Genomes and Genes
Gene Symbol: ascl1a
Description: achaete-scute family bHLH transcription factor 1a
Alias: Zash-1a, ash, asha, id:ibd5085, im:7138587, si:dkey-264k15.2, zash1a, zasha, achaete-scute homolog 1a, pia, pituitary absent, pituitary-absent protein
- Lee J, Wu S, Goering L, Dorsky R. Canonical Wnt signaling through Lef1 is required for hypothalamic neurogenesis. Development. 2006;133:4451-61 pubmed..The conserved presence of this pathway in other vertebrates suggests a common mechanism for regulating hypothalamic neurogenesis. ..
- Guo Y, Ma L, Cristofanilli M, Hart R, Hao A, Schachner M. Transcription factor Sox11b is involved in spinal cord regeneration in adult zebrafish. Neuroscience. 2011;172:329-41 pubmed publisher..In the injured spinal cord, expression of the neural stem cell associated gene Nestin, and the proneural gene Ascl1a (Mash1a), which are involved in the self-renewal and cell fate specification of endogenous neural stem cells, ..
- Riley B, Chiang M, Storch E, Heck R, Buckles G, Lekven A. Rhombomere boundaries are Wnt signaling centers that regulate metameric patterning in the zebrafish hindbrain. Dev Dyn. 2004;231:278-91 pubmed..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. ..
- Cau E, Wilson S. Ash1a and Neurogenin1 function downstream of Floating head to regulate epiphysial neurogenesis. Development. 2003;130:2455-66 pubmed..These results suggest that the genetic pathways that involve ash1a and ngn1 are common to both neuronal types. ..
- Nelson C, Gorsuch R, Bailey T, Ackerman K, Kassen S, Hyde D. Stat3 defines three populations of Müller glia and is required for initiating maximal müller glia proliferation in the regenerating zebrafish retina. J Comp Neurol. 2012;520:4294-311 pubmed publisherWe analyzed the role of Stat3, Ascl1a, and Lin28a in Müller glia reentry into the cell cycle following damage to the zebrafish retina...
- Lucas M, Muller F, Rüdiger R, Henion P, Rohrer H. The bHLH transcription factor hand2 is essential for noradrenergic differentiation of sympathetic neurons. Development. 2006;133:4015-24 pubmed..ganglion primordia characterized by the expression of phox2b, phox2a and the achaete-scute family member zash1a/ascl1...
- Qin Z, Barthel L, Raymond P. Genetic evidence for shared mechanisms of epimorphic regeneration in zebrafish. Proc Natl Acad Sci U S A. 2009;106:9310-5 pubmed publisher..Comparison of gene expression profiles from regenerating zebrafish retina, caudal fin, and heart muscle revealed additional candidate genes potentially implicated in injury-induced epimorphic regeneration in diverse zebrafish tissues. ..
- Chapouton P, Adolf B, Leucht C, Tannhäuser B, Ryu S, Driever W, et al. her5 expression reveals a pool of neural stem cells in the adult zebrafish midbrain. Development. 2006;133:4293-303 pubmed..In addition, the first transcription factor characteristic of this cell population, Her5, points to the E(Spl) as a promising family of candidate adult neural stem cell regulators. ..
- Williams R, Venkatesh I, Pearse D, Udvadia A, Bunge M. MASH1/Ascl1a leads to GAP43 expression and axon regeneration in the adult CNS. PLoS ONE. 2015;10:e0118918 pubmed publisher..The basic helix-loop-helix (bHLH) transcription factor, MASH1/Ascl1a, is transiently expressed during the development of many neuronal subtypes and regulates the expression of genes ..
- Mahler J, Filippi A, Driever W. DeltaA/DeltaD regulate multiple and temporally distinct phases of notch signaling during dopaminergic neurogenesis in zebrafish. J Neurosci. 2010;30:16621-35 pubmed publisher..Rather, DeltaA/D limits the size of the sim1a- and otpa-expressing precursor pool from which dopaminergic neurons differentiate. ..
- Conner C, Ackerman K, Lahne M, Hobgood J, Hyde D. Repressing notch signaling and expressing TNFÎ± are sufficient to mimic retinal regeneration by inducing MÃ¼ller glial proliferation to generate committed progenitor cells. J Neurosci. 2014;34:14403-19 pubmed publisher..This RO4929097-induced proliferation requires Ascl1a expression and Jak1-mediated Stat3 phosphorylation/activation, analogous to the light-damaged retina...
