title: High resolution cell lineage tracing reveals developmental variability in leech.
abstract: Knowing the normal patterns of embryonic cell proliferation, migration, and differentiation is a cornerstone for understanding development. Yet for most species, the precision with which embryonic cell lineages can be determined is limited by technical considerations (the large numbers of cells, extended developmental times, opacity of the embryos), and these are exacerbated by the inherent variability of the lineages themselves. Here, we present an improved method of cell lineage tracing in the leech Helobdella, driving the expression of a nuclearly localized histone H2B:GFP (green fluorescent protein) fusion protein in selected lineages by microinjection of a plasmid vector. This construct generates a long lasting and minimally mosaic signal with single cell resolution, and does not disrupt the development of most lineages tested. We have validated this technique by elucidating details of cell lineages contributing to segmental and prostomial tissues that could not be observed with standard dextran lineage tracers.
authors.affiliation: Department of Molecular and Cell Biology, University of California, Berkeley, California 94720-3200, USA. sgline@berkeley.edu
authors.forename: Stephanie E
authors.initials: SE
authors.lastname: Gline
authors.forename: Dian-Han
authors.initials: DH
authors.lastname: Kuo
authors.forename: Alberto
authors.initials: A
authors.lastname: Stolfi
authors.forename: David A
authors.initials: DA
authors.lastname: Weisblat
mesh_terms: D000818:Animals; D030801:Animals, Genetically Modified; D002454:Cell Differentiation / Q000502:physiology; D002455:Cell Division / Q000502:physiology; D019070:Cell Lineage / Q000235:genetics / Q000502:physiology; D004625:Embryo, Nonmammalian; D047108:Embryonic Development / Q000235:genetics / Q000502:physiology; D005455:Fluorescent Antibody Technique / Q000379:methods; D018507:Gene Expression Regulation, Developmental; D049452:Green Fluorescent Proteins / Q000235:genetics / Q000378:metabolism; D007206:Individuality; D007865:Leeches / Q000196:embryology* / Q000235:genetics / Q000378:metabolism; D008954:Models, Biological; D009928:Organ Specificity / Q000502:physiology; D013045:Species Specificity; D019076:Transgenes
chemical_list: D049452:Green Fluorescent Proteins