title: Ikaros expression as a marker for lymphoid progenitors during zebrafish development.
abstract: The Ikaros gene encodes a transcription factor that, in mice, has been shown to be essential for the correct differentiation of B and T lymphocytes and is expressed in all cells of the lymphoid lineage, including pluripotent hematopoietic stem cells. During development in zebrafish, Ikaros expression begins in lateral mesoderm, and continues in the intermediate cell mass (ICM), which is derived from lateral mesoderm and has been shown to generate primitive hematopoietic precursors. Cells expressing Ikaros were then seen on the ventral side of the dorsal aorta, known to be a location of definitive hematopoietic precursors in birds and mammals. Ikaros-expressing cells were also found in the pharyngeal region, near the forming thymus. Later, such cells were seen in the pronephros, the site of hematopoiesis in adult fish. The timing of appearance of Ikaros-expressing cells suggests that, similar to other vertebrates, lymphocytes in the thymus arise from hematopoietic tissue located near the dorsal aorta or in the ICM.
authors.affiliation: Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA.
authors.forename: C E
authors.initials: CE
authors.lastname: Willett
authors.forename: H
authors.initials: H
authors.lastname: Kawasaki
authors.forename: C T
authors.initials: CT
authors.lastname: Amemiya
authors.forename: S
authors.initials: S
authors.lastname: Lin
authors.forename: L A
authors.initials: LA
authors.lastname: Steiner
mesh_terms: D000818:Animals; D001011:Aorta / Q000196:embryology; D015415:Biomarkers; D004268:DNA-Binding Proteins; D004625:Embryo, Nonmammalian / Q000502:physiology; D015870:Gene Expression; D051740:Ikaros Transcription Factor; D007668:Kidney / Q000196:embryology; D008221:Lymphoid Tissue / Q000166:cytology*; D008648:Mesoderm / Q000166:cytology / Q000378:metabolism; D010614:Pharynx / Q000196:embryology; D013234:Stem Cells / Q000166:cytology*; D013950:Thymus Gland / Q000196:embryology; D014018:Tissue Distribution; D014157:Transcription Factors / Q000235:genetics* / Q000378:metabolism; D015027:Zebrafish / Q000196:embryology* / Q000235:genetics*; D029961:Zebrafish Proteins
chemical_list: D015415:Biomarkers; D004268:DNA-Binding Proteins; D014157:Transcription Factors; D029961:Zebrafish Proteins; C497240:ikzf1 protein, zebrafish; D051740:Ikaros Transcription Factor