Paired box protein 6 (PAX6) is a master regulator of the eye development. Over the last past two decades, our understanding of eye development, especially the molecular function of PAX6, has focused on transcriptional control of the Pax6 expression. However, other regulatory mechanisms for gene expression, including alternative splicing (AS), have been understudied in the eye development. Recent findings suggest that two PAX6 isoforms generated by AS of Pax6 pre-mRNA may play previously underappreciated role(s) during eye development, especially, the corneal development.
Get full access to this article
View all access options for this article.
References
1.
NilsenTW and GraveleyBR. (2010). Expansion of the eukaryotic proteome by alternative splicing. Nature, 463:457–463.
2.
ManiatisT and TasicB. (2002). Alternative pre-mRNA splicing and proteome expansion in metazoans. Nature, 418:236–243.
3.
WangET, SandbergR, LuoS, KhrebtukovaI, ZhangL, MayrC, KingsmoreSF, SchrothGP and BurgeCB. (2008). Alternative isoform regulation in human tissue transcriptomes. Nature, 456:470–476.
4.
LeeY and RioDC. (2015). Mechanisms and regulation of alternative pre-mRNA splicing. Annu Rev Biochem, 84:291–323.
5.
YangL, ParkJ and GraveleyBR. (2007). Splicing from the outside in. Mol Cell, 27:861–862.
6.
ChoS, MoonH, LohTJ, JangHN, LiuY, ZhouJ, OhnT, ZhengX and ShenH. (2015). Splicing inhibition of U2AF65 leads to alternative exon skipping. Proc Natl Acad Sci U S A, 112:9926–9931.
7.
ParkJW, PariskyK, CelottoAM, ReenanRA and GraveleyBR. (2004). Identification of alternative splicing regulators by RNA interference in Drosophila. Proc Natl Acad Sci U S A, 101:15974–15979.
8.
DavidCJ and ManleyJL. (2010). Alternative pre-mRNA splicing regulation in cancer: pathways and programs unhinged. Genes Dev, 24:2343–2364.
9.
TraunmullerL, GomezAM, NguyenTM and ScheiffeleP. (2016). Control of neuronal synapse specification by a highly dedicated alternative splicing program. Science, 352:982–986.
10.
LamouilleS, XuJ and DerynckR. (2014). Molecular mechanisms of epithelial-mesenchymal transition. Nat Rev Mol Cell Biol, 15:178–196.
11.
NellesDA and YeoGW. (2010). Alternative splicing in stem cell self-renewal and diferentiation. Adv Exp Med Biol, 695:92–104.
12.
GabutM, Samavarchi-TehraniP, WangX, SlobodeniucV, O'HanlonD, SungHK, AlvarezM, TalukderS, PanQ, et al. (2011). An alternative splicing switch regulates embryonic stem cell pluripotency and reprogramming. Cell, 147:132–146.
13.
HanH, IrimiaM, RossPJ, SungHK, AlipanahiB, DavidL, GolipourA, GabutM, MichaelIP, et al. (2013). MBNL proteins repress ES-cell-specific alternative splicing and reprogramming. Nature, 498:241–245.
14.
SuCH, HungKY, HungSC and TarnWY. (2017). RBM4 regulates neuronal differentiation of mesenchymal stem cells by modulating alternative splicing of pyruvate kinase M. Mol Cell Biol, 37:e00466-16.
15.
SalomonisN, SchlieveCR, PereiraL, WahlquistC, ColasA, ZambonAC, VranizanK, SpindlerMJ, PicoAR, et al. (2010). Alternative splicing regulates mouse embryonic stem cell pluripotency and differentiation. Proc Natl Acad Sci U S A, 107:10514–10519.
16.
ChepelevI and ChenX. (2013). Alternative splicing switching in stem cell lineages. Front Biol, 8:50–59.
17.
ChowRL and LangRA. (2001). Early eye development in vertebrates. Annu Rev Cell Dev Biol, 17:255–296.
18.
GrawJ. (2010). Eye development. Curr Top Dev Biol, 90:343–386.
19.
YoonJJ, IsmailS and SherwinT. (2014). Limbal stem cells: central concepts of corneal epithelial homeostasis. World J Stem Cells, 6:391–403.
20.
