The Experts below are selected from a list of 216 Experts worldwide ranked by ideXlab platform
David J Price - One of the best experts on this subject based on the ideXlab platform.
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foxg1 is required to limit the formation of ciliary margin tissue and wnt β catenin signalling in the developing Nasal Retina of the mouse
Developmental Biology, 2013Co-Authors: Vassiliki Fotaki, Thomas Pratt, Rowena Smith, David J PriceAbstract:The ciliary margin (CM) develops in the peripheral Retina and gives rise to the iris and the ciliary body. The Wnt/β-catenin signalling pathway has been implicated in ciliary margin development. Here, we tested the hypothesis that in the developing mouse Retina Foxg1 is responsible for suppressing the Wnt/β-catenin pathway and restricting CM development. We showed that there is excess CM tissue in Foxg1−/− null embryos and this expansion is more pronounced in the Nasal Retina where Foxg1 normally shows its highest expression levels. Results on expression of a reporter allele for Wnt/β-catenin signalling and of Lef1, a target of Wnt/β-catenin signalling, displayed significant upregulation of this pathway in Foxg1−/− nulls at embryonic days 12.5 and 14.5. Interestingly, this upregulation was observed specifically in the Nasal Retina, where normally very few Wnt-responsive cells are observed. These results indicate a suppressive role of Foxg1 on this signalling pathway. Our results reveal a new role of Foxg1 in limiting CM development in the Nasal peripheral Retina and add a new molecular player in the developmental network involved in CM specification.
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Foxg1 is required to limit the formation of ciliary margin tissue and Wnt/β-catenin signalling in the developing Nasal Retina of the mouse
Developmental Biology, 2013Co-Authors: Vassiliki Fotaki, Thomas Pratt, Rowena Smith, David J PriceAbstract:The ciliary margin (CM) develops in the peripheral Retina and gives rise to the iris and the ciliary body. The Wnt/β-catenin signalling pathway has been implicated in ciliary margin development. Here, we tested the hypothesis that in the developing mouse Retina Foxg1 is responsible for suppressing the Wnt/β-catenin pathway and restricting CM development. We showed that there is excess CM tissue in Foxg1−/− null embryos and this expansion is more pronounced in the Nasal Retina where Foxg1 normally shows its highest expression levels. Results on expression of a reporter allele for Wnt/β-catenin signalling and of Lef1, a target of Wnt/β-catenin signalling, displayed significant upregulation of this pathway in Foxg1−/− nulls at embryonic days 12.5 and 14.5. Interestingly, this upregulation was observed specifically in the Nasal Retina, where normally very few Wnt-responsive cells are observed. These results indicate a suppressive role of Foxg1 on this signalling pathway. Our results reveal a new role of Foxg1 in limiting CM development in the Nasal peripheral Retina and add a new molecular player in the developmental network involved in CM specification.
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foxg1 regulates Retinal axon pathfinding by repressing an ipsilateral program in Nasal Retina and by causing optic chiasm cells to exert a net axonal growth promoting activity
Development, 2008Co-Authors: Natasha M Tian, Thomas Pratt, David J PriceAbstract:Mammalian binocular vision relies on the divergence of Retinal ganglion cell axons at the optic chiasm, with strictly controlled numbers projecting contralaterally and ipsilaterally. In mouse, contralateral projections arise from the entire Retina, whereas ipsilateral projections arise from ventrotemporal Retina. We investigate how development of these patterns of projection is regulated by the contralateral determinant Foxg1, a forkhead box transcription factor expressed in Nasal Retina and at the chiasm. In Nasal Retina, loss of Foxg1 causes increased numbers of ipsilateral projections and ectopic expression of the ipsilateral determinants Zic2, Ephb1 and Foxd1 , indicating that Nasal Retina is competent to express an ipsilateral program that is normally suppressed by Foxg1. Using co-cultures that combine Foxg1-expressing with Foxg1 -null Retinal explants and chiasm cells, we provide functional evidence that Foxg1 promotes contralateral projections through actions in Nasal Retina, and that in chiasm cells, Foxg1 is required for the generation of a hitherto unrecognized activity supporting RGC axon growth.
