proteins plays important roles in post-transcriptional regulation and has been implicated in several developmental processes. In this study, we describe the cloning and expression patterns of five Brunol genes in Xenopus laevis. Among them, only Brunol2 is maternally expressed and the zygotic expression of the other four Brunol genes starts at different developmental stages. During Xenopus development, Brunol1, 4-5 are exclusively expressed in the nervous system including domains in the brain, spinal cord, optic and otic vesicles. Brunol2 and 3 are expressed in both the somatic mesoderm and the nervous system. Brunol2 is also extensively expressed in the lens. In transfected Hela cells, BRUNOL1, 2 and 3 proteins are localized in both the cytoplasm and the nucleus, while BRUNOL4 and 5 are only present in the cytoplasm, indicating their different functions.

We thank two anonymous reviewers for helpful comments on the manuscript. We also thank Haifeng Tian, Hao Shen and Yonghai Jiang for technical assistance and discussion. We thank Crystal Conn for reading our manuscript. This work was supported by 973 program (2007CB815705), the National Natural Science Foundation of China (30830018; 30021004; 30623007), and the Knowledge Innovation Program (KSCX2-YW-R-091) to JW.