ShahamO, MenuchinY, FarhyC and Ashery-PadanR. (2012). Pax6: a multi-level regulator of ocular development. Prog Retin Eye Res, 31:351–376.
21.
PichaudF and DesplanC. (2002). Pax genes and eye organogenesis. Curr Opin Genet Dev, 12:430–434.
22.
HansonI and Van HeyningenV. (1995). Pax6: more than meets the eye. Trends Genet, 11:268–272.
23.
DavisJ, DuncanMK, RobisonWGJr., and PiatigorskyJ. (2003). Requirement for Pax6 in corneal morphogenesis: a role in adhesion. J Cell Sci, 116:2157–2167.
24.
CollinsonJM, QuinnJC, HillRE and WestJD. (2003). The roles of Pax6 in the cornea, retina, and olfactory epithelium of the developing mouse embryo. Dev Biol, 255:303–312.
25.
RamaeshT, RamaeshK, Martin CollinsonJ, ChanasSA, DhillonB and WestJD. (2005). Developmental and cellular factors underlying corneal epithelial dysgenesis in the Pax6+/− mouse model of aniridia. Exp Eye Res, 81:224–235.
26.
LiT and LuL. (2005). Epidermal growth factor-induced proliferation requires down-regulation of Pax6 in corneal epithelial cells. J Biol Chem, 280:12988–12995.
27.
OuyangJ, ShenYC, YehLK, LiW, CoyleBM, LiuCY and FiniME. (2006). Pax6 overexpression suppresses cell proliferation and retards the cell cycle in corneal epithelial cells. Invest Ophthalmol Vis Sci, 47:2397–2407.
28.
PeartonDJ, YangY and DhouaillyD. (2005). Transdifferentiation of corneal epithelium into epidermis occurs by means of a multistep process triggered by dermal developmental signals. Proc Natl Acad Sci U S A, 102:3714–3719.
29.
OuyangH, XueY, LinY, ZhangX, XiL, PatelS, CaiH, LuoJ, ZhangM, et al. (2014). WNT7A and PAX6 define corneal epithelium homeostasis and pathogenesis. Nature, 511:358–361.
30.
LiW, ChenYT, HayashidaY, BlancoG, KheirkahA, HeH, ChenSY, LiuCY and TsengSC. (2008). Down-regulation of Pax6 is associated with abnormal differentiation of corneal epithelial cells in severe ocular surface diseases. J Pathol, 214:114–122.
31.
Shalom-FeuersteinR, SerrorL, De La Forest DivonneS, PetitI, AberdamE, CamargoL, DamourO, VigourouxC, SolomonA, et al. (2012). Pluripotent stem cell model reveals essential roles for miR-450b-5p and miR-184 in embryonic corneal lineage specification. Stem Cells, 30:898–909.
32.
EpsteinJA, GlaserT, CaiJ, JepealL, WaltonDS and MaasRL. (1994). Two independent and interactive DNA-binding subdomains of the Pax6 paired domain are regulated by alternative splicing. Genes Dev, 8:2022–2034.
33.
DavisJ and PiatigorskyJ. (2011). Overexpression of Pax6 in mouse cornea directly alters corneal epithelial cells: changes in immune function, vascularization, and differentiation. Invest Ophthalmol Vis Sci, 52:4158–4168.
34.
EpsteinJ, CaiJ, GlaserT, JepealL and MaasR. (1994). Identification of a Pax paired domain recognition sequence and evidence for DNA-dependent conformational changes. J Biol Chem, 269:8355–8361.
35.
FavorJ, BradleyA, ConteN, JanikD, PretschW, ReitmeirP, RosemannM, SchmahlW, WienbergJ and ZausI. (2009). Analysis of Pax6 contiguous gene deletions in the mouse, Mus musculus, identifies regions distinct from Pax6 responsible for extreme small-eye and belly-spotting phenotypes. Genetics, 182:1077–1088.
36.
SasamotoY, HayashiR, ParkSJ, Saito-AdachiM, SuzukiY, KawasakiS, QuantockAJ, NakaiK, TsujikawaM and NishidaK. (2016). PAX6 isoforms, along with reprogramming factors, differentially regulate the induction of cornea-specific genes. Sci Rep, 6:20807.
37.
GlaserT, WaltonDS and MaasRL. (1992). Genomic structure, evolutionary conservation and aniridia mutations in the human PAX6 gene. Nat Genet, 2:232–239.
