Marsupial retinocollicular system shows differential expression of messenger RNA encoding EphA receptors and their ligands during development

Vidovic, Maria; Marotte, L.R.; Mark, R. F.

doi:10.1002/(sici)1097-4547(19990715)57:2<244::aid-jnr10>3.0.co;2-d

Cited by 14 publications

(24 citation statements)

References 47 publications

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“…The expression pattern of EphA3 receptor in the wallaby retina, being higher in temporal than nasal retina up to P65, is compatible with our previous ®nding on the differential expression of mRNA for EphA3 over this period (Vidovic et al, 1999). However, in that study nasotemporal differences in mRNA expression could also be detected at P95, whereas such differences in protein expression could not.…”

Section: Expression Of Epha3 In the Retina And Scsupporting

confidence: 91%

“…The cellular distribution of EphA3 in the SC and ephrin-A2 in the retina have also been determined. Messenger RNA for EphA7 was also reported previously to be differentially expressed in the SC of the wallaby (Vidovic et al, 1999) and its cellular distribution in the retina and the SC is also described here.…”

Section: Introductionsupporting

confidence: 70%

“…Expression of EphA3 in the SC did not show rostrocaudal differences over the developmental period studied, re¯ecting reported mRNA levels (Vidovic et al, 1999). If the nasotemporal differences in levels of expression of EphA3 in retinal ganglion cells are mirrored in their terminals one might have expected to see higher levels of EphA3 in processes rostrally in the SC but this was not apparent.…”

Section: Expression Of Epha3 In the Retina And Scmentioning

confidence: 86%

“…We recently reported that mRNAs for the EphA3 receptor and two of its ligands, ephrin-A2 and ephrin-A5, were differentially expressed in the wallaby retinocollicular system during development, suggesting that they have a role in the development of topographic mapping in this mammalian model (Vidovic et al, 1999). The main aim of the present study was to examine expression of protein for the EphA3 receptor and one of its ligands, ephrin-A2, in the retina and SC, respectively, during the different stages of development of the retinocollicular projection.…”

Section: Introductionmentioning

confidence: 99%

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Graded expression of EphA3 in the retina and ephrin‐A2 in the superior colliculus during initial development of coarse topography in the wallaby retinocollicular projection

Stubbs

Palmer

Vidovic

et al. 2000

Eur J of Neuroscience

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We describe the expression of EphA3 and EphA7 receptors and ephrin-A2 ligand in the retina and the superior colliculus during the development of the retinocollicular projection in the marsupial wallaby (Macropus eugenii), using immunoblotting and immunohistochemistry. EphA3 in the retina was in a striking, low central to high peripheral gradient, superimposed on which was a high temporal to low nasal level of expression. This distribution was evident from postnatal day 30, when axons are growing into the colliculus and forming a coarsely organized topographic projection, to postnatal day 65, when axons have arborized in their correct retinotopic positions. EphA7 showed a shallow centroperipheral gradient with no nasotemporal differences in expression. In the superior colliculus no rostrocaudal differences in distribution were detected for either of these receptors. Ephrin-A2 was distributed in a gradient increasing from the rostral to the caudal pole in the superficial layers of the superior colliculus only up to postnatal day 30. Ephrin-A2 was evenly distributed in the retina throughout development of the projection. Expression of EphA3 in the retina increased, while the expression of ephrin-A2 in the colliculus was downregulated over time. The graded expression of EphA3 and ephrin-A2 early in the development of the projection suggests that they play a role in establishment of coarse topography of retinal axons along the rostrocaudal axis of the superior colliculus. However, the gradients were not complementary, meaning that EphA3 alone cannot mediate the repulsive interactions with ephrin-A2 that have been postulated to underlie formation of the topographic map.