Jumpei Naito - One of the best experts on this subject based on the ideXlab platform.
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Changes in the Distribution of Labeled Retinal Ganglion Cells after an Implant of DiI into the Optic Nerve in the Chick Embryos
Journal of Veterinary Medical Science, 2003Co-Authors: Yaoxing Chen, Man Hu, Hideshi Shibata, Jumpei NaitoAbstract:Changes in the distribution of Retinal ganglion cells (RGCs) were studied using the retrograde labeling of DiI in chicks and chick embryos. The small Retinal area filled with labeled RGCs was observed in the Retinal fundus on E8. The labeled Retinal area expanded radially toward the peripheral Retina as the Retina grew, and finally occupied a whole Retina by P1. The temporal Retina was labeled more rapidly than in the Nasal Retina. The observed-increasing rate of the labeled area was corrected with the growing rate of the Retina. Consequently, the corrected-increasing rate of the labeled area was estimated to be about 390% between E8 and E11, and 20-50% after E11. This means that spreading speed of the maturated RGCs lowered until 1/10-1/20 after E11.
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changes in the retinotopical fiber order along the horizontal and dorsoventral axes of the Nasal Retina in the monkey optic chiasm
Cell and Tissue Research, 2000Co-Authors: Jumpei NaitoAbstract:The fiber arrangement of the retinogeniculate pathways was investigated in the Japanese monkey chiasm by iontophoretical injections into the lateral geniculate nucleus of wheat germ agglutinin conjugated to horseradish peroxidase. The present data demonstrated that the horizontal and dorsoventral axes of the Nasal Retina were rearranged in gross dorsoventral and posteroanterior orders in the chiasm. Thus, foveal/parafoveal fibers passed across the dorsal chiasm in a cluster and midperipheral Nasal fibers passed across the central and ventral chiasms. Far-peripheral Nasal fibers progressed in the ventral chiasm. Chiasmal fibers from the dorsal and ventral Nasal Retinas took pathways exactly similar to those from the midperipheral and the far-peripheral Nasal Retinas, respectively. In the anteroposterior direction, foveal/parafoveal fibers crossed the chiasmal midline extensively. However, midperipheral Nasal fibers and dorsal Nasal fibers crossed the posterior chiasm, and far-peripheral Nasal fibers and ventral Nasal fibers crossed the anterior chiasm. The correspondence of the retinotopical order in the chiasm with the chronological order is discussed.
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DIFFERENCES IN DISPERSION OF MONKEY OPTIC NERVE FIBERS ACCORDING TO THEIR TERMINAL LAYERS IN THE LATERAL GENICULATE NUCLEUS
Neuroscience Research, 1995Co-Authors: Jumpei NaitoAbstract:Abstract Dispersion of retinogeniculate fibers in the monkey optic nerve was investigated in relation to their terminal layers in the lateral geniculate nucleus (LGN) using a retrograde axonal tracer (wheat germ agglutinin conjugated to horseradish peroxidase, WGA-HRP). Dispersion of fibers projecting to the parvocellular layer of the LGN (LGNp) is clearly less extensive compared with that of fibers projecting to the magnocellular layer of the LGN (LGNm) in the most distal part of the optic nerve. The occupation rate of retrogradely labeled fibers projecting from the periphery of the Nasal Retina to the LGNp increases only 1.2 times in the initial part of the nerve. In contrast, the occupation rate increases up to 1.6 times for labeled fibers projecting from a similar part of the Nasal peripheral Retina to the LGNm in the same part of the optic nerve. The morphological features of the labeled ganglion cells indicate that these fibers arise from Pβ and Pa ganglion cells, respectively.
