foxi2 is an animally localized maternal mrna in xenopus, and an activator of the zygotic ectoderm activator foxi1efoxi2是一个肉体上局部孕产妇mrna在非洲爪蟾蜍,并激活受精卵的外胚层活化剂foxi1e.pdfVIP

Foxi2 Is an Animally Localized Maternal mRNA in Xenopus, and an Activator of the Zygotic Ectoderm Activator Foxi1e 1 1 2 1 1 Sang-Wook Cha , Meredith McAdams , Jay Kormish , Christopher Wylie , Matthew Kofron * 1 Cincinnati Children’s Hospital Medical Center, Cincinnati, Ohio, United States of America, 2 University of Calgary, Calgary, Alberta, Canada Abstract Foxi1e is a zygotic transcription factor that is essential for the expression of early ectodermal genes. It is expressed in a highly specific pattern, only in the deep cell layers of the animal hemisphere, and in a mosaic pattern in which expressing cells are interspersed with non-expressing cells. Previous work has shown that several signals in the blastula control this expression pattern, including nodals, the TGFb family member Vg1, and Notch. However, these are all inhibitory, which raises the question of what activates Foxi1e. In this work, we show that a related Forkhead family protein, Foxi2, is a maternal activator of Foxi1e. Foxi2 mRNA is maternally encoded, and highly enriched in animal hemisphere cells of the blastula. ChIP assays show that it acts directly on upstream regulatory elements of Foxi1e. Its effect is specific, since animal cells depleted of Foxi2 are able to respond normally to mesoderm inducing signals from vegetal cells. Foxi2 thus acts as a link between the oocyte and the early pathway to ectoderm, in a similar fashion to the vegetally localized VegT acts to initiate endoderm and mesoderm formation. Citation: Cha S-W, McAdams M, Kormish J, Wylie C, Kofron M (2012) Foxi2 Is an Animally Localized Maternal mRNA in Xenopus, and an Activator of the Zygotic Ectoderm Activator Foxi1e. PLoS ONE 7(7): e41782. doi:1