Gata is ubiquitously required for the earliest zygotic gene transcription in the ascidian embryo.

Gata is ubiquitously required for the earliest zygotic gene transcription in the ascidian embryo.
Dev Biol. 2019 Nov 18;:
Authors: Imai KS, Kobayashi K, Kari W, Rothbächer U, Ookubo N, Oda-Ishii I, Satou Y
Abstract
In ascidian embryos, the earliest transcription from the zygotic genome begins between the 8-cell and 16-cell stages. Gata.a, a maternally expressed Gata transcription factor, activates target genes specifically in the animal hemisphere, whereas the complex of β-catenin and Tcf7 antagonizes the activity of Gata.a and activates target genes specifically in the vegetal hemisphere. Here, we show that genes zygotically expressed at the 16-cell stage have significantly more Gata motifs in their upstream regions. These genes included not only genes with animal hemisphere-specific expression but also genes with vegetal hemisphere-specific expression. On the basis of this finding, we performed knockdown experiments for Gata.a and reporter assays, and found that Gata.a is required for the expression of not only genes with animal hemisphere-specific expression, but also genes with vegetal hemisphere-specific expression. Our data indicated that weak Gata.a activity that cannot induce animal hemisphere-specific expression can allow β-catenin/Tcf7 targets to be expressed in the vegetal cells. Because genes zygotically expressed at the 32-cell stage also had significantly more Gata motifs in their upstream regions, Gata.a function ma...

Source: Developmental Biology - November 17, 2019 Category: Biology Authors: Imai KS, Kobayashi K, Kari W, Rothbächer U, Ookubo N, Oda-Ishii I, Satou Y Tags: Dev Biol Source Type: research