- Yin L, Maddison L, Li M, Kara N, LaFave M, Varshney G, et al. Multiplex Conditional Mutagenesis Using Transgenic Expression of Cas9 and sgRNAs. Genetics. 2015;200:431-41 pubmed publisher..We also show that delivery of sgRNAs targeting ascl1a into the eye leads to impaired damage-induced photoreceptor regeneration...
- Ryu S, Mahler J, Acampora D, Holzschuh J, Erhardt S, Omodei D, et al. Orthopedia homeodomain protein is essential for diencephalic dopaminergic neuron development. Curr Biol. 2007;17:873-80 pubmed..Thus, Otp is one of the few known transcription factors that can determine aspects of the dopaminergic phenotype and the first known factor to control the development of the diencephalospinal dopaminergic system. ..
- Han R, Wang R, Zhao Q, Han Y, Zong S, Miao S, et al. Trim69 regulates zebrafish brain development by ap-1 pathway. Sci Rep. 2016;6:24034 pubmed publisher..Overall, our results support a role for trim69 in the development of the zebrafish brain through ap-1 pathway. ..
- Xu Q, Alldus G, Macdonald R, Wilkinson D, Holder N. Function of the Eph-related kinase rtk1 in patterning of the zebrafish forebrain. Nature. 1996;381:319-22 pubmed..We find that expression of a truncated receptor leads to expansion of the eye field into diencephalic territory and loss of diencephalic structures, indicating a role for Rtk1 in patterning the developing forebrain. ..
- Rai K, Jafri I, Chidester S, James S, Karpf A, Cairns B, et al. Dnmt3 and G9a cooperate for tissue-specific development in zebrafish. J Biol Chem. 2010;285:4110-21 pubmed publisher..We propose a model wherein specific DNMT-histone methyltransferase networks are utilized to silence critical regulators of cell fate in a tissue-specific manner. ..
- Tallafuss A, Adolf B, Bally Cuif L. Selective control of neuronal cluster size at the forebrain/midbrain boundary by signaling from the prechordal plate. Dev Dyn. 2003;227:524-35 pubmed..Together, our results suggest that a combination of patterning-related and -unrelated mechanisms specifically controls the size of individual early neuronal clusters within the anterior neural plate. ..
- Lauter G, Söll I, Hauptmann G. Molecular characterization of prosomeric and intraprosomeric subdivisions of the embryonic zebrafish diencephalon. J Comp Neurol. 2013;521:1093-118 pubmed publisher..Our comparative gene expression analysis conformed with the idea of a common bauplan for the diencephalon of anamniote and amniote vertebrates from fish to mammals. ..
- Zhu S, Lee J, Guo F, Shin J, Perez Atayde A, Kutok J, et al. Activated ALK collaborates with MYCN in neuroblastoma pathogenesis. Cancer Cell. 2012;21:362-73 pubmed publisher..Coexpression of activated ALK with MYCN provides prosurvival signals that block this apoptotic response and allow continued expansion and oncogenic transformation of hyperplastic neuroblasts, thus promoting progression to neuroblastoma...
- Ignatius M, Unal Eroglu A, Malireddy S, Gallagher G, Nambiar R, Henion P. Distinct functional and temporal requirements for zebrafish Hdac1 during neural crest-derived craniofacial and peripheral neuron development. PLoS ONE. 2013;8:e63218 pubmed publisher..Our study reveals distinct functional and temporal requirements for zebrafish hdac1 during neural crest-derived craniofacial and peripheral neuron development...
- Ganassi M, Badodi S, Polacchini A, Baruffaldi F, Battini R, Hughes S, et al. Distinct functions of alternatively spliced isoforms encoded by zebrafish mef2ca and mef2cb. Biochim Biophys Acta. 2014;1839:559-70 pubmed publisher..Taken together, the data show that AS is a significant regulator of Mef2c activity. ..
- Mueller T, Vernier P, Wullimann M. A phylotypic stage in vertebrate brain development: GABA cell patterns in zebrafish compared with mouse. J Comp Neurol. 2006;494:620-34 pubmed..expression patterns of developmentally relevant genes, for example, of proneural (Neurogenin1, NeuroD, Mash1/Zash1a) genes involved in neurogenesis at a particular time window (mouse: embryonic day 12.5/13.5; zebrafish: 3 days)...
