Meeting Abstract
In bilaterians the Kruppel-like factors (KLFs) are transcription factors that play critical roles in stem cell maintenance and balancing aspects of both cell proliferation and differentiation. Information regarding KLF expression and function are lacking in earlier diverging non-bilaterian lineages. In this study we examine the molecular function of KLF orthologs in the lobate ctenophore, Mnemiopsis leidyi, using a combination of developmental expression analyses, immunohistochemistry, and targeted gene knockdown using two independent methods. The Mnemiopsis genome contains 3 KLF genes, MleKlf5a, MleKlf5b, and MleKlfX. MleKLF5a and MleKLF5b are closely related to bilaterian KLF5 and KLF4, which have been shown to play competing roles in proliferation and differentiation in the vertebrate gut epithelium. MleKLFX has no clear orthology to other metazoan KLFs. Here we show that MleKlf5a and MleKlf5b genes are expressed in tissues and organs derived from endoderm. Our functional work shows that knockdown of KLF orthologs in Mnemiopsis results in extensive endodermal patterning defects. These results suggest an ancient role for KLF transcription factors in mediating aspects of transcriptional regulation associated with endodermal patterning and differentiation in metazoans.