38.
CinarHN and ChisholmAD. (2004). Genetic analysis of the Caenorhabditis elegans pax-6 locus: roles of paired domain-containing and nonpaired domain-containing isoforms. Genetics, 168:1307–1322.
39.
CallaertsP, ClementsJ, FrancisC and HensK. (2006). Pax6 and eye development in Arthropoda. Arthropod Struct Dev, 35:379–391.
40.
KozmikZ, DaubeM, FreiE, NormanB, KosL, DishawLJ, NollM and PiatigorskyJ. (2003). Role of Pax genes in eye evolution: a cnidarian PaxB gene uniting Pax2 and Pax6 functions. Dev Cell, 5:773–785.
41.
ArendtD, TessmarK, de Campos-BaptistaMI, DorresteijnA and WittbrodtJ. (2002). Development of pigment-cup eyes in the polychaete Platynereis dumerilii and evolutionary conservation of larval eyes in Bilateria. Development, 129:1143–1154.
42.
LoosliF, Kmita-CunisseM and GehringWJ. (1996). Isolation of a Pax-6 homolog from the ribbonworm Lineus sanguineus. Proc Natl Acad Sci U S A, 93:2658–2663.
43.
TomarevSI, CallaertsP, KosL, ZinovievaR, HalderG, GehringW and PiatigorskyJ. (1997). Squid Pax-6 and eye development. Proc Natl Acad Sci U S A, 94:2421–2426.
44.
QuiringR, WalldorfU, KloterU and GehringWJ. (1994). Homology of the eyeless gene of Drosophila to the small eye gene in mice and Aniridia in humans. Science, 265:785–789.
45.
JacobssonL, KronhamnJ and Rasmuson-LestanderA. (2009). The Drosophila Pax6 paralogs have different functions in head development but can partially substitute for each other. Mol Genet Genomics, 282:217–231.
46.
CzernyT, HalderG, KloterU, SouabniA, GehringWJ and BusslingerM. (1999). Twin of eyeless, a second Pax-6 gene of Drosophila, acts upstream of eyeless in the control of eye development. Mol Cell, 3:297–307.
47.
DominguezM, Ferres-MarcoD, Gutierrez-AvinoFJ, SpeicherSA and BeneytoM. (2004). Growth and specification of the eye are controlled independently by eyegone and eyeless in Drosophila melanogaster. Nat Genet, 36:31–39.
48.
DansaultA, DavidG, SchwartzC, JaliffaC, VieiraV, de la HoussayeG, BigotK, CatinF, TattuL, et al. (2007). Three new PAX6 mutations including one causing an unusual ophthalmic phenotype associated with neurodevelopmental abnormalities. Mol Vis, 13:511–523.
49.
XuHE, RouldMA, XuW, EpsteinJA, MaasRL and PaboCO. (1999). Crystal structure of the human Pax6 paired domain-DNA complex reveals specific roles for the linker region and carboxy-terminal subdomain in DNA binding. Genes Dev, 13:1263–1275.
50.
KiselevY, EriksenTE, ForsdahlS, NguyenLH and MikkolaI. (2012). 3T3 cell lines stably expressing Pax6 or Pax6(5a)—a new tool used for identification of common and isoform specific target genes. PLoS One, 7:e31915.
51.
KozmikZ, CzernyT and BusslingerM. (1997). Alternatively spliced insertions in the paired domain restrict the DNA sequence specificity of Pax6 and Pax8. EMBO J, 16:6793–6803.
52.
ChauhanBK, YangY, CveklovaK and CveklA. (2004). Functional interactions between alternatively spliced forms of Pax6 in crystallin gene regulation and in haploinsufficiency. Nucleic Acids Res, 32:1696–1709.
53.
CarriereC, PlazaS, CabocheJ, DozierC, BaillyM, MartinP and SauleS. (1995). Nuclear localization signals, DNA binding, and transactivation properties of quail Pax-6 (Pax-QNR) isoforms. Cell Growth Differ, 6:1531–1540.
54.
ShinDH, KwonBS, ChangYP, BaeSR, KimJ and KimJW. (2003). Ultramicroscopical immunolocalization of PAX6 in the adult chicken retina. Acta Histochem, 105:267–272.
55.
