Isolation and developmental expression of the amphioxus Pax-6 gene (AmphiPax-6): insights into eye and photoreceptor evolution
- PMID:9636084
- DOI: 10.1242/dev.125.14.2701
Isolation and developmental expression of the amphioxus Pax-6 gene (AmphiPax-6): insights into eye and photoreceptor evolution
Abstract
Pax-6 genes have been identified from a broad range of invertebrate and vertebrate animals and shown to be always involved in early eye development. Therefore, it has been proposed that the various types of eyes evolved from a single eye prototype, by a Pax-6-dependent mechanism. Here we describe the characterization of a cephalochordate Pax-6 gene. The single amphioxus Pax-6 gene (AmphiPax-6) can produce several alternatively spliced transcripts, resulting in proteins with markedly different amino and carboxy termini. The amphioxus Pax-6 proteins are 92% identical to mammalian Pax-6 proteins in the paired domain and 100% identical in the homeodomain. Expression of AmphiPax-6 in the anterior epidermis of embryos may be related to development of an olfactory epithelium. Expression is also detectable in Hatschek's left diverticulum as it forms the preoral ciliated pit, part of which gives rise to the homolog of the vertebrate anterior pituitary. A zone of expression in the anterior neural plate of early embryos is carried into the cerebral vesicle (a probable diencephalic homolog) during neurulation. This zone includes cells that will differentiate into the lamellar body, a presumed homolog of the vertebrate pineal eye. In neurulae, AmphiPax-6 is also expressed in ventral cells at the anterior tip of the nerve cord; these cells are precursors of the photoreceptive neurons of the frontal eye, the presumed homolog of the vertebrate paired eyes. However, AmphiPax-6 expression was not detected in two additional types of photoreceptors, the Joseph cells or the organs of Hesse, which are evidently relatively recent adaptations (ganglionic photoreceptors) and appear to be rare exceptions to the general rule that animal photoreceptors develop from a genetic program triggered by Pax-6.
Similar articles
- Isolation and expression of a Pax-6 gene in the regenerating and intact Planarian Dugesia(G)tigrina.Callaerts P, Munoz-Marmol AM, Glardon S, Castillo E, Sun H, Li WH, Gehring WJ, Salo E.Callaerts P, et al.Proc Natl Acad Sci U S A. 1999 Jan 19;96(2):558-63. doi: 10.1073/pnas.96.2.558.Proc Natl Acad Sci U S A. 1999.PMID:9892672Free PMC article.
- An amphioxus Pax gene, AmphiPax-1, expressed in embryonic endoderm, but not in mesoderm: implications for the evolution of class I paired box genes.Holland ND, Holland LZ, Kozmik Z.Holland ND, et al.Mol Mar Biol Biotechnol. 1995 Sep;4(3):206-14.Mol Mar Biol Biotechnol. 1995.PMID:7670596
- Conservation of Pax-6 in a lower chordate, the ascidian Phallusia mammillata.Glardon S, Callaerts P, Halder G, Gehring WJ.Glardon S, et al.Development. 1997 Feb;124(4):817-25. doi: 10.1242/dev.124.4.817.Development. 1997.PMID:9043063
- Pax 6: mastering eye morphogenesis and eye evolution.Gehring WJ, Ikeo K.Gehring WJ, et al.Trends Genet. 1999 Sep;15(9):371-7. doi: 10.1016/s0168-9525(99)01776-x.Trends Genet. 1999.PMID:10461206Review.
- The master control gene for morphogenesis and evolution of the eye.Gehring WJ.Gehring WJ.Genes Cells. 1996 Jan;1(1):11-5. doi: 10.1046/j.1365-2443.1996.11011.x.Genes Cells. 1996.PMID:9078363Review.
Cited by
- An amphioxus neurula stage cell atlas supports a complex scenario for the emergence of vertebrate head mesoderm.Grau-Bové X, Subirana L, Meister L, Soubigou A, Neto A, Elek A, Naranjo S, Fornas O, Gomez-Skarmeta JL, Tena JJ, Irimia M, Bertrand S, Sebé-Pedrós A, Escriva H.Grau-Bové X, et al.Nat Commun. 2024 May 29;15(1):4550. doi: 10.1038/s41467-024-48774-4.Nat Commun. 2024.PMID:38811547Free PMC article.
- Pitx controls amphioxus asymmetric morphogenesis by promoting left-side development and repressing right-side formation.Xing C, Pan R, Hu G, Liu X, Wang Y, Li G.Xing C, et al.BMC Biol. 2021 Aug 20;19(1):166. doi: 10.1186/s12915-021-01095-0.BMC Biol. 2021.PMID:34416880Free PMC article.
- Getting the proto-Pax by the tail.Vorobyov E, Horst J.Vorobyov E, et al.J Mol Evol. 2006 Aug;63(2):153-64. doi: 10.1007/s00239-005-0163-7. Epub 2006 Jul 7.J Mol Evol. 2006.PMID:16830101
- Isolation and expression of a Pax-6 gene in the regenerating and intact Planarian Dugesia(G)tigrina.Callaerts P, Munoz-Marmol AM, Glardon S, Castillo E, Sun H, Li WH, Gehring WJ, Salo E.Callaerts P, et al.Proc Natl Acad Sci U S A. 1999 Jan 19;96(2):558-63. doi: 10.1073/pnas.96.2.558.Proc Natl Acad Sci U S A. 1999.PMID:9892672Free PMC article.
- Transcription Factors of the bHLH Family Delineate Vertebrate Landmarks in the Nervous System of a Simple Chordate.Negrón-Piñeiro LJ, Wu Y, Di Gregorio A.Negrón-Piñeiro LJ, et al.Genes (Basel). 2020 Oct 26;11(11):1262. doi: 10.3390/genes11111262.Genes (Basel). 2020.PMID:33114624Free PMC article.Review.
Publication types
MeSH terms
Substances
Associated data
- Actions
- Actions
- Actions
- Actions
Related information
LinkOut - more resources
Full Text Sources
Medical