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

Abstract

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 <I>Brunol</I> genes in <I>Xenopus laevis</I>. Among them, only <I>Brunol2</I> is maternally expressed and the zygotic expression of the other four <I>Brunol</I> genes starts at different developmental stages. During <I>Xenopus</I> development, <I>Brunol1, 4-5</I> are exclusively expressed in the nervous system including domains in the brain, spinal cord, optic and otic vesicles. <I>Brunol2</I> and <I>3</I> are expressed in both the somatic mesoderm and the nervous system. <I>Brunol2</I> 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.