title: Developmental regulation of yolk sac hematopoiesis by Kruppel-like factor 6.
abstract: Krüppel-like factor 6 (KLF6) is a member of a growing family of transcription factors that share a common 3 C2H2 zinc finger DNA binding domain and have broad activity in regulating proliferation and development. We have previously established that Klf6 is expressed in neuronal tissue, hindgut, heart, lung, kidney, and limb buds during midgestation. To explore the potential role of Klf6 in mouse development, we analyzed Klf6-/- mice and found that the homozygous mutation is embryonic lethal by embryonic day (E) 12.5 and associated with markedly reduced hematopoiesis and poorly organized yolk sac vascularization. Additionally, mRNA levels of Scl and Gata1 were reduced by approximately 80% in Klf6-/- yolk sacs. To further analyze this phenotype, we generated Klf6-/- embryonic stem (ES) cells by homologous recombination, and compared their capacity to differentiate into the hematopoietic lineage with that of either Klf6+/- or Klf6+/+ ES cells. Consistent with the phenotype in the early embryo, Klf6-/- ES cells displayed significant hematopoietic defects following differentiation into EBs. Prolongation of epiblast-like cells and delays in mesoderm induction were also observed in the Klf6-/- EBs, associated with delayed expression of Brachyury, Klf1, and Gata1. Forced expression of KLF6 using a tet-inducible system enhanced the hematopoietic potential of wild-type EBs. Collectively, these findings implicate Klf6 in ES-cell differentiation and hematopoiesis.
authors.affiliation: Division of Liver Diseases, Department of Medicine, Mount Sinai School of Medicine, 1425 Madison Ave, Rm 1170F, New York, NY 10029, USA.
authors.forename: Nobuyuki
authors.initials: N
authors.lastname: Matsumoto
authors.forename: Atsushi
authors.initials: A
authors.lastname: Kubo
authors.forename: Huixian
authors.initials: H
authors.lastname: Liu
authors.forename: Kuniharu
authors.initials: K
authors.lastname: Akita
authors.forename: Friedrich
authors.initials: F
authors.lastname: Laub
authors.forename: Francesco
authors.initials: F
authors.lastname: Ramirez
authors.forename: Gordon
authors.initials: G
authors.lastname: Keller
authors.forename: Scott L
authors.initials: SL
authors.lastname: Friedman
mesh_terms: D000818:Animals; D018929:Cell Culture Techniques; D002454:Cell Differentiation; D005313:Fetal Death; D006410:Hematopoiesis / Q000502:physiology*; D006720:Homozygote; D000075723:Kruppel-Like Factor 6; D051741:Kruppel-Like Transcription Factors / Q000172:deficiency* / Q000235:genetics* / Q000502:physiology; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D009154:Mutation; D011518:Proto-Oncogene Proteins / Q000172:deficiency* / Q000235:genetics* / Q000502:physiology; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013234:Stem Cells / Q000166:cytology / Q000502:physiology; D015017:Yolk Sac / Q000502:physiology*; D016335:Zinc Fingers
chemical_list: C491358:Klf6 protein, mouse; D000075723:Kruppel-Like Factor 6; D051741:Kruppel-Like Transcription Factors; D011518:Proto-Oncogene Proteins