Kruppel‐like factor family genes are expressed during Xenopus embryogenesis and involved in germ layer formation and body axis patterning

Background: Kruppel‐like factors (Klfs) are a family of transcription factors consisting of 17 members in mammals, Klf1–Klf17, which are involved in fundamental cellular physiological procedures, such as cell proliferation, differentiation, and apoptosis. However, their functions in embryonic development have been poorly understood. Our previous study has demonstrated that the pluripotency factor Klf4 participates in germ layer formation and axis patterning of Xenopus embryos by means of the regulation of key developmental signals. In the present study, we further investigated comprehensively the expression and functions of the klf family genes, klf2, klf5, klf6, klf7, klf8, klf11, klf15, and klf17, during the embryogenesis of Xenopus laevis. Results: Spatio‐temporal expression analyses demonstrate that these genes are transcribed both maternally and zygotically in Xenopus embryos, and during organogenesis and tissue differentiation, they are localized to a variety of placodes and tissues. Gain and loss of function studies manifest that Klf factors play different roles in germ layer formation and body axis patterning. Moreover, each Klf factor exhibits distinct regulatory effects on the expression of genes that are essential for germ layer formation and body axis patterning. Conclusions: These results suggest that Klf factors are involved in the fine‐tuning of these genes during early embryogenesis. Developmental Dynamics 244:1328–1346, 2015. © 2015 Wiley Periodicals, Inc. Key Findings klf family genes are expressed during early embryonic development and organogenesis. The genes are required for germ layer formation and body axis patterning. The Klf factors regulate the expression of key developmental genes.