GrocottT, FrostV, MaillardM, JohansenT, WheelerGN, DawesLJ, WormstoneIM and ChantryA. (2007). The MH1 domain of Smad3 interacts with Pax6 and represses autoregulation of the Pax6 P1 promoter. Nucleic Acids Res, 35:890–901.
56.
ShubhamK and MishraR. (2012). Pax6 interacts with SPARC and TGF-beta in murine eyes. Mol Vis, 18:951–956.
57.
JangCC, ChaoJL, JonesN, YaoLC, BessarabDA, KuoYM, JunS, DesplanC, BeckendorfSK and SunYH. (2003). Two Pax genes, eye gone and eyeless, act cooperatively in promoting Drosophila eye development. Development, 130:2939–2951.
58.
AzumaN, TadokoroK, AsakaA, YamadaM, YamaguchiY, HandaH, MatsushimaS, WatanabeT, KohsakaS, et al. (2005). The Pax6 isoform bearing an alternative spliced exon promotes the development of the neural retinal structure. Hum Mol Genet, 14:735–745.
59.
JaworskiC, SperbeckS, GrahamC and WistowG. (1997). Alternative splicing of Pax6 in bovine eye and evolutionary conservation of intron sequences. Biochem Biophys Res Commun, 240:196–202.
60.
LakowskiJ, MajumderA and LauderdaleJD. (2007). Mechanisms controlling Pax6 isoform expression in the retina have been conserved between teleosts and mammals. Dev Biol, 307:498–520.
61.
RichardsonJ, CveklA and WistowG. (1995). Pax-6 is essential for lens-specific expression of zeta-crystallin. Proc Natl Acad Sci U S A, 92:4676–4680.
62.
DuncanMK, KozmikZ, CveklovaK, PiatigorskyJ and CveklA. (2000). Overexpression of PAX6(5a) in lens fiber cells results in cataract and upregulation of (alpha)5(beta)1 integrin expression. J Cell Sci 113, (Pt 18)::3173–3185.
63.
ChauhanBK, ReedNA, ZhangW, DuncanMK, KilimannMW and CveklA. (2002). Identification of genes downstream of Pax6 in the mouse lens using cDNA microarrays. J Biol Chem, 277:11539–11548.
64.
PinsonJ, MasonJO, SimpsonTI and PriceDJ. (2005). Regulation of the Pax6: Pax6(5a) mRNA ratio in the developing mammalian brain. BMC Dev Biol, 5:13.
65.
DoraN, OuJ, KucerovaR, ParisiI, WestJD and CollinsonJM. (2008). PAX6 dosage effects on corneal development, growth, and wound healing. Dev Dyn, 237:1295–1306.
66.
HaubstN, BergerJ, RadjendiraneV, GrawJ, FavorJ, SaundersGF, StoykovaA and GotzM. (2004). Molecular dissection of Pax6 function: the specific roles of the paired domain and homeodomain in brain development. Development, 131:6131–6140.
67.
ZhangX, HuangCT, ChenJ, PankratzMT, XiJ, LiJ, YangY, LavauteTM, LiXJ, et al. (2010). Pax6 is a human neuroectoderm cell fate determinant. Cell Stem Cell, 7:90–100.
68.
CarbeC, GargA, CaiZ, LiH, PowersA and ZhangX. (2013). An allelic series at the paired box gene 6 (Pax6) locus reveals the functional specificity of Pax genes. J Biol Chem, 288:12130–12141.
69.
AzumaN, YamaguchiY, HandaH, HayakawaM, KanaiA and YamadaM. (1999). Missense mutation in the alternative splice region of the PAX6 gene in eye anomalies. Am J Hum Genet, 65:656–663.
70.
NanjoY, KawasakiS, MoriK, SotozonoC, InatomiT and KinoshitaS. (2004). A novel mutation in the alternative splice region of the PAX6 gene in a patient with Peters' anomaly. Br J Ophthalmol, 88:720–721.
71.
GronskovK, RosenbergT, SandA and Brondum-NielsenK. (1999). Mutational analysis of PAX6: 16 novel mutations including 5 missense mutations with a mild aniridia phenotype. Eur J Hum Genet, 7:274–286.
72.
SinghS, MishraR, ArangoNA, DengJM, BehringerRR and SaundersGF. (2002). Iris hypoplasia in mice that lack the alternatively spliced Pax6(5a) isoform. Proc Natl Acad Sci U S A, 99:6812–6815.
