Reverse genetics in zebrafish

Lekven, Arne C.; Helde, Kathryn Ann; Thorpe, Christopher J.; Rooke, Rebecca; Moon, Randall T.

doi:10.1152/physiolgenomics.2000.2.2.37

Cited by 29 publications

(19 citation statements)

References 45 publications

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“…These cultures were not able to be maintained long enough to allow for gene transfer and cell selection for targeted gene insertion, but further elaboration of this technology may eventually lead to the ability to target specific genes for disruption as in the mouse. In the mean time, morpholinos provide a reliable method of transient gene "knockdown", and reverse genetics can still be accomplished by screening for randomly induced mutations affecting genes of interest (Appel et al, 1999;Lekven et al, 2001; reviewed in Lekven et al, 2000).…”

Section: Transgenic Techniquesmentioning

confidence: 99%

Development of the zebrafish inner ear

Whitfield

Riley

Chiang

et al. 2002

Developmental Dynamics

214

186

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Recent years have seen a renaissance of investigation into the mechanisms of inner ear development. Genetic analysis of zebrafish has contributed significantly to this endeavour, with several dramatic advances reported over the past year or two. Here, we review the major findings from recent work in zebrafish. Several cellular and molecular mechanisms have been elucidated, including the signaling pathways controlling induction of the otic placode, morphogenesis and patterning of the otic vesicle, and elaboration of functional attributes of inner ear.

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Section: Transgenic Techniquesmentioning

confidence: 99%

Development of the zebrafish inner ear

Whitfield

Riley

Chiang

et al. 2002

Developmental Dynamics

214

186

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“…The Dfw8 mutation was induced by γ irradiation (Lekven et al, 2000;Lekven et al, 2001). Embryos were developed in an incubator at 28.5°C in water containing 0.008% Instant Ocean salts.…”

Section: Strains and Developmental Conditionsmentioning

confidence: 99%

A direct role for Fgf but not Wnt in otic placode induction

et al. 2004

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Induction of the otic placode, which gives rise to all tissues comprising the inner ear, is a fundamental aspect of vertebrate development. A number of studies indicate that fibroblast growth factor (Fgf), especially Fgf3, is necessary and sufficient for otic induction. However, an alternative model proposes that Fgf must cooperate with Wnt8 to induce otic differentiation. Using a genetic approach in zebrafish, we tested the roles of Fgf3, Fgf8 and Wnt8. We demonstrate that localized misexpression of either Fgf3 or Fgf8 is sufficient to induce ectopic otic placodes and vesicles, even in embryos lacking Wnt8. Wnt8 is expressed in the hindbrain around the time of otic induction, but loss of Wnt8 merely delays expression of preotic markers and otic vesicles form eventually. The delay in otic induction correlates closely with delayed expression of fgf3 and fgf8 in the hindbrain. Localized misexpression of Wnt8 is insufficient to induce ectopic otic tissue. By contrast, global misexpression of Wnt8 causes development of supernumerary placodes/vesicles, but this reflects posteriorization of the neural plate and consequent expansion of the hindbrain expression domains of Fgf3 and Fgf8. Embryos that misexpress Wnt8 globally but are depleted for Fgf3 and Fgf8 produce no otic tissue. Finally, cells in the preotic ectoderm express Fgf(but not Wnt) reporter genes. Thus, preotic cells respond directly to Fgf but not Wnt8. We propose that Wnt8 serves to regulate timely expression of Fgf3 and Fgf8 in the hindbrain, and that Fgf from the hindbrain then acts directly on preplacodal cells to induce otic differentiation.

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“…The val b337 mutation was induced in the AB strain with ENU and is thought to be a null allele (Moens et al, 1996). The Df(LG23)wnt1 w5 deletion (herein referred to as Df w5 ) was induced by gamma-irradiation and identified in a polymerase chain reactionbased screen for loss of wnt1 (Lekven et al, 2000). Subsequent mapping showed that Df w5 removes 500 kb or less of LG 23, including the closely linked wnt10b locus (Lekven et al, 2003).…”

Section: Strains and Developmental Conditionsmentioning

confidence: 99%

Rhombomere boundaries are Wnt signaling centers that regulate metameric patterning in the zebrafish hindbrain

Riley

Chiang

Storch

et al. 2004

Developmental Dynamics

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The vertebrate hindbrain develops from a series of segments (rhombomeres) distributed along the anteroposterior axis. We are studying the roles of Wnt and Delta-Notch signaling in maintaining rhombomere boundaries as organizing centers in the zebrafish hindbrain. Several wnt genes (wnt1, wnt3a, wnt8b, and wnt10b) show elevated expression at rhombomere boundaries, whereas several delta genes (dlA, dlB, and dlD) are expressed in transverse stripes flanking rhombomere boundaries. Partial disruption of Wnt signaling by knockdown of multiple wnt genes, or the Wnt mediator tcf3b, ablates boundaries and associated cell types. Expression of dlA is chaotic, and cell types associated with rhombomere centers are disorganized. Similar patterning defects are observed in segmentation mutants spiel-ohne-grenzen (spg) and valentino (val), which fail to form rhombomere boundaries due to faulty interactions between adjacent rhombomeres. Stripes of wnt expression are variably disrupted, with corresponding disturbances in metameric patterning. Mutations in dlA or mind bomb (mib) disrupt Delta-Notch signaling and cause a wide range of patterning defects in the hindbrain. Stripes of wnt1 are initially normal but subsequently dissipate, and metameric patterning becomes increasingly disorganized. Driving wnt1 expression using a heat-shock construct partially rescues metameric patterning in mib mutants. Thus, rhombomere boundaries act as Wnt signaling centers required for precise metameric patterning, and Delta signals from flanking cells provide feedback to maintain wnt expression at boundaries. Similar feedback mechanisms operate in the Drosophila wing disc and vertebrate limb bud, suggesting coaptation of a conserved signaling module that spatially organizes cells in complex organ systems.

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Reverse genetics in zebrafish

Cited by 29 publications

References 45 publications

Development of the zebrafish inner ear

Development of the zebrafish inner ear

A direct role for Fgf but not Wnt in otic placode induction

Rhombomere boundaries are Wnt signaling centers that regulate metameric patterning in the zebrafish hindbrain

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