- Masai I, Heisenberg C, Barth K, Macdonald R, Adamek S, Wilson S. floating head and masterblind regulate neuronal patterning in the roof of the forebrain. Neuron. 1997;18:43-57 pubmed..We propose a role for Flh in linking the signaling pathways that regulate regional patterning to the signaling pathways that regulate neurogenesis. ..
- Hans S, Campos Ortega J. On the organisation of the regulatory region of the zebrafish deltaD gene. Development. 2002;129:4773-84 pubmed..controlled by two relatively small genomic regions, which are regulated by the proneural proteins neurogenin 1 and zash1a/b acting as transcriptional activators that bind to so-called E-boxes...
- Yang N, Dong Z, Guo S. Fezf2 regulates multilineage neuronal differentiation through activating basic helix-loop-helix and homeodomain genes in the zebrafish ventral forebrain. J Neurosci. 2012;32:10940-8 pubmed publisher..First, our genetic analyses reveal the requirement of the achaete-scute-like genes ascl1a and 1b in serotonergic and GABAergic neuron development, but they are dispensable for the specification of ..
- Khuansuwan S, Clanton J, Dean B, Patton J, Gamse J. A transcription factor network controls cell migration and fate decisions in the developing zebrafish pineal complex. Development. 2016;143:2641-50 pubmed publisher..We conclude that cell specification and migration in the pineal complex are regulated by a network of at least three transcription factors. ..
- Dickmeis T, Lahiri K, Nica G, Vallone D, Santoriello C, Neumann C, et al. Glucocorticoids play a key role in circadian cell cycle rhythms. PLoS Biol. 2007;5:e78 pubmed..Instead, they act in concert with a systemic signaling environment of which glucocorticoids are an essential part. ..
- Zhao X, Wan J, Powell C, Ramachandran R, Myers M, Goldman D. Leptin and IL-6 family cytokines synergize to stimulate Müller glia reprogramming and retina regeneration. Cell Rep. 2014;9:272-284 pubmed publisher..Importantly, we find that ascl1a gene expression, which drives MG reprogramming in fish and mammals, is regulated in a Jak/Stat-dependent manner ..
- Powell C, Cornblath E, Goldman D. Zinc-binding domain-dependent, deaminase-independent actions of apolipoprotein B mRNA-editing enzyme, catalytic polypeptide 2 (Apobec2), mediate its effect on zebrafish retina regeneration. J Biol Chem. 2014;289:28924-41 pubmed publisher..Importantly, mutations in the zinc-binding domain of Apobec2 diminished its ability to stimulate Pou6f2 binding to DNA, and knockdown of Ubc9 or Pou6f2 suppressed retina regeneration. ..
- Matsuda N, Mishina M. Identification of chaperonin CCT gamma subunit as a determinant of retinotectal development by whole-genome subtraction cloning from zebrafish no tectal neuron mutant. Development. 2004;131:1913-25 pubmed..Similarly, the expression of brn3b was normal in the tectum of ntn mutants, but tectal neuropil formation was abolished. These results suggest that the gamma subunit of chaperonin CCT plays an essential role in retinotectal development. ..
- Wullimann M, Mueller T. Expression of Zash-1a in the postembryonic zebrafish brain allows comparison to mouse Mash1 domains. Brain Res Gene Expr Patterns. 2002;1:187-92 pubmed..Furthermore, previous initial identification of early postembryonic brain subdivisions in the zebrafish is strongly corroborated by these expression patterns. ..
- Wang X, Yang N, Uno E, Roeder R, Guo S. A subunit of the mediator complex regulates vertebrate neuronal development. Proc Natl Acad Sci U S A. 2006;103:17284-9 pubmed..when overexpressed is capable of increasing, the expression of distinct neuronal determination genes, including zash1a and lim1, and serves as an in vivo cofactor for Sox9 in this process...
