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1.  A zebrafish SKIV2L2-enhancer trap line provides a useful tool for the study of peripheral sensory circuit development 
Gene expression patterns : GEP  2011;11(7):409-414.
The zebrafish is an ideal model for elucidating the cellular and molecular mechanisms that underlie development of the peripheral nervous system. A transgenic line that selectively labels all the sensory circuits would be a valuable tool for such investigations. In this study, we describe such a line: the enhancer trap zebrafish line Tg(SKIV2L2:gfp)j1775 which expresses green fluorescent protein (gfp) in the peripheral sensory ganglia. We show that this transgene marks all peripheral ganglia and sensory nerves, beginning at the time when the neurons are first extending their processes, but does not label the efferent nerves. The trapped reporter is inserted just upstream of a previously poorly described gene: lhfpl4 on LG6. The expression pattern of this gene by in situ hybridization reveals a different, but overlapping, pattern of expression compared to that of the transgene. This pattern also does not mimic that of the gene (skiv2l2), which provided the promoter element in the construct. These findings indicate that reporter expression is not dictated by an endogenous enhancer element, but instead arises through an unknown mechanism. Regardless, this reporter line should prove to be a valuable tool in the investigation of peripheral nervous system formation in the zebrafish.
PMCID: PMC3163734  PMID: 21742057
2.  Diverse mechanisms for assembly of branchiomeric nerves 
Developmental biology  2011;357(2):305-317.
The formation of branchiomeric nerves (cranial nerves V, VII, IX and X) from their sensory, motor and glial components is poorly understood. The current model for cranial nerve formation is based on the Vth nerve, in which sensory afferents are formed first and must enter the hindbrain in order for the motor efferents to exit. Using transgenic zebrafish lines to discriminate between motor neurons, sensory neurons and peripheral glia, we show that this model does not apply to the remaining three branchiomeric nerves. For these nerves, the motor efferents form prior to the sensory afferents, and their pathfinding show no dependence on sensory axons, as ablation of cranial sensory neurons by ngn1 knockdown had no effect. In contrast, the sensory limbs of the IXth and Xth nerves (but not the Vth or VIIth) were misrouted in gli1 mutants, which lack hindbrain bmn, suggesting that the motor efferents are crucial for appropriate sensory axon projection in some branchiomeric nerves. For all four nerves, peripheral glia were the intermediate component added and had a critical role in nerve integrity but not in axon guidance, as foxd3 null mutants lacking peripheral glia exhibited defasciculation of gVII, gIX, and gX axons. The bmn efferents were unaffected in these mutants. These data demonstrate that multiple mechanisms underlie formation of the four branchiomeric nerves. For the Vth, sensory axons initiate nerve formation, for the VIIth the sensory and motor limbs are independent, and for the IXth/Xth motor axons initiate formation. In all cases the glia are patterned by the initiating set of axons and are needed to maintain axon fasciculation. These results reveal that coordinated interactions between the three neural cell types in branchiomeric nerves differ according to their axial position.
PMCID: PMC3164235  PMID: 21777575
zebrafish; sensory neurons; branchiomotor neurons; peripheral glia
3.  Ectodermal P2X receptor function plays a pivotal role in craniofacial development of the zebrafish 
Purinergic Signalling  2009;5(3):395-407.
P2X receptors are non-selective cation channels operated by extracellular ATP. Currently, little is known concerning the functions of these receptors during development. Previous work from our lab has shown that zebrafish have two paralogs of the mammalian P2X3 receptor subunit. One paralog, p2rx3.1, is expressed in subpopulations of neural and ectodermal cells in the embryonic head. To investigate the role of this subunit in early cranial development, we utilized morpholino oligonucleotides to disrupt its translation. Loss of this subunit resulted in craniofacial defects that included malformation of the pharyngeal skeleton. During formation of these structures, there was a marked increase in cell death within the branchial arches. In addition, the epibranchial (facial, glossopharyngeal, and vagal) cranial sensory ganglia and their circuits were perturbed. These data suggest that p2rx3.1 function in ectodermal cells is involved in purinergic signaling essential for proper craniofacial development and sensory circuit formation in the embryonic and larval zebrafish.
PMCID: PMC2717322  PMID: 19529983
P2X; Zebrafish; Morpholino; Chondrogenesis; Sensory ganglia
4.  Domestic violence. Incidence and prevalence in a northern emergency department. 
Canadian Family Physician  2004;50:90-97.
OBJECTIVE: To examine the incidence and prevalence of domestic violence (DV) against women presenting to emergency departments. DESIGN: Prospective cohort study to determine health status and exposure to DV. SETTING: Hospital emergency department in urban northern Canada. PARTICIPANTS: Random sample of women older than 16 presenting to the emergency department for any reason. MAIN OUTCOME MEASURES: Demographic variables, exposure to DV. RESULTS: Of 1800 potential subjects, 577 (32%) did not fit inclusion criteria. Of the remaining 1223, 983 (80%) agreed to participate. Mean age was 41, 135 of participants (14%) were aboriginal, and 546 (56%) were married. Overall, 725 (74%) had current partners. Incidence of DV resulting in emergency department presentation on the day of assessment was 2%. Of women with partners, 66 (9%) had previously been threatened or injured by those partners. Lifetime prevalence of DV was 51%; physical DV was experienced by 40%. One-year prevalence was 26%. CONCLUSION: Incidence of DV was lower than expected; prevalence of DV was high.
PMCID: PMC2214492  PMID: 14761109

Results 1-4 (4)