The Xenopus laevis zinc finger protein gene Xfin: developmental expression and in vivo functional studies

Xfin is a Krüppel‐type zinc finger protein characterized by the highest number of zinc finger motives (37) found to date. An interesting feature of this protein is the cytoplasmic location, coupled by in vitro RNA binding activity: both these properties may suggest a role for Xfin in RNA metabolism. As the corresponding mRNA, the protein product of Xfin is part of the maternal store in Xenopus and is present throughout embryogenesis. We used in situ hybridization to establish the expression pattern of Xfin in developmental stages. We show here that it is expressed evenly throughout gastrula and neurula stages embryos, while in later stages its transcripts are mainly enriched in the endoderm. In addition, we performed some in vivo perturbation experiments. We found that overexpression of Xfin by injection of synthetic mRNA in early Xenopus embryos causes disruption of posterior development; also, Xfin overexpression inhibits the normal expression of the pan‐mesodermal marker Xbra.