title: Genome-wide analysis of the zebrafish Klf family identifies two genes important for erythroid maturation.
abstract: Krüppel-like transcription factors (Klfs), each of which contains a CACCC-box binding domain, have been investigated in a variety of developmental processes, such as angiogenesis, neurogenesis and somatic-cell reprogramming. However, the function and molecular mechanism by which the Klf family acts during developmental hematopoiesis remain elusive. Here, we report identification of 24 Klf family genes in zebrafish using bioinformatics. Gene expression profiling shows that 6 of these genes are expressed in blood and/or vascular endothelial cells during embryogenesis. Loss of function of 2 factors (klf3 or klf6a) leads to a decreased number of mature erythrocytes. Molecular studies indicate that both Klf3 and Klf6a are essential for erythroid cell differentiation and maturation but that these two proteins function in distinct manners. We find that Klf3 inhibits the expression of ferric-chelate reductase 1b (frrs1b), thereby promoting the maturation of erythroid cells, whereas Klf6a controls the erythroid cell cycle by negatively regulating cdkn1a expression to determine the rate of red blood cell proliferation. Taken together, our study provides a global view of the Klf family members that contribute to hematopoiesis in zebrafish and sheds new light on the function and molecular mechanism by which Klf3 and Klf6a act during erythropoiesis in vertebrates.
authors.affiliation: State Key Laboratory of Biomembrane and Membrane Biotechnology, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China.
authors.forename: Yuanyuan
authors.initials: Y
authors.lastname: Xue
authors.affiliation: State Key Laboratory of Biomembrane and Membrane Biotechnology, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China.
authors.forename: Shuai
authors.initials: S
authors.lastname: Gao
authors.affiliation: State Key Laboratory of Biomembrane and Membrane Biotechnology, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China. Electronic address: liuf@ioz.ac.cn.
authors.forename: Feng
authors.initials: F
authors.lastname: Liu
mesh_terms: D000818:Animals; D050759:Cyclin-Dependent Kinase Inhibitor p21 / Q000378:metabolism; D004625:Embryo, Nonmammalian / Q000378:metabolism; D041905:Erythroid Cells / Q000166:cytology / Q000378:metabolism*; D015870:Gene Expression; D051741:Kruppel-Like Transcription Factors / Q000235:genetics* / Q000378:metabolism*; D010802:Phylogeny; D015027:Zebrafish; D029961:Zebrafish Proteins / Q000235:genetics* / Q000378:metabolism*
chemical_list: D050759:Cyclin-Dependent Kinase Inhibitor p21; D051741:Kruppel-Like Transcription Factors; D029961:Zebrafish Proteins
keywords: Klf family; Klf3; Klf6a; erythropoiesis; zebrafish