Vegetally localised Vrtn functions as a novel repressor to modulate bmp2b transcription during dorsoventral patterning in zebrafish

• DOI: 10.1242/dev.152553
• Publication Date: 2017-09-19T11:25:13Z
• Authors: Ming Shao; Min Wang; Yuan-Yuan Liu; Yi-Wen Ge; Yan-Jun Zhang; De-Li Shi
• Keywords: Polarity in embryogenesis

The vegetal pole cytoplasm represents a crucial source of maternal dorsal determinants for patterning the dorsoventral axis early embryo. Removal yolk in zebrafish fertilised egg before completion first cleavage results embryonic ventralisation, but removal this part at two-cell stage leads to dorsalisation. How is achieved remains unknown. Here, we report novel mode regulation BMP signalling during zebrafish. We identify Vrtn as vegetally localised factor with dorsalising activity and rapid transport towards animal region after fertilisation. Co-injection vrtn mRNA RNAs from different stages suggests presence putative antagonists slower transport. Thus, ablation could remove most antagonists, allows produce effect. Mechanistically, binds bmp2b regulatory sequence acts repressor inhibit its zygotic transcription. Analysis maternal-zygotic mutants further shows that required constrain excessive expression margin. Our work unveils mechanism regulating gradient patterning.