- Adolf B, Chapouton P, Lam C, Topp S, Tannhäuser B, Strahle U, et al. Conserved and acquired features of adult neurogenesis in the zebrafish telencephalon. Dev Biol. 2006;295:278-93 pubmed
- Paridaen J, Janson E, Utami K, Pereboom T, Essers P, van Rooijen C, et al. The nucleolar GTP-binding proteins Gnl2 and nucleostemin are required for retinal neurogenesis in developing zebrafish. Dev Biol. 2011;355:286-301 pubmed publisher..Finally, the data suggest that Gnl2 and NS affect cell cycle exit of neural progenitors by regulating the expression of cell cycle regulators independently of p53. ..
- Walshe J, Mason I. Unique and combinatorial functions of Fgf3 and Fgf8 during zebrafish forebrain development. Development. 2003;130:4337-49 pubmed..Analysis of embryos treated with an FGFR inhibitor suggests that continuous FGF signalling is required from gastrulation stages for normal forebrain patterning, and identifies additional requirements for FGFR activity. ..
- Powell C, Elsaeidi F, Goldman D. Injury-dependent Müller glia and ganglion cell reprogramming during tissue regeneration requires Apobec2a and Apobec2b. J Neurosci. 2012;32:1096-109 pubmed publisher..The maximal induction of apobec2b required Ascl1a, but was independent of Lin28, and therefore defines an independent signaling pathway stemming from Ascl1a...
- Ganz J, Kaslin J, Freudenreich D, Machate A, Geffarth M, Brand M. Subdivisions of the adult zebrafish subpallium by molecular marker analysis. J Comp Neurol. 2012;520:633-55 pubmed publisher..Further, the septal nuclei derive from both the pallium and subpallium. On this basis, we present a new model for the subdivisions of the subpallium in teleost fish. ..
- Chow E, Hui M, Lin C, Cheng S. Cadmium inhibits neurogenesis in zebrafish embryonic brain development. Aquat Toxicol. 2008;87:157-69 pubmed publisher..We observe prominent reductions in the expression of several proneuronal genes including ngn1 in cell clusters, zash1a in the developing optic tectum, and zash1b in the telencephalon and tectum...
- Fortuna V, Pardanaud L, Brunet I, Ola R, Ristori E, Santoro M, et al. Vascular Mural Cells Promote Noradrenergic Differentiation of Embryonic Sympathetic Neurons. Cell Rep. 2015;11:1786-96 pubmed publisher..Thus, PDGFR-mediated mural cell recruitment mediates neurovascular interactions between the aorta and sympathetic precursors and promotes their noradrenergic differentiation. ..
- Flasse L, Pirson J, Stern D, Von Berg V, Manfroid I, Peers B, et al. Ascl1b and Neurod1, instead of Neurog3, control pancreatic endocrine cell fate in zebrafish. BMC Biol. 2013;11:78 pubmed publisher..It is repressed by Notch signaling that prevents pancreatic cell differentiation by maintaining precursors in an undifferentiated state...
- Miyake A, Mekata Y, Fujibayashi H, Nakanishi K, Konishi M, Itoh N. Brorin is required for neurogenesis, gliogenesis, and commissural axon guidance in the zebrafish forebrain. PLoS ONE. 2017;12:e0176036 pubmed publisher..The present results suggest that Brorin is a secreted Bmp antagonist predominantly expressed in developing neural tissues and that it plays multiple roles in the development of the zebrafish forebrain. ..
- McGaughey D, McCallion A. Efficient discovery of ASCL1 regulatory sequences through transgene pooling. Genomics. 2010;95:363-9 pubmed publisher..These data demonstrate the utility of this approach and its potential for further adaptation and higher throughput application. ..
- Ganz J, Kroehne V, Freudenreich D, Machate A, Geffarth M, Braasch I, et al. Subdivisions of the adult zebrafish pallium based on molecular marker analysis. F1000Res. 2014;3:308 pubmed publisher..Combinatorial expression analysis of ascl1a, eomesa, emx1, emx2, emx3, and Prox1 identifies four main divisions in the adult zebrafish pallium...
- Solin S, Wang Y, Mauldin J, Schultz L, Lincow D, Brodskiy P, et al. Molecular and cellular characterization of a zebrafish optic pathway tumor line implicates glia-derived progenitors in tumorigenesis. PLoS ONE. 2014;9:e114888 pubmed publisher..qRT-PCR confirmed >10-fold overexpression of the Wnt pathway components hbegfa, ascl1a, and insm1a...
