The rax homeobox gene is mutated in the eyeless axolotl, Ambystoma mexicanum
| Autor: | Thomas M Glaser, Erik S. Davis, Joel B. Miesfeld, Juan Zarate-Sanchez, S. Randal Voss, Gareth J. Voss |
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| Jazyk: | angličtina |
| Rok vydání: | 2020 |
| Předmět: |
0301 basic medicine
Rax anophthalmia Eye Ambystoma pituitary Medical and Health Sciences 0302 clinical medicine leaky scanning Developmental optic vesicle hypothalamus transcription factor Pediatric biology Gene Expression Regulation Developmental Optic vesicle Rx eye morphogenesis Biological Sciences Null allele Cell biology ribosome animal structures Embryonic Development lens induction Article Frameshift mutation 03 medical and health sciences Axolotl Genetics Animals Eye Proteins urodele Eye Disease and Disorders of Vision Homeodomain Proteins Neural fold Eye morphogenesis Neuroectoderm Neurosciences biology.organism_classification salamander Ambystoma mexicanum 030104 developmental biology Gene Expression Regulation homeodomain Mutation Homeobox Congenital Structural Anomalies 030217 neurology & neurosurgery Developmental Biology Transcription Factors |
| Zdroj: | Dev Dyn Developmental dynamics : an official publication of the American Association of Anatomists, vol 250, iss 6 |
| Popis: | Background Vertebrate eye formation requires coordinated inductive interactions between different embryonic tissue layers, first described in amphibians. A network of transcription factors and signaling molecules controls these steps, with mutations causing severe ocular, neuronal, and craniofacial defects. In eyeless mutant axolotls, eye morphogenesis arrests at the optic vesicle stage, before lens induction, and development of ventral forebrain structures is disrupted. Results We identified a 5-bp deletion in the rax (retina and anterior neural fold homeobox) gene, which was tightly linked to the recessive eyeless (e) axolotl locus in an F2 cross. This frameshift mutation, in exon 2, truncates RAX protein within the homeodomain (P154fs35X). Quantitative RNA analysis shows that mutant and wild-type rax transcripts are equally abundant in E/e embryos. Translation appears to initiate from dual start codons, via leaky ribosome scanning, a conserved feature among gnathostome RAX proteins. Previous data show rax is expressed in the optic vesicle and diencephalon, deeply conserved among metazoans, and required for eye formation in other species. Conclusion The eyeless axolotl mutation is a null allele in the rax homeobox gene, with primary defects in neural ectoderm, including the retinal and hypothalamic primordia. |
| Databáze: | OpenAIRE |
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