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Retinogeniculate projection fibers in the monkey optic chiasm: A demonstration of the fiber arrangement by means of wheat germ agglutinin conjugated to horseradish peroxidase
The Journal of Comparative Neurology, 1994Co-Authors: Jumpei NaitoAbstract:The fiber arrangement of the retinogeniculate pathway was investigated in the chiasm of Japanese monkeys (Macaca fuscata) by an iontophoretic injection of wheat germ agglutinin conjugated to horseradish peroxidase into the lateral geniculate nucleus (LGN). It has been claimed that there is a distinct retinotopy in the monkey chiasm, despite lack of any clear anatomical evidence. However, the present data indicate a rather gross retinotopy or almost no discernible retinotopy. Fibers from the foveal-to-peripheral axis of the temporal Retina show substantially no retinotopy owing to a marked overlap of fibers in the anterolateral and the posterocentral parts of the ipsilateral hemichiasm. In contrast, the foveal-to-peripheral axis of the Nasal Retina is re-formed in a gross dorsoventral order in the chiasm. That is, Nasal foveal-parafoveal fibers which arise from small cells (which are Pβ mode) pass in the dorsal part of the chiasm adjacent to the brain. They widely overlap Nasal perifoveal fibers which cross the chiasm more ventrally with very little contact with the brain. The Nasal perifoveal fibers also widely overlap Nasal peripheral fibers which cross the chiasm more ventrally. Furthermore, the Nasal peripheral fibers overlap Nasal far peripheral fibers which arise from large cells (including many of the Pα mode) which run near the pial surface. Fibers from the dorsal and ventral Nasal Retina cross the midline of the posterior and anterior parts of the chiasm, respectively, and are finally positioned in the medioventral and ventrocentral parts in the tract. Consequently, the dorsoventral Retinal axis is re-formed posteroanteriorly in the midline of the chiasm and in a roughly mediolateral direction in the tract. Furthermore, the present study shows that the Nasal and temporal Retinal fibers coming from the same eye are acutely segregated in the prechiasmal region and the anterior part of the hemichiasm. © 1994 Wiley-Liss, Inc.
Thomas Pratt - One of the best experts on this subject based on the ideXlab platform.
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foxg1 is required to limit the formation of ciliary margin tissue and wnt β catenin signalling in the developing Nasal Retina of the mouse
Developmental Biology, 2013Co-Authors: Vassiliki Fotaki, Thomas Pratt, Rowena Smith, David J PriceAbstract:The ciliary margin (CM) develops in the peripheral Retina and gives rise to the iris and the ciliary body. The Wnt/β-catenin signalling pathway has been implicated in ciliary margin development. Here, we tested the hypothesis that in the developing mouse Retina Foxg1 is responsible for suppressing the Wnt/β-catenin pathway and restricting CM development. We showed that there is excess CM tissue in Foxg1−/− null embryos and this expansion is more pronounced in the Nasal Retina where Foxg1 normally shows its highest expression levels. Results on expression of a reporter allele for Wnt/β-catenin signalling and of Lef1, a target of Wnt/β-catenin signalling, displayed significant upregulation of this pathway in Foxg1−/− nulls at embryonic days 12.5 and 14.5. Interestingly, this upregulation was observed specifically in the Nasal Retina, where normally very few Wnt-responsive cells are observed. These results indicate a suppressive role of Foxg1 on this signalling pathway. Our results reveal a new role of Foxg1 in limiting CM development in the Nasal peripheral Retina and add a new molecular player in the developmental network involved in CM specification.
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Foxg1 is required to limit the formation of ciliary margin tissue and Wnt/β-catenin signalling in the developing Nasal Retina of the mouse
Developmental Biology, 2013Co-Authors: Vassiliki Fotaki, Thomas Pratt, Rowena Smith, David J PriceAbstract:The ciliary margin (CM) develops in the peripheral Retina and gives rise to the iris and the ciliary body. The Wnt/β-catenin signalling pathway has been implicated in ciliary margin development. Here, we tested the hypothesis that in the developing mouse Retina Foxg1 is responsible for suppressing the Wnt/β-catenin pathway and restricting CM development. We showed that there is excess CM tissue in Foxg1−/− null embryos and this expansion is more pronounced in the Nasal Retina where Foxg1 normally shows its highest expression levels. Results on expression of a reporter allele for Wnt/β-catenin signalling and of Lef1, a target of Wnt/β-catenin signalling, displayed significant upregulation of this pathway in Foxg1−/− nulls at embryonic days 12.5 and 14.5. Interestingly, this upregulation was observed specifically in the Nasal Retina, where normally very few Wnt-responsive cells are observed. These results indicate a suppressive role of Foxg1 on this signalling pathway. Our results reveal a new role of Foxg1 in limiting CM development in the Nasal peripheral Retina and add a new molecular player in the developmental network involved in CM specification.