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Section: Expression Of Epha3 In the Retina And Scsupporting

confidence: 91%

Section: Introductionsupporting

confidence: 70%

Section: Expression Of Epha3 In the Retina And Scmentioning

confidence: 86%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Graded expression of EphA3 in the retina and ephrin‐A2 in the superior colliculus during initial development of coarse topography in the wallaby retinocollicular projection

Stubbs

Palmer

Vidovic

et al. 2000

Eur J of Neuroscience

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“…Total cellular RNAs were extracted from fresh tissue using a single-step protocol for RNA isolation (''RNAzol B,'' Tel-Test, Friendswood, TX) as described previously (Vidovic et al, 1999;Osborne et al, 2002). Data were obtained from three separate RNA preparations at each age.…”

Section: Reverse Transcription-pcr For Analysis Of Gene Expressionmentioning

confidence: 99%

Eph receptor and ephrin signaling in developing and adult brain of the honeybee (Apis mellifera)

et al. 2006

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Roles for Eph receptor tyrosine kinase and ephrin signaling in vertebrate brain development are well established. Their involvement in the modulation of mammalian synaptic structure and physiology is also emerging. However, less is known of their effects on brain development and their function in adult invertebrate nervous systems. Here, we report on the characterization of Eph receptor and ephrin orthologs in the honeybee, Apis mellifera (Am), and their role in learning and memory. In situ hybridization for mRNA expression showed a uniform distribution of expression of both genes across the developing pupal and adult brain. However, in situ labeling with Fc fusion proteins indicated that the AmEphR and Amephrin proteins were differentially localized to cell body regions in the mushroom bodies and the developing neuropiles of the antennal and optic lobes. In adults, AmEphR protein was localized to regions of synaptic contacts in optic lobes, in the glomeruli of antennal lobes, and in the medial lobe of the mushroom body. The latter two regions are involved in olfactory learning and memory in the honeybee. Injections of EphR-Fc and ephrin-Fc proteins into the brains of adult bees, 1 h before olfactory conditioning of the proboscis extension reflex, sig-nificantly reduced memory 24 h later. Experimental amnesia in the group injected with ephrin-Fc was apparent 1 h posttraining. Experimental amnesia was also induced by post-training injections with ephrin-Fc suggesting a role in recall. This is the first demonstration that Eph molecules function to regulate the formation of memory in insects.

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Eph receptor and ephrin signaling in developing and adult brain of the honeybee (Apis mellifera)

Vidovic

Nighorn

Koblar

et al. 2007

Developmental Neurobiology

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Roles for Eph receptor tyrosine kinase and ephrin signaling in vertebrate brain development are well established. Their involvement in the modulation of mammalian synaptic structure and physiology is also emerging. However, less is known of their effects on brain development and their function in adult invertebrate nervous systems. Here, we report on the characterization of Eph receptor and ephrin orthologs in the honeybee, Apis mellifera (Am), and their role in learning and memory. In situ hybridization for mRNA expression showed a uniform distribution of expression of both genes across the developing pupal and adult brain. However, in situ labeling with Fc fusion proteins indicated that the AmEphR and Amephrin proteins were differentially localized to cell body regions in the mushroom bodies and the developing neuropiles of the antennal and optic lobes. In adults, AmEphR protein was localized to regions of synaptic contacts in optic lobes, in the glomeruli of antennal lobes, and in the medial lobe of the mushroom body. The latter two regions are involved in olfactory learning and memory in the honeybee. Injections of EphR-Fc and ephrin-Fc proteins into the brains of adult bees, 1 h before olfactory conditioning of the proboscis extension reflex, significantly reduced memory 24 h later. Experimental amnesia in the group injected with ephrin-Fc was apparent 1 h post-training. Experimental amnesia was also induced by post-training injections with ephrin-Fc suggesting a role in recall. This is the first demonstration that Eph molecules function to regulate the formation of memory in insects.

show abstract

Marsupial retinocollicular system shows differential expression of messenger RNA encoding EphA receptors and their ligands during development

Cited by 14 publications

References 47 publications

Graded expression of EphA3 in the retina and ephrin‐A2 in the superior colliculus during initial development of coarse topography in the wallaby retinocollicular projection

Graded expression of EphA3 in the retina and ephrin‐A2 in the superior colliculus during initial development of coarse topography in the wallaby retinocollicular projection

Eph receptor and ephrin signaling in developing and adult brain of the honeybee (Apis mellifera)

Eph receptor and ephrin signaling in developing and adult brain of the honeybee (Apis mellifera)

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