- Wullimann M, Mueller T. Identification and morphogenesis of the eminentia thalami in the zebrafish. J Comp Neurol. 2004;471:37-48 pubmed..In contrast, the migrated teleostean entopeduncular complex does not correspond to a pallidal division but is indeed the adult derivative of the early-recognized eminentia thalami as shown in this study. ..
- Azuma M, Embree L, Sabaawy H, Hickstein D. Ewing sarcoma protein ewsr1 maintains mitotic integrity and proneural cell survival in the zebrafish embryo. PLoS ONE. 2007;2:e979 pubmed..Ewsr1 maintains mitotic integrity and proneural cell survival in early zebrafish development. ..
- Zhang T, Zhou X, Ma X, Liu J. Mechanisms of cadmium-caused eye hypoplasia and hypopigmentation in zebrafish embryos. Aquat Toxicol. 2015;167:68-76 pubmed publisher..Moreover, we found that compounds BIO or RA could neutralize the toxic effects of Cd. ..
- Wei X, Bugni T, Harper M, Sandoval I, Manos E, Swift J, et al. Evaluation of pyridoacridine alkaloids in a zebrafish phenotypic assay. Mar Drugs. 2010;8:1769-78 pubmed publisher..Compounds 1-6 were evaluated in a zebrafish phenotype-based assay. Amphimedine (4) was the only compound that caused a phenotype in zebrafish embryos at 30 muM. No phenotype other than death was observed for compounds 1-3, 5, 6. ..
- Bailey T, Fossum S, Fimbel S, Montgomery J, Hyde D. The inhibitor of phagocytosis, O-phospho-L-serine, suppresses Müller glia proliferation and cone cell regeneration in the light-damaged zebrafish retina. Exp Eye Res. 2010;91:601-12 pubmed publisher..Furthermore, ascl1a and stat3 expression were unaffected in either the L-SOP or MSOP-injected retinas relative to controls, suggesting ..
- Gerety S, Wilkinson D. Morpholino artifacts provide pitfalls and reveal a novel role for pro-apoptotic genes in hindbrain boundary development. Dev Biol. 2011;350:279-89 pubmed publisher..In light of these findings, we discuss the precautions needed in performing morpholino knockdowns and in interpreting the data derived from their use. ..
- Kapsimali M, Kaushik A, Gibon G, Dirian L, Ernest S, Rosa F. Fgf signaling controls pharyngeal taste bud formation through miR-200 and Delta-Notch activity. Development. 2011;138:3473-84 pubmed publisher..Conversely, larvae with increased Notch activity and ascl1a(-/-) mutants are devoid of 5HT(+) cells, but have maintained and increased Calb2b(+) cells, respectively...
- Stewart R, Arduini B, Berghmans S, George R, Kanki J, Henion P, et al. Zebrafish foxd3 is selectively required for neural crest specification, migration and survival. Dev Biol. 2006;292:174-88 pubmed
- Roach G, Heath Wallace R, Cameron A, Emrah Ozel R, Hongay C, Baral R, et al. Loss of ascl1a prevents secretory cell differentiation within the zebrafish intestinal epithelium resulting in a loss of distal intestinal motility. Dev Biol. 2013;376:171-86 pubmed publisher..Here, we demonstrate that in contrast to the atoh1 in mammals, ascl1a is responsible for formation of secretory cells in zebrafish...
- Flasse L, Stern D, Pirson J, Manfroid I, Peers B, Voz M. The bHLH transcription factor Ascl1a is essential for the specification of the intestinal secretory cells and mediates Notch signaling in the zebrafish intestine. Dev Biol. 2013;376:187-97 pubmed publisher..b>ascl1a was found to be the earliest factor detected in the intestine...
- Bayramli X, Kocagoz Y, Sakizli U, Fuss S. Patterned Arrangements of Olfactory Receptor Gene Expression in Zebrafish are Established by Radial Movement of Specified Olfactory Sensory Neurons. Sci Rep. 2017;7:5572 pubmed publisher..We formulated a simple mathematical model based on exact parameters derived from our analysis of OSN neurogenesis, which accurately generates OR-like distributions without the need to invoke molecular signals to pattern the OE. ..
