Seson, a novel zinc finger protein, controls cilia integrity for the LR patterning during zebrafish embryogenesis

In zebrafish embryos, bilateral symmetry is broken by asymmetric nodal flow generated in Kupffer’s vesicle (KV), the transient cilia-rich organ, analogous to the mouse node. Asymmetric nodal flow induces the asymmetric expression of several genes, which are critical for the determination of correct LR body patterning. seson encoding three consecutive C2H2 zinc finger protein is predominantly expressed in the cilia-rich organs including KV. Inhibition of its function by the injection of a seson-specific MO inhibited the left-side biased expression of spaw, and resulted in randomization of the heart, gut looping and brain laterality. Disruption of the LR patterning in seson morphants appeared to be due to severe cilia defects in KV. Seson function was also required for ciliogenesis in other tissues such as the pronephros and olfactory organs. Collectively, our data suggest that Seson has critical roles in ciliogenesis and LR body axis patterning.

Research highlights
► seson, C2H2 Zn finger proteins, is predominantly expressed in the Kupffer’s Vesicle (KV).
► Inhibition of its function is resulted in randomization of the heart, gut looping and brain laterality.
► Disorder of heart, gut and brain laterality in seson-depleted embryos presumably through the abnormal cilia movement in KV by the midget cilia.
► Seson is a novel protein with an important role in ciliogenesis and LR patterning during the onset of LR axis specification.