73.
OuyangP and SugrueSP. (1996). Characterization of pinin, a novel protein associated with the desmosome-intermediate filament complex. J Cell Biol, 135:1027–1042.
74.
MurachelliAG, EbertJ, BasquinC, Le HirH and ContiE. (2012). The structure of the ASAP core complex reveals the existence of a Pinin-containing PSAP complex. Nat Struct Mol Biol, 19:378–386.
75.
JooJH, KimYH, DunnNW and SugrueSP. (2010). Disruption of mouse corneal epithelial differentiation by conditional inactivation of pnn. Invest Ophthalmol Vis Sci, 51:1927–1934.
76.
ZimowskaG, ShiJ, MungubaG, JacksonMR, AlpatovR, SimmonsMN, ShiY and SugrueSP. (2003). Pinin/DRS/memA interacts with SRp75, SRm300 and SRrp130 in corneal epithelial cells. Invest Ophthalmol Vis Sci, 44:4715–4723.
77.
SakashitaE, TatsumiS, WernerD, EndoH and MayedaA. (2004). Human RNPS1 and its associated factors: a versatile alternative pre-mRNA splicing regulator in vivo. Mol Cell Biol, 24:1174–1187.
78.
AkinD, NewmanJR, McIntyreLM and SugrueSP. (2016). RNA-seq analysis of impact of PNN on gene expression and alternative splicing in corneal epithelial cells. Mol Vis, 22:40–60.
79.
JooJH, RyuD, PengQ and SugrueSP. (2014). Role of Pnn in alternative splicing of a specific subset of lncRNAs of the corneal epithelium. Mol Vis, 20:1629–1642.
80.
JooJH, CorreiaGP, LiJL, LopezMC, BakerHV and SugrueSP. (2013). Transcriptomic analysis of PNN- and ESRP1-regulated alternative pre-mRNA splicing in human corneal epithelial cells. Invest Ophthalmol Vis Sci, 54:697–707.
81.
WarzechaCC, SatoTK, NabetB, HogeneschJB and CarstensRP. (2009). ESRP1 and ESRP2 are epithelial cell-type-specific regulators of FGFR2 splicing. Mol Cell, 33:591–601.
82.
ZuberME, GestriG, ViczianAS, BarsacchiG and HarrisWA. (2003). Specification of the vertebrate eye by a network of eye field transcription factors. Development, 130:5155–5167.
83.
Canto-SolerMV and AdlerR. (2006). Optic cup and lens development requires Pax6 expression in the early optic vesicle during a narrow time window. Dev Biol, 294:119–132.
84.
Furuta YHB. (1998). BMP4 is essential for lens induction in the mouse embryo. Genes Dev, 12:3764–3775.
85.
WawersikS, PurcellP, RauchmanM, DudleyAT, RobertsonEJ and MaasR. (1999). BMP7 acts in murine lens placode development. Dev Biol, 207:176–188.
86.
Ashery-PadanR, MarquardtT, ZhouX and GrussP. (2000). Pax6 activity in the lens primordium is required for lens formation and for correct placement of a single retina in the eye. Genes Dev, 14:2701–2711.
87.
MatsuoT, Osumi YamashitaN, NojiS, OhuchiH, KoyamaE, MyokaiF, MatsuoN, TaniguchiS, DoiH and IsekiS. (1993). A mutation in the Pax-6 gene in rat small eye is associated with impaired migration of midbrain crest cells. Nat Genet, 3:299–304.
88.
CollinsonJM, QuinnJC, BuchananMA, KaufmanMH, WeddenSE, WestJD and HillRE. (2001). Primary defects in the lens underlie complex anterior segment abnormalities of the Pax6 heterozygous eye. Proc Natl Acad Sci U S A, 98:9688–9693.
89.
RamaeshT, CollinsonJM, RamaeshK, KaufmanMH, WestJD and DhillonB. (2003). Corneal abnormalities in Pax6+/− small eye mice mimic human aniridia-related keratopathy. Invest Ophthalmol Vis Sci, 44:1871–1878.
90.
OuJ, LowesC and CollinsonJM. (2010). Cytoskeletal and cell adhesion defects in wounded and Pax6+/− corneal epithelia. Invest Ophthalmol Vis Sci, 51:1415–1423.