- Cheng Y, Chiang M, Shih H, Ma T, Yeh T, Huang Y, et al. The transcription factor hairy/E(spl)-related 2 induces proliferation of neural progenitors and regulates neurogenesis and gliogenesis. Dev Biol. 2015;397:116-28 pubmed publisher..Together, these two mechanisms ensure the proper development of the neural progenitor cell pool. ..
- Hjorth J, Connor R, Key B. Role of hlx1 in zebrafish brain morphogenesis. Int J Dev Biol. 2002;46:583-96 pubmed..Our results indicate multiple roles for hlx1 during zebrafish brain morphogenesis. ..
- Rodriguez Viales R, Diotel N, Ferg M, Armant O, Eich J, Alunni A, et al. The helix-loop-helix protein id1 controls stem cell proliferation during regenerative neurogenesis in the adult zebrafish telencephalon. Stem Cells. 2015;33:892-903 pubmed publisher..Together, we propose that Id1 acts to maintain the neural stem cell pool by counteracting neurogenesis-promoting signals. ..
- Scholpp S, Delogu A, Gilthorpe J, Peukert D, Schindler S, Lumsden A. Her6 regulates the neurogenetic gradient and neuronal identity in the thalamus. Proc Natl Acad Sci U S A. 2009;106:19895-900 pubmed publisher..Thus, the presence or absence of a single upstream regulator of proneural gene expression, Her6, leads to the establishment of discrete neuronal domains in the thalamus. ..
- Chen Y, Sundvik M, Rozov S, Priyadarshini M, Panula P. MANF regulates dopaminergic neuron development in larval zebrafish. Dev Biol. 2012;370:237-49 pubmed publisher..Strikingly, manf mRNA could partly restore the decrease of th1 positive cells in Nr4a2-deficient larvae. These results suggest that MANF is involved in the regulation of the development of dopaminergic system in zebrafish. ..
- Uribe R, Kwon T, Marcotte E, Gross J. Id2a functions to limit Notch pathway activity and thereby influence the transition from proliferation to differentiation of retinoblasts during zebrafish retinogenesis. Dev Biol. 2012;371:280-92 pubmed publisher..These data highlight the integral role played by Id2a in the gene regulatory network governing the transition from retinoblast proliferation to terminal differentiation during vertebrate retinogenesis. ..
- Li Y, Allende M, Finkelstein R, Weinberg E. Expression of two zebrafish orthodenticle-related genes in the embryonic brain. Mech Dev. 1994;48:229-44 pubmed..However, there are a number of interesting differences between the forebrain and midbrain regions which express the genes in the two species. ..
- Jacob J, Ribes V, Moore S, Constable S, Sasai N, Gerety S, et al. Valproic acid silencing of ascl1b/Ascl1 results in the failure of serotonergic differentiation in a zebrafish model of fetal valproate syndrome. Dis Model Mech. 2014;7:107-17 pubmed publisher..Together, these data provide a molecular explanation for serotonergic defects in FVS and highlight an epigenetic mechanism for genome-environment interaction in disease. ..
- Kroehne V, Freudenreich D, Hans S, Kaslin J, Brand M. Regeneration of the adult zebrafish brain from neurogenic radial glia-type progenitors. Development. 2011;138:4831-41 pubmed publisher..Thus, regeneration after traumatic lesion of the adult zebrafish brain occurs efficiently from radial glia-type stem/progenitor cells. ..
- Zhang S, Mu Z, He C, Zhou M, Liu D, Zhao X, et al. Antiviral Drug Ganciclovir Is a Potent Inhibitor of the Proliferation of Müller Glia-Derived Progenitors During Zebrafish Retinal Regeneration. Invest Ophthalmol Vis Sci. 2016;57:1991-2000 pubmed publisher..Our study uncovered a novel inhibitory effect of GCV on MGPC proliferation and suggests its potential use as a tool to uncover molecular mechanisms underlying retinal regeneration in zebrafish. ..
- Gorsuch R, Lahne M, Yarka C, Petravick M, Li J, Hyde D. Sox2 regulates Müller glia reprogramming and proliferation in the regenerating zebrafish retina via Lin28 and Ascl1a. Exp Eye Res. 2017;161:174-192 pubmed publisher..Sox2 expression was also necessary for ascl1a (neurogenic) and lin28a (reprogramming) expression, but not stat3 expression following retinal damage...