English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

Background  Although vertebrates are bilaterally symmetric organisms, their internal organs are distributed asymmetrically along a left-right axis. Disruption of left-right axis asymmetric patterning often occurs in human genetic disorders. In zebrafish embryos, Kupffer’s vesicle, like the mouse node, breaks symmetry by inducing asymmetric expression of the  Nodal -related gene,  spaw , in the left lateral plate mesoderm (LPM). Spaw then stimulates transcription of itself and downstream genes, including  lft1 ,  lft2 , and  pitx2 , specifically in the left side of the diencephalon, heart and LPM. This developmental step is essential to establish subsequent asymmetric organ positioning. In this study, we evaluated the role of  krüppel-like factor 8  ( klf8 ) in regulating left-right asymmetric patterning in zebrafish embryos.    Methods  Zebrafish  klf8  expression was disrupted by both morpholino antisense oligomer-mediated knockdown and a CRISPR-Cas9 system. Whole-mount in situ hybridization was conducted to evaluate gene expression patterns of Nodal signalling components and the positions of heart and visceral organs. Dorsal forerunner cell number was evaluated in  Tg(sox17:gfp)  embryos and the length and number of cilia in Kupffer’s vesicle were analyzed by immunocytochemistry using an acetylated tubulin antibody.    Results  Heart jogging, looping and visceral organ positioning were all defective in zebrafish  klf8  morphants. At the 18–22 s stages,  klf8  morphants showed reduced expression of genes encoding Nodal signalling components ( spaw ,  lft1 ,  lft2 , and  pitx2 ) in the left LPM, diencephalon, and heart. Co-injection of  klf8  mRNA with  klf8  morpholino partially rescued  spaw  expression. Furthermore,  klf8  but not  klf8△zf  overexpressing embryos showed dysregulated bilateral expression of Nodal signalling components at late somite stages. At the 10s stage,  klf8  morphants exhibited reductions in length and number of cilia in Kupffer’s vesicle, while at 75% epiboly, fewer dorsal forerunner cells were observed. Interestingly,  klf8  mutant embryos, generated by a CRISPR-Cas9 system, showed bilateral  spaw  expression in the LPM at late somite stages. This observation may be partly attributed to compensatory upregulation of  klf12b , because  klf12b  knockdown reduced the percentage of  klf8  mutants exhibiting bilateral  spaw  expression.    Conclusions  Our results demonstrate that zebrafish Klf8 regulates left-right asymmetric patterning by modulating both Kupffer’s vesicle morphogenesis and  spaw  expression in the left LPM.    Electronic supplementary material  The online version of this article (doi:10.1186/s12929-017-0351-y) contains supplementary material, which is available to authorized users.

Klf8 regulates left-right asymmetric patterning through modulation of Kupffer’s vesicle morphogenesis and spaw expression