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foxg1 regulates Retinal axon pathfinding by repressing an ipsilateral program in Nasal Retina and by causing optic chiasm cells to exert a net axonal growth promoting activity
Development, 2008Co-Authors: Natasha M Tian, Thomas Pratt, David J PriceAbstract:Mammalian binocular vision relies on the divergence of Retinal ganglion cell axons at the optic chiasm, with strictly controlled numbers projecting contralaterally and ipsilaterally. In mouse, contralateral projections arise from the entire Retina, whereas ipsilateral projections arise from ventrotemporal Retina. We investigate how development of these patterns of projection is regulated by the contralateral determinant Foxg1, a forkhead box transcription factor expressed in Nasal Retina and at the chiasm. In Nasal Retina, loss of Foxg1 causes increased numbers of ipsilateral projections and ectopic expression of the ipsilateral determinants Zic2, Ephb1 and Foxd1 , indicating that Nasal Retina is competent to express an ipsilateral program that is normally suppressed by Foxg1. Using co-cultures that combine Foxg1-expressing with Foxg1 -null Retinal explants and chiasm cells, we provide functional evidence that Foxg1 promotes contralateral projections through actions in Nasal Retina, and that in chiasm cells, Foxg1 is required for the generation of a hitherto unrecognized activity supporting RGC axon growth.
Vassiliki Fotaki - One of the best experts on this subject based on the ideXlab platform.
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foxg1 is required to limit the formation of ciliary margin tissue and wnt β catenin signalling in the developing Nasal Retina of the mouse
Developmental Biology, 2013Co-Authors: Vassiliki Fotaki, Thomas Pratt, Rowena Smith, David J PriceAbstract:The ciliary margin (CM) develops in the peripheral Retina and gives rise to the iris and the ciliary body. The Wnt/β-catenin signalling pathway has been implicated in ciliary margin development. Here, we tested the hypothesis that in the developing mouse Retina Foxg1 is responsible for suppressing the Wnt/β-catenin pathway and restricting CM development. We showed that there is excess CM tissue in Foxg1−/− null embryos and this expansion is more pronounced in the Nasal Retina where Foxg1 normally shows its highest expression levels. Results on expression of a reporter allele for Wnt/β-catenin signalling and of Lef1, a target of Wnt/β-catenin signalling, displayed significant upregulation of this pathway in Foxg1−/− nulls at embryonic days 12.5 and 14.5. Interestingly, this upregulation was observed specifically in the Nasal Retina, where normally very few Wnt-responsive cells are observed. These results indicate a suppressive role of Foxg1 on this signalling pathway. Our results reveal a new role of Foxg1 in limiting CM development in the Nasal peripheral Retina and add a new molecular player in the developmental network involved in CM specification.
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Foxg1 is required to limit the formation of ciliary margin tissue and Wnt/β-catenin signalling in the developing Nasal Retina of the mouse
Developmental Biology, 2013Co-Authors: Vassiliki Fotaki, Thomas Pratt, Rowena Smith, David J PriceAbstract:The ciliary margin (CM) develops in the peripheral Retina and gives rise to the iris and the ciliary body. The Wnt/β-catenin signalling pathway has been implicated in ciliary margin development. Here, we tested the hypothesis that in the developing mouse Retina Foxg1 is responsible for suppressing the Wnt/β-catenin pathway and restricting CM development. We showed that there is excess CM tissue in Foxg1−/− null embryos and this expansion is more pronounced in the Nasal Retina where Foxg1 normally shows its highest expression levels. Results on expression of a reporter allele for Wnt/β-catenin signalling and of Lef1, a target of Wnt/β-catenin signalling, displayed significant upregulation of this pathway in Foxg1−/− nulls at embryonic days 12.5 and 14.5. Interestingly, this upregulation was observed specifically in the Nasal Retina, where normally very few Wnt-responsive cells are observed. These results indicate a suppressive role of Foxg1 on this signalling pathway. Our results reveal a new role of Foxg1 in limiting CM development in the Nasal peripheral Retina and add a new molecular player in the developmental network involved in CM specification.
