title: The role of stat1b in zebrafish hematopoiesis.
abstract: STAT1 mediates response to interferons and regulates immunity, cell proliferation, apoptosis, and sensitivity of Fanconi Anemia cells to apoptosis after interferon signaling; the roles of STAT1 in embryos, however, are not understood. To explore embryonic functions of STAT1, we investigated stat1b, an unstudied zebrafish co-ortholog of human STAT1. Zebrafish stat1a encodes all five domains of the human STAT1-alpha splice form but, like the human STAT1-beta splice variant, stat1b lacks a complete transactivation domain; thus, two unlinked zebrafish paralogs encode protein forms translated from two splice variants of a single human gene, as expected by sub-functionalization after genome duplication. Phylogenetic and conserved synteny studies showed that stat1b and stat1a arose as duplicates in the teleost genome duplication (TGD) and clarified the evolutionary origin of STAT1, STAT2, STAT3, STAT4, STAT5A, STAT5B and STAT6 by tandem and genome duplication. RT-PCR revealed maternal expression of stat1a and stat1b. In situ hybridization detected stat1b but not stat1a expression in embryonic hematopoietic tissues. Morpholino knockdown of stat1b, but not stat1a, decreased expression of the myeloid and granulocyte markers spi and mpo and increased expression of the hematopoietic progenitor marker scl, the erythrocyte marker gata1, and hemoglobin. These results suggest that zebrafish Stat1b promotes myeloid development at the expense of erythroid development.
authors.affiliation: Institute of Neuroscience, University of Oregon, 1425 E. 13th Avenue, Eugene, OR 97403, USA. hsong@uoregon.edu
authors.forename: Hao
authors.initials: H
authors.lastname: Song
authors.forename: Yi-lin
authors.initials: YL
authors.lastname: Yan
authors.forename: Tom
authors.initials: T
authors.lastname: Titus
authors.forename: Xinjun
authors.initials: X
authors.lastname: He
authors.forename: John H
authors.initials: JH
authors.lastname: Postlethwait
mesh_terms: D000818:Animals; D015415:Biomarkers / Q000378:metabolism; D019070:Cell Lineage; D020440:Gene Duplication; D018507:Gene Expression Regulation, Developmental; D006410:Hematopoiesis / Q000502:physiology*; D006413:Hematopoietic System / Q000196:embryology / Q000378:metabolism*; D006801:Humans; D022423:Myeloid Cells / Q000378:metabolism; D010802:Phylogeny; D020033:Protein Isoforms / Q000235:genetics / Q000378:metabolism*; D050794:STAT1 Transcription Factor / Q000235:genetics / Q000378:metabolism*; D026801:Synteny / Q000235:genetics; D015027:Zebrafish / Q000196:embryology*; D029961:Zebrafish Proteins / Q000235:genetics / Q000378:metabolism*
chemical_list: D015415:Biomarkers; D020033:Protein Isoforms; D050794:STAT1 Transcription Factor; C494079:STAT1 protein, human; D029961:Zebrafish Proteins