Scott S Whitmore - One of the best experts on this subject based on the ideXlab platform.
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transcriptomic analysis across Nasal temporal and macular regions of human neural Retina and rpe choroid by rna seq
Experimental Eye Research, 2014Co-Authors: Scott S Whitmore, Alex H Wagner, Adam P Deluca, Arlene V Drack, Edwin M Stone, Budd A TuckerAbstract:Abstract Proper spatial differentiation of Retinal cell types is necessary for normal human vision. Many Retinal diseases, such as Best disease and male germ cell associated kinase ( MAK )-associated retinitis pigmentosa, preferentially affect distinct topographic regions of the Retina. While much is known about the distribution of cell types in the Retina, the distribution of molecular components across the posterior pole of the eye has not been well-studied. To investigate regional difference in molecular composition of ocular tissues, we assessed differential gene expression across the temporal, macular, and Nasal Retina and Retinal pigment epithelium (RPE)/choroid of human eyes using RNA-Seq. RNA from temporal, macular, and Nasal Retina and RPE/choroid from four human donor eyes was extracted, poly-A selected, fragmented, and sequenced as 100 bp read pairs. Digital read files were mapped to the human genome and analyzed for differential expression using the Tuxedo software suite. Retina and RPE/choroid samples were clearly distinguishable at the transcriptome level. Numerous transcription factors were differentially expressed between regions of the Retina and RPE/choroid. Photoreceptor-specific genes were enriched in the peripheral samples, while ganglion cell and amacrine cell genes were enriched in the macula. Within the RPE/choroid, RPE-specific genes were upregulated at the periphery while endothelium associated genes were upregulated in the macula. Consistent with previous studies, BEST1 expression was lower in macular than extramacular regions. The MAK gene was expressed at lower levels in macula than in extramacular regions, but did not exhibit a significant difference between Nasal and temporal Retina. The regional molecular distinction is greatest between macula and periphery and decreases between different peripheral regions within a tissue. Datasets such as these can be used to prioritize candidate genes for possible involvement in Retinal diseases with regional phenotypes.
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Transcriptomic analysis across Nasal, temporal, and macular regions of human neural Retina and RPE/choroid by RNA-Seq
Experimental Eye Research, 2014Co-Authors: Scott S Whitmore, Alex H Wagner, Adam P Deluca, Arlene V Drack, Edwin M Stone, Budd A Tucker, Shemin Zeng, Terry A. Braun, Robert F. Mullins, Todd E. ScheetzAbstract:Abstract Proper spatial differentiation of Retinal cell types is necessary for normal human vision. Many Retinal diseases, such as Best disease and male germ cell associated kinase ( MAK )-associated retinitis pigmentosa, preferentially affect distinct topographic regions of the Retina. While much is known about the distribution of cell types in the Retina, the distribution of molecular components across the posterior pole of the eye has not been well-studied. To investigate regional difference in molecular composition of ocular tissues, we assessed differential gene expression across the temporal, macular, and Nasal Retina and Retinal pigment epithelium (RPE)/choroid of human eyes using RNA-Seq. RNA from temporal, macular, and Nasal Retina and RPE/choroid from four human donor eyes was extracted, poly-A selected, fragmented, and sequenced as 100 bp read pairs. Digital read files were mapped to the human genome and analyzed for differential expression using the Tuxedo software suite. Retina and RPE/choroid samples were clearly distinguishable at the transcriptome level. Numerous transcription factors were differentially expressed between regions of the Retina and RPE/choroid. Photoreceptor-specific genes were enriched in the peripheral samples, while ganglion cell and amacrine cell genes were enriched in the macula. Within the RPE/choroid, RPE-specific genes were upregulated at the periphery while endothelium associated genes were upregulated in the macula. Consistent with previous studies, BEST1 expression was lower in macular than extramacular regions. The MAK gene was expressed at lower levels in macula than in extramacular regions, but did not exhibit a significant difference between Nasal and temporal Retina. The regional molecular distinction is greatest between macula and periphery and decreases between different peripheral regions within a tissue. Datasets such as these can be used to prioritize candidate genes for possible involvement in Retinal diseases with regional phenotypes.
